Research On The Handling Stability Of Bus Under The Condition Of Interrupted Ice And Snow Road

As an important means of transport, bus plays a positive role in the national economy. The driving environment and road conditions are the key factors that affect the stability and safety of the bus. Based on the analysis and comparison of domestic and foreign research status, the research on the influence of the complex conditions of the interrupted ice and snow road on the handling stability of passenger cars is relatively few. At the same time, because of the complexity of the ice and snow road,the bus is more prone to dangerous conditions such as sideslip instability. Therefore,the study on handling stability of passenger cars under the condition of interrupted ice and snow road is the key to improve the stability of the passenger cars.Firstly, the bus model which includes the nonlinear tire models, the formation of the suspension model consists of leaf springs and shock absorbers, size and occupant load model of passenger car was established by Truck Sim software.Meanwhile, a normal road model, intermittent ice and snow road model and full of ice and snow road model were constructed, and the various adhesion coefficient values have been analyzed. Finally the typical driving conditions of single and double lane change model were built and analyzed.Secondly, the bus with no-load and full-load simulation under two kinds of conditions by Truck Sim, combined with the establishment of three road conditions,which are normal road model, intermittent ice and snow road, and full of ice and snow road model, respectively. The handling stability of bus in different speed and load were analyzed in single lane change, and through comparative analysis and conclusions that the road adhesion coefficient has little effect on the bus at low speed;With the increase of speed, the bus in full ice and snow road and discontinuous ice road are prone to sideslip risk, and the most dangerous in driving is the interrupted ice and snow road. By simulation full-load bus in each road condition, and contrast to the no-load and full-load bus, sideslip is the main form in bus instability in ice and snow road.Thirdly, to compensate for Truck Sim cannot solve the stability region problems,the bus dynamics model was constructed, considering the lateral motion and yaw motion and change of front wheel angle, of which the nonlinear tire magic formula model and the linear tire model were compared; The ice and snow road model construction has provided left and right sides of the adhesion coefficient that were different. At the same time, according to the different characteristics in two kinds of ice and snow road model, taking the left step response of bus as an example, for giving ultimate lateral force formula.Finally, the solution of bus dynamic stability region under interrupted ice and snow road is the key research, including different speed and different angle of bushandling and stability under left and right ice road, a conclusion that a slight angle for vehicle driving stability is benefit of steering stability; Combined with the phase plane theory, comparative analysis of the phase plane stability region in different steering angle of bus under the normal road, and the left and right of road of ice and snow conditions; Conclusions that the balancing of planar point is move to the top left, the stability region decreases by comparison of different angle changes in three kinds of road conditions.