|
A Real-Time Precise Fuzzy Algorithm for Map Matching via GPS  M.R.Mosavi Assistant Professor, Department of Electrical Engineering Behshahr University of Science and Technology, Behshahr 48518-78413, Iran Email: M_Mosavi@iust.ac.ir Abstract In this paper, a fuzzy map matching method is proposed, which uses a digital road map to correct the GPS position error. The proposed algorithm is easy to calculate. It requires little computation time without need to extra sensors and can find the mobile exact position which moves on the road. The effectiveness of this algorithm is verified by the real road experiments. For the experiments, a car navigation system is implemented with a low cost GPS receiver and a microcontroller chip. The real road experiments demonstrate the effectiveness and applicability of the proposed algorithm for accurate navigation with low cost GPS receivers. The results show that real-time positioning error reduces from 25m to less than 1.5m using proposed fuzzy map matching algorithm. Moreover, the system is cheaper and more efficient than conventional systems. I. Introduction Global Positioning System (GPS) is widely used in the real-time precise positioning. The mobile determined positions using GPS receivers could be displayed in electronic map. However, because of errors exist in GPS and also in digital maps, it is not possible to ensure that mobile positions register properly on a digital map. The result this is that a mobile may be seen to be moving over a building or into the sea. To avoid this problem, map matching method can be used to improve mobile position display precision over an electronic map [1]. A map matching method using a digital road map is a useful approach to correct these errors. In other words, map matching is a scheme for finding the mobile accurate position on the road. As the mobile is running on the road, the positioning error can be reduced by map matching algorithm if we know the road on which the mobile is [2]. There are a lot of map matching methods based on the geometric approaches. These methods find the road which is close to the mobile trajectory. In these algorithms, it is difficult to calculate the nearest road and it requires hard calculations, which leads to a time consuming. Another map matching algorithm is to use conditional probability. This algorithm is more robust than geometric method and it can cover from false positioning quickly. However, it requires more computation time and more memory to store the mobile trajectory [3]. In this paper, a new fuzzy map matching algorithm is proposed for reducing of GPS position error. It is easy to implementation and requires little computation. Also, this method can find the mobile exact position on the road. A car navigation system is developed for the real road experiments. The effectiveness and applicability of the proposed algorithm is verified by the real road experiments. This paper is organized as follow. Section II explains proposed map matching algorithm. The hardware implementation of navigation system is described in section III. Section IV shows some experimental results with real developed car navigation system. Conclusions are explained in section V. Page 1 of 3
| Next | |