Flux Regulation for Torquecontrolled Robotics Actuators Upon the employment of robots in applications beyond traditional industries, the need for development of torquecontrolled actuators has become more evident. To exploit the full capacity of torquemotion actuators, it is essential to regulate the motor flux in demand. Despite many studies in this area, major research in flux control has been dedicated to speed control. This work targets to present a novel and robust field weakening strategy for surface mounted permanent magnet motors (SPMSMs) when only a torque reference is given so that the motor velocity can adapt to operating conditions. The concept of proposed approach is elaborated and described qualitatively and mathematically. This work analyses the robustness of proposed approach to variation in motor parameters, and compares it with the performance of another approach in simulation and experimental results.

Impedance Control Strategy and Experimental Analysis of Collaborative Robots Based on Torque Feedback In this paper, through the modeling and analysis of flexible joints, an impedance controller based on torque feedback is proposed, which is used to realize the active compliance of collaborative robots. The controller includes two parts: torque controller and impedance controller. The torque controller is used to compensate the robot dynamics, and the impedance controller is used to adjust the joint stiffness and damping. The theoretical analysis of the control strategy shows that the significance of torque feedback is that it can reshape the inertia of the motor, reduce friction torque and suppress unknown disturbances. In order to ensure tracking accuracy, a task errorbased disturbance observer is designed. Experiments with a 7DOF collaborative robot show that the proposed controller in this paper can realize the body compliance and obtain better compliance performance than the traditional compliance control method.