Research On Duty Gun Positioning System Based On UWB

Guns as an important part of weapons and equipment.Once accidentally lost,they will pose a great threat to social security issues.In order to prevent a series of situations such as the snatching of guns,the attack of sentries,and the escape of guns,effective management and precise positioning of guns become inevitable.Based on this situation,a set of UWB duty gun positioning system was designed.According to the characteristics of UWB positioning technology,the system usually adopts the positioning method of ranging.The principles and mathematical models of several commonly used ranging methods are analyzed.The TOA method is used as the ranging method of the system.Environmental factors require that the SDS-TWR algorithm be used to achieve the distance measurement.Through the verification,the system can obtain a high-precision Time of Flight to calculate the distance without using a high-precision crystal oscillator,so that the algorithm has high ranging accuracy.Due to the influence of NLOS interference in the actual environment,based on the SDS-TWR algorithm to obtain the ranging value,an improved positioning algorithm is proposed to analyze and optimize the ranging value.Contrast and analyze several conventional positioning algorithms,combining biased Kalman filtering and extended Kalman filtering as the system positioning algorithm to parse data,and obtain actual position information.Considering that there are restrictions on the placement of base stations in harsh environmental conditions,a correctable triangle positioning algorithm is proposed,which can also achieve high-precision positioning requirements in the case of insufficient base stations and reduce power costs.The above algorithms are combined to form a composite positioning algorithm.Through simulation verification,the algorithm has a good positioning effect in the interference of NLOS,which further improves the system’s accuracy.The whole system consists of tag cards,base stations,switches,and the host computer.The implementation of the solution is divided into hardware and software.The tag card and base station are designed on the hardware.The tag card is placed inside the gun accessory compartment,it consists of the STM32F103 main control module,DWM1000 radio frequency module,power module,LED and reset module.The base station is fixed above the booth,and a wired Ethernet module and a Wi Fi data transmission module are added to the hardware of the tag card.The software is designed for the system’s ranging communication,low power consumption,and host computer.The distance value is calculated by using the SDS-TWR algorithm on the base station and tag card,and the calculated distance information is sent to the switch for aggregation and uploaded to the host computer.The host computer uses the proposed compound positioning algorithm to analyze the distance value.First,the partial Kalman filter is used to filter the distance value.After obtaining a stable distance value,the correctable triangle positioning algorithm is uesd to solve the tag card,and estimate the coordinate position.Finally track and through the extended Kalman filter,and display it on the host computer interface in real time.The deployment experiment environment was set up,and distance tests,static node positioning tests,and moving node tracking tests were performed to verify the positioning performance of the entire positioning system.The test results show that the ranging error obtained by the improved positioning algorithm of this system is maintained at about 19 cm,while the error of the traditional positioning system is 30 cm.Compared with this,the positioning accuracy is improved by 11 cm,and the positioning effect is more stable.