Development of Wrist Rehabilitation Device based on Coaxial Spherical Parallel 3RRR Mechanism

Aiming at the wrist movement dysfunction and rehabilitation training problems of stroke patients，a wrist rehabilitation device based on a coaxial spherical parallel 3RRR mechanism is proposed. The device is driven by three motors，and the end effector can realize spherical motion to simulate the three-degree-of-freedom compound motion of the wrist and realize wrist rehabilitation training. In order to achieve the purpose of compact design，a design scheme of three-axis coaxial spherical parallel mechanism and synchronous belt transmission is adopted. On this basis，the inverse kinematics mathematical model of the wrist rehabilitation device is established，and the relationship between the motor input angle and the output pose of the robot end is obtained，and the robot working space is determined，the maximum angle of rotation around the X axis is 32°，the maximum angle of rotation around the Y axis is 37°，and the full rotation around the Z axis. Finally，an experimental prototype is processed for experimental verifi