Design And Analysis Of Partial Body Weight Support System For Rehabilitation Therapy

Partial body weight support system is a new kind of rehabilitation robot to recover motion nerve. It has more advantages of recovering wakling ability, correcting tread,improving balance,relieving muscle spasm and reducing burden of hearts and lungs than traditional therapies and it has been developed to be the partial body weight support system drived by pneumatic system.Since pneumanc system has the advantages of low cost,simple construction, reliability in work,no air pollution,it has been widely used in the industry production. With the development of the pneumanc proportional technology, pneumanc system control is extended from logical control to proportional/servo control area. However, pneumatic systems have some inherent disadvantages such as nonlinearity, low stiffness, low damping ratio and low natural frequency, it is difficult to obtain satisfied control performance, and thus its uses in industry area are limited.Based on the characteristics of pneumatic control system with proportional valve and single piston, control of the system is achieved by researching and simulation analysis of the control strategy. The paper makes the following several aspects of research work:(1) The condition of partial body weight support system is described briefly, their principle of operation is introduced and their relative merits is analysed.(2) Design project is presented and principle of operation is introduced.(3)Mechanical structure of the system is designed and major component is checked.(4) The model of pneumanc position control system and pneumanc force control system is established by transfer function and adjusted by PID controller,and their performance is analysed.(5) The nolinear model of pneumanc position control system and pneumanc force control system is established and adjusted by PID controller,and their performance is analysed.The study results show that:the result of pneumanc position control system is ideal,but it is hard to achieve the impact of pneumanc force control system because of friction force of cylinder.