质量控制图在线智能诊断分析系统

在计算机集成制造系统环境下，为了有效实现工序质量控制，提出了质量控制图的在线智能诊断分析系统框架，它由控制图模式识别、参数估计、专家诊断分析系统和加工参数调整系统四个模块组成。在该系统中，采用了一种适用于模式识别与分类的新型神经网络模型——局部有监督特征映射网络，将其应用于该系统的控制图模式识别和参数估计中。仿真实验和应用实例表明，识别和分类结果与实际相符，并可以保证实时性。     

智能统计工序质量控制的体系研究

针对统计工序质量控制的要求，提出了智能控制体系的基本框架，论述了控制图模式的分类及其表达。对智能统计工序质量控制的控制图模式识别、控制图异常模式的参数估计和诊断分析专家系统3个主要方面进行了分析，并提出了解决方案和系统模型。在模型构造中，采用小波概率神经网络进行控制图的模式识别和控制图异常模式的参数估计。模拟仿真和实际应用结果表明：该方法结构简单、收敛速度快、识别准确率高，能够满足控制图在线检测和分析的需要。     

基于粗糙集与支持向量机的加工过程异常检测

为提高加工过程异常模式检测的自动化程度,在建立控制图数学描述的基础上,利用蒙特卡洛法构建了控制图数据集,研究了基于邻域粗糙集的控制图时域特征约简方法,提出了基于支持向量机的控制图异常模式识别模型。通过仿真实验,使用遗传算法优化了异常识别模型的主要参数,并对不同核函数、不同分类模型的识别精度进行了分析与对比。通过实际生产数据测试验证了所构建模型的有效性与可用性。     

基于多特征混合与支持向量机的动态过程异常监控

为提高动态过程异常模式的监控效率,提出基于多特征混合与多分类支持向量机的动态过程质量异常模式识别模型。采用离散小波变换提取原始数据的低频近似系数和重构数据特征;抽取重构数据的形状特征并与低频近似系数进行混合,形成质量模式的混合特征;采用粒子群优化的多分类支持向量机进行异常模式识别。仿真实验表明,所提出的识别模型比采用单一类型特征或融合特征的整体识别精度均有显著提高,且大大降低了模型训练时间。     

基于小波分析和SVM的控制图模式识别

为提高控制图模式尤其是混合控制图模式的识别精度,提出了基于小波分析和支持向量机(SVM)的控制图模式识别方法。该方法通过对工序质量特征数据进行小波包分解,提取低频逼近序列和各频带能量信息,并以此作为SVM分类器的输入,分别识别控制图模式中的趋势信号、阶跃信号和周期信号,最后通过合并这些信号以确定控制图的模式。通过仿真实验的验证,表明该方法相比传统的控制图模式识别方法,具有较好的识别精度。     

模式识别在机械自动化制造过程中的质量监控

为降低机械自动化制造过程中的废品率,提出模式识别在机械自动化制造过程中的质量监控方法,监控自动化制造过程中的产品质量,提高对产品质量的识别精准度。基于机械自动化制造过程中的质量检测环节,创建机械自动化制造过程中的产品质量监控流程。采用数字化测量仪采集机械自动化制造生产线质量数据,创建 SPC 控制图。基于 SPC 控制图模式识别的质量监控方法,将 k-means 算法与粒子群算法相结合,利用改进 k-means 算法获取控制图模式产品质量数据集聚类中心,结合欧氏距离,提取 SPC 控制图距离特征。将其输入多分类的支持向量机中,识别机械自动化制造过程中的产品质量控制图模式类型,诊断异常因素,并采取相应调控措施,实现机械自动化制造过程中的质量监控。实验表明:该方法可有效提高控制图的识别精准度,缩短训练与测试时间;并有效监控机械自动化制造过程中的产品质量。     

基于混合模型与改进多分类马田系统的控制图模式识别

为提高生产过程中产品质量的智能监控水平,提出基于时间序列混合模型及改进多分类马田系统的控制图模式识别算法。选用时间序列混合模型对控制图实时数据进行特征提取;改进马田系统的阈值计算方法并制定多类判别准则,将表征的特征向量代入改进多分类马田系统分类器中进行特征约减及模式识别。最后,将该识别算法应用于控制图公开数据集及生产案例中,以验证算法的有效性,并与其他算法对比了分析,结果表明,基于时间序列混合模型及改进多分类马田系统算法能简化识别系统,识别精度高,是一种更为有效的控制图模式识别方法。     

基于小波概率神经网络的控制图模式识别

提出了控制图模式识别的基本框架,描述了控制图异常状态的三种形式,即基本模式、特殊模式和混合模式。针对特殊模式和混合模式,提出了将输入数据经小波分解后的近似系数与各层细节系数的能量成分组成的特征向量作为概率神经网络的输入进行控制图模式识别的方法。仿真实验结果表明,该方法结构简单、收敛速度快、识别精度高、Ⅰ型错判和Ⅱ型错判低,适合于控制图模式识别。     

采用优化概率神经网络的质量异常识别方法

质量控制的核心在于对质量相关数据的充分利用和分析,如何有效组织和利用质量数据已成为企业和学者们广泛研究和关注的问题.针对质量数据库中异常实例缺失以及质量异常发现滞后的问题,提出利用遗传算法结合概率神经网络从质量控制图中挖掘质量异常现象的方法,弥补了当前广泛使用的统计过程控制(SPC)控制图在实际应用中存在的不足.首先通过分析判异准则在控制图异常判定方面的不足,引出控制图的异常模式;然后使用主成分分析法(PCA)对控制图原始数据进行降维和特征提取,以减少模型的训练时间;利用概率神经网络(PNN)结构简单、识别效果好的特点,实现控制图单一模式和混合模式的识别;通过改进的单目标优化遗传算法(SGA)对PNN的关键参数进行寻优,以消除经验取值的不足;最后通过仿真实验对所提方法进行了验证,并与传统的BP神经网络、单一的PNN、未进行参数优化的PCA-PNN模型,以及PSO优化的SVM模型进行了对比,证明了所提方法的有效性.     

基于小波概率神经网络的控制图模式识别

提出了控制图模式识别的基本框架,描述了控制图异常状态的三种形式,即基本模式、特殊模式和混合模式.针对特殊模式和混合模式,提出了将输入数据经小波分解后的近似,系数与各层细节系数的能量成分组成的特征向量作为概率神经网络的输入进行控制图模式识别的方法.仿真实验结果表明,该方法结构简单、收敛速度快、识别精度高、Ⅰ型错判和Ⅱ型错判低,适合于控制图模式识别.     

Improved recognition of control chart patterns using artificial neural networks

Recognition of abnormal patterns in control charts provides clues to reveal potential quality problems in the manufacturing processes. One potentially popular approach for recognizing different control chart patterns (CCPs) is to develop heuristics based on various shape features of the patterns. The advantage of this approach is that the users can easily understand how a particular pattern is identified. However, consistency in the recognition performance is found to be considerably poor in the heuristics approach. Since shape features represent the main characteristics of the patterns in a condensed form, artificial neural network (ANN) with features extracted from the process data as input vector representation can facilitate efficient pattern recognition with a smaller network size. In this paper, a set of seven shape features is selected, whose magnitudes are independent of the process mean and standard deviation under a special representation of the sampling interval in the control chart plot. Based on these features, the CCPs are recognized using a multilayered perceptron neural network trained by back-propagation algorithm. The recognizer can recognize all the eight commonly observed CCPs. Extensive performance evaluation of this recognizer is carried out using simulated pattern data. Numerical results indicate that the developed ANN recognizer can perform well in real time process control applications with respect to both recognition accuracy and consistency.     

Statistical process control with intelligence using fuzzy ART neural networks

With the automation development of manufacturing processes, artificial intelligence technology has been gradually employed to increase the automation and intelligence degree in quality control using statistical process control (SPC) method. In this paper, an SPC method based on a fuzzy adaptive resonance theory (ART) neural network is presented. The fuzzy ART neural network is applied to recognize the special disturbance of the manufacturing processes based on the classification on the histograms, which shows that the fuzzy ART neural network can adaptively learn the features of the histograms of the quality parameters in manufacturing processes. As a result, the special disturbance can be automatically detected when a feature of the special disturbance starts to appear in the histograms. At the same time, combined with spectrum analysis of the autoregressive model of quality parameters, the fuzzy ART neural network can also be utilized to adaptively detect the abnormal patterns in the control chart.     

Statistical process control with intelligence using fuzzy ART neural networks

With the automation development of manufacturing processes, artificial intelligence technology has been gradually employed to increase the automation and intelligence degree in quality control using statistical process control (SPC) method. In this paper, an SPC method based on a fuzzy adaptive resonance theory (ART) neural network is presented. The fuzzy ART neural network is applied to recognize the special disturbance of the manufacturing processes based on the classification on the histograms, which shows that the fuzzy ART neural network can adaptively learn the features of the histograms of the quality parameters in manufacturing processes. As a result, the special disturbance can be automatically detected when a feature of the special disturbance starts to appear in the histograms. At the same time, combined with spectrum analysis of the autoregressive model of quality parameters, the fuzzy ART neural network can also be utilized to adaptively detect the abnormal patterns in the control chart.     

Control chart pattern recognition using an optimized neural network and efficient features

Automatic recognition of abnormal patterns in control charts has seen increasing demands nowadays in manufacturing processes. This study investigates the design of an accurate system for control chart pattern (CCP) recognition from two aspects. First, an efficient system is introduced that includes two main modules: the feature extraction module and the classifier module. The feature extraction module uses the entropies of the wavelet packets. These are applied for the first time in this area. In the classifier module several neural networks, such as the multilayer perceptron and radial basis function, are investigated. Using an experimental study, we choose the best classifier in order to recognize the CCPs. Second, we propose a hybrid heuristic recognition system based on particle swarm optimization to improve the generalization performance of the classifier. The results obtained clearly confirm that further improvements in terms of recognition accuracy can be achieved by the proposed recognition system.     

基于Elman网络的过程质量智能化控制研究

利用Elman型反馈神经网络对过程质量进行预测和诊断以克服前向型神经网络的缺陷,同时针对目前预测与诊断相分离的现象提出将两者相结合以实现质量的实时控制。仿真结果表明基于此网络的系统能有效预测质量特性值,识别异常变动模式并提高控制精度。     

Statistical process control using optimized neural networks: A case study

The most common statistical process control (SPC) tools employed for monitoring process changes are control charts. A control chart demonstrates that the process has altered by generating an out-of-control signal. This study investigates the design of an accurate system for the control chart patterns (CCPs) recognition in two aspects. First, an efficient system is introduced that includes two main modules: feature extraction module and classifier module. In the feature extraction module, a proper set of shape features and statistical feature are proposed as the efficient characteristics of the patterns. In the classifier module, several neural networks, such as multilayer perceptron, probabilistic neural network and radial basis function are investigated. Based on an experimental study, the best classifier is chosen in order to recognize the CCPs. Second, a hybrid heuristic recognition system is introduced based on cuckoo optimization algorithm (COA) algorithm to improve the generalization performance of the classifier. The simulation results show that the proposed algorithm has high recognition accuracy.     

FMS质量控制技术的研究

对柔性制造系统（FMS）质量控制技术的重要工具－质量控制图的模式识别问题进行了深入的研究,提出了一种基于神经网络的质量控制图模式识别的方法,实现了质量控制图的自动识别。该方法具有结构简单、识别能力强、训练时间短的特点,经过训练的神经网络能够识别质量控制图的6种基本模式,并给出仿真结果。     

关键重要零件质量控制技术

研究了加工关键、重要零件的质量控制问题.三坐标测量机将加工数据通过PCI总线传输给PC机,PC机对加工数据进行处理并形成质量控制图,利用神经网络技术对质量控制图进行模式识别和参数估计,并对国家标准的8种判异准则进行正确识别,对过程能力进行了分析研究,计算过程能力指数,最后在Matlab环境下编制了系统的GUI界面,在实际应用中取得良好效果.