Authorship：Last author   Language：English   Publishing type：Research paper (international conference proceedings)  

DOI： 10.1007/978-981-95-2098-5_9

researchmap

Other Link： https://dblp.uni-trier.de/db/conf/icira/icira2025-2.html#ZhangTM25

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

DOI： 10.23919/sicefes67750.2025.11236650

researchmap

Publishing type：Research paper (scientific journal)   Publisher：Oxford University Press (OUP)  

Abstract

Background

Robotic needle insertion under CT guidance has been developed, but data on comparison with manual insertion are still lacking.

Purpose

To compare robotic versus manual needle insertion for CT fluoroscopy-guided intervention, primarily in terms of insertion accuracy.

Materials and Methods

This was a prospective study between May 2020 and March 2023 at a single site. The cohort comprised 22 patients undergoing CT (Aquilion One or Aquilion CX; Canon Medical Systems) fluoroscopy-guided biopsy, who were randomly allocated to either the robotic or manual group. The robot used (Zerobot; Medicalnet Okayama) is not yet commercially available. A biopsy introducer needle was inserted by 1 of 3 physicians using a remote-control robot in the robotic group, versus by 1 of 3 different physicians by hand in the manual group. The primary endpoint was needle insertion accuracy, which was defined as the 3-dimensional Euclidean distance between a predetermined target point and the needle tip after insertion. The non-inferiority of robotic insertion to manual one was then tested. Adverse events were evaluated. Statistical comparisons were made between the 2 groups.

Results

Technical success and pathological findings were confirmed in all patients of the 2 groups. The mean and SD of needle insertion were 4.8 mm ± 2.6 in the robotic group and 7.0 mm ± 3.1 in the manual group (P < .001). The mean difference in accuracy between the 2 groups (robotic minus manual group) was −2.1 mm (95% CI, −4.7 to 0.4). Effective dose to physicians was zero in all cases in the robotic group, while median dose was 1.0 µSv in the manual group (P < .001). Dose length product to patients was not significantly different between the 2 groups (P = .100). No major adverse events were observed.

Conclusion

Robotic needle insertion was non-inferior to manual insertion in terms of accuracy, while it effectively eliminated radiation exposure to physicians.

Trial registration number

jRCT2062200013

DOI： 10.1093/radadv/umaf010

researchmap

Other Link： https://academic.oup.com/radadv/article-pdf/2/2/umaf010/62871840/umaf010.pdf

Language：English   Publishing type：Research paper (international conference proceedings)  

DOI： 10.1109/IJCNN64981.2025.11228805

researchmap

Other Link： https://dblp.uni-trier.de/db/conf/ijcnn/ijcnn2025.html#KatoTMNM25

Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

DOI： 10.1109/scisisis61014.2024.10760128

researchmap

Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

DOI： 10.1109/scisisis61014.2024.10760125

researchmap

Authorship：Last author   Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

DOI： 10.1109/scisisis61014.2024.10760215

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical and Electronics Engineers (IEEE)  

DOI： 10.1109/access.2024.3499364

researchmap

Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

DOI： 10.1109/ICMLC63072.2024.10935110

researchmap

Other Link： https://dblp.uni-trier.de/db/conf/icmlc/icmlc2024.html#FurutaTMZ24

Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

DOI： 10.1007/s10147-023-02344-8

researchmap

Other Link： https://link.springer.com/article/10.1007/s10147-023-02344-8/fulltext.html

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：International Press of Boston  

DOI： 10.4310/cis.2022.v22.n4.a3

researchmap

Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

DOI： 10.1109/IJCNN54540.2023.10191416

researchmap

Other Link： https://dblp.uni-trier.de/db/conf/ijcnn/ijcnn2023.html#OzasaTM23

Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

Recently, various types of autonomous robots are expected with developments of Robot technologies and AI technologies. Especially, an unsupervised learning based perception methods of the robot is required in an unknown environment. In our previous works, we proposed 2D and 3D perception system based on Growing Neural Gas (GNG) that is one of the unsupervised learning methods. This paper proposes an integration method of GNG based 3D space perception with 2D environmental map for an autonomous mobile robot. For integrating the 3D space perception and 2D environmental map, this paper uses Robot Operating System. Next, this paper conducts an experiment to verify the effectiveness of our proposed method.

DOI： 10.1299/jsmermd.2023.2a1-g02

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

DOI： 10.1007/s10015-022-00826-y

researchmap

Other Link： https://link.springer.com/article/10.1007/s10015-022-00826-y/fulltext.html

Language：Japanese   Publishing type：Research paper (international conference proceedings)  

researchmap

Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

DOI： 10.1109/ijcnn55064.2022.9892864

researchmap

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：World Scientific Pub Co Pte Ltd  

In this paper, we focused on the medical procedure to insert needles under computer tomography (CT) guidance as a target for the robotization of medical surgery, which is one of Interventional Radiology (IR). IR is a general term for treatments that use devices to visualize patients’ bodies. During surgery, our developed robot, known as Zerobot, specializes in inserting a needle into the patient under CT guidance. Its surgery is less invasive and more effective in treating small cancer tumors because the temperature of the inserted needle tip is controlled. Zerobot was originally designed to be remotely controlled by doctors, and first-in-human feasibility trials in 2018 confirmed its surgical capability. We are currently focusing on the automatic insertion function to reduce the workload of doctors. In an animal experiment, Zerobot was unable to insert the needle into the animal during IR surgery if the needle was bent. As a result, the goal of this research is to have the robot function automatically so that the needle does not bend during surgery. We propose a method for estimating the form of the needle using a force sensor. There are three different types of needle forms. Next, the proposed method distinguishes between these needle forms by measuring the difference in force sensor data when the needle root is moved slightly. In addition, we conducted tests to confirm the efficacy of the proposed method.

DOI： 10.1142/s2424905x22410045

researchmap

Publisher：MDPI AG  

<jats:p>Three-dimensional space perception is one of the most important capabilities for an autonomous mobile robot in order to operate a task in an unknown environment adaptively since the autonomous robot needs to detect the target object and estimate the 3D pose of the target object for performing given tasks efficiently. After the 3D point cloud is measured by an RGB-D camera, the autonomous robot needs to reconstruct a structure from the 3D point cloud with color information according to the given tasks since the point cloud is unstructured data. For reconstructing the unstructured point cloud, growing neural gas (GNG) based methods have been utilized in many research studies since GNG can learn the data distribution of the point cloud appropriately. However, the conventional GNG based methods have unsolved problems about the scalability and multi-viewpoint clustering. In this paper, therefore, we propose growing neural gas with different topologies (GNG-DT) as a new topological structure learning method for solving the problems. GNG-DT has multiple topologies of each property, while the conventional GNG method has a single topology of the input vector. In addition, the distance measurement in the winner node selection uses only the position information for preserving the environmental space of the point cloud. Next, we show several experimental results of the proposed method using simulation and RGB-D datasets measured by Kinect. In these experiments, we verified that our proposed method almost outperforms the other methods from the viewpoint of the quantization and clustering errors. Finally, we summarize our proposed method and discuss the future direction on this research.</jats:p>

DOI： 10.3390/app12031705

researchmap

Other Link： https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-20K19894/

Publishing type：Research paper (scientific journal)   Publisher：Fuji Technology Press Ltd.  

Hierarchical topological structure learning methods are expected to be developed in the field of data mining for extracting multiscale topological structures from an unknown dataset. However, most methods require user-defined parameters, and it is difficult for users to determine these parameters and effectively utilize the method. In this paper, we propose a new parameter-less hierarchical topological structure learning method based on growing neural gas (GNG). First, we propose batch learning GNG (BL-GNG) to improve the learning convergence and reduce the user-designed parameters in GNG. BL-GNG uses an objective function based on fuzzy C-means to improve the learning convergence. Next, we propose multilayer BL-GNG (MBL-GNG), which is a parameter-less unsupervised learning algorithm based on hierarchical topological structure learning. In MBL-GNG, the input data of each layer uses parent nodes to learn more abstract topological structures from the dataset. Furthermore, MBL-GNG can automatically determine the number of nodes and layers according to the data distribution. Finally, we conducted several experiments to evaluate our proposed method by comparing it with other hierarchical approaches and discuss the effectiveness of our proposed method.

DOI： 10.20965/jaciii.2021.p1011

researchmap

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

DOI： 10.1109/ISMR48346.2021.9661566

researchmap

Other Link： https://dblp.uni-trier.de/db/conf/ismr/ismr2021.html#MatsunoMKMSMH21

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s10015-020-00603-9

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.20965/jrm.2020.p0692

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s00330-019-06477-1

Web of Science

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s00330-019-06409-z

Web of Science

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1109/JOE.2018.2871651

Web of Science

Scopus

researchmap

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society of Computer Aided Surgery  

<p>We are developing a CT-guided needle insertion robot for the purpose of reducing physician exposure dose. Automatic needle insertion will help a physician because it is a little difficult for unskilled operators to control the robot manually. In this paper, we propose a control law to realize full automatic needle insertion for a CT-guided needle insertion robot. In the control law, speed to insert a needle is given based on the result of our observation on the animal experiment. We found that the number of corrections increases as the needle approaches the target in a robotic needle insertion controlled by a physician. We propose the idea that needle insertion velocity decreases exponentially. The effectiveness of the control law is verified by a simulation experiment in which the needle start at having offset to the target trajectory. As a result, the robot in the simulation environment achieves to reach the target point by decreasing its puncture speed as the needle approaches the target.</p>

DOI： 10.5759/jscas.22.14

CiNii Article

CiNii Books

researchmap

Other Link： http://search.jamas.or.jp/link/ui/2020210402

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s10846-018-0970-x

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s00773-018-0586-7

Web of Science

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：Institute of Electrical and Electronics Engineers Inc.  

DOI： 10.1109/UT.2019.8734353

Scopus

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：Institute of Electrical and Electronics Engineers Inc.  

DOI： 10.1109/OCEANS.2018.8604867

Scopus

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：Institute of Electrical and Electronics Engineers Inc.  

DOI： 10.1109/OCEANS.2018.8604730

Scopus

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：Institute of Electrical and Electronics Engineers Inc.  

DOI： 10.1109/OCEANS.2018.8604527

Scopus

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：Springer Verlag  

DOI： 10.1007/978-3-030-27535-8_8

Scopus

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：Institute of Electrical and Electronics Engineers Inc.  

DOI： 10.1109/OCEANSKOBE.2018.8559085

Scopus

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：Institute of Electrical and Electronics Engineers Inc.  

DOI： 10.1109/OCEANSKOBE.2018.8559303

Scopus

researchmap

Language：English  

DOI： 10.18926/AMO/56370

Web of Science

PubMed

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：Institute of Electrical and Electronics Engineers Inc.  

DOI： 10.1109/ICRA.2018.8460477

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s10015-018-0442-1

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.ejrad.2018.06.006

Web of Science

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s10015-017-0415-9

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s10015-017-0408-8

Web of Science

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

Authorship：Lead author  

J-GLOBAL

researchmap

J-GLOBAL

researchmap

Publishing type：Research paper (scientific journal)  

DOI： 10.1504/IJMA.2018.10016616

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s10015-017-0385-y

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1148/radiol.2017162856

Web of Science

PubMed

researchmap

Publishing type：Research paper (international conference proceedings)  

DOI： 10.1109/OCEANSE.2017.8084659

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s10015-017-0349-2

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.20965/jrm.2017.p0500

Web of Science

researchmap

J-GLOBAL

researchmap

Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

<p>Industrial robots are used for many purposes, especially as machining facilities. For example, there are welding, assembling and grinding operations. Many of grinding robots are controlled by using feedback control with force sensors. But, the force sensor used for force detection by means of strain gage may be easily damaged when a shock on big power be added. Therefore, this research has been trying to control a position and exerting force at the same time without using a force sensor by feedforward/feedback control. In addition, we aim to construction a system that recognizes the arbitrary shape object and autonomously grind it by using the recognition technology of 3D space with camera. Until last year, the grinding robot could only grind on the 2D plane. Therefore, this paper shows the construction of the new robot system enabling grinding a target with 3D shape.</p>

DOI： 10.1299/jsmermd.2017.2A2-H08

CiNii Article

J-GLOBAL

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1115/1.4033667

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.20965/jrm.2016.p0911

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

Web of Science

researchmap

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.20965/jrm.2016.p0674

Web of Science

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：Institute of Electrical and Electronics Engineers Inc.  

DOI： 10.1109/SII.2015.7404888

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.3233/JAE-162196

Web of Science

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1109/TMECH.2013.2280147

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1080/01691864.2013.861769

Web of Science

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

Language：Japanese   Publisher：The Japanese Society of Interventional Radiology  

Computed tomography (CT) fluoroscopy is a useful imaging modality for guiding various interventional procedures (e.g., ablation, biopsy, and drainage). However, radiation exposure is a major disadvantage of CT fluoroscopy guidance. Even if a physician uses 17-cm forceps, radiation exposure to their hand is 7.0 µGy/s (120 kV; 30 mA). The average activation time for CT fluoroscopy in a lung biopsy has been reported to be approximately 90 s. It is expected that the activation time would be longer for more complex procedures such as ablation for large tumors. Therefore, radiation exposure during CT fluoroscopy is a serious concern for physicians.<BR>Robotic surgery, which is the preferred surgical method for 80% of prostate cancer surgeries in the United States, has been shown to reduce procedural complications. We hypothesized that robotic technology might be more easily applied to CT-guided interventions. If physicians performed CT-guided interventions using a robot that they controlled from a location far from the CT gantry, radiation exposure to physicians could be minimized. However, issues such as metal artifacts and the limited workspace may hinder the development of a robot for CT-guided interventions. More specifically, the robot must be constructed of non-metal materials and it must fit in a small space within the CT gantry. Despite these limitations, we have developed a prototype model of the robot.<BR>The prototype has 5 degrees of freedom and can be remotely operated with a joystick controller. Phantom experiments using the prototype showed no radiation exposure to the operating physician during the procedure. In this article, we will provide an overview of the development of this prototype model, present the limitations of the prototype, and discuss future prospects.

DOI： 10.11407/ivr.29.375

CiNii Article

researchmap

Other Link： http://search.jamas.or.jp/link/ui/2015126063

Language：Japanese   Publisher：The Japan Joint Automatic Control Conference  

DOI： 10.11511/jacc.57.0_333

CiNii Article

researchmap

Language：Japanese   Publisher：The Japan Joint Automatic Control Conference  

DOI： 10.11511/jacc.57.0_1972

CiNii Article

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1109/TCST.2012.2214439

Web of Science

researchmap

Publishing type：Research paper (scientific journal)  

DOI： 10.20965/jrm.2013.p0262

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)  

DOI： 10.3182/20130703-3-FR-4038.00112

Scopus

researchmap

Language：English   Publishing type：Part of collection (book)   Publisher：Elsevier Inc.  

DOI： 10.1016/B978-0-12-397199-9.00001-X

Scopus

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：Society of Instrument and Control Engineers (SICE)  

Scopus

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：Society of Instrument and Control Engineers (SICE)  

Scopus

researchmap

Language：Japanese   Publisher：The Robotics Society of Japan  

Fault detection functions of a robotic manipulator are very useful for factory automation. All production has the possibility to fail due to unexpected accidents. To reduce the fatigue of human workers, small errors automatically should be corrected by a robot system. In this paper, an external thread fastening task by a robotic manipulator is investigated. To discriminate the four states of a task, linear support vector machine methods with two feature parameters are introduced. One is the estimated insertion length, and the other is the maximum reaction force. The effectiveness of the proposed algorithm is confirmed through an experiment and recognition examination.

DOI： 10.7210/jrsj.30.804

CiNii Article

CiNii Books

J-GLOBAL

researchmap

Publishing type：Research paper (scientific journal)  

DOI： 10.20965/jrm.2012.p0666

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.jfranklin.2009.02.014

Web of Science

researchmap

Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

DOI： 10.1109/MHS.2011.6102220

researchmap

Other Link： https://dblp.uni-trier.de/db/conf/mhs/mhs2011.html#DingHMF11

Publishing type：Research paper (international conference proceedings)  

DOI： 10.1109/ICMA.2011.5985708

Scopus

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)  

DOI： 10.1109/ICMA.2011.5985977

Scopus

researchmap

Publishing type：Research paper (scientific journal)  

DOI： 10.20965/jrm.2011.p0939

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1109/TCST.2009.2034735

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1109/TRO.2010.2053732

Web of Science

researchmap

Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

DOI： 10.1109/ROBIO.2010.5723487

researchmap

Other Link： https://dblp.uni-trier.de/db/conf/robio/robio2010.html#DingHWMFS10

Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

This paper proposes a kinematic model of the vehicle with low-ground pressure tire that enables to enter a minefield in order to scan remaining landmines by a ground penetrating radar in level III survey. The low-ground-pressure tire makes low pressure contact with a ground by deforming its shape of the tire, but the deformation deteriorates position and steering control accuracy. Therefore this paper models the kinematics of the low-ground pressure vehicle based on experimental results. Besides we experimentally confirmed that the vehicle could precisely trace the target trajectory by considering its kinematics in simulated minefield.

CiNii Article

CiNii Books

J-GLOBAL

researchmap

Language：Japanese   Publisher：公益社団法人精密工学会  

On a two-dimensional jumping behavior by a multi-link mechanism, a mechanism that imitated a animal&#039;s leg and a mechanism of conventional robot were compared analytically. Each joint of a conventional robot is independently controlled. On the other hand, because animal&#039;s leg has bi-articular muscle, the adjoining joints are not independent. The animal&#039;s leg mechanism was imitated by using the closed link mechanism with the rod which connects two joints. For the mechanism which imitated animal&#039;s leg and the mechanism of conventional robot, under the ideal condition, each joint torque for stabilized jump ware deduced. On the conventional robot, it is necessary to detect the center of gravity, and to be feedback. By contrast, in the mechanism which imitated the animal&#039;s leg, it does not need to feedback the position of center of gravity. Furthermore, four-legged jump robot with the mechanism which imitated animal&#039;s leg was produced, and the effectiveness of that mechanism was confirmed by an experiment.

DOI： 10.2493/jjspe.74.416

CiNii Article

CiNii Books

J-GLOBAL

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1109/TMECH.2007.915063

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

Scopus

researchmap

Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

We propose a brachiation robot named Brachiator. Brachiator is able to swing like a real gibbon. The limbs of Brachiatior are designed to be actuated through the wires. However, the elongation and slack of the wires often arise and make it difficult to estimate the joint angles accurately, which has to be resolved to attain more stable brachiation behavior. In this paper we indroduce a vision system to improve brachiation behavior in real time. A stereo vision system is mounted on Brachiator that looks like a gibbon's face. We estimate errors between a model based trajectory and a real trajectory in implementation world from the images which the vision system captures during the brachiation behavior. Based on the vision-based error estimation as to the grasping position on the target branch, the trajectory of the behavior is adjusted in real time in order to realize successful brachiation behaviors. Experimental results showed that the proposed system reduced deviation of the grasping position of brachiation behavior as much as 40% compared with previous methods.

CiNii Article

CiNii Books

J-GLOBAL

researchmap

Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

Ground Penetrating Radar (GPR) is a promissing sensor for landmine detection, however there are two major problems to overcome. One is the non-planer (e.g. rough and/or undulating) ground surface. It remains unremovable clutters on a sub-surface image output from GPR. Geography adaptive scanning is useful to image objects beneath non-planer ground surface. The other problem is the distance between the antennas of GPR. When imaging the small objects such as an antipersonnel landmine buried in shallow depth, it increases the nonlinearity of the relationship between the time for propagation and the depth of a buried object. In this paper, we modify Kirchoff migration so as to account for not only the variation of height and pose of the sensor head, but also the antennas alignment of the vector radar. The validity of this method is discussed through application to the signals acquired in experiments.

CiNii Article

CiNii Books

J-GLOBAL

researchmap

Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

This paper proposes a control algorithm for pace gait of a quadruped walking robot, using a passive dynamics autonomous control algorithm (PDAC). The PDAC realizes an efficient motion based on the intrinsic dynamics of a robot. This paper first calculates an energy consumption of the pace and a crawl gait at various walking parameters such as a stride length and a walking period. The optimal walking parameters are obtained for each gait at various walking speed in the simulation and their parameters are confirmed by applied to an experimental walking robot. The trend of the energy consumption transition measured in the experiments are similar to those in the simulation. For example the consumption energy of the pace gait becomes less than that of crawl gait when a walking speed becomes relatively high. As a result, quadruped walking parameters corresponding to the desired walking speed such as the type of gait, the stride length and the walking period are designed on the energy-consumption-basis.

CiNii Article

CiNii Books

J-GLOBAL

researchmap

Publishing type：Research paper (scientific journal)  

DOI： 10.20965/jaciii.2007.p0735

researchmap

Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

We propose tailor-made multilayer piezoelectric actuators (TAMPA) having large displacements and large forces. In existing piezoelectric actuators, production of small, low-cost actuators having large displacements and large forces is difficult to achieve. We solved this problem by combining two bimorph-type piezoelectric elements with both ends simply supported, and stacking several elements on top of each other. Moreover, TAMPA is a tailor-made actuator whose displacement to force ratio can be varied widely by adjusting the size of the bimorph-type piezoelectric elements even when the total size of the actuator is kept constant. In this study, the bimorph-type piezoelectric element was analyzed, and the relationship between the displacement and the force under fixed conditions was experimentally determined. The relationship between the displacement and the force of TAMPA was theoretically derived. The analytical results showed that a TAMPA having dimensions of approximately 10×10×10mm is capable of generating displacements of several hundred μm or the force of several N. A prototype was produced and its performance was evaluated. These results agreed well with the analytical results, confirming the validity of the analytical results. Finally, because the lead in PZT can cause environmental problems, a TAMPA was produced that used (K, Na) (Nb, Ta) O_3 piezoelectric ceramics instead of lead.

CiNii Article

CiNii Books

J-GLOBAL

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1002/int.20172

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1109/TMECH.2006.878557

Web of Science

researchmap

Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

This paper proposes the novel control method named Passive Dynamic Autonomous Control (PDAC). PDAC is based on the following concept which Grizzle et al.^<(6)(9)> employed previously : 1) point-contact 2) Virtual constraint. Point contact means that the contact state between a robot and the ground is point. This makes it possible to generate the robot motion based on the robot inherent dynamics although it becomes difficult to control. Virtual constraint means that all robot joints are connected and interlocked. We present the new approach by means of these concepts to express the whole robot dynamics an an 1-dimensional autonomous system. Due to autonomy, this approach has two following notable points : 1) period from foot-contact to next foot contact can be obtained 2) there is a conservative quantity to make it possible to stabilize the motion. As the first step of realization of 3 D dynamic walking, this paper applies PDAC to the lateral motion and builds the controller. In addition, the stabilization and motion period control are reported. The validity of these control is confirmed by experiment and desired lateral motion is realized.

CiNii Article

CiNii Books

J-GLOBAL

researchmap

Authorship：Lead author   Language：English   Publishing type：Research paper (international conference proceedings)  

DOI： 10.1109/IROS.2006.281944

Web of Science

researchmap

Other Link： https://dblp.uni-trier.de/db/conf/iros/iros2006.html#MatsunoF06

Language：English   Publishing type：Research paper (international conference proceedings)  

Scopus

researchmap

Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

DOI： 10.1109/ROBOT.2005.1570460

researchmap

Other Link： https://dblp.uni-trier.de/db/conf/icra/icra2005.html#MatsunoKAMF05

Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

DOI： 10.1109/ROBOT.2005.1570502

researchmap

Other Link： https://dblp.uni-trier.de/db/conf/icra/icra2005.html#MotooAYFMM05

Publishing type：Research paper (international conference proceedings)  

Scopus

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)  

DOI： 10.1109/ICSENS.2005.1597684

Scopus

researchmap

Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

This paper proposes adaptive adjustment methods of a preplanned regrasping strategy according to position and orientation errors of a grasping object. We had already derived a generation algorithm for the regrasping strategy by evolutionary programming. However position and orientation errors of a grasping object from those in numerical simulation are experimentally inevitable since there are many indeterminable factors such as slip contact between a fingertip and an object surface, imbalance of grasping forces, and so on. Those errors are getting bigger according to the task progress, and it is finally difficult to recover those errors due to a limitation of hand's work space and so on. We therefore propose some adaptive adjustment methods that can change an grasping point or intermediate posture of a grasping object so that it could continue to manipulate an object against larger errors. We investigate the allowable error range of the proposed methods in numerical simulations and confirm its reality by experiment.

CiNii Article

CiNii Books

J-GLOBAL

researchmap

Publishing type：Research paper (scientific journal)  

DOI： 10.20965/jrm.2004.p0031

researchmap

Publishing type：Research paper (scientific journal)  

DOI： 10.20965/jrm.2004.p0613

researchmap

Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

DOI： 10.1109/IROS.2004.1389444

researchmap

Other Link： https://dblp.uni-trier.de/db/conf/iros/iros2004.html#FukudaZHMH04

Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

DOI： 10.1109/ROBOT.2004.1307975

researchmap

Other Link： https://dblp.uni-trier.de/db/conf/icra/icra2004-2.html#MatsunoFH04

Language：English   Publishing type：Research paper (international conference proceedings)  

Scopus

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)  

Scopus

researchmap

Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)  

researchmap

Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)  

researchmap

Language：English   Publisher：IEEE  

DOI： 10.1109/SMC53992.2023.10394655

researchmap

Other Link： https://dblp.uni-trier.de/db/conf/smc/smc2023.html#KobayashiTMMMFT23

Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)  

researchmap

Authorship：Lead author   Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)  

researchmap

J-GLOBAL

researchmap

Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)  

J-GLOBAL

researchmap

Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)  

J-GLOBAL

researchmap

Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)  

J-GLOBAL

researchmap

Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)  

J-GLOBAL

researchmap

Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：The Society of Instrument and Control Engineers  

DOI： 10.9746/sicetr.57.1

CiNii Article

researchmap

Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)  

J-GLOBAL

researchmap

Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)  

J-GLOBAL

researchmap

Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)  

J-GLOBAL

researchmap

Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)  

J-GLOBAL

researchmap

Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)  

J-GLOBAL

researchmap

Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)  

J-GLOBAL

researchmap

Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)  

J-GLOBAL

researchmap

Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

<p>In recent years, interventional radiology (IR) which is a medical procedure has been attracting considerable attention. Since this surgical method is less invasive, the number of this surgery tends to increase. However, doctors are exposed to strong radiation in the case under CT-guidance. In order to overcome this problem, we developed remote-controlled IR assistance robot. When doctors operate by remote control, there is possibility that parts of the robot collide with peripheral devices or a patient. Especially, if in the case of collision with the patient, it could become a serious incident. Accordingly, it is important to build a suitable path plan of the needle insertion before the surgery. Doctors, however, currently, do not have methods to grasp the possibility of the collision. Therefore, a simulation which detect collision with a patient in the advanced planning is proposed in this paper. The effectiveness of proposed simulation is confirmed.</p>

DOI： 10.1299/jsmermd.2020.2A1-E06

CiNii Article

researchmap

Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：(一社)日本インターベンショナルラジオロジー学会  

researchmap

Language：Japanese   Publisher：(株)メジカルビュー社  

researchmap

Other Link： https://search.jamas.or.jp/index.php?module=Default&action=Link&pub_year=2019&ichushi_jid=J01843&link_issn=&doc_id=20190401110008&doc_link_id=10.18885%2FJ01843.2019198415&url=https%3A%2F%2Fdoi.org%2F10.18885%2FJ01843.2019198415&type=%88%E3%8F%91.jp_%83I%81%5B%83%8B%83A%83N%83Z%83X&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F00024_2.gif

Language：Japanese   Publisher：(株)北隆館  

J-GLOBAL

researchmap

Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

J-GLOBAL

researchmap

Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

<p>In recent years, interventional radiology (IR) which is a medical procedure has been attracting considerable attention. Since this surgical method is less invasive, but doctors are exposed to strong radiation in the case under CT-guidance. In order to overcome this problem, we developed remote-controlled IR assistance robot. As a research topic, automated needle puncturing by the robot is focused on. However, currently the robot cannot obtain CT image in real time. So, the robot cannot obtain the form of needle based on CT image and cannot control state of needle accurately. On the other hands, we aim that the robot moves automatically for restraining a bend of needle. As the first step for this, the method to estimate a form of needle by using a force sensor information is proposed in this paper. If a form of the needle is displayed in user interface, it become easy for doctors to remove a bend of the needle during surgery with remote-controlled IR assistance robot. Additionally, we conducts the experiment to confirm effectiveness of proposed method.</p>

DOI： 10.1299/jsmermd.2019.1P1-A02

CiNii Article

researchmap

Language：English   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

DOI： 10.1080/01691864.2016.1206680

Web of Science

researchmap

Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

Interventional radiology is a minimally invasive image-guided procedure that can be performed percutaneously. When computed tomography (CT) is used as an image-guidance for interventional radiology, the radiation exposure is a major problem to an operator who stands close to a CT gantry. To solve this problem, we are developing a remote control needle puncture robot which has five degrees of freedom. However, evaluation of the positioning performance of the robot was not conducted. In this paper, evaluation criteria of positioning performance required for a needle puncture robot is determined, and the performance of the robot is evaluated.

CiNii Article

CiNii Books

researchmap

Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

Helicopter has a unique performance such as vertical ascent, decent and hovering. So, it is applied to large field because of that performance. On the other hand, there is a disadvantage that its structure is complex, and it is difficult to stabilize the posture under a windy environment. In the previous research, although we have considered the stabilization of the posture of underactuated flying object experimental device, the control result of the experimental device has been affected by the conducting wire of electrical supply and encoder. Therefore an experimental device is newly manufactured aiming to eliminate the influence of conducting wire by unwiring and wireless communication. And we have explored the control performance for new experimental device by switching the controller gain adaptively based on the predicted value of the posture of underactuated flying object.

CiNii Article

CiNii Books

researchmap

Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

The deformable object such as string, cloth or paper, is soft and can change its form easily. It is difficult for a robot to manipulate deformable object, because it needs to deal with various form. The demand is growing in industry and domestic work. On manipulating deformable objects using robot manipulator, it is important to recognize their form. In this research, distance camera is used to get point cloud data of string. In addition, point chain model is adapted to describe form of string. To create point chain model from point cloud data, vector sequence that describes center line of string needs to be made. Therefore string form recognition algorithm is suggested. This algorithm estimates center line of string using surface normal vectors evaluated by normal estimation algorithm, and creates point chain model by matching method. In addition, experiment to evaluate the effectiveness of this method is conducted.

CiNii Article

CiNii Books

researchmap

Language：Japanese   Publisher：ライフサポート学会  

DOI： 10.5136/lifesupport.20.Supplement_78

CiNii Article

J-GLOBAL

researchmap

Language：Japanese   Publisher：ライフサポート学会  

DOI： 10.5136/lifesupport.18.Supplement_139

CiNii Article

J-GLOBAL

researchmap

Event date： 2021.7.8 - 2021.7.10

Language：English   Presentation type：Poster presentation  

File： arso2021_ivr.pdf

researchmap

Event date： 2021.6.6 - 2021.6.8

Language：Japanese   Presentation type：Poster presentation  

researchmap

Event date： 2021.5.27 - 2021.5.28

Language：Japanese   Presentation type：Oral presentation (general)  

researchmap

Event date： 2020

researchmap

Event date： 2019

Language：English  

This paper proposes a real-time topological structure learning method based on concentrated/distributed sensing for a 2D/3D point cloud. First of all, we explain a modified Growing Neural Gas with Utility (GNG-U2) that can learn the topological structure of 3D space environment and color information simultaneously by using a weight vector. Next, we propose a Region Of Interest Growing Neural Gas (ROI-GNG) for realizing concentrated/distributed sensing in real-time. In ROI-GNG, the discount rates of the accumulated error and utility value are variable according to the situation. We show experimental results of the proposed method and discuss the effectiveness of the proposed method.

researchmap

Event date： 2019

Language：English  

Aiming at developing underwater battery recharging system, the author developed a docking system using stereo-vision-based visual servoing and a 3D marker. The 3D marker consists of red, green, blue spheres that do not emit the light which is named as a passive marker. Real-time relative pose (position and orientation) estimation was implemented utilizing the 3D model-based matching method and real-time multistep genetic algorithm (RM-GA). Given the situation that the docking aims for battery recharging in the deep-sea bottom, the pitch-dark and turbid environment should be considered as an inevitable condition for battery recharging. In our previous works, the docking experiments were conducted in the actual sea, having verified the effectiveness of the proposed system using the passive 3D marker in the daytime environment with turbid water condition. Since lighting passive 3D marker by light from the vehicle in turbid water environment results in a situation that the images taken by video cameras set on the vehicle were looked wholly white, some new idea seems to be required. To overcome this difficulty, the newly lighting 3D marker (active 3D maker) has LEDs inside was introduced in the previous work. The main objective of this study is to check the feasibility area of the proposed system for the docking application, comparison of recognition performance using the active and passive 3D marker that was conducted in the simulated pool with the turbid water is focused. And then, the experiment using the active 3D marker in the actual sea has been performed. The experimental results have confirmed that the new active 3D marker with no-lighting from the vehicle could be recognizable in dark and turbid environment than the passive 3D marker with the lighting from the vehicle.

researchmap

Event date： 2019

researchmap

Event date： 2019

researchmap

Event date： 2019

researchmap

Event date： 2019

researchmap

Event date： 2019

researchmap

Event date： 2019

researchmap

Event date： 2019

researchmap

Event date： 2019

researchmap

Event date： 2019

researchmap

Event date： 2019

researchmap

Event date： 2018

Language：English  

Disturbances of turbidity and low illuminance are problems in real sea areas when recognizing objects with cameras. Therefore, the recognition target was made to emit light so that it can be recognized correctly even in that environment. However, a suitable light intensity of the target was not decided and it is obvious that recognition results was changed by light intensity of the target. This paper presents the analysis of recognition accuracy of the Real-time 3D estimation system by changing the current value of each color LED (red, green, blue) under turbid and low illuminance. Recognition experiments were conducted at the distance 600 [mm] between the ROV and 3D marker. The turbidity level was set constant value. The current value was changing from 0 [mA] to 16 [mA] for each LED individually. The best current for each LED was optimized by the fitness value and estimation value of position and orientation. The results showed that the recognition accuracy of the proposed system was improved by using optimized lighting intensity.

researchmap

Event date： 2018

Language：English  

A stereo-vision-based system of autonomous under-water vehicles (AUVs) for sea-bottom docking that enables for battery recharging to extend persistence time of underwater operation has been developed. This paper presents the docking experiment using a developed V-shaped-thruster typed under-water vehicle. A real-time 3D pose (position and orientation) estimation method using a real-time multi-step genetic algorithm (RM-GA) has been proposed by the authors in previous works and used for docking based on 3D recognition as a feedback pose information in real-time, named as 3D Move on Sensing (3D-MoS). Sea docking experiment results have confirmed the functionality and practicality of proposed docking approach using a hovering typed ROV in previous works. Since the hovering typed underwater vehicles are limited in mobilities concerning speed and operational space, verification of the 3D-MoS system using underwater vehicle that has more mobility deem to be meaningful direction for vision-based docking system to expand the utility value of AUVs. Therefore, in this study, control system for a new V-shaped-thruster typed vehicle is developed and docking experiment is conducted. This paper presents the development of the hardware design of V-shaped-thruster typed underwater vehicle and improvement of controlling with consideration of coupled configuration of thrusters.

researchmap

Event date： 2018

Language：English  

Recently, the demand to manipulate deformable objects such as a string and cloth by robots is growing. The reason is that it has the possibility of making our lives more convenient in many domains. The manipulation of deformable objects, however, is more difficult than that of rigid objects, because deformable objects have diversity of shape and behavior. Therefore, our research group has been focusing on the string shape operation. This paper describes planning method of string untying operation based on knot theory and algorithms to generate the motion of a manipulator. The novel contribution of our planning method is automatic selection of optimal shape operation based on cost function. At final, the results of string untying experiments are reported.

researchmap

Event date： 2018

Language：English  

This paper presents that our proposed docking system could apply for a new Remotely Operated Vehicle(ROV). The authors have proposed a 3D-perception based Move on Sensing (3D-MoS) system using a new 3D position and orientation (pose) estimation method with dual-eye camera that exploits the parallactic nature that enables reliable 3D pose estimation in real-time, named as "Real-time Multi-step Genetic Algorithm (RM-GA)." We confirmed ROV have conducted docking that assumes charging battery under water by the system, having shown it effective. As a next step, docking experiment using the new ROV were conducted to verify the proposed system apply for new ROV. But, the new ROV is different from a ROV that have used previous experiments, on the point of thruster setting structure. Then, a new control system using Jacobian that shows relationship voltage and velocity was constructed. After it is confirmed the system is effective, docking experiments In the pool have been conducted. In this report, the structure and result of experiments are reported in detail.

researchmap

Event date： 2018

Language：English  

To extend the persistence time of an underwater operation of AUVs in the sea, many studies have been performed worldwide. The docking function takes place as an important role not only for battery recharging but also for other advanced applications. Therefore, we developed the visual-servoing-based underwater vehicle using 3D perception based move on sensing (3D-MoS) system with dual-eye cameras and 3D marker for the docking operation. The vision-based underwater vehicle cannot avoid the turbidity and low illumination in the deep sea. In the present study, the active/lighting marker was newly designed and constructed to improve the recognizing ability of the proposed system for the real-time 3D pose estimation. The experiments were conducted in a simulated pool against different turbidity levels and illumination variations by adjusting the LED's brightness of the active marker in both day and night environments. This paper presents the analyses on the relations of the currents of LED installed inside each ball of the 3D marker and recognition results under turbidity and changing illumination conditions. According to the experimental results, the optimum current was chosen for the docking.

researchmap

Event date： 2018

Language：English  

This paper presents the 3D pose estimation against turbidity under dark environment by using dual-eye cameras and an active meaning light emitting 3D marker for visualservoing based underwater vehicle. The authors have proposed a 3D-perception based move on sensing (3D-MoS) system using a 3D position and orientation (pose) estimation method with dual eye cameras that exploits the parallactic nature that enables reliable 3D pose estimation in real-time, named as "Real-time Multi-step Genetic Algorithm (RM-GA)." The active/lighting 3D marker was designed and constructed to improve the 3D pose estimation especially in turbidity and low illumination. In realtime pose estimation, not only recognition but also robustness are important. This paper focus on the robustness of 3D pose recognition performance using dual-eye cameras and 3D marker against turbidity. The experimental results have confirmed that the effectiveness and robustness of the proposed system for the real-time 3D pose estimation under turbidity and night condition.

researchmap

Event date： 2018

researchmap

Event date： 2018

researchmap

Event date： 2018

Language：English  

Recharging ability with underwater docking function would be a first primal step conducted to enable the AUV to operate independently of a surface vessel for extended periods. Therefore, the role of docking operation came in picture not only for battery recharging application but also other novel applications such as sleeping under mother ship, or new mission up and down loading. Moreover, docking capacity can be extended to provide navigation for other underwater vehicles on the way of their mission too. However, there are many challenging issues in achieving these applications that request high accuracy and robustness against disturbances that are provided by the underwater environment. The most challenging and unavoidable problems in sensing sphere for sea operations are, we think, turbidity and light changing. Turbidity is defined as cloudiness in a liquid caused by the presence of suspended particles that scatter and absorb light. Since underwater battery recharging are supposed as a first step to realize a full autonomous/intelligent robot, the deep-sea docking experiments cannot avoid turbidity and low light environment. In previous studies, we had conducted sea docking experiments using a passive (not lighting) marker and image-evaluation function based on only hue information, limiting its operational environment in lower turbid sea with sunshine. Whereas in this study, to improve our system removing above defects, we newly designed an active- light emitting 3D marker and a fitness function determined by HSV color components to improve the performance of the system especially in a more turbid environment. The advantage of using an active 3D marker and HSV-evaluated function is to be thought as being tolerable and seeable despite clipped whites and scattered light on the camera images caused by turbidity. Additionally, we conducted the docking experiments to verify the robustness of the proposed approach against turbidity and compared recognition results between the previous method and the improved method.

researchmap

Event date： 2018

researchmap

Event date： 2018

researchmap

Event date： 2018

researchmap

Event date： 2018

researchmap

Event date： 2018

researchmap

Event date： 2018

researchmap

Event date： 2018

researchmap

Event date： 2018

researchmap

Event date： 2018

researchmap

Event date： 2018

researchmap

Event date： 2018

researchmap

Event date： 2018

researchmap

Event date： 2018

researchmap

Event date： 2018

researchmap

Event date： 2018

researchmap

Event date： 2018

researchmap

Event date： 2017

Language：English  

This paper explores a strong stability system, which regulates safety for generalized minimum variance control (GMVC). GMVC is one of the control methods for application in industry and the controller is designed by generalized output to make the closed-loop system stable. Once the generalized output is designed, the derived controller cannot be re-designed without changing the closed-loop characteristic. For safe applications in industry, it is desirable that both of the closed-loop system and the controller are stable. That is, the strong stability system, which means that both of the closed-loop system and the controller are stable, is desirable to develop the applications. Although authors have proposed the extended GMVC design methods and the strong stability systems by using coprime factorization, there is a problem that the degree of controller may be higher than the conventional method because stable polynomial is needed in order to obtain coprime factorization. Therefore this paper directly extends GMVC without coprime factoriz ation, and a strong stability system regulating safety is studied from the view point of the quantity of feedback signal. Some numerical examples are shown in order to check the characteristic of the proposed method.

researchmap

Event date： 2017

Language：English  

In recent years, interventional radiology (IR) which is a medical procedure has been attracting considerable attention. Doctors can perform IR percutaneously while observing the fluoroscopic image, such as CT and MRI images, of patients. Therefore, this surgical method is less invasive. However, doctors are exposed to strong radiation in the case of CT-guidance. In order to overcome this problem, we have developed remote-controlled IR assistance robot. The phenomena that the needle tip deviates from target tissue at the end sometimes occur, even if the needle is aligned with target tissue before puncturing. In this research a method to adjust pose of a needle in lateral direction based on information of force sensor for reducing deflection of needle is proposed. First, deflection of needle was modeled as a simply cantilever beam. Next, pose of needle gripper of robot to reduce the force is calculated. Finally, validity of the proposed method was verified based on the result of phantom puncture experiment.

researchmap

Event date： 2017

Language：English  

This paper presents docking experiments for AUV using stereo vision for sea bottom battery recharging application. Real-time 3D pose tracking system was installed in AUV ''Tuna-Sand 2". Underwater battery recharging unit with unidirectional docking function was simulated in a pool. Thna-Sand 2 approached to the docking station using other sensors and docking operation was performed by visual servoing when a 3D marker was detected. Experimental results showed the performance of the proposed system with accurate docking accuracy in a short time.

researchmap

Event date： 2017

Language：English  

A medical procedure called Interventional Radiology(IR) is paid much attention in recent years. IR can be performed percutaneously while a doctor observes patient' s fluoroscopic image. Therefore this surgical method is low-invasiveness method. In this surgery, computed tomography (CT) equipment is often used. But a doctor is exposed to strong radiation from CT. Thus, we have developed a remote-controlled surgery support robot called "Zerobot". Because Zerobot is placed front of CT equipment by human, an angle offset from installation target position occurs. If a doctor punctures without noticing that Zerobot has an installation angle offset, there is danger of hurting the part that should not be hurt around a target cancer. In order to solve this problem, we propose an angle offset compensation method and the installation angle offset derivation method using a CT equipment is proposed. Then, effectiveness of proposed method is confirmed through experiments.

researchmap

Event date： 2017

Language：English  

Recently, the demand to manipulate deformable objects such as a string and cloth by robots is growing. The reason is that it has the possibility of making our lives more convenient in many domains such as housework, manufacturing and medical field. However, manipulation of deformable objects is more difficult than that of rigid objects, because deformable objects have variety of shape and variety of appearance. Therefore, our research group has been focusing on the string shape operation by a robot. This paper describes planning method of string tying operation based on knot theory and algorithms to generate the motion of a manipulator. Face List is proposed as shape abstraction data of string projection. Face List is data in which a plurality of faces included in the string projection are listed in a list form. Finally, the result of string tying experiment is reported.

researchmap

Event date： 2017

researchmap

Event date： 2017

researchmap

Event date： 2017

researchmap

Event date： 2017

researchmap

Event date： 2017

researchmap

Event date： 2017

researchmap

Event date： 2017

researchmap

Event date： 2017

researchmap

Event date： 2017

researchmap

Event date： 2017

researchmap

Event date： 2017

researchmap

Event date： 2016

researchmap

Event date： 2016

researchmap

Event date： 2016

Language：English  

Interventional radiology is a minimally invasive image-guided procedure. In the case of using computed tomography (CT) as an image-guidance for interventional radiology, the radiation exposure is a major problem to an operator who stands close to a CT gantry. To solve this problem, we are developing a remote-controlled puncturing robot which has five degrees of freedom. In this paper, we describe the details of the prototype robot and show experimental results to evaluate the robot's repeatability and a result of puncturing to a phantom.

researchmap

Event date： 2016

Language：English  

This paper deals with estimation of thermal conductivity for temperature control of an aluminum plate considering radiative heat transfer. Aiming at accurate control results, model-based control method needs true values of plant parameters. In our previous research, the nominal values of plant parameters have been used for temperature control experiment. However, for the actual environment in industrial field, physical parameters such as thermal conductivity will change. Therefore this paper reports the estimation result of thermal conductivity of aluminum plate considering radiative heat transfer through experimental data.

researchmap

Event date： 2016

Language：English  

In this paper, we define a new index of dynamic manipulability for humanoid biped walking to measure dynamic flexibility of changing mechanics by using residual redundancy, when primary work is being assigned, such as face and eyes being targeted to certain object. Although some measurements have been arranged so far to evaluate statical or dynamical flexibility of hand manipulator. This paper displays a new measurement of Dynamic Reconfiguration Manipulability Shape Index (DRMSI) which is the combination of dynamic manipulability and reconfiguration manipulability, and we have applied the DRMSI into humanoid robot experiments to evaluate its dynamical reconfiguration ability during walking. According to the value of DRMSI in our experiments, we have verified our humanoid robot model is reliable and effective since the results have indicated that the kinematic and dynamic characteristics of our model are similar to human-being.

researchmap

Event date： 2016

researchmap

Event date： 2016

researchmap

Event date： 2016

researchmap

Event date： 2016

researchmap

Event date： 2016

researchmap

Event date： 2016

researchmap

Event date： 2016

Language：English  

Genetic algorithm (GA) has been applied for real-time pose estimation in this research because of its simplicity, global perspective and repeatable ability. In many of these different situations or problems, optimum selection parameters are a critical factors in the performance of GA. We have developed visual-servo type underwater vehicle using dual-eye camera and 3D marker using real-time pose tracking, named as Real-time Multi-step GA. The relative pose between a vehicle and a 3D-marker can be estimated by Model-based matching method. To recognize the pose of the marker with respect to the vehicle, it is needed to utilize the optimum searching in real-time, and the real-time pose estimation problem can be converted into an optimization problem over a time-varying distribution function with multiple variables. Therefore, analyses the convergence performance of real-time multi-step GA for 3D model-based recognition for underwater vehicle was conducted and reported in this paper. The main aim of this paper is to choose the best parameters for GA that are optimized over population size, selection rate, mutation rate based on their relative fitness value to improve the performance of searching in time domain. The experimental results show that the proposed system effectively improved the searching performance of Real-time multi-step GA for real time pose tracking, having enable an automatic docking of underwater vehicle by dual-eyes visual servoing.

researchmap

Event date： 2016

Language：English  

Biped locomotion created by controlling me-thods based on Zero-Moment Point (ZMP) has been realized in real world and been well verified its efficacy for stable walking. However the walking strategies that have been proposed so far seem to avoid such considerations as slipping of foot on the floor, even though there should exist the slipping large or small in real world. In this research, a dynamical model of humanoid robot including slipping of foot is proposed, which is derived by the Newton-Euler (NE) method. To confirm the veracity of the derived dynamicl model, the model has been verified from the view point that when all friction coefficients are identical to zero, the total kinetic energy should be conserved to be unchanged, and when the coefficients are not zero, the total kinetic energy should decrease monotonously.

researchmap

Event date： 2016

Language：English  

There is minimally invasive method called Interventional Radiology (IR) that achieves an operation by using diagnostic imaging equipment such as Computed Tomography (CT). IR has advantages that it is a minimally invasive method and it is applied widely such as lung cancer treatment, liver cancer treatment, biopsy, and so on. However, it has a problem that doctors are exposed by X-ray due to a procedure in the vicinity of the CT gantry. To solve this problem, we have developed a robot so we calling "Zerobot". Zerobot has six DOF and controlled remotely. We previously conducted animal experiment using a rabbit to evaluate Zerobot. As a result, percutaneous puncture was impossible without epidermis cutting. Therefore, we developed a new function called instantaneously puncture that can achieve high speed and short stroke puncture like a human operator. In this paper, overview of Zerobot is described first. Then, measurement of puncture speed of a human operator is described. Furthermore, design and system structure of instantaneously puncture system is described. Finally, we present results of animal experiment using the instantaneously puncture system.

researchmap

Event date： 2015

researchmap

Event date： 2015

researchmap

Event date： 2015

Language：English  

This paper considers an application of two degree of-freedom generalized predictive control (Two DOF GPC) to an aluminum mold model of temperature control experimental device. In our research, Two DOF GPC can achieve to design the output response for the aluminum plate model independently of modeling error or disturbance. The present study aims at controlling the temperature for various mold models in order to develop the proposed method for application to industry. Therefore, this paper shows an aluminum mold model, which we newly constructed, for temperature control by extending the conventional model. And we increased the number of input and output to examine the interference of heat with temperature control of the derived model by using two DOF GPC. The numerical examples are shown to verify the validity of the model and the proposed method.

researchmap

Event date： 2015

researchmap

Event date： 2015

Language：English  

This paper proposes on-demand type feedback controller for state space based generalized minimum variance control (GMVC) using coprime factorization. GMVC can be extended by using coprime factorization, and a new design parameter is introduced to the extended controller. Then the parameter can determine the characteristics of the extended controller without changing the closed-loop characteristics. In order to design safe systems, strong stability systems are effective because both closed-loop system and the controller are stable. So the parameter mentioned above is seemed to be useful to design safe systems. Moreover, focusing on feedback signal, the extended controller can adjust the magnitude of the feedback signal. It means that the proposed controller has the possibility to make the magnitude of the feedback signal be zero when the control objective is achieved. In other words the proposed method has the ability that the feedback signal emerges on demand of achieving the control objective. Therefore this paper explores the design method of on-demand type feedback controller using state space based GMVC and coprime factorization. A numerical example is given in order to check the characteristics of the proposed method.

researchmap

Event date： 2015

Language：English  

This paper proposes a design method of on-demand type feedback controller using coprime factorization. A controller, such as generalized minimum variance control (GMVC), generalized predictive control (CPC) and so on, can be extended by using coprime factorization. Then the extended controller has a new design parameter, and the parameter can select the characteristic of the extended controller without changing the closed-loop characteristic. Considering to design safe systems, strong stability systems can be obtained by the extended controller. Moreover, focusing on feedback signal, the extended controller can adjust the magnitude of the feedback signal. That is, the proposed controller can drive the magnitude of the feedback signal to zero if the control object was achieved. In other words the feedback signal by the proposed method can appear on demand of achieving the control object. At first step, this paper proposes on-demand type feedback controller using GMVC and coprime factorization. A numerical example is given in order to check the characteristic of the proposed method.

researchmap

Event date： 2015

Language：English  

The demand is growing that a robot manipulates a deformable object. Scenarios for both of a grasping point and transfer of grasped point are required, in order to manipulate a deformable object by a robot. Therefore, it is important for a robot to recognize its form by using image information. In this paper, three-dimensional points groups of a string are obtained by a camera that has distance measure equipment. A shape model called "point chain model" is obtained from points group based on proposed algorithm. In this algorithm, first, points which are estimated to be outside of target object are removed from obtained points groups. Secondly, points groups obtained from various viewpoints are combined to reconstruct three-dimensional shape of a string. Thirdly, central axes of a string are abstracted from combined points groups. Finally, central axes are chained to construct the point chain model. Effectiveness of proposed algorithm is confirmed by experiment.

researchmap

Event date： 2015

Language：English  

There are two principal methods to derivate motion of equation of robot manipulator, which are Newton-Euler (NE) method and Lagrange method. The NE method enables to make a dynamical model of robots and it is possible to calculate internal force and torque not generating real motion of robot manipulator, seemed to be an advantage of the NE method that Lagrange method does not have. This merit can be applicable for propagations of constraint and impact force/torque when discussing humanoids walking based on strict dynamical models. So far, the NE method has been applied to a robot of open-loop serial-linkage structure. However, the NE method has been limited to a motion without contacting with environment. Although robot task to the hand contact with environment, for example assembly task, grinding task is important, it has not been formulated in the way of the NE method. So, this paper proposes iterative calculation method for representing constraint dynamical motion of robot manipulator utilizing inverse dynamic calculation the NE method, leading and enabling the forward dynamics calculation of constraint motions to be dealt recursively through proposed the extended NE method for constraint motions, with no use of explicit representation of equation of motions. We applied this method to 2-linkage and 3-linkage manipulators and evaluated its validity by numerical simulations.

researchmap

Event date： 2015

Language：English  

A medical procedure called Interventional Radiology (IR) is paid much attention in recent years. IR can be performed percutaneously while a doctor observes patient's fluoroscopic image. It has advantage that invasiveness is low compared with conventional surgery. In order to take patient's fluoroscopic image, computed tomography (CT) equipment is often used. In this case, it is problem that the doctor is exposed to radiation because the doctor should conduct the procedure close to CT equipment. Thus, we have developed a robot called "Zerobot" which has six DOF and remote-control feature with dedicated input device. In this paper, first, overview of Robotic IR is described. Then, we describes about animal puncture experiment of Zerobot, and discuss the result of puncture reaction force analysis in the experiment.

researchmap

Event date： 2015

Language：English  

The deformable object such as string, cloth and paper, is soft and can change its shape easily. It is difficult for a robot to manipulate deformable object because it needs to deal with various shape. For the operation of deformable object, it is important to recognize the shape of them. In our previous research, point chain model and the string shape recognition method were proposed. Point chain model is a structure to describe a string shape by a series of connections of points. And the string shape recognition method are algorithms to recognize a string shape from 3D point cloud data and output point chain model. However, the previous method sometimes occurred misrecognition of segments. Therefore, enhanced matching method is proposed to improve recognition performance.

researchmap

Event date： 2015

Language：English  

This paper explores switching PID controller for an underactuated flying object through model-based prediction. Helicopter is applied in large field because of flight ability such as vertical ascent, vertical descent and hovering. However the helicopter, which is one of the underactuated flight objects, is complex and has nonlinear dynamics. In this research, controlled target is an underactuated flight object with two inputs and three outputs. The proposed method predicts the system outputs using the model of controlled target, and the control inputs are calculated by using their values. That is, PID gains arc switched at each sampling tune by the model-based controlled result with time passing virtually. A numerical example is shown to verify the validity of the proposed method.

researchmap

Event date： 2015

researchmap

Event date： 2015

researchmap

Event date： 2015

researchmap

Event date： 2015

researchmap

Event date： 2015

researchmap

Event date： 2015

researchmap

Event date： 2015

researchmap

Event date： 2015

researchmap

Event date： 2015

researchmap

Event date： 2014

Language：English  

This paper considers an application of two degree-of-freedom generalized predictive control (Two DOF GPC) to the model of temperature control experimental device of two dimensional aluminum plate. In our research, Two DOF GPC can achieve to design the output response for the aluminum plate model with modeling error or disturbance, and without them independently. The present study aims at three dimensional temperature control by expanding the model of the one dimensional aluminum plate into two dimensional one.

researchmap

Event date： 2014

Language：English  

A lot of researches on inverted pendulum cart are conducted in recent years. And it attracts as a personal vehicle that realizes energy saving for many practical applications. However, because most conventional personal vehicles require a certain level of physical ability from the driver, it is not suitable for elderly and disabled people to drive.Therefore, an inverted pendulum cart with a sliding mechanism for posture control that could be ridden by anyone has been developed. In this paper, we propose that inverted pendulum cart runs keeping posture perpendicularly. First, algorithm to estimate the lean angle, that is calculated based on the center of gravity of the cart, using the full-order state observer is proposed. Secondly, algorithm to keep the posture of cart perpendicular against the change of the center of gravity is proposed. Then, desired position of slider is calculated based on the estimated lean angle. Finally, the effectiveness of algorithm is confirmed through a simulation.

researchmap

Event date： 2014

Language：English  

There is a surgical method called Interventional Radiology (IVR) as one of lung cancer treatments. It has a problem that doctors are exposed to radiation because IVR is conducted in CT apparatus. In order to avoid the problem, a robotic IVR system that doctors conduct the puncture with a robot is developed. An operation test is necessary to develop the robotic IVR system, however, an experiment with real patients is rejected based on ethic regulation. Therefore, a phantom is used for experiments instead of patients. A phantom is a model of human used for both evaluation and adjustment of medical imaging equipments such as CT and MRI. However, ready-made phantoms can not be punctured, because they are only aimed to radiography and their surface are hard. Therefore a phantom for CT-IVR which can be punctured is developed.

researchmap

Event date： 2014

researchmap

Event date： 2014

researchmap

Event date： 2014

researchmap

Event date： 2014

researchmap

Event date： 2014

researchmap

Event date： 2014

researchmap

Event date： 2014

researchmap

Event date： 2014

researchmap

Event date： 2014

researchmap

Event date： 2014

researchmap

Event date： 2014

researchmap

Event date： 2014

researchmap

Event date： 2014

researchmap

Event date： 2013

Language：English  

There are surgical methods called Interventional Radiology (IVR) using CT equipments in medical treatments of lung cancers, a blood vessels, and so on. IVR has an advantage that invasiveness is low and medical treatments with local anesthesia are possible as compare with the fact that laparotomy surgeries require general one. Therefore the number of IVR surgery has been increasing in recent years. However, radiation exposure to doctors has been concerned in the current IVR, since medical doctors conduct the treatment using CT equipment. Thus, the IVR robot should be developed in order to avoid the radioactive exposure to doctors. In this research, a robot using a parallel link mechanism is developed from the viewpoints that hand accuracy and hand rigidity are high and motors can be arranged far from CT scanning plane. The dual delta-type parallel link is proposed. It has the structure which is arranged the delta-type parallel link mechanism with three degrees of freedom (DOF). First, the arm which has offset of the axis in consideration of interference was designed. Secondly, inverse kinematics of parallel link was analyzed. Next, Delta-type parallel link mechanism with three DOF was manufactured. Finally, basic motion of parallel link robot was confirmed.

researchmap

Event date： 2013

Language：English  

Fault detection functions with learning method of a robotic manipulator are very useful for factory automation. All production has the possibility to fail due to unexpected accidents. To reduce the fatigue of human workers, small errors automatically should be corrected by a robot system. Also a learning method is important for fault detection, because labor of system integrator should be reduced. In this paper, an external thread fastening task by a robotic manipulator is investigated. To discriminate the four states of a task, linear support vector machine methods with two feature parameters are introduced. The effectiveness of the proposed algorithm is confirmed through an experiment and recognition examination. Finally, the ability of linear SVM is compared with artificial neural network method.

researchmap

Event date： 2013

researchmap

Event date： 2013

researchmap

Event date： 2013

researchmap

Event date： 2013

researchmap

Event date： 2013

researchmap

Event date： 2013

researchmap

Event date： 2013

researchmap

Event date： 2013

researchmap

Event date： 2012.5.27

Language：Japanese  

This paper proposes a dynamic model of general behavior using a new concept Narrow Tilting Vehicle (NTV). Our NTV has one wheel on the front and two wheels on the rear. Also, it is very narrow and all three wheels will tilt to make stable during turn. We derive three types of dynamic model. One is the model when all three wheels are on the ground. Other two are the model when each right and left rear wheel floats. These dynamic models are useful to control the real vehicle. Then, we made simulations to indicate the availability of our dynamic model. We also made some simulations to validate our three dynamic models.

researchmap

Event date： 2012

researchmap

Event date： 2012

Language：English  

The traffic congestion is growing in urban area these days. This is because the number of the automobiles is increasing rapidly. To solve this problem, there are many solutions. One of them is to increase the flow rate of a particular traffic artery. A converse approach to increase the flow rate is to make the vehicle smaller and narrower. We developed a new conceptual Narrow Tilting Vehicle (NTV) that has one front wheel and two rear wheels. Also, it is very narrow and all three wheels can tilt to improve the stability during turning. In this paper, we derive a new switching dynamical model of NTV. This model considers several NTV states including normal running, temporary running with one rear wheel not on the ground and totally falling down. Based on this model, a simulation platform is established, which is useful to test different control methods and to investigate dangerous driving situations in case hurt drivers in real experiments. The effectiveness of proposed dynamical model is verified through comparison study of simulations and corresponding experiments.

researchmap

Event date： 2012

Language：English  

Biped locomotion created by a controller based on Zero-Moment Point [ZMP] known as reliable control method looks different from human's walking on the view point that ZMP-based walking does not include falling state. However, the walking control that does not depend on ZMP is vulnerable to turnover. Therefore, keeping the event-driven walking of dynamical motion stable is important issue for realization of human-like natural walking. In this paper, walking model of humanoid including slipping, bumping, surface-contacting and point-contacting of foot is discussed, and its dynamical equation is derived by Newton-Euler method. Then, we propose walking stabilizer named "Visual Lifting Stabilization" strategy to enhance standing robustness and prevent the robot from falling down. Simulation results indicate that this strategy helps stabilize pose and bipedal walking even though ZMP is not kept inside convex hull of supporting area.

researchmap

Event date： 2012

Language：English  

This paper proposes and analyses an approach named predictive control of redundant manipulators based on avoidance manipulability to achieve an on-line control of trajectory tracking and obstacle avoidance for redundant manipulators. In the trajectory tracking process, manipulator is required to keep a configuration with maximal avoidance manipulability in real time. Predictive control in this paper uses manipulators' future configurations to control current configuration aiming at completing tasks of trajectory tracking and obstacle avoidance on-line and simultaneously with higher avoidance manipulability. We compare first order prediction with second order prediction and show the results through simulation. Moreover, we validate the effectiveness of predictive control through Avoidance Manipulability Shape Index with Potential (AMSIP) distribution.

researchmap

Event date： 2012

Language：English  

There is much attraction of automation of difficult assembly by robotic manipulator. However, robots in factory should be overseen by human workers in order to check whether task condition is anomaly or not. In order to reduce human cost, anomaly detection for assembly task is important. A task to tighten a screw as one of assembly tasks is focused on. In this paper, we propose a method to generate high confidence area in the map of features based on nonlinear support vector machine with Gaussian kernel. By proposed method, a robot system can reduce occasions to make mistake in recognition of task conditions.

researchmap

Event date： 2012

Language：English  

There has been an increasing interest in a kind of underactuated mechanical systems, mobile wheeled inverted pendulum (MWIP) models, which are widely used in the field of autonomous robotics and intelligent vehicles. A novel transportation system, UW-Car, which is composed of an MWIP system and a movable seat is proposed. The reduced-order dynamic model of a UW-Car system running in a rough terrain is obtained by applying Lagrangian motion equations. A sliding mode control approach is proposed based on the dynamic model. Comparing with the linear quadratic regulator (LQR) approach, the new method guarantees that a UW-Car system can run in a rough terrain while keeping the body upright and the seat on some fixed position. The theoretical results are finally demonstrated through numerical simulations.

researchmap

Event date： 2012

Language：English  

The traffic congestion is growing in urban area these days due to the rapidly increasing number of automobiles. One of the traffic problem solutions is to increase the flow rate of a particular traffic artery. To make the vehicle smaller and narrower might be a good idea. We developed a new conceptual Narrow Tilting Vehicle (NTV) that has one front wheel and two rear wheels. The proposed NTV is very narrow and all three wheels can tilt to improve the stability during turning. We also derive a new switching dynamical model of the NTV. This model considers several states including normal running, temporary running with one rear wheel not on the ground and totally falling down. Based on this model, a simulation platform is established, which is useful to test different control methods and to investigate dangerous driving situations in case hurt drivers in real experiments. The effectiveness of proposed dynamical model is verified through comparison study of simulations and corresponding experiments.

researchmap

Event date： 2012

researchmap

Event date： 2012

Language：Japanese  

Fault detection functions of a robotic manipulator are very useful for factory automation. All production has the possibility to fail due to unexpected accidents. To reduce the fatigue of human workers, small errors automatically should be corrected by a robot system. In this paper, an external thread fastening task by a robotic manipulator is investigated. To discriminate the four states of a task, linear support vector machine methods with two feature parameters are introduced. One is the estimated insertion length, and the other is the maximum reaction force. The effectiveness of the proposed algorithm is confirmed through an experiment and recognition examination.

researchmap

Event date： 2012

Language：English  

This paper shows effectiveness of bracing for precise and low electrical energy consumption of the end-effector in the case with and without the constraint of the joint of mobile manipulator. Considering that human can do accurate task with less power by bracing elbow on the table, we believe that manipulators can save energy and do a task more precisely like human by bracing itself. Therefore this paper first discuss the motion equation of robot with constraint condition, and robots dynamics including motor's dynamics also. Then the effects of bracing are analyzed and displayed.

researchmap

Event date： 2012

Language：English  

The objective of this research is to analyze humanoid's jumping and landing motions on a view point of arms' dynamical coupling onto jumping. Humans seem to use arms' swinging for walking or running effectively and jump highly by swinging up arms high. So, we gave input torques to arms in such a way as to swing arms similar to humans, and changed timing to start swinging them, comparing them with humanoid's motion that does not swing the arms through numerical simulation. Then we have confirmed that appropriate swinging motions of arms help the jumping to be higher than those without arms' swinging.

researchmap

Event date： 2012

researchmap

Event date： 2012

researchmap

Event date： 2011.5.26

Language：Japanese  

To obtain a secured mating of electric connectors is one of the most important steps in a robotic wiring harness assembly system. Although there are plentiful results about complex peg-in-hole assembly problems, little work has been done with respect to this special issue. In many cases, mating connectors can be regarded as a hole search process of a multiple hole-in-peg problem. Because various faults might occur during the search, a reliable error recovery strategy is necessary in the mating task. In the paper, the error detection algorithm and the error recovery algorithm for various connectors are mainly realized by using force/torque sensor. The experiment results show the proposed system can detect and diagnose the position errors, and realize error recovery and mating successfully. It shows the fault-tolerable capability of the system is improved evidently.

researchmap

Event date： 2011

researchmap

Event date： 2011

researchmap

Event date： 2011

Language：Japanese  

Recently, industrial robots have engaged in various works. In the near future, robots will be required to work out some difficult assemblies instead of human. Even though high sensitivity of force sensor is needed for difficult assemblies, it is inferior to that of human. Therefore, a force sensor should be developed so that sensitivity can catch up with that of human. In conventional research, some researches concerned with force sensors are conducted. However, they do not have both wide range and high durability. In this paper, we propose a tuning fork structured piezoelectric vibration sensor. It is possible to realize both of high sensitivity and high durability due to multi vibration mode. And, it applied for robot control in order to confirm the availability.

researchmap

Event date： 2011

researchmap

Event date： 2011

Language：English  

Three-dimensional dynamic modeling and numerical simulation of manipulating deformable linear objects (DLOs) such as hoses, wire and cables are studied in this paper. Several coordinate systems are introduced first to describe the deformation of DLOs. The dynamic three-dimensional deformation of an inextensible linear object is formulated using finite element method (FEM) and lagrange motion equations. The proposed method provides more efficient simulation of dynamic manipulating DLOs with faster computation speed. Two simulation examples are illustrated to confirm the effectiveness of our methods. One is a comparison simulation study and the other shows the three-dimensional dynamic character of the DLO.

researchmap

Event date： 2009

Language：English  

There has been an increasing interest in a kind of underactuated mechanical systems, mobile wheeled inverted pendulum (MWIP) models, which are widely used in the field of autonomous robotics and intelligent vehicles. A novel structure including an MWIP system and a movable seat called UW-Car is proposed in the study. The dynamic model of UW-Car system running in the flat ground is obtained by applying Lagrange's motion equation. A sliding mode control (SMC) method is proposed for the dynamic model, which is capable of both handling the mismatched perturbation and keeping the body upright. An optimal braking scheme is introduced which reduces the velocity of UW-Car to zero first and adjusts the displacement of seat to the centre position. Genetic Algorithm (GA) is adopted to search the optimal parameters for sliding mode controller. The optimal braking scheme is implemented by on-line switching three sliding mode controllers. The effectiveness of the proposed methods is finally confirmed by numerical simulation.

researchmap

Event date： 2009

Language：English  

There has been an increasing interest in a kind of underactuated mechanical systems, mobile wheeled inverted pendulum (MWIP) models, which are widely used in the field of autonomous robotics and intelligent vehicles. Robust velocity tracking problem of MWIP systems is investigated in this study. In the velocity control problem, model uncertainties accompany uncertain equilibriums, which make the controller design become more difficult A sliding mode control (SMC) method based on a novel sliding surface is proposed for the systems, which are capable of handling both parameter uncertainties and external disturbances. By assuming the specially designed sliding surface, the proposed SMC controller is capable of eliminating the steady velocity tracking error. The asyrnptotical stability of the closed-loop system is achieved through selecting sliding surface parameters in terms of some rules. The effectiveness of the proposed methods is finally confirmed by numerical simulations.

researchmap

Event date： 2008

researchmap

Event date： 2008

Language：English  

Deformable linear objects (DLOs) such as cables, hoses and wires are widely used in the real life, electric industries and medical operations. In this paper, we propose a new approach to simulate manipulating DLOs in the robotic assembly. The dynamic 2D deformation of an inextensible linear object is formulated using FEM approach. Based on the model, simulation can be efficiently implemented by matrix computation and numerical solvers for differential equations. The proposed method provides faster computation speed than methods based on differential geometry coordinate systems. Some simulation examples are illustrated to confirm the effectiveness of our methods.

researchmap

Event date： 2008

Language：English  

To obtain a secured mating of electric connectors is one of the most important steps in a robotic wiring harness assembly system. Although there are plentiful results about complex peg-in-hole assembly problems, little work has been done with respect to this special issue. In many cases, mating connectors can be regarded as a hole search process of a multiple hole-in-peg problem. Because various faults might occur during the search, a reliable error recovery strategy is necessary in the mating task. In this paper, we model possible faults as "trap regions" in the configure space (C-space) of the assembly. Fault isolation methods are obtained from elaborated force analyses as well. Based on these fault isolation results, error recovery strategies are proposed according to the fault models. A fault-tolerant mating of electric connectors can then be achieved. The effectiveness of the methods is finally confirmed by experiments.

researchmap

Event date： 2008

Language：English  

A three-wheeled omni-directional cane robot is designed for aiding the elderly walking. Possible move modes are analyzed and a corresponding hybrid model is constructed to describe walking behavior. A concept called intentional direction is presented to denote the moving intention of a human. Based on experiments and some assumptions, dynamic model of intentional direction is obtained as well as its online estimation method. A new admittance control scheme is presented based on intentional direction, which provides natural and intuitive human machine interface. Experiment results show the effectiveness of the design.

researchmap

Event date： 2008

researchmap

Event date： 2008

researchmap

Event date： 2008

researchmap

Event date： 2007

Language：English  

Mating a pair of electric connectors is one of the most important steps in a robotic wiring harness assembly system, which can be modeled by static piecewise affine (PWA) systems. To design a fault detection system for this application, a set-membership approach for static PWA systems is proposed, in which parallelotopic approximation of feasible parameter sets (FPS) is adopted. An online algorithm is obtained to estimate bounds of uncertain transition points of the PWA model. Based on the estimation, a robust online fault detection algorithm is proposed. The effectiveness of these methods is finally confirmed through experiments.

researchmap

Event date： 2007

Language：English  

Mating a pair of electric connectors is one of the most important steps in a robotic wiring harness assembly system. A piece-wise linear force model is reported to describe the successful mating process of connectors via elaborate analysis of force during different phases. The corresponding parameter estimation method of this model is also presented by adapting regular least square estimation methods. A typical type of connectors are investigated in this paper. The results can be extended to other types easily. Experiments show that the presented model has good prospects in fault diagnostic tasks.

researchmap

Event date： 2007

Language：English  

As one of dynamics-based control of biped walking, some researchers presented the control method to take advantage of robot dynamics directly by use of point-contact state between a robot and the ground. We proposed Passive Dynamic Autonomous Control (PDAC) previously[13] as one of point-contact methods. PDAC expresses the robot dynamics as an 1-dimensional autonomous system based on the two concepts: 1) point-contact 2) Virtual Constraint (proposed by Grizzle and Westervelt et al[8], [10]). We actually realized 3D dynamic walking by means of proposed method, however stability is not proved and the convergence domain is not clear. Thus, this paper finds the convergence domain of the previously proposed controller and proves the stability by the Liapunov Theory. Finally, the correctness of stability proof is confirmed by the numerical simulation.

researchmap

Event date： 2007

Language：English  

In proposing the jumping mechanism imitating the leg of vertebrate, unique mechanical function of bi-articular muscle was analyzed. The bi-articular muscle is an actuator which exists only in vertebrate. The ground reaction force and/or jumping motion were examined using the following three jumping mechanisms, 1) the mechanism which arranged two actuators on the knee and ankle joint independently (Mechanism-A), 2) the mechanism which arranged two actuators on the knee and ankle joint, and connected two joints by a wire (Mechanism-B), 3) the mechanism which arranged one actuator only on the knee joint, and connected two joints by a wire (Mechanism-C). It became clear that the Mechanism-C is excellent as the result of analyses in this study. A pantograph mechanism is constituted by the wire equivalent to the biarticular muscle which transmits the joint torque between two joints. And, ideal ground reaction force for jumping motion is generated. Furthermore, the jumping mechanism or robot which has the function of bi-articular muscle was made and the vertebrate like jumping motion was realized. In this study, it is said that the muscular arrangement of vertebrate is ideal arrangement. It is also an answer to the general question why is the crus very thinner than the femur of vertebrate which makes a jump elated.

researchmap

Event date： 2007

Language：English  

The purpose of this study is development of a passive type virtual reality glove, which represents force sensations of grasping virtual objects and rather enhances immersive feelings in virtual space. VR technologies are recently actively researched for application or practical use, and actually some sensor gloves were commercialized. Though, force display gloves have not become popular. One of the major reasons would be safety of the device. We aim to develop a passive force display glove which consists of only passive elements like brakes, have no danger of hurting operator even if the controller runs away, and is to have characteristics of safety, high performance and inexpensive. This paper reports the prototype glove and its improved type.

researchmap

Event date： 2007

Language：English  

Nowadays, robots manipluated by human are aggressively researched and developed. Such robots need large generative force, high speed response, good controllability, high safety, low friction, backdriveability and so on. We have put emphasis on the backdriveability and created a novel prototype linear actuator with new structure applying an ER (Electro-Rheological) gel, a recent functional material. It is an all-purpose actuator satisfying characteristics for human-coexistence welfare robot.

researchmap

Event date： 2007

researchmap

Event date： 2006

Language：English  

In this paper, a sensor fusion based fuzzy rules for humanitarian demining are presented. A fuzzy learning algorithm for extracting fuzzy fusion rules from experimental data of robot-manipulated ground penetrating radar (GPR) and metal detector (MD) is presented. The inputs to the fuzzy learning algorithm are features extracted from both a GPR and an MD while its output is a set of fuzzy rules. Applying the learnt fuzzy fusion rules and knowing GPR and the MD features of a given scan, it is possible to decide if there is a land mine and its approximate depth underground. The features chosen for this fusion algorithm are the peak amplitude of a processed GPR output signal and the peak value of the cumulative sum of amplitudes of MD output signal for the same scanned area. Experimental test results are presented for verifying the validity of the proposed learnt fuzzy fusion rule base.

researchmap

Event date： 2006

researchmap

Event date： 2006

Language：English  

We propose a new tactile sensor utilizing piezoelectric vibration. This tactile sensor has a high sensitivity, wide measurement range, pressure resistance, flexibility, and self-sensing function. This tactile sensor comprises two piezoelectric materials. One is used for the vibration of the sensor element and the other is used for the measurement of the change in mechanical impedance induced by an external force. We achieved the wide measurement range by implementing two ideas. One was to apply the external force to the sensor element through an elastic body and the other was to use two or more modes of vibration. Moreover, for the elastic body, it is preferable to use a material whose elasticity and viscosity are easily changed by an external force, such as a gel. In this study, first, this tactile sensor was analyzed, and then its characteristics were derived. The analytical results qualitatively corresponded to the experimental results. Next, a prototype tactile sensor was fabricated and evaluated. The evaluation results showed that this tactile sensor can measure a pressure of 2.5 Pa or less and a pressure of 10 kPa or more and its pressure resistance is 1 MPa or more.

researchmap

Event date： 2006

Language：English  

Most of landmine detection robots proposed before have been strongly restricted to locomote because they have not been able to enter the minefield. So we have proposed a mine detection vehicle which can enter minefield with low-ground-pressure tires and scan landmines directly using GPR. Low-ground-pressure tire decrease ground contact pressure. And we are intended to make accurate map that point out the position where landmines are buried. The position of the vehicle is able to be observed with internal sensors (for the posture measurement) and external sensors (for the position measurement). However, when controlling the vehicle, the sampling time of external sensors and communication time from external sensors to the vehicle cannot be disregarded. Exact position of the vehicle must be predicted with dynandcal model of the vehicle. We therefore propose dynamical model of the vehicle for low-ground-pressure vehicle. Based on experimental results, the dynamical model for low-ground-pressure vehicle is in consistency with acutual behavior of it.

researchmap

Event date： 2006

Language：Japanese  

In this papar, we proposed a new method of rotary height control. Our method can estimate absolute height of ground level only using pitching sensor. But this ground level estimation method has a error caused by unknown ground height between front wheel rear wheels, we solved this problem by observing the difference between a rear cover angle of an internal model and an actual rear cover angle. In additon, we proposed hybrid control system of preview control and rotary height control. Finally, the effectiveness of proposed methods was confirmed.

researchmap

Event date： 2006

Language：Japanese  

This paper proposes the control method of biped walking with heel-off motion. Heel-off motion made it possible to avoid the problem for the impact shock at foot-contact to break the stabilization of walking. The 3D motion is separated into lateral and sagittal motion and the approximate 1-mass model in both planes is employed. In the sagittal plane, there are two phases: 1) the center of rotation (contact point) is ankle joint. 2) the center of rotation is toe. In phase 2), heel-off motion is designed to diminish the impact shock at foot-contact. The phase of dynamics derived by means of PDAC makes it possible to inspect heel-off motion analytically. We design the stabilizing controller for each plane and confirm the convergency of dynamics with the numerical simulation.

researchmap

Event date： 2006

Language：Japanese  

We integrated the piezoelectric vibration-type tactile sensor with high sensitivity and wide measurement range. It was a problem that the vibration of a certain sensor element influenced other sensor elements when this tactile sensor was integrated. In this paper, first, we solved this problem by placing the vibration absorption material between sensor elements. Next, the structure of the integrated piezoelectric vibration-type tactile sensor was proposed and produced. As a result, we succeeded in integrating 18 sensor elements in the area of 20×20 mm. However, the vibration was not absorbed enough by the vibration absorption material with the acrylic resin and the conductive epoxy resin. This problem was solved by using a flexible conductive tape as the vibration absorption material, and the integrated tactile sensor with high sensitivity and wide measurement range was realized.

researchmap

Event date： 2006

Language：Japanese  

Ground Penetrating Radar (GPR) is a promising sensor for landmine detection, however there are several problems to overcome. One is adaptability to non-planer(e.g. rough and/or undulating) ground surface. It remains unremovable clutters on a sub-surface image output from GPR. Geography adaptive scanning is useful to image objects beneath non-planer ground surface. The other problem is the distance between the antennas of GPR. When imaging a small object such as an anti-personnel landmine close to antennas, it increases the nonlinearity of the relationship between the time for propagation and the depth of a buried object. In this paper, we modify Kirchoff migration so as to account for not only the variation of height and pose of the sensor head, but also the antennas alignment of the vector radar. The validity of this method is discussed through application to the signals acquired in experiments.

researchmap

Event date： 2006

researchmap

Event date： 2006

researchmap

Event date： 2006

Language：Japanese  

We propose the tailor-made multilayer piezoelectric actuator with large displacement and large force. In a past piezoelectric actuator, the achievement of a small, low-cost actuator with large displacement and large force was difficult. We solved these problems by combining two bimorph type piezoelectric elements by the both ends being supported, and accumulating it. Moreover, the ratio of displacement and force of this multilayer piezoelectric actuator can be widely changed by changing the size of bimorph type piezoelectric element. In this study, first, we show the structure of this multilayer piezoelectric actuator. Next, displacement and force of this multilayer piezoelectric actuator were theoretically derived. The analytical results almost corresponded to the experimental results. Next, prototype multilayer piezoelectric actuators were fabricated and evaluated. The evaluation results showed that this multilayer piezoelectric actuator can generate a displacement of several 100 μm or a force of several N within the size of 10×10×10 mm.

researchmap

Event date： 2006

Language：Japanese  

In this paper, we propose the wearable sleep control system and estimation method of the sleep state using pulse wave. We are trying to make an adaptive human interface of sleep control system above mentioned. There are 3 steps for realize the system. At first, the system could be estimate human sleep state. Secondly, system must be an adaptive system for differences among individuals. At last, the system must be able to do something to human to control user's state. We are considering about most simple way to control human's sleep cycle phase is to control awakening timing and sleep time. Now, the ordinary alarm clock operates according to the time. And we have to set the "time" in advance. But human has a rhythms in one's sleep cycle. The cycle affects one's sleep depth and wake-up timing.

researchmap

Event date： 2006

Language：Japanese  

In this paper, we present the control method to achieve the continuous brachiation on the irregular ladder. The uniform ladder problem was solved by means of symmetric property previously. However, as for the irregular ladder problem, it's impossible to build the controller based on symmetric property since the motion cannot be designed symmetrically. Therefore, it is necessary to estimate the energy difference caused by symmetry breaking.We apply Passive Dynamic Autonomous Control (PDAC), which was proposed previously, to the locomotion action and evaluate the energy difference. Swing motion is adjusted so as to satisfy the desired energy calculated from the energy difference. The validity of proposed method is tested by the experiment of Gorilla Robot III and the irregular ladder brachiation is realized.

researchmap

Event date： 2006

Language：English  

We propose tailor-made multilayer piezoelectric actuators (TAMPA) having large displacements and large forces. In existing piezoelectric actuators, production of small, low-cost actuators having large displacements and large forces is difficult to achieve. We solved this problem by combining two bimorph-type piezoelectric elements with both ends simply supported, and stacking several elements on top of each other. Moreover, TAMPA is a tailor-made actuator whose displacement to force ratio can be varied widely by adjusting the size of the bimorph-type piezoelectric elements even when the total size of the actuator is kept constant. In this study, the bimorph-type piezoelectric element was analyzed, and the relationship between the displacement and the force under fixed conditions was experimentally determined. The relationship between the displacement and the force of TAMPA was theoretically derived. The analytical results showed that a TAMPA having dimensions of approximately 10x10x10 mm is capable of generating displacements of several hundred mu m or the force of several N. A prototype was produced and its performance was evaluated. These results agreed well with the analytical results, confirming the validity of the analytical results. Finally, because the lead in PZT can cause environmental problems, a TAMPA was produced that used (K,Na)(Nb,Ta)O-3 piezoelectric ceramics instead of PZT.

researchmap

Event date： 2006

Language：English  

This paper proposes the control method of biped walking with heel-off motion. Heel-off motion made it possible to avoid the problem for the impact shock at foot-contact to break the stabilization of walking. The 3D motion is separated into lateral and sagittal motion and each motion is designed individually under the assumption that each motion is possible to be treated independently each other. We adopt the approximate 1-mass model in both planes and derive the dynamics based on these models. It is assumed that the lateral motion is relevant to heel-off motion. On the other hand, in the sagittal plane, there are two phases: 1) the center of rotation (contact point) is ankle joint. 2) the center of rotation is toe. In phase 2), heel-off motion is designed to diminish the impact shock at foot-contact. By applying PDAC to the dynamics, phase around the contact point can be derived. By means of this phase of dynamics, it is possible to inspect heel-off motion analytically. We design the stabilizing controller for each plane and confirm the convergency of dynamics with the numerical simulation.

researchmap

Event date： 2006

Language：English  

Ground Penetrating Radar (GPR) is a promising sensor for landmine detection, but there are two major problems to overcome. One is the non-planer(e.g. rough and/or undulating) ground surface. It remains irremovable clutters on a sub-surface image output from GPR. Geography adaptive scanning is useful to image objects beneath non-planer ground surface. The other problem is the distance between the antennas of GPR. When imaging the small objects such as an anti-personnel landmine close to antennas, it increases the nonlinearity of the relationship between the time for propagation and the depth of a buried object. In this paper, we modify Kirchhoff migration so as to account for not only the variation of height and pose of the sensor head, but also the antennas alignment of the vector radar. The validity of this method is discussed through application to the signals acquired in experiments.

researchmap

Event date： 2005

researchmap

Event date： 2005

researchmap

Event date： 2005

researchmap

Event date： 2005

Language：Japanese  

researchmap

Event date： 2005

Language：Japanese  

researchmap

Event date： 2005

Language：Japanese  

researchmap

Event date： 2004

researchmap

Event date： 2004

Language：English  

researchmap

Event date： 2004

researchmap

Event date： 2003

researchmap

Event date： 2000