Integration Of Ground-Based Pseudolites And Ultra-Wideband Systems

In modern society,with the rise of Internet of things,mobile Internet and other industries,high-precision and efficient location-based services have become an urgent need for the transformation and upgrading of Chinese tertiary industry.The independently netted ground-based pseudo-satellite system is a ground-based radio navigation and positioning system that can provide users with all-weather threedimensional coordinates and speed in a certain area,but when it is positioned in a complex environment,it will be inevitable that the positioning accuracy of the system can not meet our needs due to accidental errors caused by clock error or multipath effect and other factors.Ultra-wideband positioning system is also a high-precision positioning system with independent positioning ability,which can effectively restrain the error caused by multipath effect by using ultra-wideband pulses,but its positioning distance is close,and the stability of the system is poor.It is easily affected by the environment.The joint positioning of ground-based pseudo-satellite system and ultrawideband system can not only improve the positioning accuracy of the system,but also increase the adaptability of the system to the complex environment,so as to improve the stability of the positioning system.In this paper,the system fusion is studied,and the main contents of this paper are as follows.(1)The UWB positioning system is researched,including the ranging principle and positioning algorithm of the UWB system.A CHAN-TAYLOR cascade positioning algorithm is designed,and the superiority of the algorithm is verified by simulation experiments with matlab.(2)Researched the system structure,time-hopping signal system,and positioning principle of the pseudolite system,and analyzed the error sources of the pseudolite system,and performed static and dynamic positioning tests on the pseudolite system at Xiamen Hairun Terminal.Through this test,the advantages of the high precision and high time update rate of the pseudolite system were obtained.At the same time,the shortcomings of the system,such as being easily affected by the environment and poor stability,were also found.(3)A positioning algorithm based on the federated Kalman filter for the combined pseudolite / UWB system is proposed.The Kalman filter models for the pseudolite system and the UWB system are established respectively.The system fusion factors are analyzed,and the federation of the combined system is finally determined.Kalman filter model.The final simulation results show that the combined positioning system has higher positioning accuracy and more stable positioning effect.(4)pseudo-satellite / UWB combined positioning algorithm based on improved particle filtering is proposed.Aiming at the phenomenon of particle degradation commonly found in particle filtering,this paper proposes a particle filtering algorithm based on the importance sampling of federal Kalman filter,completes the construction of the system model,and proposes the state confidence obtained by using federal Kalman filter and The covariance matrix constructs the importance sampling function of particle filtering to solve the problem of particle degradation.Finally,experiments show that the algorithm effectively realizes the combined positioning of pseudolite and UWB system,and improves the positioning accuracy of the system.