1991 Volume 9 Issue 7 Pages 857-864
Self-posture changeability (SPC), which is the characteristics that a link system changes its posture with keeping contact between link system and environment, is discussed for a general 3 D link system. Assuming that link system moves slow enough to suppress any dynamic effects, we first define the (ω0, ω) -posture changeability which is the characteristic that a link system has posture changeability for every force within a cone having the direction of ω0 and the solid angle of ω. The necessary and sufficient condition leading to (ω0, ω) -posture changeability is examined with the joint role assignments, namely, selection of compliant joint and position-controlled joint. Linking (ω0, ω) -posture changeability with physical parameters expressing friction cone, we also show a sufficient condition to realize self-posture changeability under the condition that contact point moves continuously over an object and no contact-point-jump appears. Finally, basic behaviors of SPC were confirmed by simulation using a simple 3 D link system and a sphere.
