Research On Active Anti-rollover Control Of Heavy-duty Truck Based On Dynamic TTR

With the growing prosperity of China's road logistics market,cargo vehicles are playing an increasingly important role in it.Heavy duty truck as a cargo vehicle,has a unique advantage in terms of transport goods.However,due to its large load capacity,high center of mass and the track is relatively narrow and so on,making its driving stability is very poor.Especially in the high speed,large steering and emergency avoidance conditions,rollover phenomenon is happened easily.Therefore,in order to improve the heavy duty truck driving safety performance and reduce vehicle rollover accident.In this paper,on the basis of the vehicle roll stability,the study of heavy-duty truck rollover early warning system and anti-rollover control system are launched respectively.The research focuses on establish a dynamic model that accurately reflects the rollover of heavy goods vehicles,put forward the risk index of vehicle rollover and design heavy duty truck rollover warning system and using state estimation theory to improve real-time of early-warning algorithm.Aiming at the structure and driving characteristics of heavy goods vehicles,this paper studies the technology of roll stability control and explores the effective anti-rollover control strategy for heavy-duty truck.The main research contents of this paper are from the following points:(1)A three-degree-of-freed(3-DOF)rollover model of heavy-duty truck include lateral movement,yaw movement and roll movement is established.By establishing the mathematical model of heavy duty truck rollover,using Matlab/Simulink heavy duty truck rollover simulation model is established,and through the Trucksim heavy-duty truck parameters were set.By means of joint simulation,respectively in the Angle step condition and a hook to conditions to contrast analysis of the heavy duty truck lateral velocity,lateral acceleration,tilting angle and yawing angular velocity fitting,in order to verify the accuracy of the 3-DOF model.(2)Based on the 3-DOF rollover model of heavy-duty truck,a TTR-based rollover warning algorithm is designed.The disadvantages of selecting the roll angle and the lateral acceleration as the vehicle rollover index are analyzed.Deciding to choose the lateral load transfer rate(LTR)as indicators of rollover warning algorithm,and gives the method of calculating LTR.In order to improve the real-time of the rollover warning algorithm of heavy goods vehicles,the Kalman filter algorithm is designed based on the state estimation theory to forecast and estimate the running status of heavy goods vehicles.By analyzing the results of the simulation,the changes of the LTR and rollover warning time(TTR)of Kalman filter before and after are analyzed and compared,and on the improvement of the early warning and real-time performance.(3)Based on the analysis of the dumping of heavy duty-truck,the advantages and disadvantages of active steering,differential braking and semi / active suspension as vehicle anti-rollover control are analyzed and compared.Based on the continuously adjustable damping force characteristic of semi-active suspension,the semi-active suspension is used to generate the anti-rollover control.The anti-rollover control strategy of semi-active suspension is established based on rollover warning.For sliding mode controller of sliding mode function and reaching law has carried respectively on the rational design,to ensure that the sliding mode control in the fast approaching and weaken chattering at the same time.