Modelling and Control of Constrained Robots

Abstract

This paper deals with modeling and control of constrained industrial robots. The considered constraints arise during the contact of a robot with an external object in its environment. A novel method that is based on task-space formulations and on the modes-of-motion approach is developed to represent constraints and constrained tasks. It is shown that this methodology can handle constrained motions generally without having any of the substantial limitations of other proposed methods. For control purposes, a novel method is developed. The key feature of this method is to transform nonlinear effects (disturbances) acting on the system to where they can be estimated and statically compensated. For these purposes, only a rough model knowledge and only the position and force measurements are required. Simulation results show the superiority of the proposed method.