Publication

A transparency-optimized feedback controller with robustness is designed for a multi-axis haptic device, where a disturbance observer is employed to decouple the coupling effect existing in the multi-axis haptic device. A performance index for the transparency is defined from the viewpoint of admittance matching, and the optimal solution minimizing the performance index is obtained by solving an H/sub 2/ optimal problem. To implement a stabilizing haptic controller robust to parametric uncertainties of the haptic device, a robust stable condition using an H/sub /spl infin// norm derived from small gain theorem is proposed. The effectiveness of the proposed haptic control scheme has been experimentally verified for a virtual wall characterized by stiffness and damping properties.