Zhang Tisheng, Niu Xiaoji, Ban Yalong, Zhang Hongping, Shi Chuang, Liu Jingnan
GNSS Research Center, Wuhan University, No 129 Luoyu Road, Wuhan 430079, China.
Sensors (Basel). 2015 Jan 5;15(1):733-59. doi: 10.3390/s150100733.
A GNSS/INS deeply-coupled system can improve the satellite signals tracking performance by INS aiding tracking loops under dynamics. However, there was no literature available on the complete modeling of the INS branch in the INS-aided tracking loop, which caused the lack of a theoretical tool to guide the selections of inertial sensors, parameter optimization and quantitative analysis of INS-aided PLLs. This paper makes an effort on the INS branch in modeling and parameter optimization of phase-locked loops (PLLs) based on the scalar-based GNSS/INS deeply-coupled system. It establishes the transfer function between all known error sources and the PLL tracking error, which can be used to quantitatively evaluate the candidate inertial measurement unit (IMU) affecting the carrier phase tracking error. Based on that, a steady-state error model is proposed to design INS-aided PLLs and to analyze their tracking performance. Based on the modeling and error analysis, an integrated deeply-coupled hardware prototype is developed, with the optimization of the aiding information. Finally, the performance of the INS-aided PLLs designed based on the proposed steady-state error model is evaluated through the simulation and road tests of the hardware prototype.
全球导航卫星系统/惯性导航系统（GNSS/INS）深度耦合系统可以通过在动态环境下利用惯性导航系统（INS）辅助跟踪环路来提高卫星信号跟踪性能。然而，关于INS辅助跟踪环路中INS支路的完整建模尚无文献报道，这导致缺乏一种理论工具来指导惯性传感器的选择、参数优化以及对INS辅助锁相环（PLL）进行定量分析。本文基于标量型GNSS/INS深度耦合系统，对锁相环（PLL）的INS支路进行建模和参数优化。它建立了所有已知误差源与PLL跟踪误差之间的传递函数，可用于定量评估影响载波相位跟踪误差的候选惯性测量单元（IMU）。在此基础上，提出了一种稳态误差模型，用于设计INS辅助PLL并分析其跟踪性能。基于建模和误差分析，开发了一个集成深度耦合硬件原型，并对辅助信息进行了优化。最后，通过硬件原型的仿真和道路测试，评估了基于所提出的稳态误差模型设计的INS辅助PLL的性能。
