An Indoor Positioning Algorithm Against NLOS Error Based on UWB

Ultra-wideband (UWB) positioning technology has absolute advantages due to its centimeter-level accurate positioning accuracy. However, the positioning accuracy is greatly reduced because of the inability to completely solve the error caused by non-line-of-sight (NLOS) and multi-path interference. At present, the Chan-Taylor (C-T) combination algorithm proposed by scholars can achieve a good positioning effect in the line-of-sight (LOS) environment, but in the NLOS environment, positioning deviation of this algorithm is large
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. Aiming at the problem of low localization accuracy in NLOS environment, this paper presents a Chan-Taylor-Kalman (CTK) joint positioning algorithm based on UWB and adapted to NLOS environment. The basic idea of CTK joint positioning algorithm is to introduce weight coefficients on the basis of C-T combination algorithm to reduce the situation of non-convergence of positioning results; then combined with the improved Kalman filter to eliminate outliers and eliminate the influence of the non-line-of-sight error._Experiments show that under the same NLOS environment, the probability of the positioning error of the C-T combination positioning algorithm greater than 20cm is about 60%, while the probability of the positioning error of the CTK joint positioning algorithm greater than 10cm is only about 10%.