Intelligent robotic impedance control using embedded system structure

Abstract

For dexterous interactive manipulations, the robot end-effector must follow a motion trajectory and exert an appropriate force against the contacted environment to provide a specified dynamic working compliance. Hence, the robotic impedance is an important function for future applications of intelligent robots. For this purpose, a generalized hybrid control strategy is developed to monitor the motion trajectory and the end-effector interaction force in the task space simultaneously. Here, the Altera development board-based embedded robotic control structure is constructed and the related intelligent position/force hybrid control strategy is developed. A new model-free intelligent fuzzy sliding mode controller is designed to monitor the force and position specifications for hybrid impedance control purposes. It has the advantages of one-dimensional fuzzy control features with online gain scheduling and sliding mode stability. A force sensor is installed in a Mitsubishi robot end-effector to measure the dynamic contact force during compliant operations. The experimental results show that the dynamic performance of the proposed hybrid impedance control system can reach the contouring error of less than 1 mm and a contact force error of less than 3 N, respectively.