GNSS拒止环境中无人机UHF频段测控链路高精度授时方法研究1讲解.docVIP

GNSS拒止环境中无人机UHF频段测控链路高精度授时方法研究 UAV High precious timing method based on UHF band of TTC data-link in GNSS　denial environment 刘亚擎、窦荣鑫 摘要： 针对无人机进入GNSS (Global Navigation Satellite System)拒止环境中无法获取时间信息的问题，提出利用无人机UHF (ultra-high frequency)频段的测控链路，进行高精度授时的算法。该算法利用DDS (digital direct synthesizer)产生调整精度为2-16ns的时钟信号，供给GNSS接收机和测控链路使用；利用接收信号频差和载波相位信息，将单向测时精度提高到0.05ns；使用双向双频授时算法进行测距授时处理。MATLAB仿真结果表明，无人机UHF频段测控链路双向测时精度达到0.1ns。但由于无人机地面站的GNSS接收机的授时精度为10ns，无人机的授时精度为10ns。该方法无需占用新的频谱，只需在硬件上增加成本低体积小的高精度时钟源，在软件上按需增加测控信息中的授时电文，就能达到和GNSS接收机一致的授时精度，并附带获得精度为0.03米的测距信息，能满足无人机在GNSS拒止环境中编队飞行、协同检测、协同控制等任务的授时要求。 关键词：无人机 测控链路 高精度授时 Abstract: An UAV (Unmanned aerial vehicle ) high precious timing method based on UHF (ultra-high frequency) band of TTC (tracking control) data-link was proposed to provide the time information in the GNSS denial environment. A shared clock source architecture with 2-16ns control accuracy based on DDS (digital direct synthesizer) was proposed for GNSS receiver and TTC data-link. Solo-direction timing measure accuracy was improved to 0.05ns by using the frequency difference and carrier phase. Dual-direction dual-frequency timing algorithm was proposed. That algorithm could achieve 0.1ns timing accuracy. The UAV timing accuracy is 10ns, because of the GCS (Ground Control Station) timing accuracy is 10ns. This method required no more frequency band, only a DDS in hardware, and a timing message in software, then it will get the similar timing ability like GNSS, and ranging ability with 0.03m accuracy. It could satisfy the timing demands of UAV mission, such as formation flight, cooperative detect or cooperative control. KEYWORD： UAV, TTC data-link, high precious timing 引言 无人机有低成本、体积小、无人员值守等优势，适合在执行重复、危险、枯燥任务，在军民领域有广泛的应用。随着，网络技术的发展无人机编队飞行，协同完成任务，将是未来趋势。想要遂行协同控制、组网探测或协同攻击等任务，需要无人机具备统一的时空基准和时空信息。 通常来说，GNSS设备是提供时空信息的主要设备，具有低成本、小体积的优势，但由于卫星信号的脆弱性和公开性，容易受到遮挡、多径、干扰、欺骗，形成GNSS拒止环境，影响时空信息的获取。通常无人机的还带有惯导等设备，可提供空间信息，但没有设备提供时间信息，只能依靠本地时钟，来外推时间信息，由于无人机的体积、功耗、成本的限制，不可能使用原子钟或者高性能的恒温晶振