A unified approach to position and force control by fuzzy logic

This paper proposes a unified control strategy of position and force. The authors´ technique is based on impedance control with fuzzy logic and realizes the smooth shift from position control to force control and vice versa. At first, a robust impedance controller based on a disturbance observer is shown, and the method to unify the position and the force control through one controller is described. Next, an algorithm to estimate the dynamic characteristics of the environment is shown, and a force tracking control using the estimated parameters is proposed. Finally, the unified control algorithm of position and force based on fuzzy logic is established. The validity of this method is confirmed by several experimental results