共查询到20条相似文献,搜索用时 937 毫秒
1.
通过电流传感器分别测量驱动正常铣刀以及发生破损铣刀旋转的主轴电机电流,将其作为原始采集信号,并对该信号进行消噪处理。其次,利用消噪后的电流信号数据,以MATLAB分析时域均方根和信号功率谱密度随频率的分布情况,从而提取刀具破损特征。最后,针对提取到的样本特征,应用最小二乘支持向量分类机模型进行刀具破损模式识别,实验结果表明,通过小波消噪、burg功率谱特征提取和应用最小二乘支持向量分类机判断,刀具破损状态的识别准确率可达95%。 相似文献
2.
根据无损蛋和有损蛋声学特性的差异,设计了一种基于DSP的鸡蛋蛋壳破损检测硬件系统.该硬件系统具有声音信号采集与处理、破损识别、结果显示以及与PC机通信等功能,可实现破损蛋壳的检测. 相似文献
3.
4.
5.
为了在蛋品加工中能够快速地检测并剔除破损蛋,将声卡采集到的蛋在敲击时的声脉冲信号送入计算机,利用倒谱和功率谱进行分析,分别提取出6个特征参数,并进行逐步判别分析,选择出最优判别因子,建立判别模型.实践表明:其对破损蛋的识别准确率达到95%,对禽蛋破损检测提供了参考方法. 相似文献
6.
鸡蛋敲击响应特性与蛋壳裂纹检测 总被引:7,自引:6,他引:7
鸡蛋经敲击激励后用传感器获取时域特性信号,并进行信号频域分析。结果表明,无裂纹鸡蛋的频域特征有相似的规律性。存在一个较明显的主频率值。峰值突出;有裂纹鸡蛋频域特征无规律性,没有明显的主频率值。峰值较紊乱;裂纹蛋上不同测点的频域特性有较大差异。提出了检测鸡蛋裂纹的主要参数:主频率值、功率谱平均值、归一化功率谱平均值、x轴及y轴质心等。主频率值、功率谱平均幅值、归一化功率谱平均幅值等参数可以用于检测鸡蛋有无裂纹,其中采用主频率值、归一化功率谱平均幅值检测时精度较高。 相似文献
7.
好壳与破损皮蛋因结构的不同而使其声音信号表现出的特征参数也不同,分析蛋壳被敲击时发出声音的机理,本文提出了一种基于DSP的皮蛋蛋壳破损检测系统,该系统讨论DM642和音频芯片TLV320AIC23B的硬件接口,并对采集声音信号进行频谱分析,实现皮蛋破损的检测。 相似文献
8.
设计了一种基于DSP的蛋壳无损检测硬件系统,该硬件系统具有控制敲蛋装置、声音信号采集与处理、破损识别和与PC机通信等功能。实践应用证明该系统可实现蛋壳无损检测工作快速、机动、可靠和高效的要求。 相似文献
9.
10.
11.
12.
13.
14.
15.
《Journal of Agricultural Engineering Research》1998,69(3):249-254
A model to represent the discolouration of dried powder of carrots as a function of temperature was developed. Two types of carrots, Asian and European, containing large amount of lycopene and β-carotene, respectively, were tested. The dried powder was stored under an atmosphere with O2and at three different temperatures, 5,20 and 35°C. The surface colour of the powder was monitored during storage by a Hunter colour ratioa/b. In the proposed model, the rate of oxidation was assumed to be represented by the product of the fraction of concentration of oxidized pigment at arbitrary time and a specific rate of oxidation of pigment. The rate parameters in the proposed model were calculated by fitting the experimental data with smooth curves by trial and error at the end of the induction period but before discolouration took place. The frequency constant and activation energy, expressing the temperature dependence of the rate parameters, were expressed by the Arrhenius relation. The simulation results of a Hunter colour ratioa/bof dried powder at 25°C showed good agreement with the experimental data, suggesting that the proposed model was effective for the prediction of discolouration of dried powder of both types of carrot. The use of the induction period in the manner described may enable the shelf life of dried powder to be predicted. 相似文献
16.
17.
感官检验棉花的品级,这是农村常见的一种检测手段.它的一个主要特点就是存在不确定性.这是由于检验员的品级检验水平存在一定的差异,其中有很多因素制约着检验的结果.文章对影响感官检验结果的因素进行了系统的分析. 相似文献
18.
19.
The fractional outflow rate of water from the rumen, measured as the rate of disappearance of the chromium complex of ethylenediamine tetra-acetic acid, was related to a number of dietary factors. A multiple regression equation was derived which expressed fractional outflow rate as a function of the intakes of dry matter, ash, acid-detergent fibre and crude protein.The data analysed consisted of 243 observations for sheep on 59 diets, including forage, concentrate and mixed diets. The ranges covered by the data were: fractional outflow rate 0.7–3.6 day?1; dry matter intake 560–1400g/day; ash 4–30%, acid-detergent fibre 7–41%, crude protein 5–26 % of dry matter; there were no observations for sheep of less than 34 kg liveweight.The equation accounted for 56·3 % of the total variance. Between-sheep variance could not be calculated for the whole of the data but was undoubtedly substantial since, for a sixth of the data, it was known to account for 38 % of the total variance. 相似文献
20.
从灾害经济学的角度探讨了城镇供水优化调度的必要性和可能性,认为在缺水不可避免的情况下,对供水进行优化调度可以减小缺水带来的损失,产生较好的减灾效益,特别是可以大大减小严重干旱的灾害效应。并根据水资源的特性,提出了缺水损失的计算模式以及优化调度的原则和方法。 相似文献