Bilateral control of teleoperation systems via robust PID controllers based on LMI

Time-delay in communication channels and uncertainty in different parts of the teleoperation systems are considered to be a major group of destructive factors in stability and performance of these systems. This paper suggests a new method based on a Linear Matrix Inequality (LMI) approach to establish robust PID controllers. The stability and performance of the system must be ensured by these controllers in spite of mentioned sources of instability. The proposed method requires two controllers: one for the slave site called slave controller in addition to a master controller in the master site. The local slave controller is in charge of motion tracking. Simultaneously, the master controller is responsible for force tracking, as well as stabilizing of the overall system. Both of the local PIP controllers are established to meet objectives of the design via employing the LMI-based H_∞ theory. Applying the proposed structure provides a control scheme for bilateral teleoperation systems with the lowest number of signal transmission. Additionally an LMI-based approach raises the feasibility of the related convex optimization problems using in control design procedure for a wide range of weighting functions.