Optimal Digital Filtering for Tremor Suppression in a Master-Slave Robot Remote Welding System

Master-slave robot remote welding system requires the generation of an intermediate control signal which will be transmitted to the controlled subsystem: slave robot. The control signal is generated by human operation of the master manipulator such as a space-mouse, a joystick and a master hand. When a human operates the master robot, the human tremor signal will be transmitted to the slave robot, welding seam tracking precision will be decreased. Digital filtering could “clean” human tremor signals, so welding seam tracking precision will be improved if the intermediate signal is filtered before it reaches the slave robot. In this paper, a master-slave robot remote welding system was built consisting of a master manipulator with six degree of freedom (DOF), an industrial computer control system and a slave MOTOMAN robot, and an optimal digital filter designed to “clean” human tremor signal and to improve the welding seam tracking precision. Experimental results show that the digital filter indeed suppresses the operator’s tremor signal.