This paper presents a motion-copying system of different master-slave mechanism in variable speed of motion reproduction. The motion-saving system is performed by bilateral control algorithm to preserve arbitrary motions of human operator to a data memory. The slave actuator is affected by friction
hence, a friction-free disturbance observer is employed for force estimation on the slave side. The motion-loading system is able to reproduce human motion saved in data memory with changeable speed of motion reproduction. To improve the performance of motion-loading system, a displacement-based reproduction correction is used to eliminate the effect of unpredictable disturbances in variable speed of motion regeneration. The effectiveness of the proposed method is confirmed by simulation results. © 2014 IEEE.