Adaptive Control for Dual-Master/Single-Slave Nonlinear Teleoperation Systems With Time-Varying Communication Delays

In this article, two types of new control strategies are proposed with respect to dual-master/single-slave trilateral teleoperation systems in the presence of symmetrical and unsymmetrical time-varying communication delay, respectively. First, the problems of stability and expected position coordination of trilateral teleoperation system are solved on the basis of controller design of bilateral teleoperation system. Second, some impedance features of interaction forces between human and dual-master as well as single-slave and remote environment are measured by adaptive control strategies. Adaptive control methods are also used to deal with the problem that is relevant to gravities loading of dual-master and single-slave manipulators. Furthermore, the stability of trilateral teleoperation systems under the symmetrical and unsymmetrical time-varying communication delay is analyzed through constructing suitable delay-dependent Lyapunov-Krasovskii functionals. Finally, simulation results are presented to verify the effectiveness of proposed control strategies.