A novel contour error compensator for 3-PRPS platform

Abstract

Using a mathematical model to represent the nonlinear characteristics in dynamics of robot manipulators is rather difficult. To reduce the Cartesian space contour error, this study presents a novel contour error compensator influenced by the parameter and unstructured uncertainties in robot manipulators. The proposed compensator is based on the strategy of a Cartesian space cross-coupled control and the transform relations between Cartesian space and joint space. In addition, the joint space compensated control effort derives reducing the Cartesian space contour error. Consequently, the contour error can be reduced via the theoretical analysis. Moreover, a PC based, 3-PRPS platform control system is constructed to closely examine the effects of the controller. Experiment results indicate that the controller can reduce the contour error as expected. Furthermore, the forward and the inverse kinematics are derived, along with the forward kinematics solved using the numerical method. The work space of the platform is also described in a three-dimensional Cartesian space. © 2000 John Wiley & Sons, Inc.