Robust Controller Design for Teleoperation Systems

The controller design for a bilateral teleoperation system involves trade-offs between performance and robust stability. Beyond simple intuition, little is known how performance and robust stability trade off. This paper shows that it is possible to achieve robust stability and nominal performance of a bilateral teleoperation system by using a four-channel control architecture [1, 2]. The controller design problem is formulated as a multiple objective optimization problem, which is shown to be convex if parametrizing all stabilizing controllers via the Youla parametrization. Performance specifications, such as kinematic correspondence error, force tracking error, etc., are defined; and robust stability is also incorporated into the controller design. The controller design problem is formulated as a multiple objective optimization problem, which is shown to be convex if parametrizing all stabilizing controllers via the Youla parametrization. The limit of performance achievable with the designed controller, thus the exact form of the trade-offs between performance and robust stability, can be computed numerically. To demonstrate those, this paper treats the design of a controller for a simple one degree-of-freedom (DOF) system model of a motion-scaling teleoperation system.