An Xinyuan, Zhao Sihao, Cui Xiaowei, Shi Qin, Lu Mingquan
Department of Electronic Engineering, Tsinghua University, Beijing 100084, China.
Luoyang Electronic Equipment Test Centre, Luoyang 471000, China.
Sensors (Basel). 2020 Feb 20;20(4):1155. doi: 10.3390/s20041155.
Radio-based positioning systems are typically utilized to provide high-precision position information for automatic-guided vehicles (AGVs). However, the presence of obstacles in harsh environments, as well as carried cargoes on the AGV, will degrade the localization performance, since they block the propagation of radio signals. In this paper, a distributed multi-antenna positioning system is proposed, where multiple synchronous antennas are equipped on corners of an AGV to improve the availability and accuracy of positioning. An estimator based on the Levenberg-Marquardt algorithm is introduced to solve the nonlinear pseudo-range equations. To obtain the global optimal solutions, we propose a coarse estimator that utilizes the displacement knowledge of the antennas to provide a rough initial guess. Simulation results show a better availability of our system compared with the single antenna positioning system. Decimeter accuracy can be obtained under a Gaussian measurement noise with a standard deviation of 0.2 m. The results also demonstrate that the proposed algorithm can achieve positioning accuracy close to the theoretical Cramer-Rao lower bound. Furthermore, given prior information of the yaw angle, the same level of accuracy can be obtained by the proposed algorithm without the coarse estimation step.
基于无线电的定位系统通常用于为自动导引车（AGV）提供高精度位置信息。然而，在恶劣环境中存在障碍物以及AGV上所载货物，都会降低定位性能，因为它们会阻挡无线电信号的传播。本文提出了一种分布式多天线定位系统，在AGV的角落配备多个同步天线，以提高定位的可用性和准确性。引入了一种基于列文伯格-马夸尔特算法的估计器来求解非线性伪距方程。为了获得全局最优解，我们提出了一种粗估计器，它利用天线的位移知识来提供一个粗略的初始猜测。仿真结果表明，与单天线定位系统相比，我们的系统具有更好的可用性。在标准差为0.2 m的高斯测量噪声下可获得分米级精度。结果还表明，所提出的算法能够实现接近理论克拉美-罗下界的定位精度。此外，在给定偏航角先验信息的情况下，所提出的算法无需粗估计步骤即可获得相同水平的精度。
