Research On Indoor And Outdoor Location Technology Based On Communication And Navigation Fusion

With the increasing demand for location services,indoor or outdoor positioning systems alone can no longer meet the demand for location services,making indooroutdoor fusion positioning a hot research topic in the field of navigation and positioning today.China’s Beidou-3 system(BDS-3)has completed its full networking in June 2020 and can provide positioning services worldwide.Outdoor positioning accuracy based on the Beidou system can reach centimetre level.The emergence of Ultra Wide Band(UWB)positioning technology has compensated for the weakness of indoor positioning signals,which are susceptible to interference.Therefore,this paper will focus on the integration of Beidou and UWB systems for positioning.Based on the research on indoor,outdoor and fusion positioning systems conducted by domestic and foreign researchers,this paper investigates the basic principles of indoor and outdoor positioning and analyses the main sources of errors in indoor and outdoor positioning,and then proposes a modified Chan Kalman Gauss-Newton iterative(CKG)joint positioning method based on UWB systems for indoor positioning systems with low and unstable positioning accuracy in the None Line of Sight(NLOS)propagation environment.The main idea of the method is to filter and optimise the initial value of the Chan solution and then perform a Gaussian Newton iteration to achieve suppression.Simulations have demonstrated that the method can achieve high accuracy positioning in a non-line-of-sight propagation environment,and that the stability of the positioning system is improved.At the same time,to address the problem that the accuracy of the pseudo-range single-point positioning method decreases due to the influence of unhealthy positioning satellites in the Bei Dou positioning system,a weighted least squares algorithm based on the combination of weights is proposed,which assigns weights to positioning satellites from the perspectives of pseudo-range residuals and satellite elevation angles,so that positioning satellites carrying small errors can obtain larger weights.The algorithm is proved to be effective in improving the accuracy of pseudorange single-point positioning through simulation.Finally,based on the research of indoor and outdoor positioning algorithms.The indoor and outdoor positioning model of through-conductor fusion is proposed,which fuses the Bei Dou outdoor positioning system with the UWB indoor system and realises seamless indoor and outdoor positioning systems switching with each other according to the indoor and outdoor signal characteristics,and describes in detail how the positioning model switches and locates indoors,outdoors and in the switching area through a typical case study.