Artificial Leg Movement Control Research Based On Pneumatic Artificial Muscle

A large number of the performance test experiments need to do during the process of the research and development of intelligent prostheses(IP),however,it is not realistic to let the limb disabled wear prostheses to conduct these experiments.Consequently,to provide an ideal experimental platform for performance testing of intelligent prostheses,this paper puts forward the heterogeneous legs walking mode.Artificial leg as an important part of the experimental platform during the process of IP,its main function is to simulate normal gait of the healthy leg of the disabled and to provide the trajectory of gait follow the target for intelligent bionic leg.Therefore,the movement control research of the artificial leg has a very important significance for the study of entire heterogeneous biped walking robot.Knee joint control system is a focus in the study of this paper,combined with the drive way of pneumatic artificial muscle,we have designed the knee joint pneumatic control system composed of pneumatic artificial muscles and pneumatic high-speed on-off valve.Due to pneumatic artificial muscles(PMA)itself nonlinear,it is very difficult to realize the PMA's modeling by the way of analytic calculation,so this paper utilize the completed pneumatic artificial muscle performance test experiment platform for analyzing artificial muscle characteristics,and a mathematic model of PMA is established.Based on the knee joint control system as the research object,on the basis of dynamics analysis,this paper established the mathematical model of the joints and set up a joint simulation platform by virtual prototype technology.In order to improve the accuracy of control system,we realize the gait trajectory tracking control simulation by taking advantage of PID control strategy and sliding mode variable structure control strategy,respectively.Finally,the good simulation results are obtainedOn the basis of theoretical research,this paper completed the construction of the artificial leg control system experimental platform,and the gait trajectories experimental research of three joint respectively.The experimental research results show that the designed artificial leg structure system and control system can better meet the designed goals.