An Automatic Calibration System of Vehicle Motion Error under GPS Blind Area

Visual odometer or wheel speed sensor (WPS) is often used for vehicle positioning when GPS signals are obstructed for a long time in urban complex environments. Because they have always accumulated error, an automatic calibration system of vehicle motion error under GPS blind area is proposed. Firstly, when a vehicle moves to the detected area, the self-organizing network based on Zigbee sends signals to trigger the camera of road side unit (RSU), starting to collect images and preprocess. And then the signals of four different RFID tags read by vehicle mounted RFID reader are used to implement vehicle positioning. Meanwhile, vehicle position is also detected and calculated by image processing based on background difference method. Finally, two kinds of positioning information are fused according to time synchronization, which result is applied to amend accumulated positioning error produced by odometer method, to realize vehicle location automatic calibration. Experimental data shows that this method has accurate positioning information, and can effectively eliminate the vehicle accumulated error. The system has simple devices, is easy to mount and use, and can be suitable for the vehicle-road environment.