The Simulation Analysis About Rollover Of Multi-axle Vehicle And Early Warning Method Study

With the r apid development of soci al economy and the im provement of transportation demand,the Multi-axle vehicle with high ef ficiency,low cost,strong obstacle capability and strong ground capac ity,has becom e the m ain force of transportation market.But due to the heavy duty,complex road co nditions and the particularity of stowage,once an accident happened,it will cause huge econom ic loss.The adverse effect of vehicle ro llover is just behind collision ac cident,in the second member of all the accid ent.So the study of the Multi-axle vehicle about rolling is very necessary.This paper takes the four axis vehicle as the res earch object.On the basis of the traditional single model of two degrees of freedom vehicle dynamics model,this paper joins the roll motion and establishes the vehicle model including horizontal pendulum,roll and pitch.Then,getting the f our axis vehicle all-wheel stee ring dynamics state equation,and setting up the four axis vehicle sim ulation model of dynam ic state equation in the Matlab/Simulink.Taking the tire rotation and vertical speed as the input of the model,and simulating the vehicle at different speed and different tire rotation of J-tu rn ?fish hook and dou ble line w orking condition of the vehicle lateral acceleration and roll angle curve.The results show that the faster of the vehicle speed,the larger of the tire ro tation,the side tumbling stability of vehicle will b e worse.And analysising the veh icle mass center height,suspension equivalent roll stif fness and equivalent damping suspension,tire stif fness inherent param eter how to im pact on vehicle rollover.It is concluded that the height of the center,the sprung mass impact the vehicle rollover more,equivalent roll stif fness and equivalent dam ping suspension of vehicle impact the vehicle rollover less.Through the sensitivity analysis of the vehi cle intrinsic parameters,chosing the roll angle of the rollover threshold value evaluation index.The TTR early warning model is established in the Matlab/Simulink,and chosing the fish hook and J-turn conditions to verify the early warning model and early warning method.By Contrast of the roll angle output curve and TTR e vent output curve,it is concluded that the designed event early warning method based on the TTR can have very good effect.Finally,considering the sensor m easurement error in practical application,this paper joins the jamming signal in the model.Then under the J-turn condition,getting the roll angle of the output graph and TTR event output curve,but they are quite differ a lot,and the ideal state of early warning effect can not meet the requirements.Therefore,using the theory of w avelet filtering the error of ro ll angle of the output curve to improve the early warning model and work f low chart,an d filtering the TTR event model calculation,got the roll Angle of gra ph and TTR event graph after filtering.The comparison shows that the curve of the lateral angle after filtering and TTR,the graphs shake smaller,more smooth and better than the warning contains error conditions,this paper has completed the study of wavelet denoising method on the model.