Sliding mode control of a spherical haptic device featuring electrorheological fluid

摘要

This paper presents force-feedback control performance of a new type of haptic device featuring spherical geometry and smart materials that can be used for minimally invasive surgery (MIS). A spherical electrorheological (ER) joint is designed and optimized based on the mathematical torque modeling. Force response of the manufactured ER joint is then experimentally evaluated. Subsequently, the 2-DOF force-feedback device is manufactured by integrating the spherical ER joint with AC motor. In order to achieve desired force trajectories of the haptic device, a sliding mode controller* (SMC), which is robust to uncertainty, is formulated and experimentally realized. Tracking control performances for various force trajectories are presented in time domain, and their tracking errors are evaluated.