Sun Yongrong

Development of an algorithm for car navigation system based on Dempster-Shafer evidence reasoning

GPS (Global Position System) has been widely used in car navigation system. It helps the users to determine the car position and velocity. But the unknown GPS noise characteristic makes the position information with undesirable position errors. The map matching process can improve the position accuracy and availability of the vehicular position system. In this paper, general principle of map matching is investigated according to segmentation and feature extraction, and an algorithm based on D-S (Dempster-Shafer) evidence reasoning for GPS/MM integrated navigation system was proposed. A simulation example demonstrates the effectives of the algorithm for the car location and navigation. The simulation errors of GPS and GPS/MM integrated system were presented.

Fast Algorithm of Selecting Satellites for Multiple Satellite Integrated Navigation System

As complexity is the feature of the structure of constellation and numerous satellites of multiple satellite integrated navigation system, on some special occasions or during some unusual period, selecting and recombining of constellation and satellites should be completed quickly. An innovational strategy was adopted to apply the fast algorithm of selecting satellites into the field of system modeling of multiple satellite integrated navigation system. Our method only concerned the judgment and selection of the elevation angle and azimuth angle of the visible satellites, and in the case of ensuring the positioning accuracy of integrated system. This method avoided the difficulty of object modeling and took full advantage of relationship among satellite constellations. Therefore, the potential was fully explored of multiple satellite integrated navigation system itself. The simulation results show that the anti-jamming performance and self-healing ability of the whole navigation system have been strengthened by fast algorithm of selecting satellites. That is to say, the computational complexity has been decreased to such an effect as to improve the real-time performance of the system by sacrificing very limited positioning precision.