基于 YOLOv5-EA-FPNs 的芯片缺陷检测方法研究

针对芯片缺陷检测中,缺陷尺寸跨度大、特征相似、小目标难识别、漏检等问题,本文提出基于YOLOv5改进的缺陷检测方法。针对小目标缺陷检测中出现的漏检、误检等问题,提出新增小目标特征检测器(small target feature detector, S-Detector),提升模型对小目标缺陷的学习能力;针对缺陷尺寸跨度大、特征相似等问题,提出具有高效聚焦学习能力的特征金字塔结构(efficient attention feature pyramid networks, EA-FPNs),提升模型对不同尺寸缺陷的检测能力;针对预测阶段冗余框较多导致时间开销大的问题,提出基于面积的边界框融合算法(bounding box fusion algorithm, BFA),减少冗余框。实验结果表明,本文方法相较于改进前,检测精确度提升1.2%,小目标缺陷精确度提升1.6%;采用BFA消除冗余框的同时,平均检测时长为26.8μs/张,较使用BFA前减少了5.2μs。本文所提方法具有良好性能,能够提升检测效率。     

Fault diagnosis and cause analysis using fuzzy evidential reasoning approach and dynamic adaptive fuzzy Petri nets

Fault diagnosis is of great importance to all kinds of industries in the competitive global market today. However, as a promising fault diagnosis tool, fuzzy Petri nets (FPNs) still suffer a couple of deficiencies. First, traditional FPN-based fault diagnosis methods are insufficient to take into account incomplete and unknown information in diagnosis process. Second, most of the fault diagnosis methods using FPNs are only concerned with forward fault diagnosis, and no or less consider backward cause analysis. In this paper, we present a novel fault diagnosis and cause analysis (FDCA) model using fuzzy evidential reasoning (FER) approach and dynamic adaptive fuzzy Petri nets (DAFPNs) to address the problems mentioned above. The FER is employed to capture all types of abnormal event information which can be provided by experts, and processed by DAFPNs to identify the root causes and determine the consequences of the identified abnormal events. Finally, a practical fault diagnosis example is provided to demonstrate the feasibility and efficacy of the proposed model.     

Evolutionary design of hybrid self-organizing fuzzy polynomial neural networks with the aid of information granulation

We introduce a new architecture of information granulation-based and genetically optimized Hybrid Self-Organizing Fuzzy Polynomial Neural Networks (HSOFPNN). Such networks are based on genetically optimized multi-layer perceptrons. We develop their comprehensive design methodology involving mechanisms of genetic optimization and information granulation. The architecture of the resulting HSOFPNN combines fuzzy polynomial neurons (FPNs) that are located at the first layer of the network with polynomial neurons (PNs) forming the remaining layers of the network. The augmented version of the HSOFPNN, “IG_gHSOFPNN”, for brief, embraces the concept of information granulation and subsequently exhibits higher level of flexibility and leads to simpler architectures and rapid convergence speed to optimal structure in comparison with the HSOFPNNs and SOFPNNs.

The GA-based design procedure being applied at each layer of HSOFPNN leads to the selection of preferred nodes of the network (FPNs or PNs) whose local characteristics (such as the number of input variables, the order of the polynomial, a collection of the specific subset of input variables, the number of membership functions for each input variable, and the type of membership function) can be easily adjusted. In the sequel, two general optimization mechanisms are explored. The structural optimization is realized via GAs whereas the ensuing detailed parametric optimization is afterwards carried out in the setting of a standard least square method-based learning. The obtained results demonstrate a superiority of the proposed networks over the existing fuzzy and neural models.