Research And Implementation Of Tightly-coupled Compass/SINS Integration Navigation System Based On Vehicle Platform

Accuracy, timeliness and stability of positioning and navigation are always the key indicators to evaluate the navigation system. It attracted widespread attention from many researchers in the issue:how to maintain long-term accuracy, timeliness, stability of navigation system in complex circumstances. The thesis based on practice, carried out series of experiments and researched on Compass/SINS loosely-coupled, listed many inadequacies in practical projects, and further integrated software and hardware platforms of tightly-coupled integration of Compass and SINS, simultaneously adopted several improvements on loosely-coupled integration.Firstly, research revealed that the integration system will be observed rapid growing error caused by individual system’s low-precision. In regard to the issue, NW-EKF method was studied and experimented. In this method, GDOP and gyro drift rate, which are the two important parameters of positioning accuracy in Compass and SINS, are normalized into the same dimension and converted into weight factor which acts as the basis of discriminant by EKF. The experiments show that the positioning accuracy of Compass/SINS tightly-coupled integration system is effectively improved and the curve of position is smoother after using NW-EKF method.Subsequent, aiming at issue that the traditional methods such as optimal GDOP selection and maximum tetrahedron selection is poor in real-time to select satellites, fast suboptimal selection based on EICH method is adopted. In the static condition, EICH method can reduce time consuming of first time satellite selection, and additionally reduce total time of system initialization. In the dynamic condition, SINS is applied to calculate and temporarily replace the optimum satellite which is losing lock, and then supports the EICH method. The experiments show that using EICH method and SINS supporting will improve the real-time and stability of Compass/SINS tightly-coupled integration system effectivelyFinally, the hardware and software system of Compass/SINS tightly-coupled integration system is designed in this dissertation, In order to adapt to different environments and extend the applications of Compass/SINS tightly-coupled integration system, three kinds of carriers that hold the hardware platform are designed, which is pushcart, electric motorcar and motor vehicle. In terms of software system, mobile computers, which act as software receiver, take the place of hardware receiver to solver navigation results. In addition, the NW-EKF method and the EICH method were added into algorithm. Large scale navigation experiments indicate that the Compass/SINS tightly-coupled integration system based on NW-EKF and EICH method which is proposed in this dissertation can export real-time and accurate navigation information in a long range.