摘要
数学形态学滤波方法作为一种非线性的滤波工具拥有良好的消噪特性和低通特性,准确描述形态学滤波器特性是其应用的理论依据和前提条件。通过对给定的数学形态滤波器输入激励信号,得到了数学形态滤波器的频响特性,给出结构元素宽度与形态学组合滤波器截止频率的对应关系表。研究表明:在采样频率确定时,结构元素宽度越大,截止频率越低,截止频率随着结构元素宽度的增长而变小,并呈非线性关系。当结构元素宽度确定时,采样频率越大,截止频率越高,采样频率与截止频率成正比例变化。仿真分析表明,形态学组合滤波器具有更好的滤波效果,且具有保相的突出优点。形态学滤波器对实际故障信号的处理验证了结论的有效性。研究成果为形态学在振动信号处理中的应用提供了理论依据。
As a nonlinear filtering tool,morphological filtering method has good characteristics such as noise suppressing and low-pass characteristics.Accurate description of the mathematical morphological filter＇s characteristics supplies the theoretical basis and prerequisite for its application.The frequency response characteristic of the combined morphological filter is presented by excitation signal inputted into the given morphological filter,and the normalized cutoff frequency table with structure elements of different width is given.The research indicates when the sampling frequency is fixed,as the width of the structure element increases,the cutoff frequency decreases.The cutoff frequency gets smaller as the width of structure element grows,and the relationship between them is nonlinear.When the width of the structure element is fixed,as the sampling frequency increases,the cutoff frequency varies directly with the sampling frequency.The simulation result shows that the morphological filter has better noise suppressing and phase keeping ability.Finally,through processing the fault signal by the morphological filter,the effectiveness of the conclusions is verified.The results supply the theoretical basis for the application of mathematical morphology in vibration signal processing.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2012年第1期98-103,共6页
Journal of Mechanical Engineering
基金
国家自然科学基金(11072078)
中央高校基本科研业务费专项资金资助项目
关键词
振动
数学形态学
滤波器
频率响应
截止频率
Vibration Mathematical morphology Filter Frequency response Cutoff frequency
