摘要
通过微型话筒和声卡采集敲击鸡蛋后的脉冲时域信号,利用信号的小波变换模极大值建立了反映信号奇异性强度和频带位置的奇异性指标。分析表明,裂纹蛋的奇异性指标主要位于低频带、指标值较大;好壳蛋的奇异性指标分布相对分散、指标值较小,二者有明显的区别。基于奇异指标的多层分布特征和奇异性强度,定义一个以加权平均值为奇异指标的标准值,提出了蛋壳裂纹的多层检测方法。通过实际检验检测精度达96%。
A singularity indicator of time-domain pulse response signal, related with the singular intensity and frequency band, was presented by using wavelet transform modulus maxima, in which the response signal has been detected by a mini-microphone and sound adapter when egg-shell was excited with a mechanical impact. The analysis showed that the most singularity indicators of the cracked eggs only located in the low-frequency bands with big indicator values, meanwhile those of the intact eggs were found in the more frequency bands with small indicator values. A standard value, as singular indicator was defined with weighted average value, and a multi-level scheme for egg-shell crack detection has been proposed. Test results with 96% recognition ratio showed the efficiency of the proposed multi-level detection method.
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2008年第12期127-131,共5页
Transactions of the Chinese Society for Agricultural Machinery
基金
国家"863"高技术研究发展计划资助项目(项目编号:2007AA10Z214)
湖北省科技攻关计划项目(项目编号:2007AA201C07)
关键词
鸡蛋
响应信号
小波变换
奇异性
多层检测
Egg, Response signal, Wavelet transform, Singularity feature, Multi-level detection
