Study On Key Technologies Of Urban Microscopic Traffic Simulation

To raise the utilization of the urban road availably and resolve the traffic blockage problem, It is necessary to analyze present urban traffic condition scientifically and find out the reasonable improvement measure. As an important traffic optimizing measure, Microscopic traffic simulation can simulate traffic condition in different cross design, traffic organizing and traffic control measure. Bringing out evaluated results, make out optimized scheme spending less money and time. Therefore, the main research contents of this text is as follows: establishing the Urban Microscopic traffic simulation model system structures. Take the model system structure as the frame, put forward some solutions of key technique problems within Urban Microscopic traffic simulation System development, include the object-oriented software design technique, system design and program design, the software user interface technique etc. Design the core model of Urban Microscopic traffic simulation System; and develop Urban Microscopic traffic simulation System. Concrete contents is as follows: (1)Urban Microscopic traffic simulation model system, it is the core content of Urban Microscopic traffic simulation System. The validity of model system decided the success or failure of Urban Microscopic traffic simulation System directly. In this part we look at the structure of the model system and the contents of car-generation model, car-following model, road network model, traffic control model, route choice model respectively. (2)Car Driving model . The validity of Car Driving model decides the veracity of Urban Microscopic traffic simulation System. Car Driving model include Free Driving model, Car-Following model, Lane-Changing model, Cross Car-driving model. This part presents why the driver-vehicle objects correspond to the Intelligent agent and developed Car-Driving model that correspond to multi-agent systems. This text developed a Car-following model that correspond to multi-agent systems through modified the CELLSIM model. This text adopt a Lane-changing model , which correspond to multi-agent systems , developed by Peter Hidas. This text developed a Cross-Car-driving model according to behavior of competing conflict area which correspond to multi-agent systems. (3) Urban Microscopic traffic simulation System Design. This part accomplished the System design, Program design, user interface design and System test in Object-Oriented method. System Function design. According to the requirements , this system should include Simulation environment constructing, Car-driving simulation, traffic control simulation, route choice simulation and good user interface. System Structure Design. This system adopts hierarchy and plug-in type structure combine together. The system is divided into three layers totally, from the lowest layer to the upper level is the data layer, the performance layer and the assistance layer. The plug-in type structure divided the system into several plug that independently each other. The plugs communicate through interface. There are only virtual interface between plugs. The function and interface design by system, so the system is more flexible. The Object design. This system mainly includes the car class, the detector class, the lane class, the segment class, the way class, the cross class, the traffic control class, the phase class, the OD point class. This text presents the detail of properties and method of classes and analyzed the relations in classes. The User Interface. The contents that should be input are Road Network information, traffic control information and car generation information. The information output have two types ,one is animation and the other is document. Computational speed. The execution times were computed on a Dell Dimension XPS Intel Pentium IV Processor, with a processor speed of 2.8 GHz and 256 MB of RAM. The time step of running is 0.1s.This system was able to simulate a total of...