Mechanical Analysis and Controller Design of the Permanent Magnetic Variable Stiffness Flexible Joint

doi:10.3901/JME.2019.05.089

Abstract

Abstract: An antagonistic variable stiffness flexible robot joint with magnetic spring, wire-driven and trapezoidal arrangement is proposed, which can adjust the joint stiffness in real time according to the task requirements. The magnetic spring device increases the variable stiffness range of the joint, without increasing the wire tension, while reducing the weight and inertia of the operating arm. It is of great significance to improve the joint performance. The relationship between the joint space and wire space is promoted and Jacobi matrix and static relationship between the models are used to obtain the joint stiffness model, which realize the decoupling of stiffness and position. Based on trajectory control, a double closed-loop decoupling controller is designed, then do experimental verification. The simulation and experimental results show that the joint has good position response and trajectory tracking ability within a wide stiffness range. This configuration and control method is also suitable for multi-degree of freedom parallel joints.

Key words: decoupling control, permanent magnet spring, variable-stiffness, wire-driven

CLC Number:

TH39
TH135

ZHANG Ming, FANG Lijin, SUN Feng, OKA Koichi. Mechanical Analysis and Controller Design of the Permanent Magnetic Variable Stiffness Flexible Joint[J]. Journal of Mechanical Engineering, 2019, 55(5): 89-96.

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