H∞ control of bilateral telesurgical systems with communication constraints

Telesurgery has come to the forefront because of many merits such as a small incision, less bleeding and a short period of hospitalization. By means of internet, telesurgery is practical even the master and the slave are not physically in the same place. Internet, however, causes communication constraints such as time-varying delay and packet loss which induce instability and performance degradations in teleoperation systems. In this paper, we consider teleoperation systems including bilateral communications with asynchronous packet loss and time-varying delay. We define teleoper-ation sytsems as polytopic linear differential inclusions (PLDIs) to cope with switchings between subsystems which are divided by the status of communication channels. A sufficient condition which guarantees asymptotic stability and H_∞ performance is derived for teleoperation systems modeled as PLDIs. Then, we propose a H_∞ control design method, using linear matrix inequalities (LMIs).