Research On Ubiquitous Positioning Based On GNSS And UWB Combination

Ubiquitous positioning refers to a seamless coverage positioning that associates with various positioning methods in order to meet various positioning demand in all the people's activities space. It achieves a smooth handover in location algorithm and accuracy. At present, any positioning system can not finish ubiquitous positioning task independently. For example, GPS can not play its high precision advantages in tall buildings, and can not achieve positioning in indoor shelter extremely serious observation environment. We put forward that GPS mixes together with other satellite systems (BDS, GLONASS), in order to solve the positioning problem of city tall buildings circumstances.Ubiquitous convergence can be achieved from outdoor to indoor, if we combined GNSS and indoor positioning technology (WLAN, UWB).The paper discusses along with two main lines that GNSS multi-satellite systems integrated position and GNSS/UWB position, the main work is as follows:The paper discusses the mathematical model of UWB positioning, develops further based on UWB ranging procedure, realizes the real-time dynamic location function indoor, verify the UWB positioning mathematical model, evaluates the accuracy level of dynamic positioning.It gives the GNSS errors correction model, calculation method of clock error and satellite position, and explains the difference between BDS and GPS and realizes the theory by program.lt deduces the formation process of double differential equation and its variance matrix, and gets floating point using Kalman filtering method and integer ambiguity fixed solution using LAMBDA method. The paper compares the positioning accuracy, stability and reliability between single satellite system and combined GNSS satellite system and draws the conclusion that combination system is better than single system in harsh environment.It discusses the combination positioning mode of GNSS and UWB, and gives antenna phase center of domestication and unified method of GNSS/UWB combination system and time synchronization method. The paper puts forward a method to harmonize the weight ratio between GNSS and UWB by using Helmert variance estimation way and tests the correctness with an example.Finally, the paper verifies the GNSS multi-satellite systems combined positioning principle and GNSS/UWB combination principle with tight coupling static and dynamic experiment, realizes the mutual fusion of GNSS relative positioning and UWB indoor positioning, completes the ubiquitous positioning from outdoor to indoor.