Research On Active Control Of Stability Of Straddle-Monorail Vehicle With Single-Axle Bogie

As a distinctive urban rail transit system,straddle-type monorail transit has broad application prospects.There are two structural types of straddle-type monorail vehicle(STMV),namely,STMV with double-axle bogie and STMV with single-axle bogie.Compared with the STMV with double-axle bogie,the STMV with single-axle bogie is mainly aimed at the rail transit in small and medium-sized cities,and has the advantages of lightweight,low floor and small turning radius.It is found that the stability of STMV with single-axle bogie is worse than that of STMV with double-axle bogie,especially the shimmy problem is prominent,the vertical stability and vehicle body pitch are not easy to control,and the attitude stability of small curve passing needs to be improved.These problems will have an important impact on driving safety and structural fatigue life.Therefore,in order to improve the operation quality and the stability of STMV with single-axle bogie,it is necessary to carry out active control of stability of STMV with single-axle bogie.In this paper,the STMV with single-axle bogie is considersed as the research object,the instability mechanism of STMV with single-axle bogie is analyzed,the dynamic model of STMV with single-axle bogie based on active control is established,the research on the stability active control system and related control algorithms of STMV with single-axle bogie are carried out,and the design scheme is formed.The main research contents and conclusions of this paper are shown as follows:(1)Rearch on the instability mechanism of STMV with single-axle bogie.The vehicle-track coupling dynamic model of STMV with single-axle bogie based on multi-body dynamics theory is established and verified by real vehicle vibration test,and the structural and mechanical causes of instability of STMV with single-axle bogie are analyzed.Compared the STMV with single-axle bogie and with double-axle bogie through simulation experiments,the simulation results show that compared with STMV with double-axle bogie,the stability of STMV with single-axle bogie is poor,especially the shimmy is very serious.(2)Rearch on the active control scheme of stability and evaluating indicator of STMV with single-axle bogie.Firstly,the current control schemes and related research of automobile and railway vehicles are analyzed.The scheme design of STMV with single-axle bogie based on active control are proposed,and the active control dynamic model of STMV with single-axle bogie is established,the stability evaluation index of STMV with single-axle bogie is given,which lays a foundation for the further research on the active control of stability of STMV with single-axle bogie.(3)Rearch on the electro-hydraulic servo actuator for stability control of STMV with single-axle bogie.Aiming at the nonlinear control problem of electro-hydraulic actuator,its dynamic characteristics are analyzed,the nonlinear model of electro-hydraulic actuator is established,and a linear active disturbance rejection control(LADRC)is designed for actuator force tracking.The effectiveness of the algorithm in improving actuator tracking accuracy and response speed is verified by simulation analysis.(4)Rearch on the active control of shimmy of STMV with single-axle bogie.A shimmy coordinated control strategy of vehicle body with lateral controller and yaw controller in parallel is proposed,which decomposes the two expected forces into four lateral electro-hydraulic servo actuators.Combined with the sliding mode control theory and the active control model of canopy damping control,a sliding mode controller based on reference model is designed to control the lateral acceleration and yaw angular acceleration of STMV with single-axle bogie.The results show that compared with passive control,the root mean square(RMS)value of lateral acceleration of monorail vehicle controlled by sliding mode is reduced by 62.63%,the RMS of yaw angle acceleration is reduced by 58.15%,and the lateral stability index is reduced by 27.88%.The designed control algorithm effectively improves the stability of STMV with single-axle bogie.The Kalman filter algorithm is used to estimate the vibration state after control,which verifies the effectiveness of the control algorithm proposed in this paper.(5)Rearch on the active control of multi-dimensional vibration of STMV with single-axle bogie.A multi-dimensional vibration control strategy with lateral controller,vertical controller,roll controller,pitch controller and yaw controller in parallel is proposed.The five expected forces are decomposed into four lateral and four vertical electro-hydraulic servo actuators.The ANFIS-PID controller of STMV with single-axle bogie is designed by combining fuzzy control,neural network control and PID control.The multi-dimensional vibration control of lateral vibration,vertical vibration,roll vibration,pitch vibration and yaw vibration is realized.Under random irregularity excitation and finger plate excitation,the influence of different vehicle speeds on multi-dimensional vibration control are sudied.(6)Rearch on active control of attitude stability of curve passing of STMV with single-axle bogie.The curve line model of STMV with single-axle bogie is established,and an attitude stability of curve passing control strategy is proposed.The series LARDC controller of STMV with single-axle bogie is designed to control the roll angle of STMV with single-axle bogie.The results show that compared with passive control,the maximum roll angle of monorail vehicle controlled by series LADRC is reduced by22.67% under no-load condition,the maximum roll angle of monorail vehicle controlled by series LADRC is reduced by 24.80% under full load condition.The designed control algorithm effectively improves the attitude stability of curve passing of STMV with single-axle bogie.