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A novel digital twin-enabled three-stage feature imputation framework for non-contact intelligent fault diagnosis

Advanced engineering Informatics 2025年 66卷

作者： Yu, Yue Karimi, Hamid Reza Gelman, Len Liu, Xin Department of Mechanical Engineering Politecnico di Milano via La Masa 1 Milan20156 Italy School of Computing and Engineering University of Huddersfield Queensgate HuddersfieldHD1 3DH United Kingdom Department of Key Lab of Industrial Computer Control Engineering of Hebei Province Yanshan University Qinhuangdao06600 China

Vibration-based fault diagnosis methods are widely used in industrial applications due to their high accuracy and reliability. However, their implementation is often hindered by challenges such as confined spaces, harsh environmental conditions, and cost limitations. Moreover, traditional deep learning-based approaches frequently overlook the critical relationship between virtual and physical signals, which can limit their diagnostic performance. To overcome these challenges, this study introduces a novel digital twin-driven feature imputation framework (NIFD-Net) for non-contact intelligent fault diagnosis. The NIFD-Net framework consists of three key stages: (1) codebook generation, where features from simulated vibration signals (SVS) and non-contact signals (NCS) are compressed and regularized using diagnosis-oriented codebooks;(2) mapping construction, where a Transformer is employed to establish the relationship between SVS and NCS in a compressed feature space;and (3) diagnostic enhancement, where imputed SVS features are integrated with original NCS features to improve diagnostic performance. First, digital twin (DT)-enabled models, developed using structural parameters and fault characteristics, dynamically simulate the operating conditions of rolling bearings to generate high-quality SVS samples. The relationship between the two feature spaces of SVS and NCS is then learned by a transformer to impute the SVS features. Finally, the imputed SVS features are integrated with the original NCS features to enhance fault diagnostic performance. Extensive experiments on three case studies demonstrate that NIFD-Net outperforms state-of-the-art methods, achieving an average accuracy of 98.34% across diverse tasks. Notably, the framework exhibits strong noise robustness, maintaining high diagnostic performance even under adverse conditions (e.g., SNR = -10 dB). The results highlight the effectiveness of integrating simulated and real signals for non-contact fault diag

关键词： Vibrations (mechanical)

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Thermal Management of Large-Sized Lifepo4 Pouch Cell Using Simplified Mini-Channel Cold Plates

SSRN

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SSRN 2023年

作者： Kausthubharam Koorata, Poornesh Kumar Panchal, Satyam Department of Mechanical Engineering Seoul National University Seoul08826 Korea Republic of Electrochemical Energy System Design Lab Department of Mechanical Engineering National Institute of Technology Karnataka Surathkal Mangalore575 025 India Mechanical and Mechatronics Engineering Department University of Waterloo 200 University Avenue West WaterlooONN2L 3G1 Canada

An efficient, simplified mini-channel cooling plate-based thermal management system is presented for LiFePO4 pouch cell. The proposed design improves the uniformity in surface temperature difference by more than 100% compared to existing literature data on similar designs. The proposed coolant design is tested for temperature distribution and cooling efficiency parameters by varying the cooling fluid volume flow rate and inlet temperatures from 15ml/min to 150ml/min and 5°C to 35°C, respectively. The proposed design maintains the maximum temperature in the cell well below 40ºC even under a 4C discharge rate and a high coolant inlet temperature of 35ºC. Increasing the coolant temperature is observed to positively impact the temperature homogeneity in the pouch cell. Further, an increase in cooling liquid flow rate is observed to have a reduced impact on the maximum temperature reduction at all discharge rates. The proposed simple design can be scaled to modular packs of pouch cells. © 2023, The Authors. All rights reserved.

关键词： Flow patterns

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On the Process Optimization, Microstructure Evolution, and mechanical Properties of Cucrzr Produced by Laser Directed Energy Deposition

SSRN

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SSRN 2022年

作者： Zardoshtian, Ali Ansari, Mazyar Esmaeilzadeh, Reza Keshavarzkermai, Ali Jahed, Hamid Toyserkani, Ehsan Multi-Scale Additive Manufacturing Lab Department of Mechanical and Mechatronics Engineering University of Waterloo WaterlooONN2L 3G1 Canada Department of Mechanical & Mechatronics Engineering University of Waterloo 200 University Avenue West WaterlooONN2L 3G1 Canada

Laser Directed Energy Deposition (LDED) is a suitable manufacturing technology for processing CuCrZr alloy that has recently gained interest to be used in high heat flux applications due to its unique thermal properties. However, the low laser absorptivity of this alloy at the laser wavelength of 1060 nm and high thermal conductivity make it challenging to reach a successful deposition. This study reports a systematic investigation into the LDED processing of CuCrZr alloy. The effects of main process parameters, which are laser power, scanning speed, and powder feed rate on the geometry, microstructure, and microhardness of single tracks are studied. Process parameters are optimized to achieve acceptable track geometries that consists of proper bead shape and sufficient dilution as well as maximizing the deposition rate. Further, the results from the investigations on microstructure of the printed samples by optical microscopy, SEM, and EBSD methods show a realistic correlation between the microstructure and the process parameters. Laser power and a combined parameter of powder feed rate over scanning speed are found to play a key role in the grain structure morphology and nucleation. Finally, the microhardness results reveal a moderate transition of hardness from the top of the bead to the bottom of the melt pool for all samples. © 2022, The Authors. All rights reserved.

关键词： Microstructure

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A Constant Force Tracking Strategy for Complex Surface Robots Fused with NURBS Speed Planning and Teaching/Learning Mode

A Constant Force Tracking Strategy for Complex Surface Robot...

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WRC Symposium on Advanced Robotics and Automation (WRC SARA)

作者： Duan Jinjun Cui Kunkun Guo An Wang Lingyu BinYiming Wan Minhong Huang Qiulan School of Mechatronics Nanjing University of Aeronautics and Astronautics China School of Automation Southeast University China College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and Astronautics China Chinese Academy of Sciences Shenyang Institute of Automation China Zhejiang Lab Hangzhou China Control Theory and Control Egineering Zhejiang University

Compliance control technology is particularly im-portant in contact operations such as grinding and polishing, surface tracking, and medical diagnosis. The core technology achieves contact control of a constant force for complex heterogeneous surfaces. However, due to the unknown environmental stiffness/position and dynamic changes, there are some problems, such as poor position/force tracking accuracy and a low degree of complex surface fit. To solve the above problems, a piecewise trajectory planning algorithm based on speed controllable NURBS and a teaching and learning mode constant force tracking strategy based on position/force coordination planning are proposed in this paper. First, a NURBS segmented trajectory planning algorithm with controllable speed is proposed by combining the NURBS trajectory planning algorithm with the T-type speed interpolation algorithm, and constant force tracking control based on the FCPressNURBS instruction set is realized by combining the adaptive admittance control algorithm. Second, based on the concept of teaching and learning modes, the position/force tracking parameters are obtained by the compliant control method, and the learning ideas is used to optimize the constant force tracking trajectory of the robot. Finally, the algorithm is tested on the ROKAE xMate robot, and the results show that the proposed algorithm improves the constant force tracking accuracy of the robot to the complex contact surface in the heterogeneous environment and can realize the adaptive constant force tracking effect of the robot to the unknown environment.

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Virtual sensing of wheel direction from redundant sensors in aircraft ground-steering systems

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CEAS Aeronautical Journal 2022年第1期13卷 199-213页

作者： Dal Borgo, Mattia Elliott, Stephen J. Ghandchi Tehrani, Maryam Stothers, Ian M. Institute of Sound and Vibration Research University of Southampton SouthamptonSO17 1BJ United Kingdom Department of Mechanical Engineering KU Leuven Leuven3001 Belgium DMMS Lab Flanders Make Leuven3001 Belgium ENTEG Engineering and Technology Institute Groningen University of Groningen Groningen Netherlands Ultra Electronics Precision Control Systems St Johns Innovation Park CambridgeCB4 0DS United Kingdom

Many safety-critical control systems use multiple redundant sensors to estimate the same controlled signal. If the sensors were to operate perfectly, only a subset of them would need to be used for the estimation. In practice, however, the sensors are subject to uncertainty, minor or major faults and their operation may be nonlinear. It is thus important to reliably estimate the controlled signal under these conditions, and also to assess the degree of confidence with which each sensor should be treated. An example of such a control system is the ground-steering control system of an aircraft nose landing gear. A virtual sensing technique is commonly employed, which estimates the steering angle using the measurements of multiple remote displacement sensors. The wheel position is then calculated as a nonlinear function of these sensor outputs. This paper describes how a digital twin of the ground-steering system, in which the effects of uncertainties and faults can be systematically analysed and studied, is used to assess the accuracy and integrity of the steering angle estimation for a number of different estimation algorithms. Two of these algorithms are based on a least-squares approach, while another is a soft-computing technique based on fuzzy logic. These methods are investigated for several scenarios where model uncertainty, measurement noise and sensor faults are included. It is shown that the soft-computing approach is more robust than the least squares based methods under these conditions. © 2021, Deutsches Zentrum für Luft- und Raumfahrt e.V.

关键词： Wheels

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Analysis of actuation characteristics of CuAlNiMn/Polyimide thin film shape memory alloy

引用

Materials Today: Proceedings 2021年 46卷 9580-9585页

作者： M. Geetha K. Dhanalakshmi S. Jayachandran I.A. Palani V. Sathish Kumar Department of Instrumentation and Control Engineering National Institute of Technology Tiruchirappalli 620021 India Mechatronics and Instrumentation Lab Discipline of Mechanical Engineering Indian Institute of Technology Indore 453331 India Mechanical Engineering Kongunadu College of Engineering and Technology Tiruchirappalli 621215 India

The article presents the study of the deformation of an SMA bimorph actuator during static heating. The thermomechanical behavior of thin film CuAlNiMn shape memory alloy (SMA) on polyimide substrate is analyzed using finite element method. The analysis is carried out for three different geometries to obtain the displacement when temperature is varied. The actuation characteristics of the SMA bimorph are studied through direct heating and joule heating techniques. The surface morphology and composition of the bimorph sample are obtained using the Scanning Electron Microscope (SEM). The numerical analysis of the thermomechanical behavior of a thin film CuAlNiMn SMA bimorph is carried out using the finite element method. The procedure is applied for a double-legged cantilever configuration of the bimorph to obtain the actuation in terms of displacement; by varying the temperature. The same is repeated for semi-circular and pentagon shapes of the bimorph to obtain the influence of area on the displacement. It is observed that SMA bimorph displaces with the rise in temperature and the magnitude of displacement increases with the increase in surface area of different geometries. The physical actuation characteristic of CuAlNiMn-polyamide bimorph is studied by thermal heating and electrical heating of the sample, which confirm the shape memory effect of the SMA and provide the displacement characteristics of the bimorph when applying an electrical current.

关键词： CuAlNiMn shape memory alloy Bimorph Static Plate heating Joule heating

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Real-Time Unified Trajectory Planning and Optimal control for Urban Autonomous Driving Under Static and Dynamic Obstacle Constraints

arXiv

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arXiv 2022年

作者： Dempster, Rowan Al-Sharman, Mohammad Rayside, Derek Melek, William The Department of Electrical and Computer Engineering University of Waterloo Canada The Department of Mechanical and Mechatronics Engineering University of Waterloo Canada The WATonomous lab University of Waterloo ONN2L3G1 Canada

Trajectory planning and control have historically been separated into two modules in automated driving stacks. Trajectory planning focuses on higher-level tasks like avoiding obstacles and staying on the road surface, whereas the controller tries its best to follow an ever changing reference trajectory. We argue that this separation is (1) flawed due to the mismatch between planned trajectories and what the controller can feasibly execute, and (2) unnecessary due to the flexibility of the model predictive control (MPC) paradigm. Instead, in this paper, we present a unified MPC-based trajectory planning and control scheme that guarantees feasibility with respect to road boundaries, the static and dynamic environment, and enforces passenger comfort constraints. The scheme is evaluated rigorously in a variety of scenarios focused on proving the effectiveness of the optimal control problem (OCP) design and real-time solution methods. The prototype code will be released at ***/WATonomous/control. © 2022, CC BY-NC-ND.

关键词： Model predictive control

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Fabrication of translucent graded dental crown using zirconia-yttrium multi-slurry tape casting 3D printer

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Journal of the mechanical Behavior of Biomedical Materials 2024年 152卷 106406页

作者： Romario, Yulius Shan Bhat, Chinmai Ramezani, Maziar Pasang, Tim Chen, Zhangwei Jiang, Cho-Pei Graduate Institute of Manufacturing Technology National Taipei University of Technology 1 Sec. 3 Zhongxiao E. Rd. Taipei10608 Taiwan High-value Biomaterials Research and Commercialization Center National Taipei University of Technology 1 Sec. 3 Zhongxiao E. Rd. Taipei10608 Taiwan Department of Mechanical Engineering Auckland University of Technology Auckland1010 New Zealand Department of Engineering Design Manufacturing and Management Systems Western Michigan University KalamazooMI4900-5200 United States Additive Manufacturing Institute Shenzhen University Shenzhen518060 China Guangdong Key Laboratory of Electromagnetic Control and Intelligent Robotics College of Mechatronics and Control Engineering Shenzhen University Shenzhen518060 China Department of Mechanical Engineering National Taipei University of Technology 1 Sec. 3 Zhongxiao E. Rd. Taipei10608 Taiwan

This paper aims to fabricate functionally graded dental crown using a multi-slurry tape casting additive manufacturing technology. The different luminescence of the dental crown was obtained with different composition of zirconia and yttria. Zirconia with tunable mechanical properties and translucency are obtained by adding 3, 3.5, 4, 4.5, and 5 mol% of yttrium oxide to zirconia powder. After obtaining the printable slurry with maximum solid loading, the green bodies are prepared using the in-house built high-speed multi-ceramic tape casting technology. They are later sintered with two-stage sintering method. After the successful fabrication, the mechanical properties and translucency of the specimens were evaluated with Vickers hardness, three-point bending and translucency parameter tests. Finally, an FGM tooth crown with five photocurable slurries is proposed to demonstrate the translucent gradient effect of sintered part. The solid loading of 80% zirconia and 20% resin delivered samples without any surface cracks. The shrinkage ratio analysis showed that the sintered sample dimension was reduced by 20%, 20%, and 23% along X, Y, and Z directions. The samples fabricated with 3% yttrium oxide to zirconia delivered excellent hardness (1687 HV) and flexural strength (650.6 MPa). However, the relative luminescence increased with increasing the yttrium oxide for 3–5 mol%. With the optimized process parameters, the proposed dental crown is fabricated and analyzed for their shrinkage ratio, mechanical, and translucency properties. The study proposes the potential of fabricating customized dental crown with gradient translucent appearance. © 2024

关键词： Zirconia

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Deep Reinforcement Learning Enabled Decision-Making for Autonomous Driving at Intersections

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Automotive Innovation 2020年第4期3卷 374-385页

作者： Guofa Li Shenglong Li Shen Li Yechen Qin Dongpu Cao Xingda Qu Bo Cheng Institute of Human Factors and Ergonomics College of Mechatronics and Control EngineeringShenzhen UniversityShenzhen 518060China Department of Mechanical and Mechatronics Engineering University of WaterlooWaterlooON N2L 3G1Canada Department of Civil and Environmental Engineering University of Wisconsin-MadisonMadisonWI 53706USA School of Mechanical Engineering Beijing Institute of TechnologyBeijing 100081China State Key Laboratory of Automotive Safety and Energy School of Vehicle and MobilityTsinghua UniversityBeijing 100084China

Road intersection is one of the most complex and accident-prone traffic scenarios,so it’s challenging for autonomous vehicles(AVs)to make safe and efficient decisions at the *** of the related studies focus on the solution to a single scenario or only guarantee safety without considering driving *** address these problems,this study proposed a deep reinforcement learning enabled decision-making framework for AVs to drive through intersections automatically,safely and *** mapping relationship between traffic images and vehicle operations was obtained by an end-to-end decision-making framework established by convolutional neural *** images collected at two timesteps were used to calculate the relative velocity between *** decision process was employed to model the interaction between AVs and other vehicles,and the deep Q-network algorithm was utilized to obtain the optimal driving policy regarding safety and *** verify the effectiveness of the proposed decision-making framework,the top three accident-prone crossing path crash scenarios at intersections were simulated,when different initial vehicle states were adopted for better generalization *** results showed that the developed method could make AVs drive safely and efficiently through intersections in all of the tested scenarios.

关键词： Autonomous vehicles Driving safety and efficiency Intersection Decision-making Deep reinforcement learning

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Multiple α sub-variants and anisotropic mechanical properties of an additively-manufactured Ti-6Al-4V alloy

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Journal of Materials Science & Technology 2021年第11期70卷 113-124页

作者： Yinling Zhang Zhuo Chen Shoujiang Qu Aihan Feng Guangbao Mi Jun Shen Xu Huang Daolun Chen School of Materials Science and Engineering Tongji UniversityShanghai 201804China Department of Mechanical and Industrial Engineering Ryerson UniversityTorontoOntario M5B 2K3Canada Aerospace Hiwing(Harbin)Titanium Industrial Co. Ltd.Harbin High Tech ZoneHarbin 150028China Shanghai Key Lab.of D&A for Metal-Functional Materials School of Materials Science&EngineeringTongji UniversityShanghai 201804China Aviation Key Laboratory of Science and Technology on Advanced Titanium Alloys AECC Beijing Institute of Aeronautical MaterialsBeijing 100095China College of Mechatronics and Control Engineering Shenzhen UniversityShenzhen 518060China

Additive manu facturing(AM)is a promising material processing method which gains significant momentum in the aerospace and biomedical ***,the anisotropy in the mechanical properties of additively-manufactured materials is still poorly *** study was aimed at elucidating crystallographic feature-anisotropy-mechanical property relationship for a Ti-6Al-4V alloy manufactured via selective electron beam melting(SEBM).Abundantαlamellae with six variants were present inside the columnar prior-βgrains with a<100>fiber texture duringβ→αphase *** sixαvariants followed the Burgers orientation relationship of{110}_(β)//{0001}_(α)and<1-11>_(β)//<11-20>_(α).Multiple sub-variants in eachαvariant were observed for the first *** anisotropy in the mechanical properties was mainly related to the relative amount of sixα*** the horizontally-oriented samples had a lower yield strength,they exhibited a higher ductility and longer fatigue life than the vertically-oriented *** softening occurred at higher strain amplitudes,and cyclic stabilization sustained at lower strain *** crack mainly initiated from the specimen surface at lower strain amplitudes,while multiple crack initiation tended to occur at higher strain *** propagation was characterized by fatigue striations along with some secondary cracks.

关键词： Titanium alloy 3D printing Deformation behavior Anisotropy Burgers orientation relationship

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