Development Of Soft Pneumatic Wearable Power Assist Suit

In the elderly assistance and rehabilitation robotics field, there are mainly two types of solutions can provide assist force for human limbs, which are called electric system and pneumatic system. Among them, the electric system is complex in mechanism and poor in security, so it is not suitable for wearing in the body. As for pneumatic system, most of them use metal air cylinder which is cold, rigid and heavy in weight, which is also not suitable for wearing. Therefore, the development of a suitable and soft wearable power assisting robot which is easy and safe to use is necessary.In this paper, the researches of the soft wearable power assisting robot at home and abroad had been analyzed. We found this kind of researches are not many and most of them have shortcomings of heavy in weight, using expensive materials, small in assist force and lack of functions. This paper proposed a novel design of a soft wearable pneumatic power assisting suit. In order to provide the power assist function, this power assisting suit uses a new kind of soft airbag to drive the corresponding joints by connecting it to the different part of the clothes. The most important and the most difficult part of the design is the soft airbag. Cutting the PVC plastic cloth into certain shape, then pasting them together by heat sealing process, A U-shape airbag is made. The U-shape airbag is cheap in price and easy to be made. The U-shape airbag has the shape which is suitable for clamping and fixing onto human limbs, thus is suitable for providing power assisting force. The airbag is soft and light thus is safe and comfortable for wearing. In addition, all the airbags use the united design, only different in the connection position in clothe, so the producing procedure of soft wearable power assisting suit is simple and convenient.In order to accurately assess the performance of the power assisting suit and realize the function of the rehabilitation training, a test platform is made. The test platform consists of mechanical system, control system and pneumatic system. The mechanical system is made up of aluminum mechanical arms and the self-locking mechanism. Each arm has three degrees of freedom, so it can simulate human upper limb’s movement such as flexion and extension of elbow joint, flexion and extension of shoulder joint and adduction and abduction of shoulder joint. The control system is made up of Angle sensors and torque sensors which can collect signal. The signal from those sensors can be transmitted to computer through the PCI-1710 data acquisition card and can be processed by Matlab/simulink software. Then the computer will output a command to the pneumatic system, eventually the power assisting function will be completed by soft airbag. Several experiments have been executed to collect relevant data such as the joint angle, torque and pressure during the movement, which can prove the good dynamical performance of this power assisting suit. And with the control program, arms’ rehabilitation training function has been executed successfully, which also can prove the practicability of this power assisting suit.