Research On Vehicle Positioning And Its Optimization Technology In Vehicle Networking

With the rapid development of networking of vehicles, vehicle positioning problem gets moreand more attention. GPS (Global Positioning System) and SINS (strapdown inertial navigationsystem) are the two technologies in the field of vehicle location. Although the GPS has arelatively high positioning accuracy, it can not get the positioning where satellites are blocked,which requires auxiliary of the other positioning means, to achieve AGPS (Assited GlobalPositioning System) positioning. SINS can get the vehicle driving parameters by IMU (InertialMeasurement Unit) in the case of no GPS signal and then make use of kinematics law to realizeself-positioning. But due to error having a time cumulative, and the external device in theinstallation process, there is mounting error, and thus can not achieve a higher accuracy location.To solve this problem, this thesis proposes a method based on the self-positioning of the carinertial devices named VSSA, meaning vehicle speed&steering angle, measuring speed by thevehicle speed sensor and angle by steering wheel angle sensor. Then takes use of kinematics lawto give distance incremental projection algorithm, simulation analysis proved the projectedtrajectory of this method is consistent with the actual running track.On this basis, this papercarried out studies on combination positioning method, makes the gyro of SINS system and theVSSA system compose dead reckoning (DR) system, and then use the position and attitudediscrepancy between DR system and the SINS system to compensate for the SINS system errorthrough Sage-husa adaptive filtering, resulting in a relatively high accuracy of the the SINSsystem output, realizing vehicle autonomous positioning. Simulation results show that both thepositioning accuracy and the heading accuracy of this method are higher. Finally, this thesiscompose GPS with SINS/VSSA system combination by fusion filtering, under different GPSsignal conditions, according to the distribution coefficient select different positioning methods, toachieve the complete positioning of the vehicle driving process.