Event-based predictive control strategy for teleoperation via Internet

The variable time delay and the packet loss degrade the performance of Internet based teleoperation system severely, even make the system unstable. Most of the previous work on Internet-based teleoperations rest on many assumptions, for example, time delay is constant or has upper bound, control is not in real-time. This paper presents a new predictive control strategy for the Internet based teleoperation system. The strategy is quite different from traditional methods. Instead of using time as motion reference for the control and sensor signals, the proposed method, called event based method, choose another motion reference which can efficiently carry the sensory information of the teleoperator. To improve the tracking control performance, a discrete-time device called path governor (PG) generates on line a suitable time-parameterization of the predictive path to be tracked by solving a look-ahead optimization problem. And then a global predictive control (GPC) controller is designed at the slave site to generate the redundant control information to diminish the influence of the packet loss and the large time delay in the internet. In this paper, analysis and design of event based method for internet-based teleoperation is described. Stability of teleoperation system is proven. And stability conditions are also given. Simulations and results demonstrate the effectiveness of the strategy.