Research On Fault-tolerant Control Of Vehicle Magnetorheological Semi-active Suspension

The ride comfort and handling stability of the semi-active suspension system based on magneto-rheological dampers are better than passive suspension systems.However,due to the variability of road conditions and the complexity of the working environment,the sensors or actuators of the suspension system are prone to failure.If the traditional controller is used to improve the suspension performance,regardless of the possible failure of the system,and no design response method,the suspension performance of the system may be greatly affected after the failure occurs.In order to ensure the safety and reliability of the suspension system during the operation of the vehicle,it is necessary to diagnose the possible faults of the magneto-rheological(MR)semi-active suspension system sensor or actuator,and design corresponding fault-tolerant control to make the suspension The research has important theoretical research significance for the suspension performance when the frame system is restored to failure-free.The main research contents of the thesis are as follows:1.Based on the vehicle dynamics theory,a two-degree-of-freedom MR semi-active suspension model is established.The Bouc-Wen phenomenon model and the improved Skyhook control strategy are selected.Comfort and handling stability are selected as the suspension system performance evaluation indicators.The correctness of the model is built,and the simulation results show that the comprehensive performance under the Skyhook control is significantly improved.2.The sensor constant deviation and gain fault model,the actuator current input gain,and the output gain fault model are established separately.An unknown input observer is designed to determine whether the MR semi-active suspension system has a failure,and the correlation coefficient method is used to locate and isolate the failure.The designed fault detection method is verified,and the simulation results show that the adopted fault diagnosis method can judge and isolate the moment the fault occurs.3.For sensor failures,a fault-tolerant control method for output reconstruction of the system state is designed.For actuator failures,a fault-tolerant control method for the groundhook is designed.The control effect is verified when sensors break down.The simulation results show that the designed fault-tolerant control method can improve the overall performance of suspension.4.The two-degree-of-freedom MR suspension hardware-in-the-loop test simulation platform is built,and the designed fault-tolerant control algorithm of the MR semi-active suspension against sensor and actuator failures is also verified.The experimental results show that adding fault-tolerant control can effectively improve Ride comfort and safety after the failure.