Study On Dynamic Variable Damping Knee Prosthesis Based On Hydraulic Damper

Knee prosthesis is an important assistant device to restore the function and appearance of the patients with thigh amputation.Dynamic variable damping knee joint based on hydraulic damper can effectively compe,nsate part of the motion ability of patients with thigh amputation.In order to make the knee prosthesis simulate the normal people’s daily life well and make the amputees have the normal gait,the research on the variable damping knee prosthesis was carried out under the support of the National Natural Science Foundation of China(91748110).According to the structural characteristics of human knee joint and the kinematic characteristics of knee joint in the process of motion,the prosthetic mechanism of knee joint was analyzed and designed.According to the gait state and energy conversion characteristics of walking state,a walking mode of knee joint prosthetic with energy recovery in the process of motion of prosthetic limb was formulated,according to the working mode,the hydraulic oil circuit of the prosthetic damper cylinder and the control method in walking state were designed.Based on the mechanical structure of prosthetic limb,the key parameters needed to be measured in the sensor system of prosthetic limb were analyzed.The measurement methods of key parameters of prosthetic limb and the selection of sensors are discussed.The software and hardware of the prosthetic limb sensor system and the prosthetic limb controller are designed to enable the prosthetic limb controller to collect sensor data,control seirvo valves,and debug the operation of the prosthetic limb algorithm.Finally,the sensor measurement test and servo valve control test of prosthetic limb were carried out.The designed prosthetic sensor system and prosthetic control board have practical and reliable characteristics,and can effectively collect key parameters of prosthetic limb control.The restrictor valve of hydraulic circuit is controlled by the prosthetic control board,which has achieved good results.The research laid a foundation for the follow-up study of variable damping prosthetic limb,and has important application value.