Vehicle State Estimation System Aided by Inertial Sensors in GPS Navigation

Despite the development of the GPS navigation system, problems still lies in two topics: GPS signal losses and unreliable positioning in the elevation direction. This paper proposes a vehicle state estimation system to produce integrate information including the slope angle, as well as continuous positioning in case GPS losses happen. The system uses low-cost inertial sensors, including an accelerometer and a gyro, rather than the vehicle odometer. Therefore it´s easier to be mounted on a vehicle than the traditional Dead-Reckoning system. The system estimates the slope angle using the vehicle velocity from GPS and the acceleration data from the accelerometer. While GPS is lost, the reckoned positions can be provided using the acceleration and the angle velocity data. Vehicle tests show that the slop angle estimation results can agree with the actual road conditions, and the reckoned positions can guarantee continuous navigation on a flat road in case of GPS losses in a short time.