Design, Kinematic and Variable Stiffness Analysis of a Tensegrity-Based Joint

In this paper, a new compact, low-inertia, and flexible tensegrity joint is proposed, which aims to overcome the shortcomings of traditional collaborative robots and tendon-driven robots. The joint is composed of two circular frames, and is connected by three surrounding pneumatic muscles and an intermediate spring. The stiffness of the joint is changed by inflating and releasing air to the pneumatic muscles, which is also the principle of the joint's variable stiffness. Firstly, a detailed kinematic analysis of the proposed tensegrity joint was carried out to explore its position change in multi-axis motion. Secondly, the stiffness analysis was carried out to evaluate the deformation response and stiffness characteristics of the joint under different loads, which provided an important reference for its design optimization. Finally, the performance of the model is verified by simulation analysis, and the reliability and practicability of the model in dynamic work are verified by comparison with actual data. This study provides a theoretical and experimental basis for the promotion of new tensegrity joints in robot applications, and provides new design ideas and methods for the development and innovation of future robotics technology.