Research On The Key Technology Of The Urban Vehicle Dynamic Guidance System

With the development of urban transport, the volume of traffic is increasing day by day,and road network becomes more and more complex. The efficient use of resources in urbantransport is seriously affected by traffic congestion and the road blocking. Vehicle navigation isa branch of the modern intelligent traffic. Path planning is the core part of the vehicle navigationsystem. The main role of it is based on the urban road network information and real-time roadtraffic information to realize the path planning function before the trip and in the travel of theuser. This shows that the road network and traffic information is the basis for path planning.Currently, most of the vehicle navigation systems in the market are based on the static networkmodel. However, when there are traffic accidents or traffic jams, the traditional path planningcan not meet the current demand for practical application.This thesis presents the concept of a generalized network model, and on the basis of thestatic network model, adds dynamic traffic information. Combined with the basic idea of object-oriented modelling and module modelling, the layer-by-layer hierarchical independent model isabstracted form the entities of the road network. It can be seen from the above analysis, startingfrom the road models and road relational model, a hierarchical, modular transportation networkmodel can be established after a series of system decomposition. Moreover, each transportentity is abstracted as an object model, so you can through expansion of the function of eachmodel to achieve realistic simulation all kinds of traffic behaviour in road network. Also, it is ahierarchical architecture, so that the whole model structure is clear, specific functions,convenient for further perfection. In the path planning, first this paper analyses the classicalshortest path search algorithms: Dijkstra algorithm, Floyd algorithm, ant colony algorithm andA*algorithm, then based on the road network model proposed, improves the A*algorithm topropose the shortest path search algorithm in dynamic environment. Using the embedded Linuxoperating system platform, based on the analysis of the storage format of MapInfo Interchangedata file and map objects models, the displaying, zooming, dragging and other functions for theembedded electronic map in the graphical user interface development software QT are implemented by using Mitab library to read geometry data and attribute data of vector map.GPRS communication and receiving GPS information are realized by the serial port, and thedisplay results of the real-time latitude and longitude information, which is obtained by parsingthe GPS information, are given. Simulation experiments were done on the path planningmethod proposed in the thesis. The results show that the method is a reasonable and effective.