Synchronization of Robot Manipulators Actuated By Induction Motors with Velocity Estimator

A complete modeling (including the actuator dynamics) of a robot manipulator that uses three-phase induction motors is presented in this paper. A control scheme is designed to synchronize robot manipulators actuated by induction motors under a masterslave scheme in the case where the joint velocity of the slave robots is estimated. All of the research on the synchronization of robot manipulators assumes the use of ideal actuators to drive the joints; for that reason, in this work, a three-phase induction motor is considered to be a direct-drive actuator for each joint. An entire model of the mated system is obtained by a combination of the dynamics of the induction motor and robot manipulator. Thus, the synchronization control algorithm for a master-slave scheme in both the joint space and workspace of robot manipulators driven by induction motors is developed. An observer based on the entire model is proposed to estimate the joint velocity of the slave robot manipulators. Through the Lyapunov criterion, a stability analysis of the synchronization control with a velocity estimator is detailed. The analytical results show the synchronization and estimation errors are globally, uniformly, and ultimately bounded. Simulations with multiple robots demonstrate the performance of the proposed control algorithm.