Research On Position Control Of Exoskeleton Rehabilitation Robot Hand Based On Fuzzy-PID Control

Stroke is a kind of disease which is persistent cerebral nerve function defect caused by acute cerebral vascular disease, According to statistics, the number of stroke in China reached about eight million, the disability rate is close to 75%, and nearly 38% of people hand function is damaged. At present, for the stroke, the predominant treatment is one-on-one treatment which restoration of damaged nerve by repetitive motion. This rehabilitation therapy is not only high cost and low efficiency, but also can not quantify the process of rehabilitation. To solve the above issues, research on position control of exoskeleton rehabilitation robot hand is proposed, which aimed at controlling the finger movement by exoskeleton rehabilitation robot hand precisely, recording the process of rehabilitation exercise and providing a scientific basis for the quantitative for the stroke patients. The research works based on the foreign and domestic research achievement are as follows:Firstly, the human anatomical structure, finger kinematic model and external structure and working principle of exoskeleton rehabilitation robot hand had been studied in the beginning. The mathematical model of exoskeleton rehabilitation robot hand was established. The control strategy of fuzzy-PID was presented based on the high nonlinear and time varying characteristics of the system model.Secondly, the motion simulation model of the exoskeleton rehabilitation robot hand was established by ADAMS, and then the relationship between the linear displacement of the stepping motor and cylinder and the displacement of the joint angle is obtained. The simulation model of PID control and fuzzy-PID control was established by Simulink, comparing the simulation results of the two controllers, it is concluded that the fuzzy-PID control has the advantages of small overshoot, high stability and high accuracy. And to determine the stability of the closed-loop system based on open-loop Bode diagram of system.Then, the experimental hardware platform and software control interface of exoskeleton rehabilitation robot hand was established. The master computer system of exoskeleton rehabilitation robot hand was programmed by LabVIEW, which was used to control, receive, display and save the data send from slaver computer system in real-time. The master computer system is a significant human-computer interaction platform. The slaver computer system, which used STC89C52RC MCU as the core processor, was responsible for the control of exoskeleton driver, the measurement of exoskeleton data glove and the communication with the master computer system.Finally, the experiment of hardware performance and controller position control were performed on the test platform. The experimental results show that the position control effect of fuzzy-PID controller is better than PID control, and the maximum error is less than 3 degree, which proves the effectiveness of the fuzzy PID control strategy in the exoskeleton rehabilitation robot hand system.