Modeling and Experiment of Passive Variable Stiffness Actuator for Upper Limb Rehabilitation Robot

The joints of rehabilitation robots often require good variable stiffness characteristics to adapt to the compliance of the human body. According to the characteristics of the joints and muscles of the upper limbs, the stiffness requirements of different positions in the rehabilitation circular trajectory training of the upper limbs are analyzed, and a new passive variable stiffness driver is designed on this basis. Thereby, the stiffness changes at different positions during the training of the upper limb circular trajectory can be realized. The mathematical model of the passive variable stiffness device is established, and the accuracy of the model and the feasibility of the overall scheme are verified through software simulation and experiments. The passive variable stiffness drive realizes the stiffness change in the upper limb rehabilitation training process. The structure is simple and does not require additional driving and control.