The Design And Implementation Of Map-matching Algorithm Based On GPS And DR Integrated Navigation

With the development of our society and the advancement of technology, theautomobile has become a commonly used transport in our daily travel. With theincrease in the number of cars, roads become more and more complex and roadinformation is changing everyday. It leads to car navigation systems coming intobeing. The single traditional navigation can not meet the requirements of real-time,accuracy and stability of vehicle navigation system. GPS and DR integratednavigation can compensate for each other’s shortcomings. It can still providenavigation in the case of any a navigation system invalid. The stability of the systemcan be enhanced, and the positioning accuracy can be improved in both systems workproperly. According to the reasons mentioned above, it becomes the new trends in carnavigation systems.Rough matching algorithm, precise matching algorithm and tracking-matchingalgorithm were designed for map-matching based on integrated navigation, and thefeasibility of the algorithm was demonstrated. Direct projection method is one of thecommonly used methods in selecting the currently traveling road. It is simple, but thestability is poor, and the matching efficiency is low, so it can not meet therequirements of the high stability and the correct rate of map matching. A newalgorithm was designed based on direct projection method. It combines correlationalgorithm with probability statistics method. History matching parameter isintroduced in matching process, and multi-point sampling is used to eliminateaccidental error. When the actual traveling road is selected, precise matchingalgorithm is used to project the point measured by GPS onto the road, optimal linearcombination method is used to combine GPS point with DR point to improve thepositioning accuracy of the vehicle. When the vehicle changes the traveling road,tracking-matching algorithm can selecte the right road quickly and accurately, andrectify the exact position of the vehicle in time to track the precise position accordingto the change of direction.The simulation of the three processes of map matching algorithm is completed.The parameters of the algorithm are set up according to the real driving environmentand the precision of GPS receiver and DR receiver. Matlab simulation andmathematical statistics are completed. The algorithm has good stability and compatibility with both timeliness and accuracy in selecting roads; precise positioncan be found on the traveling road to meet daily driving needs; the position of thevehicle can be rectified when the driving direction is changing. Finally, combiningwith the actual road information, the rationality of the algorithm is verified.