Position and Velocity Analysis of Free-Ended Two-Link Object for Whole Arm Manipulation.

Document Type : Research Studies

Author

RIKEN, 2270-130 Anagahora., Shimoshidami., Moriyama-ku, Nagoya 463-0003., Japan (Faculty of Engineering, Tanta University., Tanta, Egypt).

Abstract

this paper presents position and velocity analysis of free-ended two-rigid-links object manipulated by two arms as an initial step simplification of holding and manipulating a human body by a humanoid robot. Rolling as well as sliding at the points of contact of the two-links object constrained by the holding two-arms is explained. Position and velocity analysis of the manipulated object, position and velocity constraints as well as expressions for sliding displacement and sliding velocity are presented. Simulation results for sliding displacement, sliding velocity, object links displacements and velocities as well as object configurations for different input rolling velocities are presented. The presented position and velocity analysis proves that: 1- through manipulating two-links object by two-arms, rolling at one point or both points of contact is associated with sliding at both points of contact. There is no rolling without sliding and there is no sliding without rolling. 2- It is possible to define the configuration of the object from contact points and hence contact angle measurements applying tactile sensors. 3- It is possible to compute the amount of sliding at both contact points from consecutive contact angle measurements. 4 It is possible to define the object links velocity as well as sliding velocity from the contact rolling velocities estimations or measurements.

Main Subjects