The Research Of Robust Fault-tolerant Control For Walker

With the growing global population aging and the increasing patients with lowerlimb dysfunction, Walker as an auxiliary medical equipment, takes more conveniencefor the patients. Walker in actual use process will affect the safety of patients by thefriction between the wheels and axles and actuators unforeseen failure may occur. Inview of this situation, this paper design a robust controller make the walker can trackpath stability. When an walker’s actuator fault, we can diagnose the walker. Accordingto the diagnosis result judge actuator failure, then design a robust fault-tolerantcontroller corresponding. Even the actuator is failure, the walker is still can make thewalker track path safely and stability by the controller. The specific contents are asfollows:Aimed at the structure of the walker, this paper analysed the kinematics anddynamics. Considering the friction force between the components during walking, anew system model is established by constructing the energy storage function andproper evaluation of the signal, robust controller that can meet the nonlinearL2gainperformance indicators was derived based on the r dissipation inequality. Thesimulation results show that the proposed robust fault-tolerant controller designmethod can make the walker track path stability.Establishing mathematical model of walker system. This paper analysed faultmodel of actuators failure in the control system, and then the robust fault detectionmethod of walker is proposed on the basis of the nonlinear control system. Detectingthe fault signal, the simulation results show that the mathematical model designed inthis paper can detect accurately the walker’s actuators fault.Introducing the practical significance of robust fault tolerant control. For theactuators fault, a robust fault-tolerant controller is designed through adding thecompensation matrix in robust controller. The simulation results show that thecontroller designed in this paper can assure the walker continue moving safely and stably. Provide the guarantee for the safety of people.