Research On The Judgement And Simulation Of Automobile Running Security

Traffic safety is not only the important thing of national economy, but also onebasic task (safety and expedite) of road management. Recently, the situation ofglobal traffic safety is still unsatisfactory and particularly in developing countriesthe situation of traffic safety is worrisome. The situation of traffic safety in China ismuch under the level of the world and the losses caused by traffic accidents is veryhigh. The number of our cars occupies 2% of the word, but the death toll ofaccident is over 10%, number one. At present, it is high of traffic accidents inChina and the frequency of serious traffic accidents threaten the safety of people'slives and affects our economic construction. Traffic accidents have become a majorfactor in the unnatural death of human. Therefore, studying the traffic safety to reduce security risks becomes one ofthe main tasks of Governments. With the development of technology of computerand popularization of computer, the techniques of computer simulation becomes away to study security issues. The techniques of computer simulation can simulatedifferent needs, environment, vehicles and driving behaviors which is used to findsecurity risks and reduce losses. The techniques of computer simulation can alsosimulate the condition of motor vehicles traveling in critical condition and canstudy the traffic safety in limits condition. The paper relied on the ministry of communication west project which iscalled woodsy area and tour road——the traffic safety research of S203 in theinner Mongolia belonging to the applied techniques research of highway trafficsafety, based on the numerical simulation, founded the automobile dynamicdifferential equation and the database of road module, analyzed the safety questionabout the automobile running on the roads, supported some referenced datum forthe ameliorative measures of S203, in the same time, supported some academic gistfor the road management department, the main contents was showed in thefollowing text:1,The paper introduced the actuality of road traffic safety, expatiated on thesignificance of studying traffic safety, analyzed the research condition ofsimulation technique and automobile simulation software, confirmed themain research contents basing on the facts above-mentioned.2,Establishing the differential equation of automobile movement. Above all,the author introduced the sorts of systemic modeling and the threemethods of establishing mathematical model, analyzed the five basicprincipals about establishing differential equation, second, introduced thecoordinate transformation theory of point, put forward the coordinatetransformation formula of planar and three-dimensional point, third,introduced a sort of tyre-gramary equation applied prevalently at presentand 5-DOF automobile double-track dynamics model. The paperestablished exact linear 2-DOF automobile movement differential equationthrough handling the coordinate transformation theory, regarding the basicmethod of establishing mathematic model and the basic principal ofestablishing differential equation as guidance. Finally, the author studiedsome basic theories about tapping GIS system and function belonging toroad database, regarding VC++ as tapping tool and ODBC as backgroundprocess, using the technique of object oriented.3,The movement of automobile depended on the force acting on the tyres.When the car run in the track, because of the action of centrifugal force,the side sheer force occurred in the center of tyre, the side elasticity of tyreinduced the side distortion, the centerline of print between the tyre and theground has an angle with the tyre' plane and it is called side sheer angle.The side sheer of tyre easily reduced the single-car accident which is likeside-turning over and sideslip accident when the car swerve. The paperfounded three models of automobile side-turning over and put forward thecritical speed of automobile' side-turning over basing on the side sheercharacteristic of tyre, on the other hand, also founded the two sideslipmodels in the condition of running and braking, and put forward thecritical speed of sideslip.4,System designing. Firstly, the author designed the simulation system frameof automobile safety running, regarding the automobile and road asresearch object. The system was divided into input module, calculationmodule, judgment module, and output module. The author detaileddesigned and analyzed every module' function. Then, the authorintroduced three usual numerical methods of differential equation (Eulermethod,improving Euler method and Runge-kutta method), analyzed theconvergence speed and strongpoint or shortcoming. Finally, the authordesigned the operation interface of software.5,The actual example analysis is a usual method to examine systemicanalysis result which is credible whether or not, the author analyzed anexample of turning over accident and an example of side-slide accidentusing the founded module, examined the veracity of safety questionswhich are analyzed by the numbers basing on analyzing the module.Finally, the dissertation summarizes the achievements, and bringsforward the issues for further research.