谷粒清选损失检测信号的Butterworth高通滤波器降噪

研究了提取强噪声背景下谷粒清选损失信号的方法及其硬件实现问题。提出运用Butterworth滤波器分离机组振动噪声与谷粒信号特征，根据信号过渡带宽度及阻带衰减量确定了满足滤波性能最低阶数，通过级联方式实现了以VCVS拓扑结构为基本单元的八阶Butterworth高通滤波器。利用EWB仿真软件对该滤波器进行了模拟分析，并在联合收获机上进行了清选试验。试验结果与仿真分析结果具有良好的一致性，表明该方法能从机组强噪声背景中提取出清选损失谷粒信号的频率信息。

Application of Butterworth Filter for Testing Grain Cleaning Loss

The problems about extracting cleaning signals in the heavy noise and its hardware implementation were discussed. The Butterworth filter was proposed to distinguish the vibration noise and the grain signals. The lowest order of filter to meet performance was determined according to its transition region width and stop-band attenuation. An 8-order Butterworth filter used VCVS topology structure as basic units was constructed by class-bind method. Analogue simulation of the high order filter was proceeding on EWB and refining test was proceeding on the combine. Experimental results was well coincided with simulation results and showed good filtering property in extracting grain signals in the heavy noise of combine.