基于外推和级联积分梳状滤波器的多普勒插值方法  

Doppler interpolation method based on extrapolation and CIC filter

作　　者：罗勇[1] 吴文启[1] 何晓峰[1] 郭瑶[1] 

机构地区：[1]国防科技大学机电工程与自动化学院,长沙410073

出　　处：《中国惯性技术学报》2011年第1期64-68,共5页Journal of Chinese Inertial Technology

基　　金：国家高技术研究发展计划(863计划)(2006AA12Z319)

摘　　要：INS/GPS深组合导航系统的本地码和载波数控振荡器(NCO)控制量的计算需要利用滤波修正后的惯导位置信息或速度信息,其中的多普勒频移计算需要同时利用位置和速度信息。基带I、Q信息的更新率通常为1 kHz,利用惯导信息解算出的多普勒频移为100 Hz,利用级联积分梳状(CIC)滤波器进行插值有效解决了二者更新率的匹配问题。此外,导航滤波器的更新频率通常为1 Hz,惯导解算频率为100 Hz,对于低精度惯导系统,在滤波修正周期之间误差累积较快,利用外推方法有效控制了惯导解算误差。通过半实物仿真分析,基于外推和CIC滤波器的在线插值结果与基于B-样条插值结果对比,误差标准差约为1 Hz,误差的频谱被限定在0.02 Hz以内,结果表明了该方法的有效性。The computation of local code and control value of carrier Numerical Control Oscillator（NCO） needs the modified position or velocity information of inertial navigation system（INS） in INS/GPS deep integration navigation system,in which the Doppler computation needs both the position and velocity information.Usually,the update rate of base band I/Q information is 1000 Hz,while the Doppler frequency shift computed by modified INS information is 100 Hz.The interpolation by cascaded-integration-comb（CIC） filter can effectively solve the match of the update rate and the frequency shift.Besides that,the error of INS information would cumulate between the modified periods,especially for low accuracy INS system,so the extrapolated state information of the filter is used to modify the INS information.By Hardware-in-the-loop simulation,the results of on-line Doppler interpolation are compared with extrapolation,and CIC filter is compared with that of B-Spline interpolation.The results show that the error is less than 1 Hz,and the spectrum of the error lied in 0~0.02 Hz,which show the validation of the proposed method.

关 键 词：载波数控振荡器 控制量 外推 级联积分梳状滤波器 B-样条插值 

分 类 号：U666.1[交通运输工程—船舶及航道工程]