Koh Hosoda Pengarang

3-DOF planar parallel-wire driven r obot with an active balancer and its model-based adaptive control H. Kinoa, T. Yoshitakea, R. Wadaa, K. Taharab and K. Tsudac aDepartment of Intelligent Mechanical Engineering, Fukuoka Institute of Technology, Higashi-ku, Fukuoka, Japan; bDepartment of Mechanical Engineering, Kyushu University, Nishi-ku, Fukuoka, Japan; cDepartment of Systems Innovation, Osaka University, Toyonaka, Osaka, Japan ABSTR AC T This paper has proposed a parallel-wire driven robot (PWDR) with an active balancer, which is notably useful for such applications as ceiling maintenance and object conveyance near a ceiling in a factory. Because this robot is an under-actuated system, the uncertainty of the inertial parameters of the load strongly affects the resultant motion and reduces the control accuracy because of the dynamics interference. However, to date, the dynamics of this robot has not been thoroughly elucidated. Thus, this study analyzes the dynamics of a PWDR that controls three degree-of-freedom using two wires and an active balancer. Moreover, based on the dynamic analysis, a model-based adaptive controller for the parameter uncertainty of a load is proposed, and its effectiveness is demonstrated through simulation. KEY WORDS Cable-driven; CDPR; under-actuated system; dynamics; motion control; Force control of twisted and coiled polymer actuators via active control of electrical heating and forced convective liquid cooling Hyungeun Song a and Yoichi Horib aHarvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, USA; bDepartment of Electrical Engineering, The University of Tokyo, Tokyo, Japan ABSTR AC T For decades, numerous artificial muscles have been proposed in order to implement beneficial features of biological muscles into robotics. Unfortunately, traditional artificial muscles experienced difficulties in imitating properties of the biological muscles due to mechanical and control issues. Recently, twisted and coiled polymer actuators (TCP) have been shown to produce large mechanical power via thermal stimulations and strong linearity. In this paper, a high-performance TCP thermally cycled by electrical heating and forced convective liquid cooling is designed and associated control algorithms are presented. We elaborate the model of the TCP that is simple, yet provides insight into how the electrical heating and the forced convective liquid cooling contribute to the TCP actuation. The proposed model is verified by experimental studies. Based on the proposed model, we design a feedforward–feedback controller and switching laws, which actively control the TCP in both th heating and cooling cycles. Furthermore, we extend our control methodology to agonist–antagonist TCPs. From the experimental studies, the proposed method is shown to be effective in both single TCP and antagonistic TCPs. KEY WORDS Artificial muscles; muscle-powered machines; twisted and coiled polymer actuators; forced convective cooling Learning geometric and photometric features from panoramic L iDAR scans for outdoor place categorization Kazuto Nakashima a, Hojung Jung a, Yuki Otoa, Yumi Iwashitab, Ryo Kurazume c and Oscar Martinez Mozosd aGraduate School of Information Science and Electrical Engineering, Kyushu University, Fukuoka, Japan; bJet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA; cFaculty of Information Science and Electrical Engineering, Kyushu University, Fukuoka, Japan; dTechnical University of Cartagena, Cartagena, Spain ABSTR AC T Semantic place categorization, which is one of the essential tasks for autonomous robots and vehicles, allows them to have capabilities of self-decision and navigation in unfamiliar environments. In particular, outdoor places are more difficult targets than indoor ones due to perceptual variations, such as dynamic illuminance over 24 hours and occlusions by cars and pedestrians. This paper presents a novel method of categorizing outdoor places using convolutional neural networks (CNNs), which take omnidirectional depth/reflectance images obtained by 3D LiDARs as the inputs. First, we construct a large-scale outdoor place dataset named Multi-modal Panoramic 3D Outdoor (MPO) comprising two types of point clouds captured by two different LiDARs. They are labeled with six outdoor place categories: coast, forest, indoor/outdoor parking, residential area, and urban area. Second, we provide CNNs for LiDAR-based outdoor place categorization and evaluate our approach with the MPO dataset. Our results on the MPO dataset outperform traditional approaches and show the effectiveness in which we use both depth and reflectance modalities. To analyze our trained deep networks, we visualize the learned features. KEY WORDS Outdoor place categorization; convolutional neural networks; multi-modal data; laser scanner The DCM generalized inverse: efficient body-wrench d istribution in multi-contact balance control Masahiro Hosokawa , Dragomir N . N enchev and Takahide Hamano Graduate S chool of Engineering, Tok yo Cit y Universit y, Tamazutsumi, To k yo, Japan ABSTR AC T A computationally efficient solution of the body- wrench distribution problem for bipeds and multilegged robots is introduced. The method is based on a weighted generalized inverse, the weights being determined from relationships pertinent to the divergent component of motion (DCM), baseof-support (BoS) geometry, friction constraints and center of pressure allocation. The user (or the robot) specifies appropriate weights only indirectly, by setting the desired contact transition boundaries within the net BoS. It is shown that the proposed weighted generalized inverse ensures bodywrench distribution in a way consistent with both the static and dynamic states. The dependency on the DCM yields an important advantage when the method is applied to reactive balance control in response to unknown disturbances. An admittance-type stabilizer is obtained by setting the reference DCM at the current center of mass position. This stabilizer does not require reference values for the centers of pressures and the contact wrenches. The method is implemented with a whole-body, torque-based balance controller. Its performance is examined through simulations with planar and non-coplanar contacts, during proactive and reactive tasks. KEY WORDS H u m a n o i d ro b o t ; body-wre nch d istribution problem; biped balance co nt ro l