Aiming at the difficulty of force control in impedance control puzzled by unknown stiffness and position of environment to result in tracking error
the pneumatic hydraulic combination compliant force control system is designed via sliding position controller combining with adaptive control method. The compliant force control tests are conducted under the conditions that the environment moves at 8 mm/s repeatedly on a slope and 0.1 Hz sine movement respectively. The result shows the maximum relative position errors get to 1.85% and 1.1% and the maximum relative force tracking errors get to 2.5% and 1.85% respectively
which indicates the better robusticity of the system to eliminate dependence of the precise parameter of the environment.
Xu Hong, Wu Shenglin, Zhao Keding. Pneumo-hydraulic system and the pneumatic hydraulic combination control(PHCC)system[J]. Chinese Journal of Mechanical Engineering, 2001, 37(7): 93-95.
Surdilovic D, Cojbasic Z. Robust robot compliant motion control using intelligent adaptive impedance approach [J]. Proc of IEEE Int Conf on Robotics and Automation, 1999(3):2128-2133.
Wang Hongyan, Zhao Keding, Cui Xianghua. Sliding control approach to pneumatic hydraulic combination control(PHCC)servo system[C]∥Proceedings of the World Congress on Intelligent Control and Automation(WCICA). Piscataway, USA:IEEE, 2006:2156-2159.
Drago M, Roman K, Tadej B. Adaptive impedance force control of an industrial manipulator[J]. Industrial Electronics,1999(1):129-133.