Study On Simulation And Safety Evaluation Of Curved Slope Sections Based On Vehicle Dynamics

In China, with the number of cars increasing largely, traffic safety problems are emerging more and more. In general, there are a large number of casualties and economic losses in a traffic accident, and the negative effects it brings to the society cannot be ignored. In other countries, it has been confirmed that the traffic safety evaluation in advance can reduce accidents effectively.There are a little number of research methods of the evaluation in advance at present, and the most are without the solid theory foundation and practice basis.Due to traffic safety evaluation technology limited guidance on the engineering practice, remains to be further improved.Combination for frequent occurrence of traffic accidents of curved slope sections, a modeling based on vehicle dynamics is applied to simulate the running state of vehicles on a given road in this paper, and then a vehicle dynamics response curve of the whole vehicle running process can be obtained. With analysis, we can obtain the influence of the various factors of the road environment on the vehicle running safety. This paper mainly researches the influence degree of the horizontal curve radius and the longitudinal slope of the curved slope section on the road safety.CarSim based on vehicle dynamics was used to construct the man-vehicle-road system dynamics simulation model, it made up of the whole vehicle model, tire model and road model and driver model four parts.Based on a section of curved slope of an expressway data, the simulation of vehicles whole process in this section, several targeted dynamic response curves can be output.then comparing vehicles on the road in the actual operation situation.There are four representative factors, such as car, radius of plane curve and longitudinal slope and coefficient of friction. Through the Angle of step experiment, it can be simulated that vehicle model with different factor values,vehicle steering stability can be proved, steady-state yawing angular velocity, the max yawing angular velocity, the time of reach the max yawing angular velocity, transient time is four evaluation index. Finally, we evaluat degree of road safety from vehicle handling stability. In order to research on vehicle on road safety in curved slope saction, we us CarSim software to simulat running condition in different section of curved slope road, selecting the steady-state body roll angle, lateral acceleration in vehicles running to evaluate the rollover risk of vehicle and to evaluate road safety degree in different curved slope combination. Then analyse the impact of vehicle plane curve radius and longitudinal slope on road safety.In practical engineering, simulation of using CarSim at the design stage in one section of the road running status of vehicles. it can be through the analysis of vehicle dynamic response curve of road that we find the section of frequent accidents or degree of safety, and the operation is convenient, therefore, it is worthy of promotion, as evaluation on a new road in advance.