Compliant coordination control of two moving industrial robots

When two robots execute a coordinated motion in industrial applications such as assembly, it requires not only the specification of the desired motion of each robot's end-effector, but also the specification of the desired time histories of the force exerted by the end-effectors. The involvement of the forces leads to the need of compliance. Hence the design of a compliant control system for coordinating two industrial robots assumes the importance in many industrial applications. In this paper, a compliant control scheme and its practical implementation are presented. One robot is equipped with a wrist force/torque sensor to provide force feedback signals and to enable a fine coordinated motion control for complex assembly tasks. A control strategy is derived so that the measured interactive force/torque can be used to modify the trajectory of the robot. This control scheme can be realized in real-time by using the proposed computational structure and programming method.