Adaptive Extended Kalman Filter in SINS/GPS Tightly Coupled Navigation System

Abstract

Abstract. In the practical application, the SINS/GPS tightly integrated navigation system is faced with the situation that state error model is inaccurate or noise statistical characteristics are inconsistent with the reality. However, traditional Extended Kalman Filter (EKF) method can not effectively solve it, causing large filter errors in this system. This paper presents a method of GDOP estimation and adaptive Extended Kalman Filter, which combines satellite positions of ephemeris with the output of corrected SINS position instead of GPS positioning results to calculate GDOP; On this basis, using the GDOP value and innovation realizes the online real-time estimation of measurement noise variance matrix R k while taking advantage of innovation realizes the online estimation of state noise variance matrix Q k to achieve the adaptive effect and improve navigation accuracy in tightly integrated navigation system.