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SSRN 2022年

作者： Zhang, Kunpeng Xie, Jianwei Hao, Shuying Feng, Jingjing Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin300384 China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology Tianjin300384 China

In this paper, we investigate a class of tapered beam micro-gyroscope with electrostatically driven and consider the effects of electrostatic force nonlinearity and fringing field. The governing equations of system are derived by Euler angular transformation and Hamilton principle. The ordinary differential equations with fourth-order variable coefficient are solved by the Adomian decomposition method (ADM). Influence of parameters such as shape factors and DC voltage on static deflection, pull-in voltage and natural frequency of tapered beam micro-gyroscope are investigated. Galerkin discretization is performed on the governing equations of the tapered beam micro-gyroscope. The frequency-response equation of the system is deduced and solved by applying the method of multi-scale (MMS). We obtained the influence regular of DC voltage and fringing field effect on the frequency-response curves. Finally, performance of the tapered beam micro-gyroscope is analyzed in terms of bandwidth, sensitivity, and calibration curve nonlinearity under different shape factors. In static analysis, the pull-in voltage of system gradually decreases with the increase of the shape factors of tapered beam micro-gyroscope, and it will be further reduced by considering the fringing field effect. In the dynamic analysis, the maximum amplitude of motion in the drive and sense directions increases significantly with the shape factors of the tapered beam. Softening characteristics caused by the nonlinearity of the electrostatic force are enhanced. Compared with straight beam micro-gyroscope, the tapered beam micro-gyroscope has the higher amplitude of motion and pronounced nonlinear characteristics. Due to the nonlinearity, the frequency-response curves in the drive direction shifts to the left. The amplitude of motion in the drive direction has a high response over a wide frequency band. By controlling the DC voltage, the natural frequency of the sense mode is matched with the nonlinear natural

关键词： Bandwidth

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Analysis of Strengthening Mechanism and Thermal Stability of M23c6 and Laves Phase in a Ferrite Matrix

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SSRN 2023年

作者： Jin, Tiejian Shen, Junjie Ruan, Taotao Zhang, Dechang Xu, Yu Ren, He Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin300384 China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology Tianjin300384 China

The strengthening of ferrite matrix steel depends on the strengthening mechanism and thermal stability of M23C6 and Laves phases. This study investigated M23C6(Fe,Cr)23C6 and Laves(Fe2Nb) phase-strengthened ferritic steels. The creep microstructure, the interface structure, and the nanoindentation creep behavior of the second phase were studied. Results showed that the dislocation density in (Fe,Cr)23C6 strengthened ferritic steel after creep is lower than Fe2Nb strengthened ferritic steel. The dislocations in the crept (Fe,Cr)23C6 strengthened ferritic steel are straight without accumulation, significantly bending. The dislocations bend and entangle, forming dislocation walls in the crept Fe2Nb-strengthened ferritic steel. The orientation relationships between (Fe,Cr)23C6/Fe2Nb and ferrite matrix are [001]α-Fe//[011](Fe,Cr)23C6, (020)α-Fe//(71[[EQUATION]])(***)23C6,[001]α-Fe//[5[[EQUATION]]]Fe2Nb,(01[[EQUATION]])α-Fe//(03[[EQUATION]])Fe2Nb. The atomic interface mismatch between M23C6/Fe2Nb and the ferrite matrix is 20% of the semi-coherent interface and 1.6% of the coherent interface. The thermal stability of Fe2Nb is better than (Fe,Cr)23C6. The creep stress exponents of (Fe,Cr)23C6 and Fe2Nb in the ferrite matrix are 4.4 and 12.2, respectively. The alloy’s creep deformation follows dislocation climbing over the second phase. Second-phase Fe2Nb strengthening played a more significant role than (Fe,Cr)23C6 in enhancing the ferrite matrix. The results provide a theoretical foundation for developing ferritic heat-resistant steel based on Laves (Fe2Nb) phase strengthening. © 2023, The Authors. All rights reserved.

关键词： Creep

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Thermal-Economic Optimization and Working Fluid Selection of Subcritical Organic Rankine system for Low-Temperature Waste Heat Recovery

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SSRN 2022年

作者： Zhang, Chao Li, Yongwang Fu, Wencheng Zhiting, Tong Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin300384 China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology Tianjin300384 China

In the present study, multi-objective optimization is conducted to search for the best operating condition for a subcritical organic Rankine system with the trade-off between system exergy efficiency and dynamic payback period (PBP). A 150°C wastewater heat source is employed as a typical low-temperature heat source. Five decision variables are considered: turbine inlet temperature and pressure, pinch point temperature differences in evaporator and condenser, and condensing temperature. The multi-objective genetic algorithm combined with the backpropagation neural network method is employed as the optimization approach. In addition, the improved Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) is developed to gain the optimal Pareto front solution for either working fluid and find the optimal working fluid among the candidates investigated. The results show that working fluid R236fa is the optimal solution, despite the minimum PBP for working fluid R123 and the maximum system exergy efficiency for working fluid R1234ze. Under the optimal working condition for working fluid R236fa, the system exergy efficiency and the PBP are 0.465 and 7.377 years, respectively. © 2022, The Authors. All rights reserved.

关键词： Multiobjective optimization

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A Study of Soil Modelling Methods Based on Line-Structured Light——Preparing for the Subsoiling Digital Twin

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SSRN 2024年

作者： Li, Xia You, Birong Wang, Xuhui Zhao, Zhipeng Qi, Tianyu Xu, Jinyou Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin300384 China National Demonstration Centre for Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology Tianjin300384 China

The virtual model serves as the foundation for constructing a digital twin system. In order to provide technical guidance for the construction of a digital twin system for subsoiling, this study employed the line structured light method for soil model generation. Field experiments and indoor experiments were conducted separately, using the extreme value method, grayscale centroid method, and Steger algorithm to extract the laser centrelines in the experiments. The results show that the extreme value method and grayscale centroid method have almost the same processing time when dealing with two types of images, which are 1.9ms and 18ms respectively. The Steger algorithm has a significant difference in processing time when dealing with indoor and field images, with the processing time being longer for indoor images, approximately 300ms. Regarding memory usage, there is a large difference when the extreme value method processes two sets of images. Therefore, the grayscale centroid method is the most suitable method for centreline extraction in a digital twin system for subsoiling. When performing 3D reconstruction, the camera shooting frequency is positively correlated with the reconstruction effect, while the moving speed is negatively correlated with the reconstruction effect. Of course, the reconstruction effect is also related to the performance of the binocular camera used. In addition, the processing time for each image during reconstruction is within 1ms, indicating that the method of line laser 3D reconstruction can solve the problem of soil modelling in subsoiling digital twin. © 2024, The Authors. All rights reserved.

关键词： Soils

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Soft computing for the intelligent robust control of a robotic unicycle with a new physical measure for mechanical controllability

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Soft Computing 1998年第2期2卷 73-88页

作者： Ulyanov, S. V. Watanabe, S. Ulyanov, V. S. Yamafuji, K. Litvintseva, L. V. Rizzotto, G. G. Department of Mechanical and Control Engineering The University of Electro-Communication 1-5-1 Chofugaoka Chofu Tokyo 182 Japan JP Corporate Advanced System SGS-THOMSON Microelectronics Via C. Olivetti 2 20041 Agrate Brianze Italy IT

The posture stability and driving control of a human-riding-type unicycle have been realized. The robot unicycle is considered as a biomechanical system using an internal world representation with a description of emotion, instinct and intuition mechanisms. We introduced intelligent control methods based on soft computing and confirmed that such an intelligent control and biological instinct as well as intuition together with a fuzzy inference is very important for emulating human behaviors or actions. Intuition and instinct mechanisms are considered as global and local search mechanisms of the optimal solution domains for an intelligent behavior and can be realized by genetic algorithms (GA) and fuzzy neural networks (FNN) accordingly. For the fitness function of the GA, a new physical measure as the minimum entropy production for a description of the intelligent behavior in a biological model is introduced. The calculation of robustness and controllability of the robot unicycle is presented. This paper provides a general measure to estimate the mechanical controllability qualitatively and quantitatively, even if any control scheme is applied. The measure can be computed using a Lyapunov function coupled with the thermodynamic entropy change. Interrelation between Lyapunov function (stability condition) and entropy production of motion (controllability condition) in an internal biomechanical model is a mathematical background for the design of soft computing algorithms for the intelligent control of the robotic unicycle. Fuzzy simulation and experimental results of a robust intelligent control motion for the robot unicycle are discussed. Robotic unicycle is a new Benchmark of non-linear mechatronics and intelligent smart control.

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Landing Area Prediction in Complex Terrains for Walking-assisted Lower-limb Exoskeleton Robot

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Procedia Computer Science 2023年 226卷 120-126页

作者： Yuexun Liu Du-Xin Liu Yue Ma Sheng Guo Xinyu Wu Robotics Research Center School of Mechanical Electronic and Control Engineering Beijing Jiaotong University Beijing 100044 China Guangdong Provincial Key Laboratory of Robotics and Intelligent System Shenzhen Institutes of Advanced Technology Chinese Academy of Sciences Shenzhen 518055 China

With the expansion of application scenarios, the walking-assisted lower-limb exoskeleton robot urgently needs to improve its walking ability in complex terrains. However, due to the lack of environmental understanding ability and decision-making ability, the exoskeleton can not meet the need of people with lower-limb disability in complex terrains. To improve the walking abillity, this paper proposes a method of predicting the landing area in complex terrains for walking-assisted lower-limb exoskeleton robot. Multiple sensors were used to obtain the terrain information, step length, and stride length of human walking, and a multi-type input convolutional network was built to establish the mapping relationship to learn the decision-making mechanism of human standing in a complex environment. The result shows that the established network effectively predicts the landing area. Under the condition of full training, the predicted position deviation of the landing area is controlled within 6%, and the prediction rationality of the landing area can reach 90%.

关键词： Landing area prediction Walking-assisted lower-limb exoskeleton robot Complex terrains

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Nanofabrication of DLC-dot arrays by room-temperature curing imprint-liftoff method

Nanofabrication of DLC-dot arrays by room-temperature curing...

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2012 MRS Fall Meeting

作者： Kiyohara, Shuji Matta, Shohei Ishikawa, Ippei Tanoue, Hideto Takikawa, Hirofumi Taguchi, Yoshio Sugiyama, Yoshinari Omata, Yukiko Kurashima, Yuichi Electric and Control System Engineering Course Faculty of Advanced Engineering Maizuru National College of Technology 234 Aza Shiroya Maizuru Kyoto 625-8511 Japan Department of Electrical and Electronic Information Engineering Toyohashi University of Technology 1-1 Hibarigaoka Tenpaku Toyohashi Aichi 441-8580 Japan Application and Technical Section Elionix Inc. 3-7-6 Motoyokoyama Hachioji Tokyo 192-0063 Japan Research Center for Ubiquitous MEMS and Micro Engineering AIST 1-2-1 Namiki Tsukuba Ibaraki 305-8564 Japan

ISBN: (纸本)9781632661043

As an application to the nanoemitter, we investigated the nanofabrication of diamond-like carbon (DLC)-dot arrays by room-temperature curing imprint-liftoff (RTCIL) method using aluminum mask. The DLC film which has excellent properties similar to diamond properties was used as the patterning material. A polished glass like carbon (GC) was used as a mold material. The polysiloxane in the state of sticky liquid at room temperature and stable in air exhibits a negative-exposure characteristics. Therefore, the polysiloxane was used as electron beam (EB) resist and oxide mask material in EB lithography, and also used as RTC-imprint resist material. An aluminum was used as oxide metal mask material of liftoff. We have fabricated the GC mold of dot arrays with 5 μm-square and 500 nm-height. We carried out the RTCIL process using the GC mold under the following optimum imprint conditions: 0.5 MPa-imprinting pressure and 5 min- holding time. Aluminum film on the imprinted polysiloxane was prepared by vacuum evaporation method and its thickness is 20 nm. Finally, the polysiloxane patterns were removed with acetone and aluminum mask patterns were fabricated. We found that the maximum etching selectivity of aluminum film against DLC film was as high as 35, which was obtained under an ion energy of 400 eV. Then we processed the patterned aluminum on DLC film with an ECR oxygen ion shower. We fabricated DLC-dot arrays with 5 μm-square and 400 nm-height with an aspect ratio of 0.08. © 2013 Materials Research Society.

关键词： Carbon

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TICNet: Three-Branch Real-Time Semantic Segmentation Network with Intensive Compensation of Railway Track Scenes

TICNet: Three-Branch Real-Time Semantic Segmentation Network...

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Machine Learning and Computer Application (ICMLCA), International Conference on

作者： Yiwen Bai Lu Yang Lei Zhang Yajing Song School of Transportation Science and Engineering Beihang University Beijing China Tianjin Key Laboratory for Advanced Mechanical 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 Traffic Control Technology Co. Ltd Beijing China

ISBN: (数字)9798331530334

ISBN: (纸本)9798331530341

With the rapid development of railway traffic system, real-time semantic segmentation plays a crucial role in railway track scene monitoring. However, most of the existing methods use lightweight convolution to reduce the computational complexity, which results in reduced accuracy. To solve this problem, this paper proposes a real-time semantic segmentation network called TICNet, which is specifically used for accurate segmentation of railway track scenes. TICNet uses a novel three-branch structure designed for efficient feature extraction and accurate segmentation. Results on the RailSem19 dataset show that TICNet has a segmentation accuracy of 62.36% mIoU with an inference speed of 81.2 FPS, which is significantly better than many existing methods.

关键词： Accuracy Convolution Semantic segmentation Semantics Focusing Machine learning Feature extraction Real-time systems Computational complexity Monitoring

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mechanical Analysis and Performance Optimization for the Lunar Rover’s Vane-Telescopic Walking Wheel

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engineering 2020年第8期6卷 936-943页

作者： Lu Yang Bowen Cai Ronghui Zhang Kening Li Zixian Zhang Jiehao Lei Baichao Chen Rongben Wang Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical EngineeringTianjin University of TechnologyTianjin 300384China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of TechnologyTianjin 300384China Guangdong Key Laboratory of Intelligent Transportation System School of Intelligent Systems EngineeringSun Yat-sen UniversityGuangzhou 510275China College of Transportation Jilin UniversityChangchun 130025China Department of Mechanical Science and Engineering Tokyo Institute of TechnologyTokyo 152-8550Japan Armour College of Engineering Illinois Institute of TechnologyChicagoIL 60616USA China Academy of Space Technology Beijing 100029China

It is well-known that optimizing the wheel system of lunar rovers is ***,this is a difficult task due to the complex terrain of the moon and limited resources onboard lunar *** this study,an experimental prototype was set up to analyze the existing mechanical design of a lunar rover and improve its ***,a new vane-telescopic walking wheel was proposed for the lunar rover with a positive and negative quadrangle suspension,considering the complex terrain of the ***,the performance was optimized under the limitations of preserving the slope passage and minimizing power *** was achieved via analysis of the wheel force during ***,the effectiveness of the proposed method was demonstrated by several simulation *** newly designed wheel can protrude on demand and reduce energy consumption;it can be used as a reference for lunar rover development engineering in China.

关键词： Intelligent vehicle Vane-telescopic walking wheel Performance optimization Vane spring Lunar rover

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Simulation and experiment study for the navigation of the small autonomous weeding robot in paddy fields

Simulation and experiment study for the navigation of the sm...

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SICE Annual Conference

作者： Kentaro Kameyama Yuta Umeda Yuki Hashimoto Department of Mechanical Engineering Fukui National College of Technology Geshi Sabae Fukui Japan Advanced Course of the Production and System Engineering Fukui National College of Technology Geshi Sabae Japan Sabae Murata Manufacturing Co. LTD. Technology Fukui Japan

ISBN: (纸本)9781479914951

In this paper, the autonomous weeding robot for the paddy field is developed. Developed robot is the small two-wheel robot which weeds by running around the paddy field by using the information given from the direction sensor and the GPS receiver. For this robot, the traveling model that take into account the influences of the soil and the GPS error as the w.G.n. and the Wiener process is derived and the conditions for these are investigated by experiments. Behaviors of the robot under the noisy conditions are tested by numerical examples.

关键词： Mobile robots Global Positioning system Robot kinematics Robot sensing systems Wheels Noise

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