基于梯度变步长LMS的电子天平抗震设计

以应变式电子天平为研究对象,在分析电子天平震动信号的频谱特性及其对天平计量性能影响的基础上,提出一种基于梯度变步长最小均方(LMS)自适应滤波器的电子天平抗震动设计方法。依据天平称量数据的震动影响来源和特点,通过与切比雪夫低通滤波、椭圆低通滤波、巴特沃斯低通滤波及滑动平均滤波等常用抗震动滤波方法进行仿真实验对比,证明梯度变步长LMS自适应滤波算法的有效性与优越性,该方法在实际天平中得到应用。实验表明,采用本方法研制的200 g/0.001 g应变片电子天平可以在普通木质实验台上准确称重,最大称重误差≤0.001 5%,且不受榔头敲击实验台等冲击性震动的影响。

Shock resistant design for electronic balance based on gradient variable step size LMS algorithm

Based on the gradient variable step size LMS adaptive filter, a shock resistant design method for electronic balances is proposed. For strain gauge electronic balances, this method is resulted from analyzing both the spectrum and influence on measurement performance of the vibration signals of electronic balances. The gradient variable step size LMS adaptive filter has been proved to achieve the best balance shock resistant effects compared with Chebyshev low pass filter, Elliptic low pass filter filtering, Butterworth low pass filter and moving average filtering, etc. Experimental results indicate that a strain gauge electronic balance with the capacity of 200 g and resolution 0.001 g can weigh accurately on ordinary wooden test bench. The maximum error of weighing can be reduced to 0.0015%. Moreover, the electronic balance can be free from the vibration impact, such as a hammer blowing experiment platform.