Research on the fuzzy PID-based control of haptic system

An adaptive impedance control scheme has been proposed in this paper to alleviate some of the problems associated with the impact of feedback force in a haptic system. Continuous on-line estimation of the virtual environment´s impedance is performed, and is then used as a local model for force rendering control. For the problem of the haptic system existed the impact of feedback force in virtual environment, a new algorithm is proposed which use the nonlinear-fuzzy- continuous force feedback to setup the fuzzy adaptive PID control scheme. Two performance measures are defined to assess transparency and stability of the haptic system. Simulation results have shown the superior performance of the adaptive scheme, with respect to direct operation, particularly in terms of increasing the stability and of ameliorating transparency significantly in the presence of Gravity well margin. Experimental results, using a Phantom Omni as the haptic master device, support this conclusion.