Estimating the Gravity Terms in Robot Manipulatiors for PD Control

Abstract

A method is propcmed for estimating the gravity terms in robot manipulators. It is applied in closed loop and uses steady-state meesurernents of joint positions and input voltages, and does not need force or torque measurements. It is well suited for setting up controllers requiring gravity compensation. Experimental resulta are shown for a one-degree-of-freedom robot in closed loop with a proportional derivative controller and for a two-degree robot controlled in a visual sewoing framework.