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IEEE International Conference on mechatronics and Automation

作者： Jun Liu Keguang Ren Xiaofeng Wang Weimin Ge National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology Binshui Xidao 391 Xiqing District Tianjin China Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control Tianjin University of Technology Binshui Xidao 391 Xiqing District Tianjin China

ISBN: (数字)9781728164168

ISBN: (纸本)9781728164175

To meet the requirements of online feature extraction for weld defect recognition, an Incremental 2DPCA algorithm (I2DPCA) without estimating the covariance matrix of weld surface images is firstly proposed. A set of weld features with multiple orthogonal principal components can be obtained by a recursive estimation method, instead of the eigenvalue decomposition method or the singular value decomposition method. The computational complexity will be greatly reduced and the online feature extraction speed will be improved. To extract more structure features and reduce the dimension of weld images, an Incremental row-column Bidirectional PCA (IBDPCA) algorithm is presented based on I2DPCA, which preserves the weld features in the horizontal and vertical directions of weld images, and realizes the incremental feature extraction and data dimensionality reduction in the row and column directions. Finally, a series of comparative experiments are performed on the collected weld defect dataset. The results show that the proposed algorithm is superior to other PCA algorithms in convergence rate, classification rate, and complexity. The convergence rate is more than 99%, the classification rate can reach 96%, which can meet the online feature extraction requirements for weld defect recognition.

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Research on Stress-Relaxation Property of Different Layers ment under Compression 16

Research on Stress-Relaxation Property of Different Layers m...

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16th IEEE International Conference on mechatronics and Automation, ICMA 2019

作者： Zhou, Jinlai Song, Yang Shi, Xue Xu, Chenguang Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control Tianjin University of Technology School of Mechanical Engineering Tianjin University of Technology Tianjin300384 China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology China Periodontitis Department Tianjin Stomatological Hospital Tianjin300041 China

ISBN: (纸本)9781728116983

As a connective tissue connecting teeth and alveolar bone, periodontal ligament (PDL) has the mechanical properties of nonlinearity, viscoelasticity, anisotropy. In this paper, the pig mandibular central incisors were taken as subjects, a loading machine(CARE-MI00) was used to perform compression tests and the PDL stress-relaxation characteristics under different strain conditions were obtained. The stress-time curves and the relaxation modulus curves were obtained. The three-parameters Zener model and five-parameter generalized Maxwell model proposed by the author were used to fit the data. The experimental results show that the elastic modulus of PDL decreases gradually in the apex(ranges from 2.64 to 3.06 MPa), cervical margin(ranges from 1.44 to 1.76 MPa) and midroot (ranges from 1.03 to 1. 06MPa). Zener model has a relatively high fitting degree, and the squared correction coefficient is about 0.98, however, the adjusted R square of the five-parameter model was above 0.99. Compared with the Zener model, the five-parameter model can better reflect the sudden drop of relaxation modulus at the initial stage, which is more suitable for describing stress-relaxation in viscoelastic behavior of PDL. The advantage of this paper is to compare the descriptive ability of three-parameter and five-parameter generalized Maxwell equation to the mechanical properties of PDL and to provide an effective procedure for the preparation of PDL specimens. © 2019 IEEE.

关键词： Elastic moduli

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A regular-vine copula-based evidence theory model for structural reliability analysis involving multidimensional parameter correlation

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Computer Methods in Applied Mechanics and Engineering 2025年 444卷

作者： Dequan Zhang Xinjue Xie Zhijie Hao Weipeng Liu Xu Han Qing Li State Key Laboratory of Intelligent Power Distribution Equipment and System School of Mechanical Engineering Hebei University of Technology Tianjin 300401 PR China College of Architecture and Art Design Hebei University of Technology Tianjin 300401 PR China School of Aerospace Mechanical and Mechatronic Engineering The University of Sydney Sydney 2006 New South Wales Australia

The structural reliability analysis subject to epistemic uncertainty and multidimensional correlations among input variables signifies a crucial and demanding task. To address this challenge, a new evidence theory model capable of quantifying complex multidimensional correlations is proposed in this study; and further, an efficient reliability analysis method is developed. To start with, the multidimensional correlations are investigated through the proposed regular-vine copula-based evidence theory (VCET) model by leveraging finite number of samples and the marginal distributions of evidence variables. A joint basic probability assignment reconstruction method is then developed which integrates the copula function with multidimensional correlated evidence variables using a full-factorial numerical integration approach, thereby addressing parameter correlations. Further, the proposed model is employed in reliability analysis, and an enhanced focus element reduction (EFER) technique is developed. EFER synchronously constructs multiple auxiliary regions within the frame of discernment, where the classes of joint focus elements are directly determined, bypassing the high-cost extreme value analysis. Finally, the probability interval consisting of belief and plausibility measures is derived for structures affected by parameter correlations. In this study, three numerical benchmark problems and an engineering case study on the reliability analysis of the array antenna’s maximum gain are presented to demonstrate the effectiveness of the proposed method.

关键词： Epistemic uncertainty Evidence theory Focus element reduction Multidimensional correlations Structural reliability analysis Vine copula

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PUGAN: Physical Model-Guided Underwater Image Enhancement Using GAN with Dual-Discriminators

arXiv

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arXiv 2023年

作者： Cong, Runmin Yang, Wenyu Zhang, Wei Li, Chongyi Guo, Chun-Le Huang, Qingming Kwong, Sam Institute of Information Science Beijing Jiaotong University Beijing100044 China School of Control Science and Engineering Shandong University Jinan250061 China Key Laboratory of Machine Intelligence and System Control Ministry of Education Jinan250061 China Beijing Key Laboratory of Advanced Information Science and Network Technology Beijing100044 China College of Computer Science Nankai University Tianjin300350 China School of Computer Science and Technology University of Chinese Academy of Sciences Beijing101408 China Key Laboratory of Intelligent Information Processing Institute of Computing Technology Chinese Academy of Sciences Beijing100190 China Peng Cheng Laboratory Shenzhen518055 China Department of Computer Science City University of Hong Kong Hong Kong City University of Hong Kong Shenzhen Research Institute Shenzhen51800 China

Due to the light absorption and scattering induced by the water medium, underwater images usually suffer from some degradation problems, such as low contrast, color distortion, and blurring details, which aggravate the difficulty of downstream underwater understanding tasks. Therefore, how to obtain clear and visually pleasant images has become a common concern of people, and the task of underwater image enhancement (UIE) has also emerged as the times require. Among existing UIE methods, Generative Adversarial Networks (GANs) based methods perform well in visual aesthetics, while the physical model-based methods have better scene adaptability. Inheriting the advantages of the above two types of models, we propose a physical model-guided GAN model for UIE in this paper, referred to as PUGAN. The entire network is under the GAN architecture. On the one hand, we design a Parameters Estimation subnetwork (Par-subnet) to learn the parameters for physical model inversion, and use the generated color enhancement image as auxiliary information for the Two-Stream Interaction Enhancement subnetwork (TSIE-subnet). Meanwhile, we design a Degradation Quantization (DQ) module in TSIE-subnet to quantize scene degradation, thereby achieving reinforcing enhancement of key regions. On the other hand, we design the Dual-Discriminators for the style-content adversarial constraint, promoting the authenticity and visual aesthetics of the results. Extensive experiments on three benchmark datasets demonstrate that our PUGAN outperforms state-of-the-art methods in both qualitative and quantitative metrics. The code and results can be found from the link of https://***/proj_***. © 2023, CC BY-NC-SA.

关键词： Discriminators

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Swimming Characteristics of Soft robot with Magnetoelastic Material

Swimming Characteristics of Soft robot with Magnetoelastic M...

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IEEE International Conference on Robotics and Biomimetics

作者： Hongbiao Xiang Mengwei Li Tilei Zhang Shoujun Wang Xiuping Yang Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin China

Cable-less micro-robots have exhibit great capabilities for remote applications in small and constrained environments, especially in biotechnology and healthcare. This paper presents a swimmer propelled by its undulatory deformation using magnetoelastic composite material. The robot can move freely on water surface driven through a function of magnetic field, such as forward, backward and steering with different velocity. The magnetic field is generated by 3D Helmholtz coils, and the locomotion of the micro swimming robot is controlled by different applied magnetic field. To understand the characteristics of the swimmer, the force balance equation is established, and the morphologies of swimmer with different magnetic field are analyzed and described through finite element analysis method. Furthermore, we discuss and analyze relationship between the parameters of magnetic field and the speed of the swimmer. The experimental results verified the speed model of the swimming robot, which is influenced by the frequency and strength of magnetic field.

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Finite Element Analysis of Series Elastic Actuator for Exoskeleton Robot Joint

Finite Element Analysis of Series Elastic Actuator for Exosk...

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IEEE International Conference on mechatronics and Automation

作者： Pengyu Xi Weimin Ge Sen Zhang Zhili Zhang Teresa Zielinska Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology Intelligent Manufacturing College Tianjin Sino-German University of Applied Science Tianjin China Institute of Aeronautics and Applied Mechanics Warsaw University of Technology Warsaw Poland

ISBN: (数字)9781728164168

ISBN: (纸本)9781728164175

The finite element simulation for the joints of an exoskeleton robot is conducted in this paper. Using software OpenSim to simulate the normal walking gait of the human body, the motion angle and moment of the human hip, knee and ankle joints are obtained. Using the obtained data as the input parameters in the finite element simulation of the simulation software Ls-dyna, the strain diagrams and contact force curves of the circular roller and cam disk were obtained. In this study, three commonly used materials are selected: alloy steel, ductile iron and hard aluminum alloy. Finally, the effects of different materials on the key components of the series elastic actuator are studied.

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Augmented Reality and Quick Response Code Technology in Engineering Drawing Course

Augmented Reality and Quick Response Code Technology in Engi...

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IEEE International Conference on mechatronics and Automation

作者： Xiaofei Wang Chenfei Chen Zhaotong Li Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education (Tianjin University of Technology) Tianjin China School of Electrical and Electronic Engineering Tianjin University of Technology Tianjin China School of Mechanical Engineering Tianjin University of Technology Tianjin China

ISBN: (数字)9781728164168

ISBN: (纸本)9781728164175

Augmented reality (AR) technology is a cutting technology. It can enhance the perception of reality and provide more information of the real world. AR technology is used in many fields, like medical, industry, and education. In this paper, AR is introduced into engineering drawing course. Engineering drawing course is difficult to learn as it is a knowledge that students rarely contact with. To have a close contact with the models and the views, a convenient AR application (AR app) is proposed in the paper. With the help of the AR app, virtual models and real views are combined well. The models can be moved and rotated by touching the screen. Some videos of model assembly and disassembly can be obtained when scanning the quick response code (QR code). Thus, it is convenient for students to use mobile phone to study engineering drawing effectively. The interactive teaching environment enhances students' spatial thinking and cultivates their sense of innovation.

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A novel method to increase energy density of permanent magnet machine based on multi-physical field analysis

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UPB Scientific Bulletin, Series D: Mechanical Engineering 2020年第4期82卷 79-92页

作者： Zheng, Qingchun Zhao, Yangyang Zhu, Peihao Wang, Sen Liu, Jingna Ma, Wenpeng Li, Xiang Xiao, Yinhong Wang, Naixin Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin300384 China School of Computer Science Tianjin University of Technology Tianjin300384 China School of Automation Shenyang Institute of Engineering Shenyang110136 China Baoding Power Supply Company Hebei Electric Power Company State Grid Corporation of China Baoding071000 China

As an important component of all-electric aircraft, the main propulsion machine is developing towards high energy density, high efficiency and high fault tolerance. In order to improve the energy density of main propulsion machine for all-electric aircraft, a novel approach, which can be used for excellent performance improvement of electric machine of all-electric aircraft, is reported in this paper. The analytical formula of energy density is put forward and the design method of high energy density permanent magnet machine is presented. A high energy density machine with rated power of 30kW is designed, and the electromagnetic field simulation analysis, strength and stress structure verification, temperature field simulation analysis and multi-physical field coupling analysis are obtained. A prototype is developed, the experiment platform is established, and experiments are performed. The energy density of main propulsion machine designed is up to 21kW·N·m/kg2, and the index is increased by 3.2 times. The optimal method based on the multi-physical field analysis can be also applied to other high energy density machines. © 2020, Politechnica University of Bucharest. All rights reserved.

关键词： Electromagnetic fields

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Manipulator of robust fuzzy adaptive compensation control 3

Manipulator of robust fuzzy adaptive compensation control

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3rd Asia-Pacific Conference on intelligent Robot systems, ACIRS 2018

作者： Yangjian, Wang Xiaofei, Chen Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineeringline Binshui Xidao 391 Tianjin China

ISBN: (纸本)9781538672266

Dynamics system for reconfigurable manipulator of uncertainty, based on the fuzzy adaptive algorithm is proposed to approach the system control law from adaptation to friction and external disturbance, the compensation control of the reconfigurable robot arm. At the same time in order to improve the control law of compensation precision and anti-interference performance, reduce the approximation error of the algorithm and the robust items added in the control law. By Lyapunov stability theory proves that the proposed fuzzy adaptive robust fuzzy control law and the adaptive control law can be in reconfigurable manipulator dynamics contained in friction and the external disturbance to ensure the stability of the system. Last three do f reconfigurable robot arm as an example to design a reconfigurable robotic arm controller, the simulation results show that the algorithm has good trajectory tracking performance, and proves the feasibility and effectiveness of the algorithm. © 2018 IEEE.

关键词： Friction

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Simulation of crystal plasticity of P92 heat resistant steel considering martensitic lath structure

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Journal of Physics: Conference Series 2021年第1期2079卷

作者： Xinyu Wang Junjie Shen Xiangru Guo Jixin Qiao Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin 300384 China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology Tianjin 300384 China

Based on the theory of crystal plasticity, coupled with dislocation and lath hardening models, this paper establishes a crystal plasticity finite element model describing the high temperature creep of P92 steel. Open source software was used to generate lath models with an average size of 350nm, 650nm and 950nm to explore the effect of lath coarsening on the high-temperature creep behavior of P92 steel. The results show that the roughening of the slats increases the rate of creep deformation, resulting in a decrease in the service life of the material. Observing the slat model, it can be seen that the roughening of the slats enlarges the numerical gradient of stress and strain, and aggravates the overall plastic strain of the model. The coarsening of the slats accelerates the movement of dislocations, causing the density of movable dislocations to increase, and at the same time the shear strain amplitude of the slip system increases, thereby reducing the hardening behavior of the material.

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