DEAD-RECKONING NAVIGATION AND POSITIONING METHOD AND SYSTEM FOR OBTAINING LONGITUDE AND LATITUDE OF VEHICLE BY SPEEDOMETER

摘要

A dead-reckoning navigation and positioning method for obtaining the longitude and latitude of a vehicle by a speedometer. The method comprises the steps of: (1) differencing a travelling distance acquired by a speedometer, so as to obtain a travelling speed and a heading angle of a vehicle; (2) reckoning the longitude and latitude of the vehicle according to the travelling speed and the heading angle; and (3) outputting the travelling speed, the heading angle and the longitude and latitude. In this method, the longitude and latitude of a vehicle are obtained only by taking a vehicle-mounted speedometer as a data source, and furthermore, the travelling speed and the heading angle at the current moment serve as the output of a dead-reckoning system rather than only serving as a coordinate of a plane-rectangular coordinate system, thereby realizing the dead-reckoning navigation and positioning system which directly provides the longitude and latitude of the vehicle; and there is no need to use inertial devices such as a gyroscope and an accelerometer, so that the cost of the realized dead-reckoning navigation and positioning system which directly provides the longitude and latitude of the vehicle is relatively low. Also provided is a dead-reckoning navigation and positioning system.