Hill Model-Based Adaptive Sliding Mode Tendon-Impedance Control of Robotic Manipulator With Flexible Environment

This paper presents a hill model-based adaptive sliding mode tendon-impedance control (HASTC) scheme for robotic systems. To obtain better performance on force tracking, when robotic manipulators come into contact with flexible environ-ments, the hill-type muscle-tendon model in human biomechanics is introduced to impedance control. Then, the tendon-impedance model (TIC) is used for the robotic systems and the desired trajectory is reshaped to the reference and the tracking control is achieve by an adaptive sliding mode controller. The uncertainties of the system are approximated by the fuzzy logic to improve the tracking accuracy. The stability of the closed-loop system is proven by the Lyapunov function. Finally, simulation experiments are conducted to verify that the proposed HASTC can get better performance on force tracking in flexible environments compared with the traditional impedance control.