Implementation of damped-rate resolved-acceleration robot control

Abstract

The damped least-squares method has frequently been used to solve the singularity problem of resolved-acceleration control schemes. It works by damping only the joint accelerations, so that the joint accelerations in the degenerated directions (the end-effector cannot move along these directions) are zero at a singular point. However, the joint velocities in the degenerated directions may be nonzero in some situations, in which case they will create fluctuations around the singular point. In this paper, a damped-rate resolved-acceleration control scheme (DRRAC) is proposed to overcome this drawback. The paper also shows that the DRRAC is asymptotically stable, and its convergent property is discussed. Experiments were undertaken to verify the proposed control scheme. Copyright (C) 1997 Elsevier Science Ltd.