Task space integral sliding mode controller implementation for 4DOF of a humanoid BERT II arm with posture control

Abstract

This paper presents the implementation (real time and simulation) of an integral sliding mode controller (ISMC) for the four degrees of freedom (DOF) of the humanoid BERT II robot arm, in order to deal with the inaccuracies and unmodelled nonlinearities in the dynamic model of the robot arm. This is a task space controller, tracking Cartesian coordinates x and y. The controller has been implemented using shoulder flexion, shoulder abduction, humeral rotation and elbow flexion joints of the BERT II right arm. The main controller is the combination of a feedback linearization (FL) scheme and an ISMC. The redundant DOF are controlled by a bio-mechanically inspired posture controller, to generate human like motion pattern based on recent work. Good real-time tracking results demonstrates effectiveness of the scheme. © 2011 Springer-Verlag Berlin Heidelberg.