惯导系统中惯性元件误差是影响惯性导航及其组合导航精度的重要因素。在GPS/INS组合导航自适应滤波的基础之上,提出利用小波进行阈值消噪以提高组合导航精度。首先对惯性元件输出信号进行频谱分析,确定相应的多分辨分析尺度以及不同尺度下对高频系数采取的相应措施。对噪声占主要成分的尺度将其高频系数全部置零,对噪声和有用信号共同占有的尺度将其高频系数作阈值处理。利用实测数据进行验证,结果表明这种方法能够有效地削弱惯性元件误差的影响,提高GPS/INS组合导航系统的精度和可靠性。
The errors of inertia elements are remarkable factors in influencing INS or GPS/INS. A new algorithm based on wavelet threshold de-noising for GPS/INS is presented to improve the precision of integrated navigation. First, frequency-spectral analysis for output signals of inertia elements is given to decide the scale of wavelet multiresolution analysis and the measures for their high frequency coefficients. The high frequency coefficients of the scale which mostly contains noise will be set zero and those of the scale which contains noise and useful signals will be dealt with by using the threshold value. By the calculation, it is shown that the new algorithm can effectively resist the influence of the errors of inertia elements and improve the precision of navigation.