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Time series clustering adaptive enhanced method for time-dependent reliability analysis and design optimization

Computer Methods in Applied Mechanics and Engineering 2025年 443卷

作者： Zhang, Dequan Zhao, Ying Yang, Meide Jiang, Chao Han, Xu Li, Qing State Key Laboratory of Intelligent Power Distribution Equipment and System School of Mechanical Engineering Hebei University of Technology Tianjin 300401 China State Key Laboratory of Advanced Design and Manufacturing Technology for Vehicle College of Mechanical and Vehicle Engineering Hunan University Changsha410082 China School of Aerospace Mechanical and Mechatronic Engineering The University of Sydney New South Wales Sydney2006 Australia

Adaptive Kriging model has gained growing attention for its effectiveness in reducing the computational costs in time-dependent reliability analysis (TRA). However, the existing methods struggle to identify critical sample regions, leverage parallel computational resources, and assess the value for sample trajectories, thus restricting improvement in accuracy and efficiency. To address the challenges, this study proposes a time series clustering adaptive enhanced method (TSCM). TSCM first employs the time series clustering technique to partition the sample region efficiently. A novel time-dependent Kriging occurrence learning function is then introduced to account for both the uncertainty of sample trajectories and its influence on the approximated limit state boundary. Subsequently, an adaptive sampling strategy is developed to select training samples in parallel, guided by an uncertainty-based assessment of sample regions. After that, a time-dependent error-based stopping criterion is introduced to determine the training stage and terminate the update process. Finally, TSCM is extended to time-dependent reliability-based design optimization problems. Several numerical examples and an engineering case study demonstrate the superior computational efficiency and accuracy of the proposed method. © 2025

关键词： Time-to-failure

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A clock synchronization method for EtherCAT master

A clock synchronization method for EtherCAT master

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2023智能制造与机械动力学学术大会

作者： Libo Cao Taiyong Wang Yongbin Zhang Songhui Jia Chong Tian Ying Tian Qingjian Liu School of Mechanical Engineering Tianjin University Renai College Tianjin University Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical EngineeringTianjin University of Technology

EtherCAT has been widely applied in the motion control domain due to its advantages of the fast response speed,low CPU usage and good synchronization *** the distributed clock synchronization mechanism shows strong performance between the slaves,the clock synchronization method between the master clock and the reference clock is still open for users to choose,and there are few studies in this *** paper proposed a novel clock synchronization mechanism between the master of CNC system and the reference slave which also call servo motor of drive *** mechanism relies on sync0 of the reference servo ***0 is very stable and almost no time jitter,which is a dozen *** clock of the master of the numerical control system(CNC) adjusted the trigger moment of the interpolation period adaptively and dynamically to realize synchronization between master and reference servo motor taking sync0 as *** addition,the proposed method almost hardly add computational load and modify the EtherCAT frames by adding four bytes only without increasing an excessive communication load in the interpolation *** synchronization mechanism fills the gap of distributed clock synchronization which is the synchronization mechanism between reference servo motor and the other servo *** are preformed to verify the synchronization *** results demonstrate that the jitters of EtherCAT frames are measured to be only 112ns and 95.5 ns.

关键词： the CNC system synchronization reference slave sync0

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EAN-MapNet: Efficient Vectorized HD Map Construction with Anchor Neighborhoods

arXiv

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arXiv 2024年

作者： Xiong, Huiyuan Shen, Jun Zhu, Taohong Pan, Yuelong School of Intelligent Systems Engineering Sun Yat-sen University China Guangdong Provincial Key Laboratory of Intelligent Transport System China China Nuclear Power Design Co. Ltd. China State Key Laboratory of Nuclear Power Safety Technology and Equipment China Nuclear Power Engineering Co. Ltd. Guangdong Shenzhen518172 China

High-definition (HD) map is crucial for autonomous driving systems. Most existing works design map elements detection heads based on the DETR decoder. However, the initial queries lack explicit incorporation of physical positional information, and vanilla self-attention entails high computational complexity. Therefore, we propose EAN-MapNet for Efficiently constructing HD map using Anchor Neighborhoods. Firstly, we design query units based on the anchor neighborhoods, allowing non-neighborhood central anchors to effectively assist in fitting the neighborhood central anchors to the target points representing map elements. Then, we propose grouped local self-attention (GL-SA) by leveraging the relative instance relationship among the queries. This facilitates direct feature interaction among queries of the same instances, while innovatively employing local queries as intermediaries for interaction among queries from different instances. Consequently, GL-SA significantly reduces the computational complexity of self-attention while ensuring ample feature interaction among queries. On the nuScenes dataset, EAN-MapNet achieves a state-of-the-art performance with 63.0 mAP after training for 24 epochs, surpassing MapTR by 12.7 mAP. Furthermore, it considerably reduces memory consumption by 8198M compared to MapTRv2. Copyright © 2024, The Authors. All rights reserved.

关键词： Computational complexity

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Review of Research Advances in CFD Techniques for the Simulation of Urban Wind Environments

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Fluid Dynamics & Materials Processing 2022年第2期18卷 449-462页

作者： Pengfei Ju Mingrui Li Jingying Wang 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 Technology) Tianjin300384China School of Energy and Power Engineering Shandong UniversityJinan250061China Shandong Engineering Laboratory for High-Efficiency Energy Conservation and Energy Storage Technology&Equipment Shandong UniversityJinan250061China

Computational fluid dynamics(CFD)has become the main method for the prediction of the properties of the external wind environment in cities and other urban contexts.A review is presented of the existing literature in terms of boundary conditions,building models,computational domains,computational grids,and turbulence *** specific issues,such as the accuracy/computational cost ratio and the exploitation of existing empirical correlations,are also examined.

关键词： Computational fluid dynamics wind environment pre-processing settings

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Identification Algorithm Framework and Structural model on Input Pattern of Metamorphic Relations 9

Identification Algorithm Framework and Structural model on I...

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9th International Conference on Dependable systems and Their Applications, DSA 2022

作者： Yan, Shiyu Yang, Xiaohua Lu, Zhongjian Li, Meng Gong, Helin Liu, Jie Computer School University of South China Hunan Hengyang China Intelligent Equipment Software Evaluation Engineering Technology Research Center of Hunan Hengyang China Cnnc Key Laboratory on High Trusted Computing Hunan Hengyang China Nuclear Power Institute of China Science and Technology on Reactor System Design Technology Laboratory Chengdu China

ISBN: (数字)9781665488778

ISBN: (纸本)9781665488778

Metamorphic Relation (MR) plays a crucial role in Metamorphic Testing (MT), which can be regarded as the implication relation from the input pattern to the output pattern. Based on MR's properties, the identification of Metamorphic Relations (MRs) can be from its input pattern and output pattern, respectively. However, the finding of the effective input pattern is very first and important. Especially for complicated mathematical function includes more than two input variables, we systematically analyze the structural model of input pattern in MR, propose the concept of the class of basic input pattern, as well as prove that any one input pattern can be expressed as a combination of basic input patterns in scientific computing programs. Moreover, the structural model of input pattern in MR is established based on previous proof. Finally, we put forward an identification algorithm framework and analysis its complexity. The core contribution of our method is to decompose the input pattern identification problem in multi-dimensional space into a single one-dimensional. For this reason, the examples show that the complexity of the algorithm is reduced significantly. © 2022 IEEE.

关键词： Computational complexity

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design and Experimental Evaluation of a Hexapod Mobile Robot with C-Shaped Legs 8

Design and Experimental Evaluation of a Hexapod Mobile Robot...

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8th IEEE International Conference on Advanced Robotics and Mechatronics, ICARM 2023

作者： Wu, Yujie Li, Dangchao Dong, Xia Wang, Xin Zheng, Chunli Zhu, Aibin Zhang, Zheng Zhou, Xu Zhang, Yulin Institute of Robotics & Intelligent Systems Xi'An Jiaotong University Shaanxi Key Laboratory of Intelligent Robots Xi'an710049 China Key Laboratory of Education Ministry for Modern Design and Rotor-Bearing System Xi'an710049 China School of Construction Machinery Chang'An University Xi'an710064 China Xi'An Jiaotong University Xi'an710049 China School of Energy and Power Engineering xi'An Jiaotong University Xi'an710049 China School of Mechanical Engineering Northwestern Polytechnical University Xi'an710072 China Taiyuan Research Institute of China Coal Technology & Engineering Group Co. Ltd Taiyuan030006 China

ISBN: (纸本)9798350300178

Drawing on extant literature on hexapod robots, we present a novel obstacle-crossing hexapod robot that can adapt to multiple terrains. We designed the robot's entire mechanical structure, established a mathematical model for the robot leg, deduced the kinematic equation of the leg, and determined the relationship between the robot's motion speed and the motor angle. Through force analysis of the C-shaped leg, we obtained the function between motor output torque and motion phase. Subsequently, we constructed the physical hexapod robot and conducted performance testing. Our experimental results demonstrate that the hexapod robot can move at a speed of 0.5 m/s and successfully cross a 10 cm obstacle. The robot exhibits excellent movement performance and satisfies the functional requirements. Overall, our design offers a promising approach for developing hexapod robots that can navigate a variety of terrains. © 2023 IEEE.

关键词： Machine design

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Research on vision detection technology based on photometric calibration

Research on vision detection technology based on photometric...

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2021 IEEE International Conference on Computer Science, Electronic Information Engineering and intelligent Control Technology, CEI 2021

作者： Sun, Guoqing Zhou, Haibo Li, Chenming Zhao, Yijiao Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control Tianjin300384 China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin300384 China

ISBN: (纸本)9780738146492

The camera is affected by illumination changes and vignetting effect during the shooting process, resulting in the lack of brightness information, which affects the accuracy of target detection. In order to reduce the impact of illumination changes and vignetting effect on image quality, obtain images closer to the real scene, and improve the accuracy of target detection, this paper conducts photometric calibration on the image from two aspects: the calibration of CRF (Camera Response Function) and the compensation function of vignetting effect. This paper first uses the N-degree polynomial model to construct the camera response function, proposes a functional model of vignetting compensation based on the position of the pixel point, and finally combines the first two experimental results and conducts experimental verification on the data set before and after the photometric calibration on different algorithms of target detection. The experimental results show that the application of photometric calibration in the field of machine vision can improve the adaptability of machine vision to illumination changes and vignetting effect to a certain extent. The self-made data set is trained and tested, when IoU is 0.7, the mAP calculated by the test set after photometric calibration is improved by 2.3% compared with the original data set. © 2021 IEEE.

关键词： Computer vision

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Research on intelligent Fault Diagnosis Method of Planetary Gearbox Based on ITD and CNN

Research on Intelligent Fault Diagnosis Method of Planetary ...

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Prognostics and system Health Management Conference (PHM-Qingdao)

作者： Songsong Zhu Jiwei Chen Ruitong Xie Yuhao Song Mian Zhang Mengxiong Zhao 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

ISBN: (数字)9798350354010

ISBN: (纸本)9798350354027

Accurate fault diagnosis of planetary gearboxes (PGs) is crucial for preventing equipment failures and extending their lifespan. To enhance the efficiency and accuracy of PG fault diagnosis, this paper proposes a novel method integrating intrinsic time scale decomposition (ITD) with convolutional neural network (CNN). The proposed method leverages the demodulation capability of ITD to decompose and reconstruct the original signal, effectively removing irrelevant noise and isolating core fault features, and the learning ability of CNN to accurately identify the fault features. Compared to methods relying on CNN only, the proposed method not only improves the computational efficiency but also achieves higher fault diagnosis accuracy.

关键词： Fault diagnosis Accuracy Computational modeling Noise Feature extraction Computational efficiency Convolutional neural networks Prognostics and health management Demodulation

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Kinematic analysis and trajectory planning of two-limb 4-DOF high-speed parallel robot

Kinematic analysis and trajectory planning of two-limb 4-DOF...

引用

IEEE International Conference on Mechatronics and Automation

作者： Weihua Sun Yue Ma Changrui Li Bin Li Yansen Zhao Qi Liu 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

ISBN: (数字)9798350388077

ISBN: (纸本)9798350388084

Focusing on the pick-and-place operation in the electronic, packaging, and other light industries, this paper proposed a new type 3T1R (T-Translation, R-Rotation) high-speed parallel robot with two limbs. Compared with other 4-DOF high-speed parallel robots with four limbs, its structure is simpler while the working space is larger, such that the potential for cheaper usage in the industry is achieved. The robot's kinematic analysis and trajectory planning, including key aspects, are also outlined here. Firstly, the robot's closed-loop constraint equation is established using the vector chain method. The displacement, velocity, and acceleration models are derived, and the Jacobian matrix is obtained. On this basis, the gate shape trajectory is planned using the 3-4-5 polynomial motion rule, such that the displacement, velocity, and acceleration of the driving joint are obtained using the kinematic models above. Ultimately, the accuracy of the kinematic models is confirmed by comparing the theoretical outcomes with the simulations carried out in SolidWorks. The study presented in this paper establishes a firm basis for the dimensional integration and the creation of a physical model of the robot.

关键词： Industries Solid modeling Parallel robots Trajectory planning Kinematics Logic gates Vectors

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Mechanical design of Out-pipe Detection Mechanisms for Pipeline Defects

Mechanical Design of Out-pipe Detection Mechanisms for Pipel...

引用

IEEE International Conference on Mechatronics and Automation

作者： Guangyin Nie Xinhua Zhao Yihan Ren Liang Liu 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

ISBN: (数字)9798350388077

ISBN: (纸本)9798350388084

Pipes in various are dominated in in the process of industrial production. To avoid the pipeline leak due to inner corrosion, it is essential to develop pipe inspection mechanisms to detect the wall thickness of the pipes used in production. The paper presents three kinds of out-pipe detection mechanisms (ODM) for different petrochemical pipeline detection demands based on eddy current testing (ECT) method. A linear inspection mechanism with fixed length is firstly proposed to detect defects of straight pipe. Secondly, a rotary inspection mechanism is designed for pipeline weld detection. Besides, an out-pipe scanning wheeled robotic mechanism is developed to detect wall thickness of pipes and avoid small obstacles such as valves on the pipelines. Lastly, detection experiments and simulations are carried out to verify the effectiveness of the designed out-pipe detection mechanisms.

关键词： Mechatronics Welding Pipelines Production Inspection Valves Petrochemicals

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