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摘要:
激光陀螺的高频机抖使得激光陀螺惯性测量单元(IMU)的测量数据包含较大的随机噪声。传统标定方法通过延长测量时间消除对随机噪声的影响,降低了标定效率。提出了应用自适应前向线性预测(FLP)滤波对激光陀螺IMU的标定数据进行降噪,在较小标定数据量情况下提高系统的标定精度。首先通过四方位正反速率标定试验获得原始标定数据;然后通过自适应FLP滤波器对标定数据进行噪声抑制;最后利用降噪后的数据计算标定参数。试验结果表明,该方法能够有效抑制标定数据中的随机噪声,提高信号的信噪比(SNR),从而在标定数据量较小的情况下得到较高精度的标定参数,提升系统的导航精度。
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关键词:
- 激光陀螺惯性测量单元(IMU) /
- 随机噪声 /
- 噪声抑制 /
- 自适应前向线性预测(FLP)滤波 /
- 标定
Abstract:Ring laser gyro inertial measurement unit (IMU) encounters the problem of relatively large stochastic noise because of the strenuous dithering motion. The conventional calibration method eliminates the impact on the stochastic noise by extending the measurement time, which undoubtedly reduces the calibration efficiency. To solve the problem, the adaptive forward linear prediction (FLP) filter is adopted to suppress the stochastic noises of ring laser gyro IMU calibration data and improve the calibration accuracy of the system with small amount of calibration data. Firstly, the original data is acquired from the four-position rotation calibration experiment. Secondly, the calibration data is de-noised by the adaptive FLP filter to improve its signal noise ratio (SNR). Finally, the calibration parameters are calculated with the de-noised data. The experimental results show that the stochastic noises of calibration data are de-noised effectively by the adaptive FLP filter, the SNR of the signal is improved, and more accurate calibration parameters are acquired with small amount of calibration data, which enhances the navigation accuracy of the system.
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表 1 激光陀螺IMU降噪前标定结果
Table 1. Calibration results of ring laser gyro IMU with original calibration data
参数类型 FLP降噪前结果 Gbx, Gby, Gbz/((°)·h-1) -0.024 2, -0.234 0, 0.059 0 Sgx, Sgy, Sgz/(″/^) -0.842 6, 0.842 7, -0.842 8 Abx, Aby, Abz/(10-4g) 1.399 7, 9.909 8, 22.828 9 Kax, Kay, Kaz/(10-5g·s/^) -3.386 7, 3.234 7, -3.389 6 注:(″/^)为角秒每脉冲; (s/^)为秒每脉冲。 表 2 激光陀螺IMU降噪后标定结果
Table 2. Calibration results of ring laser gyro IMU with de-noised calibration data
参数类型 FLP降噪后结果 Gbx, Gby, Gbz/(°)·h-1) -0.021 1, -0.234 5, 0.077 8 Sgx, Sgy, Sgz/(″/^) -0.842 6, 0.842 7, -0.842 8 Abx, Aby, Abz/(10-4g) 1.387 2, 9.909 0, 22.849 1 Kax, Kay, Kaz/(10-5g·s/^) -3.386 7, 3.234 7, 3.389 7 表 3 1 h车载试验导航定位误差
Table 3. 1 h positioning error of vehicle experiment
nmile 系统编号 导航定位误差 FLP降噪前 FLP降噪后 TX-R610-01 0.871 256 0.595 590 TX-R610-02 0.652 650 0.500 372 -
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