Research On Control Strategy And Dynamic Optimization Of Metro Vehicle With Active Radial Bogie

For metro vehicles,there is always a contradiction between straightline stability and curve passing performance,and the traditional bogie can not meet the requirements of further improving vehicle dynamic performance.In order to overcome this contradiction and improve the wheel/rail wear of metro vehicles,it is necessary to study a radial bogie which can not only ensure the straightline stability,but also improve the curve passing performance.Therefore,this thesis conducts detailed research on the control strategy and dynamic optimization of the active radial bogie.The main research works are as follows:(1)The steering mechanism of traditional,self-steering and forced-steering bogie,as well as the line adaptability were analyzed.The results show that the self-steering bogie can be applied to the large radius curve,but there is a problem of insufficient stability caused by high equivalent conicity.Forced-steering bogie can be applied to small radius curve,but there is a problem of instability caused by low equivalent conicity.The conventional bogie can not give full consideration to the straightline stability and the curve passing performance,so it is necessary to study the active radial bogie with better adaptability.(2)The steering mechanism of the active radial bogie was analyzed,and the scheme selection of the active radial bogie was conducted.The closed-loop controller with feedforward compensation was designed,and the co-simulation model of the active radial bogie was established.The radial line control strategy based on wheelset attack angle and the pure roll line control strategy based on longitudinal creep force were discussed from the perspective of theoretical research.The control strategies of relative yaw angle based on the yaw angle of secondary suspension and line beacon were studied from the perspective of engineering application.The feasibility of engineering control strategies were demonstrated,and the line adaptability of active radial bogies was analyzed.The results show that these control strategies can effectively reduce wheel/rail wear and the wheelset attack angle.Compared with conventional radial bogie,active radial bogie has better steering performance and can adapt to more curve conditions.(3)A dynamic optimization method for active radial bogie based on global sensitivity analysis and adaptive genetic algorithm was proposed.Firstly,the sensitivity of suspension parameters to dynamic indexes of active radial bogie was quantitatively identified.After that,the adaptive niche genetic algorithm was used for multi-objective optimization of highsensitivity parameters.Finally,the dynamic performance of the active radial bogies before and after optimization were analyzed.The results show that the proposed optimization method can better achieve the reasonable matching of wheel-rail and suspension parameters.Compared with the traditional bogie,the lateral sperling index,vertical sperling index and ride comfort of the optimized active radial bogie can be improved by about 12%,9% and 24% respectively in straight line.The optimized wheelset lateral force,derailment coefficient and wear power can be reduced by about 30%,65% and 90% when passing the 500 m radius curve at equilibrium speed.