基于期望阻抗行为的柔性关节控制器设计

A novel flexible joint controller is designed on the basis of desired impedance behavior to solve the problems of low position accuracy and torque ripple caused by the mismatch between torque input at the motor side and position output at the load side. The controller comprises a torque controller in the inner loop, and a position / impedance controller cascades in the outer loop. The inertia and friction of the motor side for the torque controller can be weakened equivalently by adding torque feedback, improving the dynamic performance. For the position / impedance controller, the stiffness and damping tuning parameters that directly interact with the environment can be obtained by directly introducing the desired torque at the load side, and the position / impedance / torque control of flexible joints can be realized by adjusting control rate parameters. The stability of the controller was proven by Lyapunov stability theory, and the controller was simulated and analyzed by Matlab / Simulink. Finally, the performance of the controller was experimentally verified on a flexible joint prototype developed by the laboratory. Results show that the proposed flexible joint controller has good control effects in trajectory tracking and vibration suppression.