A Bilateral Controller Design Method Using Delay Compensators

Since communication time delay is a serious problem for bilateral control systems, a great number of researches about delay compensation in bilateral teleoperation with time delay have been studied so far. Some of delay compensators are designed to eliminate phase lag of feedback control and applicable to 4ch-controllers. However, the desired results are not always obtained, even though those compensators are applied to the conventional bilateral 4ch-controller with time delay. This is because these compensators do not take force controllers into account. This paper presents a bilateral 4ch-controller that delay compensators are applied to by considering the force controllers. The proposed controller is designed to control both position and force of a master robot and a slave robot by using only 2 degrees of freedom (DOF). One DOF is utilized for position control, and the other is utilized for force control. Therefore, the position controller and the force controller are shared by the master and slave robots. If delay compensators are applied to the proposed bilateral controller, position and force responses of the master robot correspond with those values of the slave robot, respectively. The validity of the proposed method is verified by simulation and experimental results.