Study On Microscopic Simulation Model And System Of Cloverleaf

Traffic flow simulation is the hot issue of urban traffic simulation. In the system,the impact between vehicles and system, the vehicles and vehicles, the vehicles andthe roads should be taken into account. The simulation systems utilize thecar-following model, lane-change model, and so on, and then simulate the vehiclesrunning in the road net. The traffic flow model proposed before didn't take thegeometry of the road into account, so the result maybe not correct. This thesis firstlyanalyses the shape of the cloverleaf and considers the habits during the drivers driving,then develop the model which can be used on the road with curvature and longitudinalgradient, get the computer model of the cloverleaf, and lastly complete the traffic flowsimulation system of the cloverleaf.The shape of the cloverleaf is variable, the beeline, the round curve and theconvolute curve is the basic elements for the plane curves,the longitudinal gradientreflects the change of the vertical section. This thesis analyses the constituent parts ofthe cloverleaf, then disassembles it variable parts that have different geometryfeatures. The variable parts make up the computer model of the cloverleaf. And thisthesis designs methods that enable the vehicles moving according the establishedcloverleaf model, and displays the cloverleaf on the screen.Little or no geometry has been considered in existing traffic model,the thesistakes the vehicles' force which move on the road with longitudinal gradient andcurvature, as beginning, analyses the safety conditions of moving when the radiusesof the road change, the acceleration except for traction and Behavior that gohabitually when the vehicles move on road with longitudinal gradient. A car-followingmodel that is suitable for road with longitudinal gradient and curvature is obtained byameliorating the factors of the car-following model.The thesis established simulation module of the entrance and exit at the ramp,finished the design of cloverleaf's traffic simulation systems utilizing simulatedtechnology in accordance with the target. Simulation of the entrance and exit at theramp was done at last, the results show that the system in the thesis can simulate thecloverleaf's traffic flow. The thesis also gives some simulation cases for establishingcloverleaf's traffic flow and the results of simulation.