A loosely-coupled EMD-denoised stereo VO/INS/GPS integration system in GNSS-denied environments

Abstract

Although the Inertial Navigation System (INS) and Global Positioning System (GPS) integration framework has many advantages compared to the standalone INS and GPS systems, it suffers from limited access to GPS signals in GPS-denied environments. In this study, we propose a loosely-coupled Empirical Mode Decomposition (EMD)-denoised stereo Visual Odometry (VO)/INS/GPS integration system to address the problem of blocking GPS signals in the INS/GPS navigation system in GPS challenging environments. Furthermore, we provide the new versions of the EMD called Clear Iterative EMD Interval-Thresholding (EMD-CIIT) and EMD Hurst exponents before data fusion to enhance the signal-to-noise ratio of the inertial sensor measurements. To evaluate the effectiveness of the proposed method, we utilize the Kitti dataset. The results represent that the suggested framework has a superior performance in terms of accuracy and stability compared with other traditional methods; so that the achieved experimental accuracies verify that our presented idea outperforms INS/GPS by approximately 58%.