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摘要:
导弹自动驾驶仪在振动测试过程中存在信号基线漂移且污染严重的问题,而传统的时频处理方法难以达到去噪要求,因此基于形态学基本原理提出了一种用于解决振动信号基线漂移的滤波方法。该滤波方法由3级结构组成,前2级结构均是基于形态学基本原理,第3级进行相消与平滑处理,通过相互级联,可以有效抑制基线漂移。此外,通过引入粒子群优化(PSO)算法使得该滤波方法更具适应性。对比实验利用该滤波方法和对比方法对自动驾驶仪实测振动信号与标准ECG信号进行了处理,结果表明:该滤波方法在抑制基线漂移方面要优于小波阈值去噪和传统的形态学去噪。
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关键词:
- 形态学滤波 /
- 振动信号 /
- 基线漂移 /
- 阈值去噪 /
- 粒子群优化(PSO)
Abstract:The baseline drift and heavy pollution for vibration test of missile autopilot are still problems. The requirement of denoising is difficult to be achieved by traditional time-frequency method. In this paper, to filter out the baseline drift noise, a new morphological filtering method based on the basic principle of generalized morphology is proposed. The proposed method is composed of three-level structure:the former two are based on the morphological principle, and the third level is designed for cancellation and smoothing. Thus, baseline drift can be effectively suppressed by cascading. In addition, the proposed method is more adaptive by introducing particle swarm optimization (PSO). In the final experiments, the real signals of autopilot and ECG signals are denoised by the proposed method and reference methods. The experimental results show that the proposed method is better than wavelet denoising and traditional morphological denoising in suppressing baseline drift.
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表 1 不同分解层数下小波阈值去噪结果
Table 1. Denoising results of wavelet transformation with different wavelet-bases
小波基 分解层数 均方差 信噪比 波形相似比 sym8 2 0.151 20.80 0.94 sym8 3 0.202 13.82 0.89 sym8 4 0.428 -21.84 0.32 db3 2 0.165 18.71 0.93 db3 3 0.254 7.76 0.83 db3 4 0.428 -21.42 0.32 表 2 PSO算法优化结果
Table 2. Optimization results using PSO algorithm
实验次数 L1 θ1 L2 θ2 信噪比 1 2 2 29 40 28.7 2 3 3 30 80 28.7 3 3 2 78 72 28.7 4 3 5 68 65 27.6 5 3 5 76 40 27.6 6 2 3 36 72 28.1 -
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