Robot control system having adaptive feedforward torque control for improved accuracy.

摘要

A digital control provides adaptive feedforward torque control for a robot [Figs. 1-3] having a plurality of arm joints. An electric motor (20) drives each of the robot arm joints and a power amplifier [Fig. 1 (22)] supplies drive current to each motor under controlled operation. Each joint motor has feedback control loop means including position (PFB) and velocity control loops (VFB) driving a torque control loop (8) in accordance with position commands (PCOM) to generate motor commands for controlling the associated power amplifier. The motion of said joint motor is sent to generate position and velocity feedback signals respectively for combination with the position and velocity commands to generate an error signal (TQCOM) as a torque command for each of the torque control loops from the corresponding position and velocity control loops. Load force is sensed (19) at the endmost robot joint. A feedback signal [Fig. 1 (21)] representative of the joint motor drive current is combined [Fig. 2 (168)] with the torque command to generate a torque error signal in each torque control loop.