一种振弦传感器自适应拾振方法

A self-adaptive vibration pick-up method for vibrating wire sensor

振弦传感器输出的频率信号信噪比低、衰减快,容易受到干扰而造成测量精度下降。为提高有噪声环境下,振弦式传感器测频系统的计算精度,提出了一种基于快速傅里叶变换的自适应拾振方法。该方法使用数字傅里叶滤波自动滤除噪声干扰,然后利用Quinn算法进行高精度频率计算。在基于STM32处理器平台的振弦传感器测频系统中进行该方法的实验测试,测试结果表明:在无噪声干扰情况下,系统的频率测量相对误差小于0.01%;在严重白噪声干扰情况下(信噪比为-20 d B),系统的频率测量相对误差小于0.3%。与其他的测频方法比较,该方法具有更好的抑制噪声能力和测频精度。

The vibrating wire sensor may get low measurement accuracy due to the low Signal to Noise Ratio( SNR),fast attenuation and susceptibility to interference of its output frequency signals. To improve the calculation accuracy of the frequency measurement system of the vibrating wire sensor in the noise environment,a self-adaptive vibration pick-up method based on Fast Fourier Transform( FFT) is proposed. This method filters the noise interference using digital fourier filter,and then calculates frequency with high-precision using Quinn algorithm. The tests on this method have performed in the frequency measurement system of the vibrating wire sensor based on STM32 processor platform. Experimental results show that the method has better noise suppression capability and frequency measurement accuracy compared with other frequency measurement methods becausethe relative error of the frequency measurement of the system is less than 0. 01% in the absence of noise and less than 0. 3% in the case of severe white noise( SNR is-20 d B).