A new model-based tracking controller for robot manipulators using trajectory pattern inverse dynamics

Abstract

A novel inverse-dynamic model-based tracking controller is presented. The inverse dynamics models are derived using the trajectory pattern method. The path of motion is divided into a number of relatively large segments, along which the motion is described by a selected trajectory pattern. The resulting inverse dynamics models are in the form of a summation of a fundamental sinusoidal time function and a number of its harmonics with constant coefficients. The coefficients are computed offline using analytical expressions that are derived for the selected trajectory pattern. The controller permits ultra-high-speed generation of the desired trajectory and feedforward signals. The online computations are minimal and can all be performed in parallel. The inverse-dynamic model of a spatial 3R manipulator is derived for a specified trajectory pattern. The controller structure and simulation results indicating its effectiveness are presented.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>