Time-varying delay compensation by communication disturbance observer for teleoperation system by considering model uncertainty

This paper studies novel structure of communication disturbance observer for teleoperation systems. In time-delayed systems that time delay is unknown and unpredictable، stability of system by using time delay compensation method based on the concept of network disturbance and communication disturbance observer (CDOB)، can be obtained. Since this method works without time-delay model، it can be implemented in teleoperation systems that contain communication channel with time-varying delay. So، in this paper، first، time varying delay compensation by conventional communication disturbance observer is studied and design condition of conventional communication disturbance observer by dynamic property of network disturbance is explained. However، the system model error and disturbance seriously affects the system performance and causes steady-state error. Hence، in this paper، by considering the effects of model uncertainty and disturbance on steady state characteristics، the structure of conventional communication disturbance observer is modified and another structure for it in teleoperation systems has been proposed. By using slave''s delayed torque instead of its delayed position as one of the observer''s input، steady state error is eliminated. Also، simulation results are presented to demonstrate the effectiveness of the proposed structure.