High performance teleoperation by bumpless transfer of robust controllers

It is a challenge to design controllers for bilateral teleoperation that find a proper balance in the inherent trade-off between transparency and stability. Especially, when the environment of the teleoperation system varies within a wide range, a single, constant controller might not be sufficient to achieve desired levels of performance. Hence, we propose a controller scheme with multiple robust controllers in which every controller is performance-optimized separately. The switching among them is based on bumpless transfer and they are scheduled using an environment stiffness estimator. Limited accuracy and noise of such estimator is also taken into account during control design. We show the applicability of the approach by experiments on a 1-DOF teleoperated system.