Robust Control Of Active Seat Suspension System Based On Observer

The vibration of the vehicle in the process of driving will have a negative impact on the comfort of the driver,the stability and safety of the vehicle as well as the physical health.The active seat suspension,as a vibration absorber in direct contact with the driver,can effectively isolate the vibration caused by road excitation from the vehicle suspension to the driver at a lower cost.However,in practical application,interference,delay and failure often affect the stability of the system,thus reducing the vibration damping effect of the seat suspension device.In view of such problems,this thesis will discuss the robustness of vehicle active seat suspension system from the following three aspects:(1)The problem of actuator anti-disturbance control of vehicle active seat suspension system is studied.Firstly,considering the friction disturbance of the actuator in the seat suspension system model,the unknown input observer is designed to reconstruct the friction,assuming that the unknown input and the friction disturbance cannot be completely decoupled.Then,under the constraint of performance index,based on the Lyapunov stability theory and Linear Matrix Inequality(LMI)method,the friction interference is compensated by H_?state feedback controller.Finally,the effectiveness of the control method is verified by simulation.(2)The state measurement output delay of vehicle active seat suspension system is studied.Firstly,considering the external input interference and the output delay of state measurement in the model of the seat suspension system,an observer is designed to estimate the effect of external input on the system by using the delay measurement.Then,convex optimization is used to design the observer gain to ensure that the dynamic error system can run stably for any bounded delay at a specific performance level.Finally,the effectiveness of the proposed algorithm is verified by simulation.(3)The active fault-tolerant control of vehicle active seat suspension system based on sensor fault is studied.Firstly,taking into account the fault situations such as gain change,constant deviation,stuck saturation and so on in the sensor of active seat suspension system,an adaptive observer was designed to reconstruct the output residual and a fault diagnosis algorithm was designed to reconstruct the fault.Then,combining the fault estimation and fault output to reconstruct the sensor signal,the original control law and the sensor reconstruction signal are used for active fault tolerance control without changing the structure and parameters of the active seat suspension output feedback controller.Finally,the effectiveness of the fault-tolerant control algorithm is verified by simulation.