Abstract
Car navigation systems display the car's position on a link, which is a line representing a road in map datum, when the car is running on a road and display its estimated position when it is running in a parking area. Therefore, it is necessary for map matching to decide whether a car is running on a road. The errors of the car's estimated position and the link position cause the incorrect decision when the car is running in a parking area parallel to the road. In this paper, a road departure decision method using statistic hypothesis tests and state diagrams is proposed. The statistic hypothesis tests make decisions considering the previous errors, and the state diagrams change decision conditions in each state. This method can therefore decrease the number of incorrect decisions that are made. The performance of this method was experimentally evaluated using observation data collected with a car, and the situation that this method could correctly decide on road departure was shown.
