Deals with control and performance evaluation of a two degree-of-freedom five-bar haptic interface driven by harmonic DC servomotors. The presented haptic display has nonlinear effects such as friction and motor cogging which affect impedance fidelity. Force feedback control strategies including a feedforward friction compensator based on joint torque and a disturbance observer have been proposed and are evaluated through experiments. The first set of experiments was conducted to measure how well the impedance fidelity could be achieved for various control strategies. The second set of experiments was conducted to investigate the influence of the control strategies on discontinuity perception and to measure the upper limit of the haptic simulation range of the haptic display.
展开▼
