Research On Design And Control Method Of Hybrid Powered Ankle-foot Prosthesis

Ankle-foot prosthesis is a hot topic in the field of bioengineering and rehabilitation robot,which can compensate the movement ability of amputees in the lower leg effectively.With the support of national natural science foundation(91748110)and(51275170),this paper has carried out the study of ankle joint prosthesis.In order to make the prosthesis has a feature of normal human ankle walking,it analyses the characteristics of the ankle joint biomechanics in the process of human walking and the reasonable division of the gait cycle through the paper,so that it developed a kind of hybrid ankle-foot prosthesis prototype which is driven by series elastic actuators and parallel springs together.According to the human ankle movement characteristics,this paper proposes a control scheme based on the finite state machine and fuzzy PID.Through analyzing the kinematics of the prosthesis,Angle and torque control simulation system is established respectively in the MATLAB environment.On this basis,a set of controller hardware structure and software system is developed based on STM32F103 single chip microcomputer,which realizes the acquisition of sensor signal,the programming of control algorithm and servo control of the motor.Through the experiment of Angle control and the finite state machine control with rototype,it shows that the prosthesis can export angle curve similar to the human ankle movement and realized the switch between different sports stage based on sensor information accurately,that meets the needs of the sports of amputees.The simulation results of the control system and the prototype test verify the rationality of the design of prototype structure and the feasibility of the control scheme,which provides the basics for further application of the prototype.