Study And Simulation On Robust Non-fragile H_? Control For Semi-active Suspension System Of Rail Vehicle

Affected by the track irregularity and other factors in rail vehicle operation, resulting in a decline in the quality of operation. Generally, semi-active suspension control algorithms are based on accurate mathematical model, however the rail vehicle is a complex nonlinear system with the uncertainty factors which constraint the control strategy of vibration suppression effect.Classical robust H-infinity control is able to give full consideration to the uncertainty factors of the control object, but fail to analyze controller gain perturbations to affecting the stability of the system.Considering the controller gain perturbations, and reasonably simplifying the rail vehicle dynamics model, the yaw motion and roll pendulum motion are designed as the robust non-fragile H-infinity controller, and the models are solved with the linear matrix inequality(LMI).Finally, the ADAMS-MATLAB co-simulator is used to verify the decreasing vibration effect and comprehensive performance of controller. The specific contents are as follows:Firstly, the category and and harm of the track spectrum irregularity of are introduced, and the domestic and foreign typical track spectrumare analyzed. German low interference track spectrum samples in time domain data are acquired with the discrete Fourier transform method, and studied for its probability distribution characteristics. The results show that the three kinds of irregularity of the low interference spectrum in Germany are not strictly in line with the normal distribution.Secondly, based on the vehicle dynamics modeling criterion, the ADAMS/Rail software is used to build the rail vehicle model to be used as the control object. According to the needs of the controller design, the vehicle dynamics model is reasonably simplified, thus the semi-active suspension control model is established. Combining with the vehicle yaw and rolling pendulum motion of weak coupling, the robust non-fragile H_? control of yaw motion and rolling pendulum motion are designed respectively. Accdording to semi-active suspension design requirements, the H_? norm is used to reflect ride comfort. The sufficient conditions for the existence of robust non-fragile H_? control are developed based on linear matrix inequality(LMI) approach. The design of a robust non-fragile H_? control with gain variation is changed into an optimization issue with linear matrix inequality constrains and a linear objective function.Finally, the robust non-fragile H-infinity controller in damping effect is evaluated. Then, based on the wavelet packet analysis theory, acceleration signals are decomposited and reconstructed, and the non-fragility of controller is analyzed. The mathematical statistical analysis theory is used to study the influence on vibration acceleration probability distribution characteristics by robust non-fragile H-infinity controller. Simulation results show that the robust non-fragile H-infinity controller has good non-fragile and can effectively suppress the lateral vibration of vehicle and this change reflected indirectly in wavelet packet 3 layers of decomposition, the decomposition layer of a first frequency band energy decreased, however, improving vehicle ride comfort will not change the probability distribution category of lateral vibration acceleration, and just distribution of concentration are improved.