Research On Fuzzy-PID Control System Of Omnidirectional Mobile Robot Chassis For Lower Limbs Rehabilitation

The Full-direction lower limb rehabilitation robot is a kind of Mechanical and Electrical integration equipment,which assists the patient to finish automatic or semi-automatic rehabilitation training.It can provide various training methods,realize the walking experience and record rehabilitation training data in-time,which can be better to meet the requirements of the lower limbs' rehabilitation training in modern society.Based on the study of the motion characteristics of the rehabilitation robot,the control system of rehabilitation robot was designed and different control algorithm was implemented in the control system to optimize the control system.The main work of this paper is as follows:1)A four-wheel mobile mechanism based on Mecanum wheel is designed to realize the omnidirectional movement of the rehabilitation robot.The kinetic model of the rehabilitated robot omnidirectional mobile chassis was established and analyzed,which provides an important theoretical basis for the speed tracking,motor selection and control algorithm research.2)The control system of the omnidirectional rehabilitation robot is designed.Distributed threelayer control structure was designed in the control system of omnidirectional mobile limb rehabilitation robot,which was made up with the MCU and host computer layer,middle motor controller layer,Motors and sensors layer.The motor controllers were distributed among the nodes for the control of the omnidirectional mobile chassis.The distributed control structure is helpful to improve the reliability and stability of the rehabilitation robot system.3)The hardware circuits and software programs of omnidirectional mobile chassis control system were designed,and the experimental platform was established.Furthermore,the computer-assisted software is designed to realize the speed tracking and control system's debugging in the experiment.4)The speed control algorithm of the Omni-directional mobile robot was designed.The fuzzy PID algorithm was used to optimize the chassis control system.By using these control algorithms,the experimental results showed that the fuzzy PID algorithm can realize the controller parameters self-tuning within a certain range,and made the control system showing good anti-jamming and better control effect,compared with the classical PID algorithm.The stability and the response speed of the omnidirectional chassis control system was obviously optimized.