Improvement of force-sensorless grinding accuracy with resistance compensation

This research aims to achieve a new grinding robot system that can grind an object into desired shape with force-sensorless control. In order to grind the target object into desired shape with sufficient accuracy, the hand of the robot arm has to generate desired constrained force immediately after the grindstone being contacted with the metal object to be ground. Based on the algebraic equation, we have proposed constraint-combined force controller, which has the ability to achieve the force control without time delay if the motors should ideally generate required torques without time delay. In this paper, the relation between contacting force and grinding resistance force have been derived analytically and the relation is used for grinding force control, having brought improved grinding force accuracy.