Design And Control Of A Hybrid-driven Lower Limb Prosthesis

As important alternative motor function tools for amputees,the lower limb prostheses are artificial limbs made for amputees to make up for the loss of limbs and their functions.Compared with traditional prosthesis,intelligent prostheses have the advantages of intelligence,safety and comfort.Damping-driven intelligent prosthesis can realize the motions such as level walking and so on,they cannot provide active moment.And the gait with those prostheses is still far away with gait of healthy body.Although active intelligent prosthesis can provide active moment to accomplish the gait motion,their development is limited by their volume,weight and energy consumption.Besides,there are few intelligent lower limb prosthesis products in domestic market while the imported ones are too expensive to afford.This article is going to design a hybrid-driven lower limb prosthesis that can provide active moment and keep the advantages of damping-driven prosthesis.This article’s research contains structure design and control method of the lower limb prosthesis.Summarizes the primary coverage which this article studies as follows to show:(1)By designing the examination plan,the curve of knee and ankle durning different walking conditions are detected;then the rules of human gait are concluded from the analysis of examination results and the gait is divided into several phases,which can provide experimental basis for the design and control of the prosthesis.(2)Design the structure of the hybrid-driven prosthesis.Firstly,the Design requirements are analyzed and the overall structure of the prosthesis is put forward;the key parameters of the promoted prosthesis structure are calculated and analyzed and the whole structure of the prosthesis is determined;Secondly,the kinetic and kinematic analysis of the lower limb prosthesis are conducted,which can be the theoretical basis for the design of the prosthesis.Finally,the energy consumption of the prosthesis is theoretically analyzed.(3)The control method of the hybrid-driven prosthesis is proposed.Firstly,the gaits in different walking conditions are divided into several sections and the method to recognize the gait phase is raised;Secondly,the curve for the relationship of knee and ankle angle during different gaits is fit and simplified;Finally,according to the proposed gait phased division method and the coupling relationship of knee and ankle,on the basic of the mechanical structure of the hybrid prosthesis,the control method is proposed.(4)The production of the prosthesis prototype and the experiment with the prototype.Firstly,the prototype of the prosthesis is product,including the choice,purchase,processing and assembly of the key components and the testing experiment stage is built;Secondly,the hardware and software of the control system is designed;Finally,the experiment for the designed prosthesis is conducted and the experimental results are analyzed.