Adaptive error damping in the vertical channel of the Ins/Gps/Baro-altimeter integrated navigation system

Abstract

In the inertial navigation system (INS), the altitude error diverges exponentially, especially in low-cost sensors. To suppress divergence of the altitude error, a Global Positioning System (GPS) receiver and a barometric altimeter (baro-altimeter) are utilized. This paper describes the error dumping of the vertical channel in the integrated navigation system INS/GPS and the baro-altimeter by using the 3rd order vertical channel damping loop and the application of the adaptive error damp coefficients. The integration is done with an extended Kalman filter (EKF) with control signals. The characteristics of the proposed model for the integration of the INS, the GPS and the baro-altimeter were analyzed by a computer simulation as well as experimentally, using a vehicle. The results of the analysis show that the navigation solutions of the INS/GPS/Baro­altimeter navigation system could improve the accuracy with the adaptive error control coefficients in the EKF control signal.

Keywords

• inertial navigation
• navigation system
• global positioning system
• barometric altimeter
• kalman filters
• error correction
• algorithms