Research On UWB Based Positioning Technology Under Special Environmental Conditions

With the rapid development and progress of our society,the demand for positioning systems has gradually increased.At present,special environments such as mine passages and underground passages are affected by external factors,and there is a problem that accurate positions cannot be obtained through traditional positioning methods.Research on UWB positioning technology based on special environmental conditions can effectively solve current problems and improve special Environmental safety is of great significance to reduce the death rate of accident personnel under special circumstances.For UWB positioning in a special environment,positioning accuracy is an important criterion.The corner points of the base station are an important factor that affects the positioning accuracy.In special environments,there is also the problem of occlusion leading to positioning errors that affect the positioning accuracy.The main contents of this paper are as follows:(1)Aiming at the problem of deploying UWB base stations in special spaces,the impact of base station deployment on positioning accuracy is analyzed,and the positioning accuracy is evaluated based on the PDOP average of uniform sampling points in the positioning space.Genetic algorithm is used to establish an adaptation function based on the PODP value to find the location of the base station in the space.Approximately optimal solution.The calculated average value of PDOP in the base station layout method space reached 1.83.Comparing the method proposed in this paper with the commonly used highlevel random layout method,the error of the method in this paper is less than that of the high-level random layout method at 4 fixed points,and the overall error is reduced by 51%.(2)In view of the large positioning error in the non-line-of-sight environment,it is proposed to add an error standard deviation threshold in the Kalman filtering process to judge the line-of-sight situation,and use the unbiased Kalman filter to perform noise under the line-of-sight(LOS)condition Elimination;Under non-line-of-sight conditions,use biased Kalman filter to eliminate NLOS errors.Using the method in this paper to compare with Kalman filter and particle filter,the mean square error of the method in this paper is9.34,which has lower error and higher accuracy than other comparison algorithms.(3)Based on the above research,the positioning test system was built to design and test the UWB positioning system in a special environment,and a HDS-TWR positioning method was proposed,which effectively improved the positioning time resolution,performed the system accuracy positioning test,and tested the positioning The static average error of the system is 10.66 cm,and the dynamic positioning error is 41.86 cm.This paper studies the deployment of UWB base stations,improves the Kalman filter to deal with non-line-of-sight errors,and tests the accuracy of the positioning system.This study is suitable for real-time accurate positioning of multiple tags in different special environments and has certain engineering applications.