Research On High Precision 3D Indoor Positioning System Based On UWB

With the development and progress of wireless sensor networks(WSN)and mobile communication technologies,the increasing demand for accurate location information has led to the development and application of many location-based services.For example,the Global Positioning System(GPS)with high accuracy in outdoor environments has been widely used in logistics monitoring,shared cycling,and localized weather information services.However,GPS satellite signals cannot penetrate most of the walls and other obstacles to spread to the complex indoor environment,which means it cannot provide location services indoors.Therefore,there is an urgent need for a localization system based on different technologies to provide accurate location information for indoor applications.In this context,this thesis studies,designs and tests the indoor real-time location system(RTLS)based on UWB(Ultra-wideband)communication technology.First of all,this thesis introduces the key factors in the design of indoor positioning system,and deeply discusses the indoor positioning method and related technologies.The basic theory and technical characteristics of UWB indoor positioning are mainly studied.Theoretical analysis shows that the UWB signal has a very large bandwidth and it can emit a large amount of energy in a very short time,thus has an excellent ability to penetrate obstacles.In addition,the strong anti-interference and strong multipath resolution of the UWB signal enable the system to calculate the signal arrival time more accurately.Therefore,the UWB-based indoor positioning system can theoretically achieve high precision and good complex environment adaptability.Then,the thesis gives the designing scheme of the hardware platform of UWB indoor positioning system and the development process of the software system.The hardware part introduces the design of anchor and tag integration hardware based on ARM MCU as the control core and the DW1000 as the wireless transceiver chip.The optimization of the antenna and the design of the LNA module in the specific frequency band of the UWB transceiver channel are described in detail.The software part introduces the architecture,workflow and the principle and error analysis of asymmetric DS-TWR ranging algorithm based on signal time-of-flight.Furthermore,it expounds the development process of PC software and the configuration and application interface of related parameters.Finally,this thesis builds a test platform of indoor positioning system under suitable environment,carrying out experimental analysis and testing on the designed real-time positioning system.The results show that in the case of line-of-sight propagation,the error of indoor two-dimensional positioning is less than 10 cm and the average error of moving positioning is less than 30cm;The average error of three-dimensional static positioning is less than 25 cm.The experimental results show that the indoor positioning system designed in this thesis achieves high-precision three-dimensional positioning and has high reliability.