A neural networks-based negative selection algorithm in fault diagnosis

Inspired by the self/nonself discrimination theory of the natural immune system, the negative selection algorithm (NSA) is an emerging computational intelligence method. Generally, detectors in the original NSA are first generated in a random manner. However, those detectors matching the self samples are eliminated thereafter. The remaining detectors can therefore be employed to detect any anomaly. Unfortunately, conventional NSA detectors are not adaptive for dealing with time-varying circumstances. In the present paper, a novel neural networks-based NSA is proposed. The principle and structure of this NSA are discussed, and its training algorithm is derived. Taking advantage of efficient neural networks training, it has the distinguishing capability of adaptation, which is well suited for handling dynamical problems. A fault diagnosis scheme using the new NSA is also introduced. Two illustrative simulation examples of anomaly detection in chaotic time series and inner raceway fault diagnosis of motor bearings demonstrate the efficiency of the proposed neural networks-based NSA.     

Clonal optimization-based negative selection algorithm with applications in motor fault detection

The Negative Selection Algorithm (NSA) and clonal selection method are two typical kinds of artificial immune systems. In this paper, we first introduce their underlying inspirations and working principles. It is well known that the regular NSA detectors are not guaranteed to always occupy the maximal coverage of the nonself space. Therefore, we next employ the clonal optimization method to optimize these detectors so that the best anomaly detection performance can be achieved. A new motor fault detection scheme using the proposed NSA is also presented and discussed. We demonstrate the efficiency of our approach with an interesting example of motor bearings fault detection, in which the detection rates of three bearings faults are significantly improved.     

基于AdaBoost算法的故障诊断仿真研究

AdaBoost算法是提高预测学习系统预测能力的有效工具。提出一种基于AdaBoost算法的神经网络故障诊断方法,利用多层前向神经网络作为故障弱分类器,实现了对多类故障的诊断。为了克服AdaBoost对数据噪声比较敏感的不足,通过降低错分样本的权重改进了算法。针对一个涡轮喷气发动机气路部件故障的仿真实验表明,这种方法提高了最终故障分类器的泛化能力,改善了其噪声鲁棒性,便于工程应用。     

Nonlinear feature selection using Gaussian kernel SVM-RFE for fault diagnosis

Feature selection can directly ascertain causes of faults by selecting useful features for fault diagnosis, which can simplify the procedures of fault diagnosis. As an efficient feature selection method, the linear kernel support vector machine recursive feature elimination (SVM-RFE) has been successfully applied to fault diagnosis. However, fault diagnosis is not a linear issue. Thus, this paper introduces the Gaussian kernel SVM-RFE to extract nonlinear features for fault diagnosis. The key issue is the selection of the kernel parameter for the Gaussian kernel SVM-RFE. We introduce three classical and simple kernel parameter selection methods and compare them in experiments. The proposed fault diagnosis framework combines the Gaussian kernel SVM-RFE and the SVM classifier, which can improve the performance of fault diagnosis. Experimental results on the Tennessee Eastman process indicate that the proposed framework for fault diagnosis is an advanced technique.     

QoS-aware web service selection with negative selection algorithm

Web service selection, as an important part of web service composition, has direct influence on the quality of composite service. Many works have been carried out to find the efficient algorithms for quality of service (QoS)-aware service selection problem in recent years. In this paper, a negative selection immune algorithm (NSA) is proposed, and as far as we know, this is the first time that NSA is introduced into web service selection problem. Domain terms and operations of NSA are firstly redefined in this paper aiming at QoS-aware service selection problem. NSA is then constructed to demonstrate how to use negative selection principle to solve this question. Thirdly, an inconsistent analysis between local exploitation and global planning is presented, through which a local alteration of a composite service scheme can transfer to the global exploration correctly. It is a general adjusting method and independent to algorithms. Finally, extensive experimental results illustrate that NSA, especially for NSA with consistency weights adjusting strategy (NSA+), significantly outperforms particle swarm optimization and clonal selection algorithm for QoS-aware service selection problem. The superiority of NSA+ over others is more and more evident with the increase of component tasks and related candidate services.     

Sensor deployment for fault diagnosis using a new discrete optimization algorithm

Optimal allocation of the sensor in a wireless sensor network (WSN) is required to have a satisfactory fault diagnosis within the system. In fact, the sensor nodes in the network should be located in an arrangement to maximize the failure diagnosis. In this paper, the sensor deployment optimization to diagnose the distributed failures in a wireless unmanned aerial vehicles (UAVs) network has been studied. In this way, a novel evolutionary optimization algorithm inspired by the gases Brownian and turbulent rotational motion is utilized which is called Discrete Gases Brownian Motion Optimization (DGBMO) algorithm. An integer linear programming (ILP) approach is used to formulate the sensor deployment. Then the sensor deployment optimization is solved by DGBMO as well as generic ILP solvers and Boolean satisfiability-based ILP solvers. The results show that DGBMO is suitable for sensor disposition optimization especially in large-sized UAV networks.     

基于否定选择的身份认证技术

为了提高用户身份认证的有效性,给出了一个集成肯定认证机制和否定认证机制的双层认证模型.首先,基于人体免疫系统T细胞识别自体和非自体的原理,设计了基于否定选择的身份认证机制;接着研究了否定认证机制的关键技术;最后给出双层认证模型的实现细节及性能分析.仿真实验表明,该身份认证模型能够承受各种口令攻击,有效过滤非法用户的登录请求,具有较好的鲁棒性和可用性.     

Motor fault detection and diagnosis using a hybrid FMM-CART model with online learning

In this paper, a hybrid online learning model that combines the fuzzy min–max (FMM) neural network and the Classification and Regression Tree (CART) for motor fault detection and diagnosis tasks is described. The hybrid model, known as FMM-CART, incorporates the advantages of both FMM and CART for undertaking data classification (with FMM) and rule extraction (with CART) problems. In particular, the CART model is enhanced with an importance predictor-based feature selection measure. To evaluate the effectiveness of the proposed online FMM-CART model, a series of experiments using publicly available data sets containing motor bearing faults is first conducted. The results (primarily prediction accuracy and model complexity) are analyzed and compared with those reported in the literature. Then, an experimental study on detecting imbalanced voltage supply of an induction motor using a laboratory-scale test rig is performed. In addition to producing accurate results, a set of rules in the form of a decision tree is extracted from FMM-CART to provide explanations for its predictions. The results positively demonstrate the usefulness of FMM-CART with online learning capabilities in tackling real-world motor fault detection and diagnosis tasks.     

一种可变模糊匹配阴性选择算法

通过对人工免疫系统中阴性选择算法机理的分析,定义了连续相似度与背离度,提出了一种可变模糊匹配阴性选择免疫算法.算法通过调整匹配阈值的方法降低黑洞数量;利用模糊思想,实现了具有一定连续相似度的模糊匹配,模糊程度可控;为了消除检测器间的冗余,提高检测器集的检测效率,算法在模糊匹配的基础上,生成了有效检测器集.仿真实验表明,可变模糊匹配阴性选择算法生成的成熟检测器检测范围较大,空间覆盖率明显提高,黑洞数量大幅下降,算法具有较强的鲁棒性.     

An improved code selection algorithm for fault prediction

The goal of this study is to present an improved code selection algorithm (BCSA) for fault prediction. The contributions mainly contain three parts. The first part is on the extension of the horizontal input in the code selection algorithm (CSA). We propose that the horizontal input is also the prediction for the next coming event, not only for recalling. Thus, BCSA is able to recall and predict alternately. The second part is on the extension of the generic minicolumnar function. We propose that the function of a minicolumn is to be a k-winner-take-all competitive module (CM) and all active cells (the overall input is 1) should be chosen as winners within a CM. The third part is on the improvement of the competition mechanism. In BCSA, the winners are directly chosen with only one round competition. Thus, computing the input’s similarity G is unnecessary. BCSA is applied to analyze the disaster of the space shuttle Challenger which is a well-known example of fault prediction. Compared to other methods, the result of BCSA is specific, robust and independent of the parameters.     

基于信息融合技术的电机故障诊断

为了能够从多方面反映电机系统状态,实现对电机故障模式的自动识别与准确诊断,将信息融合技术与神经网络相结合,建立电机故障诊断系统。在数据融合级上,将故障特征量进行分类处理,然后,采用多层神经网络进行故障特征级融合与电机故障的局部诊断,获得彼此独立的证据,再运用DempserShafer(D-S)证据理论融合算法对各证据进行融合,最终,实现对电机故障的准确诊断。诊断测试试验证明:该诊断系统提高了电机故障诊断的精度,并能满足诊断的实时性要求。     

A fast detector generation algorithm for negative selection

Applied Intelligence - Inspired by biological immune systems, the field of artificial immune system (AIS), particularly the negative selection algorithm (NSA), has been proved effective in solving...     

Efficient agreement using fault diagnosis

Summary We give an extremely simple Byzantine agreement protocol that usesO(t ²) processors, min(f+2,t+1) rounds of communication,O(n·t·f·log|V|) total message bits, andO(log|V|) maximum message size, wheren is the total number of processors that actually participate in the protocol,t is an upper bound on the number of faulty processors,f is the number of processors that actually fail in a given execution, andV is the set of possible inputs. This protocol uses roughly the same resources as a more complex protocol due to Dolev, Reischuk, and Strong. By adding explicit fault diagnosis to our first protocol, we produce a some-what more complicated protocol that usesO(t ^1.5) processors, min(f+2,t+1) rounds,O(n·t ² ·f·log|V|) total message bits, andO(t·log|V|) maximum message size. Brian A. Coan received the B.S.E. degree in electrical engineering and computer science from Princeton University in 1977, the M.S. degree in computer engineering from Stanford University in 1979, and the Ph.D. degree in computer science from the Massachusetts Institute of Technology in 1987. He has worked for Amdahl Corporation and AT&T Bell Laboratories. Since 1987 he has been a member of the technical staff in the Network Systems Research Department at Bellcore. His main research interests are in distributed systems, fault tolerance, and platforms to support distributed multimedia systems.A preliminary version of this paper appeared in the Proceedings of the 26th Annual Allerton Conference on Communication, Control, and Computing, pp 663–672, 1988     

无线传感器网络软故障诊断算法

在无线传感器网络中,软故障节点会产生并传输错误数据,这不仅会形成错误的决策,还会消耗能量,为此,提出一种基于节省能量的故障诊断(EFD)算法。该算法利用节点感知数据的空间相似性,通过对邻点所感知的传感数据进行比较,确定检测节点状态。对于网络中存在的节点瞬时故障,该算法引用TF模型思想,避免了不必要的数据比较,减少了时间冗余的检测次数。仿真结果表明:EFD算法能够提高网络诊断精度,同时可以降低诊断过程的能量消耗。     

Using known nonself samples to improve negative selection algorithm

Negative selection algorithm is the core algorithm of artificial immune system. It only uses the self for training and generates detectors to detect abnormalities. Holes are feature space areas that the detector fails to cover, it is the root cause of the performance degradation of the negative selection algorithm. The conventional method generates a large number of detectors randomly to repair the holes, which is time-consuming and not effective. To alleviate the problem, we propose a V-Detector-KN algorithm in this paper. V-Detector is the abbreviation of the real-valued negative selection algorithm with Variable-sized Detectors, KN represents Known Nonself. The V-Detector-KN algorithm uses the known nonself as the candidate detector to further generate the detector based on the V-Detector randomly generated detector, so as to realize the repair of holes. Compared with the conventional method to randomly generate detectors to repair holes, our proposed V-Detector-KN method uses known nonself to repair holes, reducing the randomness and blindness of hole repair. Theoretical analysis shows that the detection rate of our algorithm is not lower than that of the conventional V-Detector algorithm. The results of experiment comparing with other 6 algorithms on 7 UCI data sets show the superiority of our proposed algorithm.

     

一种使用亚当姆斯法的双端故障测距算法

设计了一种双端故障测距算法,该算法基于精细积分法,利用故障线路两端的测量数据,计算出输电线路的沿线电压。通过比较两组电压,可得知故障点的位置。提出使用亚当姆斯法替代龙格-库塔法,从而使计算精度有了进一步的提高。仿真实验证明,亚当姆斯法优于龙格-库塔法。