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基于Prototype反向蒸馏的无监督多类别异常检测
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作者 何立仁 彭博 池明旻 《计算机科学》 北大核心 2025年第2期202-211,共10页
无监督异常检测因只需要正常样本进行训练而被广泛应用于工业质检等领域。直接将现有的单类别异常检测方法应用到多类别异常检测中会导致性能显著下降,其中基于知识蒸馏的异常检测方法将预训练的教师模型关于正常样本的特征知识蒸馏到... 无监督异常检测因只需要正常样本进行训练而被广泛应用于工业质检等领域。直接将现有的单类别异常检测方法应用到多类别异常检测中会导致性能显著下降,其中基于知识蒸馏的异常检测方法将预训练的教师模型关于正常样本的特征知识蒸馏到学生模型中,然而它们在多类别异常检测中存在无法保证学生模型只学习到正常样本知识的问题。文中提出一种基于反向知识蒸馏框架的无监督多类别异常检测方法(Prototype based Reverse Distillation,PRD),其通过Multi-class Normal Prototype模块和Sparse Prototype Recall训练策略来学习教师模型关于多类别正常样本特征的Prototype,并以此来过滤学生模型的输入特征,从而确保学生模型只学习到教师模型关于正常样本的特征知识。PRD在多种工业异常检测数据集上性能均超越了现有的SOTA方法,定性、定量和消融实验验证了PRD整体框架和内部模块的有效性。 展开更多
关键词 异常检测 无监督学习 prototype学习 知识蒸馏 预训练特征
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PPFormer:Patch Prototype Transformer for Semantic Segmentation
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作者 Shanyuan Liu Yonggang Lu 《Journal of Beijing Institute of Technology》 2025年第4期405-417,共13页
Since the introduction of vision Transformers into the computer vision field,many vision tasks such as semantic segmentation tasks,have undergone radical changes.Although Transformer enhances the correlation of each l... Since the introduction of vision Transformers into the computer vision field,many vision tasks such as semantic segmentation tasks,have undergone radical changes.Although Transformer enhances the correlation of each local feature of an image object in the hidden space through the attention mechanism,it is difficult for a segmentation head to accomplish the mask prediction for dense embedding of multi-category and multi-local features.We present patch prototype vision Transformer(PPFormer),a Transformer architecture for semantic segmentation based on knowledge-embedded patch prototypes.1)The hierarchical Transformer encoder can generate multi-scale and multi-layered patch features including seamless patch projection to obtain information of multiscale patches,and feature-clustered self-attention to enhance the interplay of multi-layered visual information with implicit position encodes.2)PPFormer utilizes a non-parametric prototype decoder to extract region observations which represent significant parts of the objects by unlearnable patch prototypes and then calculate similarity between patch prototypes and pixel embeddings.The proposed contrasting patch prototype alignment module,which uses new patch prototypes to update prototype bank,effectively maintains class boundaries for prototypes.For different application scenarios,we have launched PPFormer-S,PPFormer-M and PPFormer-L by expanding the scale.Experimental results demonstrate that PPFormer can outperform fully convolutional networks(FCN)-and attention-based semantic segmentation models on the PASCAL VOC 2012,ADE20k,and Cityscapes datasets. 展开更多
关键词 hierarchical backbones patch prototype nonparametric learning semantic segmentation
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kProtoClust:Towards Adaptive k-Prototype Clustering without Known k
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作者 Yuan Ping Huina Li +1 位作者 Chun Guo Bin Hao 《Computers, Materials & Continua》 2025年第3期4949-4976,共28页
Towards optimal k-prototype discovery,k-means-like algorithms give us inspirations of central samples collection,yet the unstable seed samples selection,the hypothesis of a circle-like pattern,and the unknown K are st... Towards optimal k-prototype discovery,k-means-like algorithms give us inspirations of central samples collection,yet the unstable seed samples selection,the hypothesis of a circle-like pattern,and the unknown K are still challenges,particularly for non-predetermined data patterns.We propose an adaptive k-prototype clustering method(kProtoClust)which launches cluster exploration with a sketchy division of K clusters and finds evidence for splitting and merging.On behalf of a group of data samples,support vectors and outliers from the perspective of support vector data description are not the appropriate candidates for prototypes,while inner samples become the first candidates for instability reduction of seeds.Different from the representation of samples in traditional,we extend sample selection by encouraging fictitious samples to emphasize the representativeness of patterns.To get out of the circle-like pattern limitation,we introduce a convex decomposition-based strategy of one-cluster-multiple-prototypes in which convex hulls of varying sizes are prototypes,and accurate connection analysis makes the support of arbitrary cluster shapes possible.Inspired by geometry,the three presented strategies make kProtoClust bypassing the K dependence well with the global and local position relationship analysis for data samples.Experimental results on twelve datasets of irregular cluster shape or high dimension suggest that kProtoClust handles arbitrary cluster shapes with prominent accuracy even without the prior knowledge K. 展开更多
关键词 prototype finding convex hull support vector data description geometrical information
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An Energy Management System with Mobile Energy Station Based Wireless Energy Transfer:System Design and Prototype Implementation
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作者 Yan Kang Li Jinhui +3 位作者 Fan Xinyu Hu Jie Yu Qin Yang Kun 《China Communications》 2025年第1期89-101,共13页
In indoor environments,various batterypowered Internet of Things(IoT)devices,such as remote controllers and electronic tags on high-level shelves,require efficient energy management.However,manually monitoring remaini... In indoor environments,various batterypowered Internet of Things(IoT)devices,such as remote controllers and electronic tags on high-level shelves,require efficient energy management.However,manually monitoring remaining energy levels and battery replacement is both inadequate and costly.This paper introduces an energy management system for indoor IoT,which includes a mobile energy station(ES)for enabling on-demand wireless energy transfer(WET)in radio frequency(RF),some energy receivers(ERs),and a cloud server.By implementing a two-stage positioning system and embedding energy receivers into traditional IoT devices,we robustly manage their energy storage.The experimental results demonstrate that the energy receiver can harvest a minimum power of 58 mW. 展开更多
关键词 angle of arrival(AOA) Internet of Things(IoT) mobile station prototype wireless energy transfer(WET)
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CPEWS:Contextual Prototype-Based End-to-End Weakly Supervised Semantic Segmentation
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作者 Xiaoyan Shao Jiaqi Han +2 位作者 Lingling Li Xuezhuan Zhao Jingjing Yan 《Computers, Materials & Continua》 2025年第4期595-617,共23页
The primary challenge in weakly supervised semantic segmentation is effectively leveraging weak annotations while minimizing the performance gap compared to fully supervised methods.End-to-end model designs have gaine... The primary challenge in weakly supervised semantic segmentation is effectively leveraging weak annotations while minimizing the performance gap compared to fully supervised methods.End-to-end model designs have gained significant attention for improving training efficiency.Most current algorithms rely on Convolutional Neural Networks(CNNs)for feature extraction.Although CNNs are proficient at capturing local features,they often struggle with global context,leading to incomplete and false Class Activation Mapping(CAM).To address these limitations,this work proposes a Contextual Prototype-Based End-to-End Weakly Supervised Semantic Segmentation(CPEWS)model,which improves feature extraction by utilizing the Vision Transformer(ViT).By incorporating its intermediate feature layers to preserve semantic information,this work introduces the Intermediate Supervised Module(ISM)to supervise the final layer’s output,reducing boundary ambiguity and mitigating issues related to incomplete activation.Additionally,the Contextual Prototype Module(CPM)generates class-specific prototypes,while the proposed Prototype Discrimination Loss and Superclass Suppression Loss guide the network’s training,(LPDL)(LSSL)effectively addressing false activation without the need for extra supervision.The CPEWS model proposed in this paper achieves state-of-the-art performance in end-to-end weakly supervised semantic segmentation without additional supervision.The validation set and test set Mean Intersection over Union(MIoU)of PASCAL VOC 2012 dataset achieved 69.8%and 72.6%,respectively.Compared with ToCo(pre trained weight ImageNet-1k),MIoU on the test set is 2.1%higher.In addition,MIoU reached 41.4%on the validation set of the MS COCO 2014 dataset. 展开更多
关键词 End-to-end weakly supervised semantic segmentation vision transformer contextual prototype class activation map
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基于k-prototypes聚类算法的混合加密敏感数据保护方案研究 被引量:1
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作者 尹飞 葛崇慧 《自动化与仪器仪表》 2024年第11期61-64,69,共5页
当今社会进入大数据时代,其挖掘工作主要依托云计算平台。然而,云计算环境复杂多变,数据安全和隐私泄露问题日益显著。针对云计算环境下的数据安全问题,提出一种混合加密方案,根据数据敏感等级采用不同加密方法。同时提出了一种隐私保... 当今社会进入大数据时代,其挖掘工作主要依托云计算平台。然而,云计算环境复杂多变,数据安全和隐私泄露问题日益显著。针对云计算环境下的数据安全问题,提出一种混合加密方案,根据数据敏感等级采用不同加密方法。同时提出了一种隐私保护的可识别性k-prototypes聚类算法,并利用信息熵对各数值属性进行权重分配进行改进,以解决大数据挖掘过程中的隐私泄露问题。结果显示,改进k-prototypes聚类算法的NMI值为0.284,准确度达到了94.95%,RI值为0.935,运行时间为924 ms。综合来看,该方案在提高数据加密效率的同时,确保了云环境下数据的安全性。 展开更多
关键词 云计算 k-prototypes聚类算法 混合加密 敏感数据
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Semi-supervised remote sensing image scene classification with prototype-based consistency 被引量:2
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作者 Yang LI Zhang LI +2 位作者 Zi WANG Kun WANG Qifeng YU 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2024年第2期459-470,共12页
Deep learning significantly improves the accuracy of remote sensing image scene classification,benefiting from the large-scale datasets.However,annotating the remote sensing images is time-consuming and even tough for... Deep learning significantly improves the accuracy of remote sensing image scene classification,benefiting from the large-scale datasets.However,annotating the remote sensing images is time-consuming and even tough for experts.Deep neural networks trained using a few labeled samples usually generalize less to new unseen images.In this paper,we propose a semi-supervised approach for remote sensing image scene classification based on the prototype-based consistency,by exploring massive unlabeled images.To this end,we,first,propose a feature enhancement module to extract discriminative features.This is achieved by focusing the model on the foreground areas.Then,the prototype-based classifier is introduced to the framework,which is used to acquire consistent feature representations.We conduct a series of experiments on NWPU-RESISC45 and Aerial Image Dataset(AID).Our method improves the State-Of-The-Art(SOTA)method on NWPU-RESISC45 from 92.03%to 93.08%and on AID from 94.25%to 95.24%in terms of accuracy. 展开更多
关键词 Semi-supervised learning Remote sensing Scene classification prototype network Deep learning
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Unknown DDoS Attack Detection with Fuzzy C-Means Clustering and Spatial Location Constraint Prototype Loss
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作者 Thanh-Lam Nguyen HaoKao +2 位作者 Thanh-Tuan Nguyen Mong-Fong Horng Chin-Shiuh Shieh 《Computers, Materials & Continua》 SCIE EI 2024年第2期2181-2205,共25页
Since its inception,the Internet has been rapidly evolving.With the advancement of science and technology and the explosive growth of the population,the demand for the Internet has been on the rise.Many applications i... Since its inception,the Internet has been rapidly evolving.With the advancement of science and technology and the explosive growth of the population,the demand for the Internet has been on the rise.Many applications in education,healthcare,entertainment,science,and more are being increasingly deployed based on the internet.Concurrently,malicious threats on the internet are on the rise as well.Distributed Denial of Service(DDoS)attacks are among the most common and dangerous threats on the internet today.The scale and complexity of DDoS attacks are constantly growing.Intrusion Detection Systems(IDS)have been deployed and have demonstrated their effectiveness in defense against those threats.In addition,the research of Machine Learning(ML)and Deep Learning(DL)in IDS has gained effective results and significant attention.However,one of the challenges when applying ML and DL techniques in intrusion detection is the identification of unknown attacks.These attacks,which are not encountered during the system’s training,can lead to misclassification with significant errors.In this research,we focused on addressing the issue of Unknown Attack Detection,combining two methods:Spatial Location Constraint Prototype Loss(SLCPL)and Fuzzy C-Means(FCM).With the proposed method,we achieved promising results compared to traditional methods.The proposed method demonstrates a very high accuracy of up to 99.8%with a low false positive rate for known attacks on the Intrusion Detection Evaluation Dataset(CICIDS2017)dataset.Particularly,the accuracy is also very high,reaching 99.7%,and the precision goes up to 99.9%for unknown DDoS attacks on the DDoS Evaluation Dataset(CICDDoS2019)dataset.The success of the proposed method is due to the combination of SLCPL,an advanced Open-Set Recognition(OSR)technique,and FCM,a traditional yet highly applicable clustering technique.This has yielded a novel method in the field of unknown attack detection.This further expands the trend of applying DL and ML techniques in the development of intrusion detection systems and cybersecurity.Finally,implementing the proposed method in real-world systems can enhance the security capabilities against increasingly complex threats on computer networks. 展开更多
关键词 CYBERSECURITY DDoS unknown attack detection machine learning deep learning incremental learning convolutional neural networks(CNN) open-set recognition(OSR) spatial location constraint prototype loss fuzzy c-means CICIDS2017 CICDDoS2019
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Pose prediction based on dynamic modeling and virtual prototype simulation of shield tunnelling machine
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作者 JIN Da-long WANG Xu-yang +2 位作者 YUAN Da-jun LI Xiu-dong DU Chang-yan 《Journal of Central South University》 CSCD 2024年第11期3854-3867,共14页
Compared with traditional feedback control,predictive control can eliminate the lag of pose control and avoid the snakelike motion of shield machines.Therefore,a shield pose prediction model was proposed based on dyna... Compared with traditional feedback control,predictive control can eliminate the lag of pose control and avoid the snakelike motion of shield machines.Therefore,a shield pose prediction model was proposed based on dynamic modeling.Firstly,the dynamic equations of shield thrust system were established to clarify the relationship between force and movement of shield machine.Secondly,an analytical model was proposed to predict future multistep pose of the shield machine.Finally,a virtual prototype model was developed to simulate the dynamic behavior of the shield machine and validate the accuracy of the proposed pose prediction method.Results reveal that the model proposed can predict the shield pose with high accuracy,which can provide a decision basis whether for manual or automatic control of shield pose. 展开更多
关键词 shield machine motion trajectory dynamic modeling virtual prototype pose prediction
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The Advertisement Translation Based on the Prototype Theory
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作者 XUE Hai-bin 《Sino-US English Teaching》 2024年第3期132-137,共6页
Based on the Prototype Theory,the prototypical feature of advertisement is found to be the combination of three language functions:the informative function,the expressive function,and the vocative function.The adverti... Based on the Prototype Theory,the prototypical feature of advertisement is found to be the combination of three language functions:the informative function,the expressive function,and the vocative function.The advertisement translation means the adjustment of the informative function and the expressive function according to the differences between languages or cultures in order to maximize the vocative function.The faithful translation is the closest to the prototype of the source text but not necessarily the best translation. 展开更多
关键词 the prototype Theory ADVERTISEMENT the informative function the expressive function the vocative function
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Rapid Prototype Development Approach for Genetic Programming
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作者 Pei He Lei Zhang 《Journal of Computer and Communications》 2024年第2期67-79,共13页
Genetic Programming (GP) is an important approach to deal with complex problem analysis and modeling, and has been applied in a wide range of areas. The development of GP involves various aspects, including design of ... Genetic Programming (GP) is an important approach to deal with complex problem analysis and modeling, and has been applied in a wide range of areas. The development of GP involves various aspects, including design of genetic operators, evolutionary controls and implementations of heuristic strategy, evaluations and other mechanisms. When designing genetic operators, it is necessary to consider the possible limitations of encoding methods of individuals. And when selecting evolutionary control strategies, it is also necessary to balance search efficiency and diversity based on representation characteristics as well as the problem itself. More importantly, all of these matters, among others, have to be implemented through tedious coding work. Therefore, GP development is both complex and time-consuming. To overcome some of these difficulties that hinder the enhancement of GP development efficiency, we explore the feasibility of mutual assistance among GP variants, and then propose a rapid GP prototyping development method based on πGrammatical Evolution (πGE). It is demonstrated through regression analysis experiments that not only is this method beneficial for the GP developers to get rid of some tedious implementations, but also enables them to concentrate on the essence of the referred problem, such as individual representation, decoding means and evaluation. Additionally, it provides new insights into the roles of individual delineations in phenotypes and semantic research of individuals. 展开更多
关键词 Genetic Programming Grammatical Evolution Gene Expression Programming Regression Analysis Mathematical Modeling Rapid prototype Development
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The Role and Place of Artificial Neural Network Architectures Structural Redundancy in the Input Data Prototypes and Generalization Development
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作者 Conrad Onésime Oboulhas Tsahat Ngoulou-A-Ndzeli Béranger Destin Ossibi 《Journal of Computer and Communications》 2024年第7期1-11,共11页
Neural Networks (NN) are the functional unit of Deep Learning and are known to mimic the behavior of the human brain to solve complex data-driven problems. Whenever we train our own neural networks, we need to take ca... Neural Networks (NN) are the functional unit of Deep Learning and are known to mimic the behavior of the human brain to solve complex data-driven problems. Whenever we train our own neural networks, we need to take care of something called the generalization of the neural network. The performance of Artificial Neural Networks (ANN) mostly depends upon its generalization capability. In this paper, we propose an innovative approach to enhance the generalization capability of artificial neural networks (ANN) using structural redundancy. A novel perspective on handling input data prototypes and their impact on the development of generalization, which could improve to ANN architectures accuracy and reliability is described. 展开更多
关键词 Multilayer Neural Network Multidimensional Nonlinear Interpolation Generalization by Similarity Artificial Intelligence prototype Development
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矿井巡检机器人复杂斜巷通过性能优化 被引量:2
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作者 宋庆军 胡程量 +1 位作者 姜海燕 张金辉 《机械设计与制造》 北大核心 2025年第1期320-324,共5页
为提高移动机器人在矿井巷道等复杂环境中的越障稳定性,通过理论分析与RecurDyn仿真试验,研究并提出了一种分析和优化摆臂履带式巡检机器人坡道越障能力和越障稳定性的方法。研究结果表明:坡度对所涉及的巡检机器人最大越障高度和稳定... 为提高移动机器人在矿井巷道等复杂环境中的越障稳定性,通过理论分析与RecurDyn仿真试验,研究并提出了一种分析和优化摆臂履带式巡检机器人坡道越障能力和越障稳定性的方法。研究结果表明:坡度对所涉及的巡检机器人最大越障高度和稳定性均有较大影响,在坡度角为(0~35)°工况下,随坡度的增加理论最大越障高度从349mm逐渐减小至221mm,且当坡度角大于30°时,机器人在越障中易处于不稳定状态,故在越障控制时须考虑稳定性因素的影响。该结论可为所涉及巡检机器人的设计和自主越障控制提供理论依据。 展开更多
关键词 巡检机器人 坡道越障 运动学建模 斜巷 RECURDYN 虚拟样机
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新型多支盘土锚的承载性能研究 被引量:1
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作者 黄炜 简文彬 +2 位作者 杨坚 豆红强 罗金妹 《工程地质学报》 北大核心 2025年第2期772-782,共11页
多支盘锚杆是新近研发的新型锚杆,具有抗拔承载力高、鲁棒性强和灵活性强等优点。为了进一步掌握多支盘锚杆的抗拔承载性能,本文在多支盘锚杆室内模型试验研究基础上,开展了现场边坡锚固原型试验。结果表明,相较于普通锚杆,单支盘锚杆... 多支盘锚杆是新近研发的新型锚杆,具有抗拔承载力高、鲁棒性强和灵活性强等优点。为了进一步掌握多支盘锚杆的抗拔承载性能,本文在多支盘锚杆室内模型试验研究基础上,开展了现场边坡锚固原型试验。结果表明,相较于普通锚杆,单支盘锚杆盘径从300 mm增大到500 mm时,抗拔承载力分别提高35.7%、50%、71.4%,变形控制能力也相应增强;在粉质黏土中,双支盘锚杆可以到达更大的抗拔承载力,支盘间距≥4倍支盘直径时更能充分发挥两个支盘的协同作用;随着支盘个数从1个增多到3个,多支盘锚杆锁紧的地层范围越大,多支盘锚杆的抗拔承载力及变形控制能力也相应增强;多支盘锚杆的荷载-位移关系符合双曲线模型,可以用于预测多支盘锚杆的承载力。研究成果可以为多支盘锚杆的工程应用奠定了较良好的理论基础。 展开更多
关键词 多支盘锚杆 极限承载力 拉拔试验 双曲线模型 原型试验
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基于K-prototypes的混合属性数据聚类算法改进
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作者 倪丹 李泽文 《科技创新与应用》 2024年第28期31-34,38,共5页
属性数据分为数值型数据和分类型数据,一般情况下对于数值型数据运算前要进行标准化处理,但是对于数值型数据差异大的数据,由于大数掩盖小数的影响,按照K-prototypes聚类算法,数值型数据标准化后而且不对相应的分类数据有任何预处理或... 属性数据分为数值型数据和分类型数据,一般情况下对于数值型数据运算前要进行标准化处理,但是对于数值型数据差异大的数据,由于大数掩盖小数的影响,按照K-prototypes聚类算法,数值型数据标准化后而且不对相应的分类数据有任何预处理或者在计算时没有进行任何改变,很可能提高分类数据在聚类中的影响,并且分类型数据并未进一步地细分,不能满足不同要求的混合属性聚类。该文在将数值型数据标准化的基础上,将分类数据细分为二元数据和类型数据,并用相异度系数距离计算分类数据之间的距离,并且赋予二元和类型数据相应的权重,来改进K-prototypes聚类算法,使该算法满足不同要求的混合属性数据聚类,最后通过C#语言,在ArcEngine2010版本上实现。 展开更多
关键词 K-prototypes算法 混合属性 类型数据 相异度系数 加权属性
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电动汽车电子制动系统液压力RBF网络滑模变结构控制 被引量:1
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作者 张梅红 魏冬至 张明柱 《机械设计与研究》 北大核心 2025年第1期352-356,共5页
为了提高电动汽车电子制动系统(EBooster)的运行控制性能,设计了一种根据径向基函数(RBF)神经网络来实现液压力滑模控制的功能。建立了电子制动系统测试平台,能够实现快速原形测试,并对控制算法可靠性进行了评价。仿真结果表明:处于正... 为了提高电动汽车电子制动系统(EBooster)的运行控制性能,设计了一种根据径向基函数(RBF)神经网络来实现液压力滑模控制的功能。建立了电子制动系统测试平台,能够实现快速原形测试,并对控制算法可靠性进行了评价。仿真结果表明:处于正弦工况下时,达到稳定的系统压力状态,RBF滑模控制器形成了比传统比例-积分-微分(PID)方法更小的压力跟随误差,RBF网络可以根据实际液压负载完成滑模控制器参数的自主调节,由此实现更准确控制的状态。试验验证结果表明:能够完全满足汽车自适应巡航控制(ACC)以及自动紧急制动(AEB)两种行驶工况的要求。处于斜坡和正弦工况下,没有产生超调与抖动的现象,可以将稳态误差保持在0.1 MPa以内,误差相对值不超过2%。该研究可以为EBooster系统压力控制奠定一定的理论基础。 展开更多
关键词 电子制动系统 液压力控制 RBF滑模 快速原型
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挖掘机工作过程动力特性仿真及主构件参数多目标优化设计方法 被引量:1
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作者 林述温 陆哲 +3 位作者 危世佳 陈剑雄 顾天奇 谢钰 《中国机械工程》 北大核心 2025年第6期1371-1379,共9页
现有挖掘机主构件参数优化设计方法无法保证挖掘作业全过程多工况位置工作性能最优,且没有考虑作业过程中的能耗特性。研究了以典型工况作业全过程动力和能耗特性为目标的挖掘机工作装置主构件参数多目标优化设计方法。通过对基于ADAMS... 现有挖掘机主构件参数优化设计方法无法保证挖掘作业全过程多工况位置工作性能最优,且没有考虑作业过程中的能耗特性。研究了以典型工况作业全过程动力和能耗特性为目标的挖掘机工作装置主构件参数多目标优化设计方法。通过对基于ADAMS的参数化挖掘机虚拟样机的动力学仿真,分析了四种典型工况作业过程的液压缸驱动力和功率特性,确定了工作装置的优化工况,建立了新的综合考虑挖掘机典型工况作业过程液压缸驱动力传动比和功率特性的多目标优化数学模型,并结合实例对挖掘机整机工作装置参数化虚拟样机的铲斗、斗杆和动臂主构件参数进行顺序多目标优化。优化结果表明:该优化设计方法可显著提高挖掘机作业全过程工作装置传递动力的性能,降低液压缸能耗。 展开更多
关键词 挖掘机 主构件参数 虚拟样机 过程特性 多目标优化 顺序优化
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基于正交试验的超高水头小流量水泵水轮机优化设计 被引量:1
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作者 李延频 李仕东 +1 位作者 李骜 张自超 《水电能源科学》 北大核心 2025年第5期173-177,181,共6页
针对分布式可再生能源消纳难题和超高水头小流量水泵水轮机优化设计理论缺乏问题,依据现有水泵水轮机设计理论,参照已建的抽蓄电站水力参数,确定超高水头小流量水泵水轮机设计参数,建立三维模型,并基于五因素三水平的正交试验优化方案,... 针对分布式可再生能源消纳难题和超高水头小流量水泵水轮机优化设计理论缺乏问题,依据现有水泵水轮机设计理论,参照已建的抽蓄电站水力参数,确定超高水头小流量水泵水轮机设计参数,建立三维模型,并基于五因素三水平的正交试验优化方案,以水轮机、水泵工况效率及扬程为目标,通过极差分析方法探讨转轮叶片进出口角、进口直径、转轮叶片数及叶片包角对水泵水轮机性能影响,对比得出最优方案,最后换算为真机性能参数,并确定其工作范围。结果表明,转轮叶片出口安放角对水泵工况扬程、效率和水轮机工况效率影响最大,优化后的水泵设计工况扬程为710.86 m,效率为89.09%,水轮机最优工况效率为91.40%。 展开更多
关键词 水泵水轮机 水力设计 正交试验 水力特性 真机参数
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地质历史时期鄂尔多斯盆地的范围、性质及其勘探意义 被引量:1
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作者 何登发 成祥 +10 位作者 张国伟 赵文智 赵喆 刘新社 包洪平 范立勇 邹松 开百泽 毛丹凤 许艳华 成昌宇 《石油勘探与开发》 北大核心 2025年第4期757-771,共15页
基于地表地质、探井、重磁电与地震勘探资料分析,将盆地与周缘造山带相结合统一成图,对地质历史时期鄂尔多斯原型盆地的边界、分布范围、地质结构与构造属性等开展系统解析。研究表明,鄂尔多斯地块的西界为恩格尔乌苏断裂带,东界为太行... 基于地表地质、探井、重磁电与地震勘探资料分析,将盆地与周缘造山带相结合统一成图,对地质历史时期鄂尔多斯原型盆地的边界、分布范围、地质结构与构造属性等开展系统解析。研究表明,鄂尔多斯地块的西界为恩格尔乌苏断裂带,东界为太行山山前断裂带,北界为索伦—西拉木伦缝合带,南界为商丹缝合带;鄂尔多斯盆地的边界在中元古代—古生代为板块边界,在中新生代为陆内变形边界;该盆地在中元古代—奥陶纪为覆盖整个鄂尔多斯地块的海相克拉通盆地、石炭纪—二叠纪为板块边缘岛弧隆起带围限下的海陆过渡相坳陷盆地、三叠纪为陆内统一湖相坳陷盆地、新生代为裂谷体系环绕的陆内克拉通盆地,盆地范围自古至今逐步缩小。大型原型盆地的广覆性决定了油气勘探范围远超现今沉积盆地范畴,勘探层系为纵向多目的层系。鄂尔多斯盆地具有“全油气(或成矿)系统”的特点,盆地深层中元古界宽裂谷体系“盆下盆”和寒武系—奥陶系被动陆缘盆地与克拉通内坳陷将成为油气勘探重要接替领域。 展开更多
关键词 盆地边界 原型盆地 构造属性 能源矿产 叠合盆地 全油气系统 油气勘探领域 鄂尔多斯盆地
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高速重载堆垛机器人设计与研究
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作者 刘送永 尹守乾 +2 位作者 江红祥 刘后广 孟德远 《机械设计》 北大核心 2025年第8期19-30,共12页
为了解决木工家具行业的搬运堆垛工作主要由人工进行、人力成本高、效率低下等问题,设计了一款6自由度的高速重载堆垛机器人。设计前在工厂进行实地调研,分析了堆垛流程及技术指标,确定了一种CRR//CRC型的6自由度串联关节型堆垛机器人构... 为了解决木工家具行业的搬运堆垛工作主要由人工进行、人力成本高、效率低下等问题,设计了一款6自由度的高速重载堆垛机器人。设计前在工厂进行实地调研,分析了堆垛流程及技术指标,确定了一种CRR//CRC型的6自由度串联关节型堆垛机器人构型,并进行三维结构的设计与绘制;建立堆垛机器人连杆坐标系,利用D-H参数法求解堆垛机器人末端的位置方程,进而得到堆垛机器人的工作空间,采用矢量积法求解出堆垛机器人的雅可比矩阵,并分类讨论了机器人的几种奇异位形与关节角的关系;通过ADAMS动力学仿真探讨了速度和负载对各关节动态响应的影响,并分析了翻转动作中J2,J3和J4轴的力矩变化情况。仿真结果表明:堆垛机器人能够很好地完成翻转动作。采用ANSYS仿真软件对大臂进行刚度及强度校核,并进行轻量化设计,得到大臂结构的最大变形量为0.28 mm,最大应力为48.583 MPa,求得其安全系数为3.29,满足刚度和强度要求。对所设计的堆垛机器人进行了样机制作,并进行负载能力测试和运动测试,设计了大臂应力-应变试验,测试和试验结果表明:堆垛机器人能够完成最大质量200 kg物件的抓取,结构设计合理可靠,并验证了大臂有限元分析的正确性。 展开更多
关键词 堆垛机器人 工作空间 动态特性 静力学分析 样机制造
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