Study On Robust Control For Vertical Vibration Of Urban Rail Vehicle

The rapid development of urban railway vehicles brings certain convenient for people, establishing solid traffic foundation for the economic regionalization. The requirements on the running stability and the ride comfort are becoming higher and higher at the same time. The railway vehicles with high speed make aggravation of the vehicle structural vibration during running and lead to a series of adverse effects. Improving the performance of bogies by active suspension is the main approach to solve the problem above. A huge amount of researches have been done on active control suspension by domestic and foreign scholars. The ultimate railway vehicle model contains many uncertainties because the running railway vehicle is a complicated uncertain system. Meanwhile, some uncertainties are contributed in the modeling process. In consideration of external disturbances and vehicle structure parameters perturbations of the running train, this thesis designs robust controller with H? robust control theory and ? control theory to resist vehicle vibration and improve the running stationarity and riding comfort. At the same time it has important meaning for prolonging the service life of the vehicle part and track subgrade, reducing the impact on the environment.Firstly, the origin of vehicle vibration happening is systemic analyzed. The track spectrum is transformed to track irregularity in time domain form by means of discrete Fourier transform method. On the other hand, based on the analysis of the urban railway vehicle vibration principle, the Hamilton theory is adopted to establish the 6-DOF vehicle vertical vibration model. Urban railway vehicle vibration status is analyzed with track irregularity regarded as external input. And the Sperling stable performance index is adopted to evaluate the vibration status.Secondly, based on the urban railway vehicle model, the vibration displacements between car-body and the pre and rear bogies are regarded as detectable quantity. And the train-body vertical vibration acceleration and displacements are regarded as the controlling output. In the consideration of the uncertainty neglected by nominal objects, the PS/T generalized plant model is built with selected weighted function. Based on the robust H? controller derived from linear matrix inequality(LMI), the controller is convex optimized to work out the robust H? controller to resist train-body vertical vibration, so that the running quality and safety level is improved. The controller has been simulated and verified in Matlab.Finally, considering the perturbation variations of the vehicle vibration parameters during running, the perturbations of the sprung mass and spring stiffness are mainly studied. The linear fractional transformation is adopted to accomplish the uncertain analysis of the vehicle vertical vibration model, and the perturbation parameters are isolated from the model with structured singluar value transform method. According to the performance requirements, the generalized plant is built with selected weighted function. The vertical vibration robust ? controller is work out with D-K iteration method. Hankel norm approximation method is adopted to reduce the controller order to improve the engineering realizability. The controller is simulated with track irregularity regarded as external motivation to verify the stability and robustness of the robust ? controller.