Force/Position Control Of Industry Robot Based On Fuzzy Strategy

With the rapid development of robotics, many efforts have been devoted to the control of robotics. Although force control has been drown attention of researchers and engineers since the early days of robot development, successful practical applications of force control are still very few. In the future, however, the force control will be definitely needed in order to widen the applications area and increase dexterity of robotic mechanism in industrial environment. There are two major approaches for robot force control: first, impedance control, and second, hybrid control. The research of practical problem based on two approaches was deeply made in this dissertation. In impedance control, the potential of a gain scheduling fuzzy self-tuning scheme was used, which was on–line tuning controller parameter in order to adapt the change end effector force. This system have strong robust and good dynamic. In addition, concerning the robot actuators, which can only deliver torques within prescribed limits, the output of fuzzy controller was limited to avoid torque saturation. The overall closed-loop system is limitary stable; In hybrid control, a fuzzy identification method is proposed to estimate parameter in dynamic of direct drive robot. Once parameters in dynamic are estimated, computed-torque method can be applied to make the robot follow a desired position and force trajectory. PD is used in position loop and PI is used in force loop. Dynamic control is easy realized and system can be proved uniformly asymptotically stable. This system shows practical characteristics.