Force and Stiffness Controller Design for a Pneumatic Haptic Glove for Virtual Palpation

This paper presents the dynamic model and sliding-mode controller design for a pneumatic actuator in the context of a Haptic Glove designed for virtual medical palpation. The desired forces in the cylinders are derived from the forces on the fingertip assuming a quasi-static state. The designed control law is tested on 3-way, 2-position electronic valves in a simulated environment. Tracking of both constant and varying desired force and stiffness functions simultaneously by the proposed controller using the cheaper on/off valves is demonstrated.