Inverse kinematics modeling and motion control of PAM bionic elbow joint

For upper limbs disabled patients, in order to improve the effects of rehabilitation training, and enhance therapeutic safety, a kind of 3-DOF pneumatic artificial muscle (PAM) bionic elbow joint was designed, and the inverse kinematic mathematical model was built by the pseudo-rigid-body model. Then, the simulation and analysis were done for inverse kinematic problems, based on the model. Finally, the experimental measurement system of the PAM bionic elbow joint was established, and then the motion control was done via a PID controller. The results show that PAM movements are continuous and stable in the designed workspace. This means the mechanism has good smoothness during movement. Furthermore, the actual and expected rotation angle curves of the forearm disc are basic overlap by adjusting PID parameters, so the inverse kinematic model is accurate.