Nonlinear H∞ Control of a Bilateral Nonlinear Teleoperation System

In this paper, we present a nonlinear H∞ control technique for the bilateral teleoperation of a nonlinear master-slave system. The proposed controller guarantees robust stability in the presence of uncertainty in operator and environment impedances. The guidelines to include nonlinear intervening tool between master and slave robot are suggested. The proposed technique enables adjusting weighting of position and force tracking error functions for both amplitude and frequency domain. To solve the corresponding partial differential equation, called HJI, an approximation method based on Taylor series expansion of the solution is used. A numerical simulation demonstrates that the linear controller tends to instability in contact tasks while the third order approximated nonlinear controller yields desired performance.