Loop Shaping Vibration Control For Lateral Semi-Active Suspension System Of High Speed Train

Passengers have higher and higher requirements for the speed and quality of the train,so the vibration reduction performance of the train must be improved when it is running at high speed.The semi-active suspension control system is the best method to suppress the lateral vibration of high-speed trains in China.In order to optimize the running quality of trains,a more effective semi-active control strategy should be adopted based on the semi-active suspension system.For the purpose of improving the train operation stability,this paper research on the suspension system of train vehicle,the theory of vibration reduction control strategy and the method of building the vehicle simulation model,the following works are carried out:(1)Based on H∞ norm optimization can handle a variety of external disturbances and model error.Therefore,for the model complexity of train,high variability of running environment,the H∞ robust control strategy is proposed to design the second suspension system vibration absorber,to control vibration of train body produced during operation and improve the operation stability.Finally,the effectiveness of the proposed strategy is verified by co-simulation.In the case of low disturbance irregularities,the operation stability of the h-infinity control strategy is improved by about 23% compared with the open loop;Under the condition of high disturbance irregularity,the operation stability of the h-infinity control strategy is improved by about 23% compared with the open loop.(2)The H∞ control method does have a good effect in dealing with non-structural uncertainty problems,but it is still not ideal in dealing with structural uncertainty problems.The train is a highly complex nonlinear system,there must exist structural uncertainty disturbance.In order to improve the operation stability of the designed controller,based on the H∞ control method,the loop shaping control strategy is further proposed to design the vibration absorber.And the uncertainty modeling of mutual prime decomposition used in this method is more general and universal than other uncertainty modeling.The loop shaping control strategy can not only realize the robust stability of the train system,but also improve the running stability.Finally,through the co-simulation,it is verified that the control effect of this strategy is better than that of the h-infinity control strategy.Under the condition of low disturbance irregularities,compared with the open loop control strategy,the H∞ loop shaping control strategy improved the running stability by about 33%.Under the condition of high disturbance irregularities,the H∞ loop shaping control strategy improved the operation stability by about 31% compared with the open loop control strategy.(3)Since the H∞ loop shaping control method is in the design of the controller,the selection of the weight function mainly depends on the design experience of the engineers,it needs repeated adjustment and trial,which is very time-consuming and has great blindness,which increases a lot of tasks for the designer.To solve these problems,an improved loop shaping control strategy based on iterative learning was proposed.By utilizing the characteristic of trajectory tracking in iterative learning,this strategy transforms the model matching problem of the controlled system in loop shaping design into the trajectory tracking problem of the expected loop function in iterative learning,which makes the design process simpler and the designed controller more consistent with the real controlled system.Finally,through the co-simulation,it is verified that the control effect of this strategy is superior to the H∞ loop shaping control strategy and superior to the H∞control strategy.When running under low disturbance irregularity excitation,the improved loop shaping control strategy based on iterative learning improves the operation stability by about 36% compared with open loop.Compared with open loop,the improved loop shaping control strategy improves the running stability by about 36.5% when operating under high disturbance irregularity excitation.