Indoor And Outdoor Seamless Positioning Based On The Integration Of GNSS/INS/UWB

In recent years,with the rapid development of modern urban infrastructure,the demand for accurate and continuous navigation performance for Location-Based Services in large indoor facilities has increased.Therefore,public safety,intelligent city,and other fields have facilitated the research of location services such as indoor high-precision positioning as well as indoor and outdoor seamless positioning.In outdoor environment,GNSS has become the mainstream positioning technology to serve people's life.However,the radio positioning principle of GNSS determines that its signals are easily disturbed.In the urban environment,the buildings and trees could cause the reflection and attenuation of radio signals,which will lead to the error of measurements,thus continuous and reliable positioning can't be guaranteed.The integrated positioning of GNSS/INS has been widely applied,nevertheless,in the environment where GNSS signals are severely degraded,the GNSS/INS integrated navigation system is difficult to maintain the availability of the positioning system due to the accumulated errors of INS after a long time of the blocked signal.As for the requirements of indoor and outdoor seamless positioning in the fields of the intelligent city and public security in modern society,and to solve the problem of the limited application of GNSS in an indoor environment,this thesis takes multi-sensor data fusion into consideration and elaborates an indoor and outdoor seamless positioning method based on GNSS,INS and UWB.The structure of scene-oriented indoor and outdoor seamless positioning method based on the integration of different sensors was established,and the model construction methods of different positioning structures were studied.Then the actual indoor and outdoor seamless positioning experiment was carried out.The main work of this thesis is as follows:(1)The high-precision indoor positioning method based on UWB/INS is proposed.The trilateral positioning equation was established by using the TOA range values of UWB.The mathematical models of UWB/INS loosely-coupled integration positioning and UWB/INS tightly-coupled integration positioning based on Extended Kalman Filter were established respectively,thus the high precision indoor positioning was realized.(2)The indoor and outdoor seamless positioning method based on GNSS/INS/UWB is proposed.In the outdoor environment,the mathematical model of GNSS/INS tightly-coupled integration positioning system via pseudorange and pseudorange rate measurement has been established,and the study of positioning and velocity detection in the outdoor open environment has been achieved.To tackle the problem of positioning availability reduction on account of degraded signal quality in the indoor-outdoor transition environment,a tightly-coupled integration positioning method based on GNSS/INS/UWB has been proposed.The measurement models of GNSS pseudorange,pseudorange rate and UWB TOA measurement were established under the Centralized Kalman Filtering structure.The performance improvements of GNSS/INS integrated navigation has been achieved through the redundant observation of UWB.Finally,based on the research of indoor and outdoor positioning,a seamless indoor and outdoor positioning system based on GNSS pseudorange and pseudorange rate has been established.(3)To keep high positioning accuracy,the mathematical model of GNSS single-differenced carrier phase with higher accuracy and the GNSS/INS integrated positioning method based on GNSS single-differenced carrier phase and the single-differenced pseudorange rate are studied.The GNSS/INS/UWB integrated positioning method based on the Federal Kalman Filter structure was proposed,and the GNSS/INS integrated positioning subsystem based on the single-differenced carrier phase and single-differenced pseudorange rate of GNSS,and the UWB/INS integrated positioning subsystem based on the UWB TOA measurement were constructed respectively.At the same time,the comparison between the algorithm of Centralized Kalman Filter structure and the Federal Kalman filter structure is carried out and the robustness performance of the Federal Kalman filter structure is verified.Finally,the validity of the indoor and outdoor seamless positioning method is always corroborated via experiments.The experiments show that the algorithm can effectively provide high-precision indoor and outdoor seamless positioning results.The experiment analysis result of the indoor and outdoor seamless positioning method in aspect(2)shows that the system can realize positioning accuracy of decimeter level.The experiment analysis result of the Federated optimized indoor and outdoor seamless positioning method based on the GNSS single-differenced carrier phase,UWB and INS in aspect(3)shows that the system can realize centimeter positioning accuracy.The DRMS of the test points is 0.0525 m.In the outdoor-indoor transition environment,the DRMS of the 5 static test points is 0.0544 m,which increased by 0.0659 m compared to the 0.1203 m of the tightly-coupled GNSS/INS/UWB positioning method with GNSS pseudorange measurements.