Koh Hosoda Pengarang

1. Design of a multilink-articulated wheeled pipeline i nspection robot u sing only passive elastic joints Atsushi K akogawa and Shugen Ma Department of Robotics, Ritsumeikan University, Kusatsu, J apan ABSTRACT This paper p resents a multilink-articulated r obot with omni and h emispherical wheels (AIRo-2.1) for inspecting and exploring pipelines. To quickly adapt t o winding pipes, holonomic r olling movement without moving forward and backward is u seful. H owever, t his r equires t he rolling actuators to r e p l a c e t h e d r i v i n g ac t u a t o r s a t t h e ex p e n s e o f t h e d r i v i n g f o r c e . Fu r t h e r m o r e , s o f a r t h e n u m b e r o f d r i v i n g wh e e l s a n d t o r s i o n s p r i n g s , m a g n i t u d e o f d r i v i n g f o r c e s , s t i ff n e s s a n d n a t u r a l a n g l e o f the s pring t hat are required t o adapt to various pipelines have not been clarified. In t his p aper, we investigate t he possibility o f h igh m aneuverability o f multilink-articulated r obots in winding pipes w i t h a s f e w d r i v i n g a c t u a t o r s as p o s s i b l e an d o n l y e l a s t i c j o i n t s ( t o r s i o n s p r i n g s ) f o r b o d y b e n d i n g . We further validate its effectiveness by experimental verification. KEYWORDS P i p e l i n e ; i n s p e c t i o n; r o b o t f o r c e a n a l y s i s Modeling and resonance suppression control for electro-hydrostatic actuator as a two-mass resonant system Tomoki Sakumaa, Kenta Tsudaa , Koudai Umedaa , Sho Sakainoa,b and Toshiaki Tsujia aGraduate School of Science and Engineering, Saitama University, Saitama, Japan; bJST, PRESTO, Saitama, Japan ABSTRACT Electro-hydrostatic actuators (EHAs) possess excellent power/weight ratio and space-saving properties. However, uncertainty exists with respect to the presence of non-linear behaviors and dynamic characteristics. Servo pumps, hydraulic motors, and oil-filled pipes can be regarded as motors, loads, and springs, respectively. Hence, EHAs can be modeled as two-mass resonant systems. In this paper, we show a parameter identification method for modeling EHAs as two-mass resonant systems. Then, in order to suppress the effect of resonance, self-resonance cancellation technique is implemented. As a result, phase delay is significantly improved in the position tracking. KEYWORDS Electro-hydrostatic actuator; hydrostatic transmission; two-mass resonant system; feedback modulator; self-resonance cancellatio Robot fih with two-DOF pectoral fis and a wire-driven caudal fi Yong Zhong a, Zheng Lib and Ruxu Du a adepartment of Mechanical and Automation engineering, chinese University of Hong Kong, Hong Kong, Hong Kong sAR; binstitute of digestive disease and chow Yuk Ho technology centre for innovative Medicine, the chinese University of Hong Kong, Hong Kong, Hong Kong sAR ABSTRACT This paper presents a robot fih with a wire-driven caudal fi and a pair of pectoral fis. First, the design of the robot fih is presented. The caudal fi is driven through wire-driven mechanism. The pectoral fis can perform two degrees-of-freedom motions, i.e. flpping (roll) and feathering (pitch). The pectoral fis can move in labriform mode for propulsion, or for other purposes such as turning and diving. Second, the propulsion analysis models for caudal fi propulsion and pectoral fis propulsion are derived. Finally, three types of experiments are conducted. Experiment results show that the swimming speed of caudal fi propulsion and pectoral fi propulsion match the model predictions. Moreover, with the caudal fi propulsion alone, the robot fih can swim up to 0.66 BL/s (body length/second); with the pectoral fi propulsion alone, the robot fih can swim up to 0.26 BL/s. The pectoral fis can signifiantly improve the maneuverability of the robot fih. Without using the pectoral fis, the turning radius of the robot fih is 0.6 BL; with the pectoral fis, the turning radius is reduced to 0.25 BL. KEYWORDS Robot fih; wire-driven mechanism; bio-inspired design; labriform locomotion The role of quantitative information about slip and grip force in prosthetic grasp stability Dana D. Damiana, Marco Fischerb, Alexandro Hernandez Arietac and Rolf Pfeiferd aDepartment of Automatic Control and System Engineering, University of Sheffield, Sheffield, UK; bAccenture, Zurich, Switzerland; cRoche Diagnostics International, Rotkreuz, Switzerland; dEngineering Science, Osaka University, Osaka, Japan ABSTRACT Prosthetic hands introduce an artificial sensorimotor interface between the prosthesis wearer and the environment that is prone to perturbations. We analyze theoretically and evaluate psychophysically the performance in stable grip control in conditions of physical grasps perturbation, such as object slip. Simulation results suggest that user-centered stable grasp control depends on two primal user parameters: reaction time to slip and grip force intensity. Experiments with human users indicate that a user’s response time can be controlled by relaying information about the speed of the slipping object, while minimal grip force intensity can be adjusted with information about grip force at the onset of the slip. Based on our theoretical and experimental findings, we propose a stable grasp control method for prosthetic hands. KEYWORDS Slip; upper-limb prosthetics; grasp stability; tactile sensor