Research On Dynamic Performance Optimization And Semi-active Control Strategy Of High-speed Variable-gauge Train

With the rapid development of economy and culture,the demand for passengers and cargo transportation across countries and regions is increasing.China's economic development is closely related to other countries in the world,and it is inevitable to rely on railway intermodal transport tools.However,China and most of the surrounding countries adopt different track gauge lines,which seriously hindes the development of China's international combined transport and the process of "one belt and one road".Variable-gauge bogie is an effective measure to realize intermodal transportation between different gauges according to the practical experience of Spain,Japan,Poland and other countries.At present,the research on the variable-gauge bogie is not mature in China,especially for the research and development of high-speed variable-gauge train is still in progress,which indicates that the task of research and production of variable-gauge bogie adapted to China's national conditions is arduous and imminent.In addition,the running quality of variable-gauge trains under the different gauge running conditions is bound to be affected,especially in the high-speed running environment,the continuous interaction between wheel and rail will have a serious impact on the stability and safety of trains.In order to ensure the smooth running performance of the high-speed variable-gauge train on different gauge lines at the same time,it is necessary to put forward higher performance requirements for its suspension system.Therefore,in view of the limitations of conventional passive suspension system,it is necessary to adopt semi-active control of suspension system.This dissertation is under the guidance of vehicle dynamics theory,taking the high-speed variable-gauge train as the research object.The structure design of gauge-changing bogie and its ground variable-gauge matching device,the dynamic modeling of train-track system,the optimization and prediction of variable-gauge train dynamic performance and the control strategy of semi-active suspension system are completed.The main research contents are listed below.1.Design the variable-gauge bogie and its ground matching deviceAccording to the design requirements of high-speed variable-gauge train,the overall structural scheme of variable-gauge bogie and its ground matching device were designed,and the strength analysis and check of the key structures of bogies were carried out.Based on the theory of system dynamics,the rigid-flexible coupling model of the variable-gauge wheelset and the ground matching device was built.The dynamic characteristics of variable-gauge wheelset and unlock-lock mechanism in the variable-gauge process were analyzed,and the feasibility of the high-speed variable-gauge bogie and its ground matching device designed in this paper is verified.2.Bulid the dynamics model of variable-gauge vehicleThe vehicle model was simplified to a multi-rigid-body system with 7 stiffness and 42 degrees of freedom.The force analysis of each rigid body was carried out and the force models of the first and second suspension systems were derived.Considering the wheel-rail relationship during train running,the wheel-rail contact model was established,and a simulation method of the track irregularity signal based on the wavelet theory was proposed.Dynamic simulation model of the high-speed variable-gauge train system was built based on Simpack,which provides a basis for the study of dynamic performance optimization of variable-gauge vehicle and the semi-active suspension system control strategy.3.Dynamic performance optimization and prediction of the high-speed variable-gauge trainBased on the vehicle dynamics simulation model constructed,the influence rules of the dynamic performance indexes of the variable-gauge high-speed train under different gauges were simulated and analyzed.The first and second suspension parameters and wheel tread types of the train were optimized and analyzed by the parameters test method,and the optimal suspension parameters combination of and the optimal wheel tread type were obtained.The running smoothness and the curve passing performance of the high-speed variable-gauge train were predicted.According to the evaluation index of vehicle dynamic performance,whether the dynamic performance indicators of the variable-gauge vehicle meet the criterions was analyzed.4.Research on the semi-active control method of the train suspension systemResearch on the control method of the semi-active suspension system is an important measure to improve the stability of the high-speed variable-gauge train.Based on the sliding mode variable structure control theory and the fractional order theory,a sliding mode reference model of the fractional ceiling damping control for a quarter vehicle was built.Two sliding mode semi-active control methods based on the double sliding surfaces and based on the fuzzy RBF were proposed respectively.The semi-active control of the quarter vehicle suspension system was realized by designing the sliding mode controller with double sliding surface and the FRBF-SMC controller,and the control effects of the two methods were compared and analyzed.5.Research on the suspension system semi-active control of the variable-gauge trainThe FRBF-SMC control strategy was applied to the semi-active control system of the vertical air spring and the transverse MR damper of the variable-gauge train.The implementation of FRBF-SMC semi-active control strategy for air spring and MR damper was analyzed.The implementation of FRBF-SMC semi-active control strategy for air spring and MR damper was analyzed,a combined simulation model of the semi-active control system for high-speed variable-gauge train was constructed.The running smoothness,running stability and curve passing performance of the variable-gauge vehicle under different gauge lines were analyzed,which verifies the effectiveness of the semi-active control strategy of the whole vehicle.