Wireless haptic communication under varying delay by switching-channel bilateral control with energy monitor

A switching-channel bilateral control with energy monitor (EM) is newly proposed to realize haptic communication through a wireless network. The varying delay in the communication line and the situation of duplex operation are considered. In such a system, human operators on two sides of the master-slave robots system feel the hardness of the remote environment placed on the contralateral side. The EM approach is presented to judge the role of the robot (manipulated by an operator or contacting an environment), which provides a beacon for the switching algorithm. The position tracking of the system is improved by switching off the channel of force control in the human manipulated robot. The problem of position drift in traditional methods is overcome. Disturbance observer is applied to simplify the design of the bilateral control law, and to guarantee the efficient force switching. Because of improved position tracking and satisfactory force fidelity, the proposed approach achieves more vivid haptic transmission. By experiments, the validity is verified.