Zhang Heng, Pan Shuguo, Sheng Chuanzhen, Gan Xingli, Yu Baoguo, Huang Lu, Li Yaning
School of Instrument Science and Engineering, Southeast University, Nanjing 210096, China.
State Key Laboratory of Satellite Navigation System and Equipment Technology, Shijiazhuang 050081, China.
Sensors (Basel). 2020 Apr 15;20(8):2225. doi: 10.3390/s20082225.
High-precision navigation and positioning technology for indoor areas has become one of the research hotspots in the current navigation field. However, due to the complexity of the indoor environment, this technology direction is also one of the research difficulties. At present, our common indoor positioning methods are WIFI, Bluetooth, LED, ultrasound and pseudo satellite. However, due to the problem of inaccurate direct or indirect ranging, the positioning accuracy is usually affected, which makes the final application difficult to achieve. In order to avoid the ranging limitations of the existing methods, a new dual-frequency entanglement constraint (DFEC) ranging method based on homologous base station is proposed in this paper. The relationship between the homologous characteristics of dual-frequency signals and the phase relationship within the cycle is used to estimate the current carrier phase adjustment the true value of the cycle count is used to get rid of the constraints of the ranging conditions and improve the ranging accuracy. In order to verify the feasibility of this method, the wired environment test and the typical characteristic points of wireless environment are tested and analyzed respectively. The analysis results show that in the wired environment, the transmitting base station and the receiving terminal will introduce a ranging error of one wavelength; in the wireless environment, due to the influence of spatial noise and multipath, the error of the estimation of the whole cycles of the ranging value increases significantly. And this phenomenon is most obvious especially in the region where the signal is shaded, but the error estimate that satisfies ± 1 wavelength still accounts for 90%. Based on this, we conduct multiple observation data collection at five typical feature points, and used existing MATLAB positioning algorithms to conduct positioning error tests. The analysis found that under this error condition, the positioning accuracy was about 0.6 m, and 93% of the points met the 1-m positioning accuracy.
室内高精度导航定位技术已成为当前导航领域的研究热点之一。然而，由于室内环境的复杂性，该技术方向也是研究难点之一。目前，常见的室内定位方法有WIFI、蓝牙、LED、超声波和伪卫星。但由于直接或间接测距不准确的问题，通常会影响定位精度，导致最终应用难以实现。为避免现有方法的测距局限性，本文提出了一种基于同源基站的新型双频纠缠约束（DFEC）测距方法。利用双频信号的同源特性与周期内相位关系来估计当前载波相位，通过调整周期计数的真值来摆脱测距条件的约束，提高测距精度。为验证该方法的可行性，分别对有线环境测试和无线环境的典型特征点进行了测试分析。分析结果表明，在有线环境中，发射基站和接收终端会引入一个波长的测距误差；在无线环境中，由于空间噪声和多径的影响，测距值整周期估计误差显著增大。这种现象在信号遮挡区域尤为明显，但满足±1波长的误差估计仍占90%。基于此，在五个典型特征点进行了多次观测数据采集，并利用现有的MATLAB定位算法进行了定位误差测试。分析发现，在此误差条件下，定位精度约为0.6米，93%的点满足1米的定位精度。
