The Train Lateral Semi-Active Suspension System Based On The Fuzzy Predictive Control Theory

The railway has clear advantages in running speed, transport capacity, energy saving and environmental protection, etc. which is also the major way of passenger travel and freight transport. However, the trains are affected by tracks irregularity disturbance and aerodynamic, which led to trains generate random vibration of multiple degrees of freedom. To solve the problem of lateral vibration and improve the smoothness and comfort of the train, this thesis accomplished following works:(1)The author uses the way of semi-active suspension control, which has characteristics of low-power, controllability, etc. It can be automatically converted to a passive suspension when the system fails to ensure the safe operation of trains. MATLAB\SIMULINK is used to build the seventeen degrees of freedom of train simulation model. Germany low interference high-speed rail Spectrum is used as the input signal simulation of the simulation experiment.(2)Because of the complexity of the high-speed train lateral vibration model, the author uses the Generalized Predictive Control with Fuzzy Constraints in the trains semi-active suspension system, which would effectively reduce the practical problems brought by inaccurate model, This thesis introduces the principle of selecting the controller parameters. The three freedom degrees of the half simplified model is taken as Forecasting model, which can effectively simplify the model identification process in algorithm design.(3) Accord to the skyhook damping principle and adjustable damping shock absorbers, the author designed the damper simulation module, which are able to simulate and study the train semi-active suspension control system at different speeds, and analysis the results based on the stability evaluation.The results from the analysis obtained:the semi-active suspension used of the generalized predictive control with fuzzy constraints compared with the passive suspension system the time-domain peak of the vehicle body’s lateral acceleration reducing46%～59%, and the rms value of the lateral acceleration is reduced about50%～58%, the train lateral stability index improved by17%to22%. Compared with GPC_PID semi-active suspension system the evaluation improves about10%, which show that the algorithm can effectively reduce the lateral vibration of the train, can improve the smoothness and stability, and can improve the traveler’s ride comfort. The simulation results prove the effectiveness as well as the practical significance of the algorithm.