检索结果-内蒙古大学图书馆

Surface-PMSM Sensorless Control Strategy Based on Reduced-Order Linear Kalman Filter Cooperating with Prediction Error Rolling Compensation

引用

IEEE Transactions on Power Electronics 2025年第8期40卷 10804-10815页

作者： Xu, Sang Shen, Anwen Tang, Qipeng Wang, Miaomiao Luo, Pan Luo, Xin Xu, Jinbang National Key Laboratory of Science and Technology on Multispectral Information Processing Key Laboratory of Image Processing and Intelligent Control School of Artificial Intelligence and Automation Wuhan430074 China Science and Technology on Reactor System Design Technology Laboratory Chengdu China

Kalman filter (KF) is increasingly attracted for sensorless control of surface permanent magnet synchronous motors (SPMSMs) due to its strong robustness against measurement and system noise. However, conventional method suffers from poor position and speed estimation accuracy under dynamic conditions, and high computational cost. In order to solve these problems, an enhanced sensorless control strategy based on reduced-order linear Kalman filter (RLKF) cooperating with prediction error rolling compensation is introduced in this paper. Differing from conventional method, a reduced-order linear state equation encompassing rotor position, speed and torque disturbance is constructed. Then, by obtaining the prediction error of system output using the motor current equation in the predictive reference frame, the optimal estimation of rotor position and speed in KF algorithm is achieved based on the reduced-order model. This not only simplifies the calculation process, but also enhances the position and speed estimation accuracy under dynamic conditions. Meanwhile, a prediction error rolling compensation algorithm is developed to minimize the estimation deviations caused by motor parameters variations. Additionally, the system's dynamic performance is further improved with an adopted speed controller based on torque disturbance feedforward and acceleration feedback. Finally, experimental results verify the effectiveness and feasibility of the proposed strategy.1 © 1986-2012 IEEE.

关键词： Permanent magnets

来源：评论

学校读者我要写书评

暂无评论

Development and verification of the higher-order mode neutron flux calculation code HARMONY2.0

引用

Nuclear Science and Techniques 2025年第1期36卷 207-225页

作者： Er-Pin Zhang Zi-Ning Ni Nian-Biao Deng Jin-Sen Xie Yong Liu Tao Yu School of Nuclear Science and Technology University of South ChinaHengyang 421000China Key Laboratory of Advanced Nuclear Energy Design and Safety Ministry of EducationHengyang 421000China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of ChinaChengdu 610213China

Higher-order modes of the neutron diffusion/transport equation can be used to study the temporal behavior of nuclear reactors and can be applied in modal analysis, transient analysis, and online monitoring of the reactor core. Both the deterministic method and the Monte Carlo(MC) method can be used to solve the higher-order modes. However, MC method, compared to the deterministic method, faces challenges in terms of computational efficiency and α mode calculation stability, whereas the deterministic method encounters issues arising from homogenization-related geometric and energy spectra *** on the higher-order mode diffusion calculation code HARMONY, we developed a new higher-order mode calculation code, HARMONY2.0, which retains the functionality of computing λ and α higher-order modes from HARMONY1.0, but enhances the ability to treat complex geometries and arbitrary energy spectra using the MC-deterministic hybrid two-step strategy. In HARMONY2.0, the mesh homogenized multigroup constants were obtained using OpenMC in the first step,and higher-order modes were then calculated with the mesh homogenized core diffusion model using the implicitly restarted Arnoldi method(IRAM), which was also adopted in the HARMONY1.0 code. In addition, to improve the calculation efficiency, particularly in large higher-order modes, event-driven parallelization/domain decomposition methods are embedded in the HARMONY2.0 code to accelerate the inner iteration of λ∕α mode using OpenMP. Furthermore, the higher-order modes of complex geometric models, such as Hoogenboom and ATR reactors for λ mode and the MUSE-4 experiment facility for the prompt α mode, were computed using diffusion theory.

关键词： Neutron diffusion equation Higher-order modes Global homogenization Two-step method Domain

来源：评论

学校读者我要写书评

暂无评论

Substrate bias effects in p-channel GaN-on-Si transistors

引用

Science China(Information Sciences) 2025年第1期68卷 404-405页

作者： Mengyao ZHAO Jie MA Lanlan YANG Chuanqi PAN Denggui WANG Jianjun ZHOU Sheng LI Jiaxing WEI Long ZHANG Siyang LIU Weifeng SUN National ASIC System Engineering Research Center School of Integrated Circuits Southeast University National Center of Technology Innovation for Electronic Design Automation Southeast University National Key Laboratory of Solid-State Microwave Devices and Circuits

The drain current （ID） of the n-channel GaN field-effecttransistor （n-FET） is influenced by the substrate-to-source bias voltage (VBS)（substrate bias effect）[1].Actually,nonzero VBSis also likely to occur in p-FET in real application,because the source electrode of p-FET is usually connected to high *** study reports the dependency between IDand VBSin p-FET for the first time,and analyzes the underlying mechanisms from the perspective of vertical electric field （EF） distribution.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Investigation on influence of gamma irradiation on piezoelectric and resonance characteristics of surface acoustic wave resonators 5

Investigation on influence of gamma irradiation on piezoelec...

引用

5th International Conference on Mechanical Engineering and Materials, ICMEM 2024

作者： Sun, Lei Peng, Bin Yang, Yuntao Sun, Zhaofeng Zhu, Jialiang Zhang, Wanli State Key Laboratory of Electronic Thin Films and Integrated Devices University of Electronic Science and Technology of China Chengdu China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu China

ISBN: (数字)9781510688971

ISBN: (纸本)9781510688964

In this work, an evaluation towards influence of high-dose gamma irradiation on surface acoustic wave (SAW) resonators, is reported. The single-port SAW resonators are fabricated using Lithium niobate (LiNbO3) and Catangasite (CTGS, Ca3TaGa3Si2O14) substrates, along respective cut directions of (0º, 38º, 0º) and (0º, 90º, 0º). Piezoelectric coefficient of substrates, and several main resonance parameters covering resonance frequency, amplitude of resonance peak in reflection coefficient, quality factor together with electromechanical coupling factor of manufactured SAW resonators are investigated, as suitable representatives of piezoelectric and resonance characteristics of SAW resonators. After exposure to gamma ray with a maximum dose of 250 kGy, substrates show insignificant variation not exceeding 6% in their piezoelectric coefficient. Meanwhile, resonance parameters of SAW resonators also alter slightly. Such excellent stability of these characteristics demonstrates credible irradiation hardness owned by both SAW resonators. Results in this study can provide supportive references for usage of LiNbO3 and CTGS-based SAW devices in harsh environments. © 2025 SPIE.

关键词： Gamma rays

来源：评论

学校读者我要写书评

暂无评论

Effect of Free-End Torsion on the Corrosion and Mechanical Properties for Mg-3Zn-0.2Ca Alloy

引用

Acta Metallurgica Sinica(English Letters) 2025年第1期38卷 59-70页

作者： Li-Lan Gao Jiang Ma Yan-Song Tan Xiao-Hao Sun Qi-Jun Gao De-Bao Liu Chun-Qiu Zhang Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical EngineeringTianjin University of TechnologyTianjin300384China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of TechnologyTianjin300384China School of Materials Science and Engineering Tianjin University of TechnologyTianjin300384China

Magnesium alloys with excellent degradability and biocompatibility are promising materials for biomedical implants,saving patients the burden of second ***,their mechanical properties and corrosion resistance are significantly below the requirements for implant *** study aims to improve the mechanical and corrosion resistance properties of Mg-3Zn-0.2Ca alloy by pre-torsion treatment,and find out the optimal shear *** rod-shaped Mg-3Zn-0.2Ca alloy specimens were pre-torsion treated at different torsion *** effect of free-end torsion on Mg-3Zn-0.2Ca alloy was characterized through microstructure analysis,mechanical testing,and corrosion ***-torsion treatment can refine grain and induce twins and dislocations in Mg-3Zn-0.2Ca *** surface hardness increases with the increase in torsion *** yield strength and ultimate strength initially increase and then decrease with increasing torsion angle,while ductility decreases with increasing torsion *** with a shear strain of 30%exhibit the highest tensile strength,reaching 284.78±10.62 MPa,with an elongation of 19.37±1.66%.Furthermore,they show a significant improvement in fatigue lives both before and after *** the stress amplitude is 120 MPa,the fatigue lives for specimens without pre-torsion treatment are 54,275 cycles and 4324 cycles before and after pre-corrosion,while they increased significantly to 92,015 cycles and 5050 cycles with the 30%shear strain,***,the 30%shear strain specimens show a significant reduction in corrosion *** conclusion,pre-torsion treatment can effectively modify the microstructure of Mg-3Zn-0.2Ca alloy,enhancing both mechanical properties and corrosion *** optimal shear strain for this improvement is 30%.This study provides a practical method to enhance the mechanical properties and corrosion resistance of Mg-3Zn-0.2Ca alloy,making it more suitable for biomedical implan

关键词： Magnesium alloy Pre-torsion Microstructure Mechanical property Corrosion resistance

来源：评论

学校读者我要写书评

暂无评论

Improving the ductility of laser directed energy deposited borated stainless steel by increasing laser power

引用

Journal of Manufacturing Processes 2025年 145卷 494-507页

作者： Huang, Sheng Li, Qingyu Zhang, Xiaoyu Cui, Bin Li, Dichen Zhang, Anfeng Miao, Kai State Key Laboratory for Manufacturing Systems Engineering School of Mechanical Engineering Xi'an Jiaotong University Xi'an710049 China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu610213 China Department of Mechanical and Electrical Engineering Yuncheng University Yuncheng044000 China Co. Ltd. Chengdu610091 China

Borated stainless steels (BSSs) are extensively applied in the nuclear energy industry due to boron's excellent thermal neutron absorption capacity, but large and brittle borides formed during casting result in a low ductility. Here, a BSS was produced by laser directed energy deposition, and an investigation was conducted to analyze the impact of laser power on both the microstructure and mechanical properties of the deposited material. Fibrous borides with relatively low volume fraction in the overlapping zone resulted in higher ductility, while lamellar borides with relatively large volume fraction in the non-overlapping zone led to higher strength. As the laser power increased from 180 W to 330 W, the size of fibrous and lamellar eutectic borides and austenite increased significantly, the width of the soft overlapping zone increased by 2.27 times, and the elongation increased by 2.03 times, although yield strength and ultimate tensile strength decreased by 46.3 % and 31.7 %, respectively. As a result, these findings confirmed the feasibility of significantly improving the ductility of the as-deposited BSS by increasing the laser power. The work here provides a way to tailoring the mechanical properties of BSS produced by laser additive manufacturing. © 2025 The Society of Manufacturing Engineers

关键词： Ductility

来源：评论

学校读者我要写书评

暂无评论

A Cost-Sensitive Multi-scale Feature Multi-order Fusion Network for Bearing Fault Diagnosis Under Data Imbalance Conditions

A Cost-Sensitive Multi-scale Feature Multi-order Fusion Netw...

引用

International Conference on Artificial Intelligence and Autonomous Transportation, AIAT 2024

作者： Deng, Shuaiqing Lei, Zihao Wen, Guangrui Su, Yu Liu, Zimin Meng, Zhangxuan Zhang, Zhifen National Key Laboratory of Aviation Power System and Plasma Technology Xi’an Jiaotong University Xi’an710049 China State Key Laboratory for Manufacturing Systems Engineering Xi’an Jiaotong University Xi’an710049 China Key Laboratory of Education Ministry for Modern Design and Rotor-Bearing System Xi’an Jiaotong University Xi’an710049 China

ISBN: (纸本)9789819639724

Railroad transportation plays a vital role in the national economy, and fault diagnosis of its key components is of great significance in ensuring its safe operation. However, due to its long-term operation in a healthy state, it is tough to obtain fault signals, and this class imbalance data seriously degrades the diagnostic capability of intelligent diagnostic algorithms, leading to increased misclassification of minority classes. To address this problem, we propose a cost-sensitive multi-scale feature multi-order fusion network for bearing fault diagnosis under data imbalance conditions. Firstly, a lightweight multi-scale convolutional layer is employed to effectively extract the multi-scale features of the signal. Then the multi-order feature fusion is performed by a hornet to fully utilize the multi-scale information and enhance the ability to mine the limited diagnostic information of the minority class. And the excellent high-dimensional discriminative features are extracted through residual blocks. In addition, an improved cost-sensitive strategy is designed through the posterior probability distribution to rebalance the contribution of each class to the training process for improving the overall diagnostic performance of the model. Finally, the effectiveness and superiority of the proposed method are comprehensively verified by several sets of experiments with different imbalance rates. © Beijing Paike Culture Commu. Co., Ltd. 2025.

关键词： Railroad transportation

来源：评论

学校读者我要写书评

暂无评论

MSC-APFNN: Fault Diagnosis Deep Transfer Network for Rotating Machine based on Multi-scale Convolutional Extraction and Adaptive Pruning Fuzzy Inference system

MSC-APFNN: Fault Diagnosis Deep Transfer Network for Rotatin...

引用

International Conference on Artificial Intelligence and Autonomous Transportation, AIAT 2024

作者： Zhou, Yanrun Lei, Zihao Wen, Guangrui Su, Yu Zhang, Zhifen National Key Lab of Aerospace Power System and Plasma Technology Xi’an Jiaotong University Xi’an710049 China State Key Laboratory for Manufacturing Systems Engineering Xi’an Jiaotong University Xi’an710049 China Key Laboratory of Education Ministry for Modern Design and Rotor-Bearing System Xi’an710049 China

ISBN: (纸本)9789819639687

Intelligent fault diagnosis on mechanical transmission system of the train is of great importance to ensure the efficient operation of high-speed trains. However, due to the complex and changeable operation conditions (OCs), it is difficult to ensure the uniformity of the data distribution obtained by real-time acquisition, which sets a higher standard for the design of intelligent algorithms. Empowered by deep transfer learning (DTL) methods, the fuzzy inference system provides an effective solution to the abovementioned problem. In this paper, an Adaptive Pruning Fuzzy Inference system (APFIS) is proposed predicated on the fuzzy theory and the basic structure of fuzzy neural network, along with the hybrid model MSC-APFNN constructed by combining the multi-scale convolutional network with the proposed APFIS. This model can be employed as a backbone for the application to transfer diagnostic detection of rotating systems based on adversarial networks. Experimental results demonstrate that the proposed model achieves excellent diagnostic results under variable operating conditions, which provide a novel insight into the optimization of the traditional convolutional and fully-connected deep network structure and offer a promising avenue for the research of fuzzy decision-making in the context of fault diagnostics for high-speed trains. © Beijing Paike Culture Commu. Co., Ltd. 2025.

关键词： Fuzzy neural networks

来源：评论

学校读者我要写书评

暂无评论

Intelligent Fault Diagnosis Method of Train Axle Box Bearing Based on Improved Deep Reinforcement Learning

Intelligent Fault Diagnosis Method of Train Axle Box Bearing...

引用

International Conference on Artificial Intelligence and Autonomous Transportation, AIAT 2024

作者： Meng, Zhangxuan Lei, Zihao Deng, Shuaiqing Gu, Shulong Zhang, Zhifen Su, Yu Wen, Guangrui National Key Lab of Aerospace Power System and Plasma Technology Xi’an Jiaotong University Xi’an 710049 China State Key Laboratory for Manufacturing Systems Engineering Xi’an Jiaotong University Xi’an 710049 China Key Laboratory of Modern Design and Rotor Bearing System of the Ministry of Education Xi’an Jiaotong University Xi’an 710049 China

ISBN: (纸本)9789819639687

Axlebox bearings are the key components of rail transit train bogies, which are crucial to the operation of the train. However, the conditions of transit are relatively complex, coupled with the fact that the optimization of the deep neural network of the existing fault diagnosis methods requires a large number of manual modifications and experience of experts, which makes it difficult to effectively diagnose the faults of axlebox bearings. To address the above issues, this paper proposes an improved deep reinforcement learning strategy based on Dueling Double Deep Q-Network (D3QN) and Prioritized Experience replay (PER) for the fault diagnosis of axlebox bearings. Firstly, D3QN combines Double DQN and Dueling DQN to solve the problem of overestimation of the Q-value of Deep Q Network (DQN) and improve the stability of training. Secondly, by introducing the prioritized experience replay and the elevated reward mechanism, the efficiency of experience utilization and the speed of model convergence is improved. Finally, the proposed method is validated by using subway train transmission system fault simulation datasets of Beijing Jiaotong University (BJTU). The results show that compared with the original DQN method, PER-DR3QN has significant improvement in training efficiency, accuracy and stability. © Beijing Paike Culture Commu. Co., Ltd. 2025.

关键词： Deep reinforcement learning

来源：评论

学校读者我要写书评

暂无评论

SeaFree-GS: Reconstructing Underwater 3D Scenes With True Appearances

引用

IEEE Signal Processing Letters 2025年 32卷 2114-2118页

作者： Liu, Shaohua Gao, Ning Fu, Shaowen Zhong, Xiaoqing Li, Hongjue Beihang University School of Astronautics Shenyuan Honors College Beijing100191 China Beihang University School of Astronautics Beijing100191 China Beijing Aerospace Automatic Control Institute Beijing100854 China National Key Laboratory of Science and Technology on Aerospace Intelligent Control Beijing100854 China China Academy of Space Technology Beijing100094 China Beijing Key Laboratory of System Design for Reusable Launch Vehicle State Key Laboratory of High- Efficiency Reusable Aerospace Transportation Technology China

Reconstructing underwater 3D scenes with accurate appearances is crucial for numerous tasks. However, existing underwater 3D reconstruction methods often fail to restore the true scene appearance due to degradation in underwater images caused by water effects. In this letter, we propose SeaFree-GS, a novel approach leveraging 3D Gaussian Splatting (3DGS) to reconstruct underwater scenes with their true appearances. Specifically, we introduce a Degradation-Aware Dual-Color Modeling strategy, where each Gaussian is assigned an intrinsic color representing the true scene appearance and a viewpoint-dependent degraded color to incorporate water effects. For a given viewpoint, this strategy physically derives the corresponding degraded colors from the intrinsic colors to render the underwater image. To improve reconstruction accuracy, we introduce a Content-Based Loss for selective enhancement of supervision over foreground and background regions, and a Coarse-Grained Depth Loss to enforce additional geometric constraints. Experiments on three datasets demonstrate that SeaFree-GS achieves state-of-the-art performance in Underwater True Appearance Reconstruction, and also performs competitively in Underwater Novel View Synthesis. © 1994-2012 IEEE.

关键词： 3D reconstruction

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：