Dynamic Characteristics Analysis Of Active Intelligent Prosthesis Used Magnetorheological Damper

With the development of the society, more and more people are amputated because of traffic accidents, natural disasters, battles or diseases. Prostheses can partially compensate for some lost athletic abilities, which is significant to the amputees to return to normal life and regain confidence in life. However, the performance of current prosthetic products is still more general and can hardly meet the demands of amputees. With the goals of improving the aesthetic property of walking gait and the capacity to cope with complex road environments, four-bar linkage knee and the hybrid-driven mode are employed to design the intelligent prosthesis. Finally the required performance is verified by theory research and simulation.The optimized design of the intelligent prosthesis is conducted. Four-bar linkage knee is chosen for prosthetic knee joint structure to get a better gait. The optimal objective functions of four-bar linkage knee, thigh and calf are established and solved with nonlinear optimization method. The prosthetic driven-mode relied mainly on MR damper while DC motor subsidiary is determined. And the knee-torque distribution method is setted up based on the principle of energy consumption minimization.Reference to the gait planning and dynamic modeling methods of humanoid robots, the kinematics model of the intelligent prosthesis is established and the dynamic model is established using Routh equation. The models are solved based on the walking date. The gait of prosthetic movement is planed and the component’s parameter is selected based on the results.The test system is constructed to conduct the MR damper dynamical test. Forward models and inverse models of the MR damper are established by using BP neural network and ANFIS. The parameter training and learning of the MR damper models are conducted based on the test data. The MR damper system model is conducted form the selected models with best integrated performance. And the accuracy of the MR damper system model is verified by simulation.The virtual prototype and united simulation platform for the intelligent prosthesis is established. The motion simulation is run under complex road environments such as walking, up stairs, down stairs and down a ramp. The results indicate that active intelligent prosthesis used MR damper has an aesthetic property of gait when walking and a strong adaptability to different road situations.