Our research goal is to realize a robust navigation in indoor and outdoor environment for autonomous vehicle. An omnidirectional vehicle driven by four Mecanum wheels was chosen for our research platform. Mecanum wheel has 16 tilted rollers (45 degrees against the direction of wheel rotation) around the wheel, so the vehicle moves omnidirectionally by controlling these wheels independently. However, it has a disadvantage in odometry because of wheel slippage. Particularly, when the robot moves laterally, same wheels' rotations generate different traveling distance depending on friction of ground surface. To cope with the problem, we estimate robot's position by detecting optical flow of ground image using vision sensor (visual dead-reckoning). The estimation method is inaccurate comparing with odometry, but it is independent from friction of ground surface. Therefore, the estimated vehicle position can be improved by fusing odometry and visual dead-reckoning based on maximum likelihood technique. This paper describes an odometry method and a visual dead-reckoning method for omnidirectional vehicle, and fusion technique to improve the estimated position of the vehicle. Finally, experimental results support above technique
en-copyright= kn-copyright= en-aut-name=NagataniKeiji en-aut-sei=Nagatani en-aut-mei=Keiji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=TachibanaSatoshi en-aut-sei=Tachibana en-aut-mei=Satoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=SofueMakoto en-aut-sei=Sofue en-aut-mei=Makoto kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=TanakaYutaka en-aut-sei=Tanaka en-aut-mei=Yutaka kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Okayama University en-keyword=distance measurement kn-keyword=distance measurement en-keyword=image sequences kn-keyword=image sequences en-keyword=mobile robots kn-keyword=mobile robots en-keyword=robot vision kn-keyword=robot vision en-keyword=vehicles kn-keyword=vehicles END start-ver=1.4 cd-journal=joma no-vol= cd-vols= no-issue= article-no= start-page=1017 end-page=1022 dt-received= dt-revised= dt-accepted= dt-pub-year=2001 dt-pub=200111 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Sensor based navigation for car-like mobile robots using generalized Voronoi graph en-subtitle= kn-subtitle= en-abstract= kn-abstract=Our research objective is to realize sensor based navigation by car-like mobile robots. The generalized Voronoi graph (GVG) can describe a mobile robot's path for sensor based navigation from the point of view of completeness and safety. However, it is impossible to apply the path to a car-like mobile robot directly, because limitation of the minimum turning radius prevents following the non-smooth GVG. To solve the problem, we propose a local smooth path planning algorithm for car-like mobile robots. Basically, an initial path is generated by a conventional path planning algorithm using GVG theory, and it is deformed smoothly to enable car-like robots' following by maximizing an evaluation function proposed in the paper. The key topics are: definition of our evaluation function; and how to modify the GVG. We introduce a local smooth path planning algorithm based on the GVG, and explain a detail of the evaluation function. Simulation results support validity of the algorithm
en-copyright= kn-copyright= en-aut-name=NagataniKeiji en-aut-sei=Nagatani en-aut-mei=Keiji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=IwaiYosuke en-aut-sei=Iwai en-aut-mei=Yosuke kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=TanakaYutaka en-aut-sei=Tanaka en-aut-mei=Yutaka kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University en-keyword=computational geometry kn-keyword=computational geometry en-keyword=mobile robots kn-keyword=mobile robots en-keyword=path planning kn-keyword=path planning END start-ver=1.4 cd-journal=joma no-vol= cd-vols= no-issue= article-no= start-page=1663 end-page=1668 dt-received= dt-revised= dt-accepted= dt-pub-year=2002 dt-pub=200210 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Motion planning for mobile manipulator with keeping manipulability en-subtitle= kn-subtitle= en-abstract= kn-abstract=Our research goal is to realize a motion planning for an intelligent mobile manipulator. To plan a mobile manipulator's motion, it is popular that the base robot motion is regarded as manipulator's extra joints, and the whole system is considered as a redundant manipulator. In this case, the locomotion controller is a part of the manipulator controller. However, it is difficult to implement both controllers as one controller, in our implementation experience, because of difference of actuators' character. In this research, we focus on a path planning algorithm for a mobile base with keeping manipulability at the tip of the mounted manipulator. In this case, the locomotion controller is independent from the manipulator controller, and a cooperative motion is realized by a communication between both controllers. In this paper, we propose a motion planning algorithm for a mobile manipulator, and report several experimental results.
en-copyright= kn-copyright= en-aut-name=NagataniKeiji en-aut-sei=Nagatani en-aut-mei=Keiji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=HirayamaTomonobu en-aut-sei=Hirayama en-aut-mei=Tomonobu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=GofukuAkio en-aut-sei=Gofuku en-aut-mei=Akio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=TanakaYutaka en-aut-sei=Tanaka en-aut-mei=Yutaka kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Okayama University en-keyword=manipulators kn-keyword=manipulators en-keyword=mobile robots kn-keyword=mobile robots en-keyword=path planning kn-keyword=path planning END start-ver=1.4 cd-journal=joma no-vol= cd-vols= no-issue= article-no= start-page=3112 end-page=3117 dt-received= dt-revised= dt-accepted= dt-pub-year=2003 dt-pub=200310 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Three-dimensional localization and mapping for mobile robot in disaster environments en-subtitle= kn-subtitle= en-abstract= kn-abstract=To relieve damages of earthquake disaster, "The Special Project for Earthquake Disaster Mitigation in Urban Areas" have been kicked off in Japan. Our research group is a part of the sub-project "modeling of disaster environment for search and rescue" since 2002. In this project, our group aims to develop a three-dimensional mapping's algorithm that is installed in a mobile robot to search victims in a collapsed building. To realize this mission, it is important to map environment information, and also the mapping requires localization simultaneously. (This is called "SLAM problem".) In this research, we use three-dimensional map by laser range finder, and we also estimate its location in a global map using correlation technique. In this paper, we introduce our localization and mapping method, and we report a result of preparatory experiment for localization.
en-copyright= kn-copyright= en-aut-name=NagataniKeiji en-aut-sei=Nagatani en-aut-mei=Keiji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=IshidaHiroshi en-aut-sei=Ishida en-aut-mei=Hiroshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=YamanakaSatoshi en-aut-sei=Yamanaka en-aut-mei=Satoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=TanakaYutaka en-aut-sei=Tanaka en-aut-mei=Yutaka kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Okayama University en-keyword=correlation theory kn-keyword=correlation theory en-keyword=disasters kn-keyword=disasters en-keyword=earthquakes kn-keyword=earthquakes en-keyword=laser ranging kn-keyword=laser ranging en-keyword=mobile robots kn-keyword=mobile robots en-keyword=terrain mapping kn-keyword=terrain mapping END start-ver=1.4 cd-journal=joma no-vol= cd-vols= no-issue= article-no= start-page=487 end-page=492 dt-received= dt-revised= dt-accepted= dt-pub-year=2005 dt-pub=20058 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Development of intelligent McKibben actuator en-subtitle= kn-subtitle= en-abstract= kn-abstract=The aim of this study is to develop an intelligent McKibben actuator with an integrated soft displacement sensor inside, so that displacement of this actuator can be controlled without having any extra devices attached. In addition, the high compliance which is a positive feature of the McKibben actuator is still conserved. This paper consists of four main parts. First of all, different types of soft displacement sensors made out of rubber were composed, and tested for their functional characteristics. Secondly, the intelligent McKibben actuator was developed with the soft displacement sensor incorporated within. Then, experiments of the position servo control with a single intelligent McKibben actuator were carried out. At last a robot arm mechanism was designed with two intelligent McKibben actuators, and those experimental results showed a great potential for its future applications.
en-copyright= kn-copyright= en-aut-name=WakimotoShuichi en-aut-sei=Wakimoto en-aut-mei=Shuichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=SuzumoriKoichi en-aut-sei=Suzumori en-aut-mei=Koichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=KandaTakefumi en-aut-sei=Kanda en-aut-mei=Takefumi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University en-keyword=Soft sensor kn-keyword=Soft sensor en-keyword=soft mechanism kn-keyword=soft mechanism en-keyword=McKibben actuator kn-keyword=McKibben actuator en-keyword=Intelligent actuator kn-keyword=Intelligent actuator END