|Enhance Transparency of Force Feedback Interaction Series Mechanism by SMC Strategy
Zhi Hu, Yueying Wang, Guohua Cui*, and Dan Zhang
International Journal of Control, Automation, and Systems, vol. 17, no. 7, pp.1738-1750, 2019
Abstract : To enhance the fidelity of virtual surgery, the force feedback interaction mechanism would simulate
the force information in real surgery. This paper first introduces evaluation methods of fidelity, then it explores
evaluation methods of force feedback fidelity, and put up the evaluation methods and indexes of force feedback
fidelity. In rigid force feedback interaction mechanism, fidelity is mainly shown as transparency. It means the
transfer function of the mechanism needs approach to 1, while friction, gravity, slip of the linear drive and other
factors would affect transparency of the mechanism. This study introduces a 5-DOF (degree of freedom) force
feedback series mechanism with long stroke. It discusses gravity compensation and simulation of typical virtual
environment. It uses sliding mode control (SMC) to eliminate the effect of parameter variety, inaccurate modeling
and other factors to improve system robustness. And it adds disturbance observer to the controller to eliminate
gravity inaccuracy. Finally, it evaluates the enhancement of force feedback fidelity.
Fidelity, force feedback, sliding mode control, transparency, virtual surgery.