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16th International Conference on Intelligent robotics and Applications, ICIRA 2023

作者： Yu, Qinghua Zhu, Zixiao Fan, Xiru Wang, Dong Institute of Robotics School of Mechanical Engineering Shanghai Jiao Tong University Shanghai200240 China

ISBN: (纸本)9789819964918

3D printing is an efficient way to fabricate flexible electronics due to its ability to fabricate complex soft structures. However, the development of 3D printing flexible electronics is hindered by the development of multi-material 3D printing system that can integrate digital light processing and direct ink writing printing technologies. In this work, we develop an integrated DLP and DIW 3D printer that can fabricate multimaterial flexible electronics automatically. Complex matrix structures can be fabricated using bottom-up DLP printing, while the conductive electronics can be directly written on the matrix using DIW printing. Flexible electronics strain sensors and a multi-material soft pneumatic actuator are successfully printed. This work paves the way to fabricate flexible electronics automatically. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd 2023.

关键词： Fabrication

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Parameter sensitivity analysis for diesel spray penetration prediction based on GA-BP neural network

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Energy and AI 2024年第4期18卷 341-354页

作者： Yifei Zhang Gengxin Zhang Dawei Wu Qian Wang Ebrahim Nadimi Penghua Shi Hongming Xu Department of Mechanical Engineering School of EngineeringUniversity of BirminghamB152TTUK Institute of Engineering Thermophysics School of Mechanical EngineeringShanghai Jiao Tong University200240ShanghaiChina Department of Mechanical Systems Engineering Hiroshima University1-4-1 KagamiyamaHigashi-HiroshimaHiroshima739-8527Japan

Machine learning has started to be used in engine research to optimize combustion and predict fuel spray *** paper presents the development of a machine learning model using a Genetic Algorithm-Backpropagation(GA-BP)neural network to predict spray *** GA-BP neural network was selected for its ability to optimize neural network weights and thresholds,thereby improving model convergence and avoiding local minima,which are common challenges in complex,non-linear problems such as spray *** model was trained using experimental data from diesel injector spray tests,and its accuracy was evaluated through parametric sensitivity analysis,examining the influence of various input factors.A comparison between the machine learning model and the traditional empirical formulas of spray penetration revealed that the machine learning model achieved greater *** terms of the sensitivity to inputs,it is interesting to find that the cognition of machines is different from that of *** an input parameter does not have any functional relationship with other input parameters,the absence of this input parameter will lead to a significant decrease in the accuracy of the output *** results demonstrate that the machine learning approach offers higher accuracy and better generalizability compared to traditional empirical *** study recommends the ways to get better results of penetration prediction with BP neural networks,which is efficient in training and utilizing Artificial Neural Networks(ANNs).

关键词： Machine learning Genetic Algorithm-Backpropagation Fuel spray penetration Parametric sensitivity analysis

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Dynamic compliance of energy-saving legged elastic parallel joints for quadruped robots:design and realization

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Frontiers of mechanical engineering 2024年第2期19卷 45-58页

作者： Yaguang ZHU Minghuan ZHANG Xiaoyu ZHANG Haipeng QIN Key Laboratory of Road Construction Technology and Equipment of Ministry of Education School of Engineering MachineryChang’an UniversityXi’an 710064China State Key Laboratory of Robotics and Systems Harbin Institute of TechnologyHarbin 150001China

Achieving dynamic compliance for energy-efficient legged robot motion is a longstanding *** recent predictive control methods based on single-rigid-body models can generate dynamic motion,they all assume infinite energy,making them unsuitable for prolonged robot *** this issue necessitates a mechanical structure with energy storage and a dynamic control strategy that incorporates feedback to ensure *** work draws inspiration from the efficiency of bio-inspired muscle–tendon networks and proposes a controllable torsion spring leg *** design integrates a spring-loaded inverted pendulum model and adopts feedback delays and yield springs to enhance the delay effects.A leg control model that incorporates motor loads is developed to validate the response and dynamic performance of a leg with elastic *** model provides torque to the knee joint,effectively reducing the robot’s energy consumption through active or passive control *** benefits of the proposed approach in agile maneuvering of quadruped robot legs in a realistic scenario are demonstrated to validate the dynamic motion performance of the leg with elastic joints with the advantage of energy-efficient legs.

关键词： dynamic responsiveness energy dissipation legged locomotion parallel joints quadruped robot

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Experimental Study on Heat Storage Properties Comparison of Paraffin/Metal Foams Phase Change Material Composites

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Journal of Thermal Science 2024年第2期33卷 469-478页

作者： Waqar AHMED Abid HUSSAIN Hanzla SHAHID Imran ALI Hafiz Muhammad ALI Department of Mechanical Engineering University of Engineering and TechnologyTaxila47080Pakistan Department of Mechanical Engineering Institute of Space TechnologyIslamabadPakistan Department of Mechanical Mechatronics and Manufacturing EngineeringUniversity of Engineering and Technology LahoreFaisalabad CampusPunjabPakistan Mechanical Engineering Department King Fahd University of Petroleum and MineralsDhahran31261Saudi Arabia Interdisciplinary Research Center for Renewable Energy and Power Systems(IRC-REPS) King Fahd University of Petroleum and MineralsDhahran31261Saudi Arabia

Heat storage properties of phase change materials(PCMs) are essential characteristics that perform a key role in thermal heat energy storage *** thermal properties of PCMs can be improved by developing metal foam/PCM *** addition of metal foam in PCMs has a significant effect on the thermal characteristics of *** this paper,the heat storage properties of two different metal foam/PCM composites were experimentally *** behavior of paraffin in metal foam(copper and iron-nickel)/paraffin composites concerning pure paraffin at a constant heat flux of 1000 W/m^(2) in three directions simultaneously(x,y,and z) was *** was infiltrated into copper and iron-nickel foams to develop composite materials which resulted in enhancing the thermal conductivity of the paraffin.A comparative analysis is made on the heat storage properties of paraffin in copper and iron-nickel foams/paraffin *** temperature distribution during the phase transition process is experimentally *** comparison indicates that temperature uniformity in copper foam/paraffin composite is better than in iron-nickel foam/paraffin composite and pure paraffin at the same heat *** results show that at heat flux of 1000 W/m^(2),the heat storage time for copper foam/paraffin composite is 20.63% of that of iron-nickel foam/paraffin composite.

关键词： heat storage capacity paraffin/metal foam composite temperature uniformity heat storage rate phase transition process

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MLP Neural Network-Based Precise Localization of Robot Assembly Parts 16th

MLP Neural Network-Based Precise Localization of Robot Assem...

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16th International Conference on Intelligent robotics and Applications, ICIRA 2023

作者： Cheng, Bin Li, Zonggang Jiao, Jianjun An, Guanglin School of Mechanical and Electrical Engineering Robotics Institute Lanzhou Jiaotong University Gansu Lanzhou China

ISBN: (纸本)9789819964796

Traditional visual servoing encounters challenges in achieving target localization during the assembly process of riveted components when target features out of the field of view or when image feature motion extends beyond the image boundaries, resulting in feature loss and inability to accomplish visual servoing positioning. To address these issues, this paper first proposes a target localization method based on the ORB feature matching algorithm to solve the problem of the target features out of the field of view. A multi-layer perceptron neural network is applied to estimate the relative error between the current camera attitude and the desired attitude through the target image features obtained by the camera at the initial pose and the preset reference image features. The robot reaches the intermediate posture according to the predicted motion vector, Then the adaptive visual control method is used for fine-tuning, which can realize the accurate positioning and grasping tasks of the assembly with fewer iterations than the traditional visual servo. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2023.

关键词： Multilayer neural networks

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Design of an Intent Recognition System for Dynamic, Rapid Motions in Unstructured Environments

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ASME Letters in Dynamic systems and Control 2022年第1期2卷 011004页

作者： Moolchandani, Pooja R. Mazumdar, Anirban Young, Aaron J. Woodruff School of Mechanical Engineering Georgia Institute of Technology AtlantaGA30332 United States Woodruff School of Mechanical Engineering Institute for Robotics and Intelligent Machines Georgia Institute of Technology AtlantaGA30332 United States

In this study, we developed an offline, hierarchical intent recognition system for inferring the timing and direction of motion intent of a human operator when operating in an unstructured environment. There has been an increasing demand for robot agents to assist in these dynamic, rapid motions that are constantly evolving and require quick, accurate estimation of a user’s direction of travel. An experiment was conducted in a motion capture space with six subjects performing threat evasion in eight directions, and their mechanical and neuromuscular signals were recorded for use in our intent recognition system (XGBoost). Investigated against current, analytical methods, our system demonstrated superior performance with quicker direction of travel estimation occurring 140 ms earlier in the movement and a 11.6 deg reduction of error. The results showed that we could also predict the start of the movement 100 ms prior to the actual, thus allowing any physical systems to start up. Our direction estimation had an optimal performance of 8.8 deg, or 2.4% of the 360 deg range of travel, using three-axis kinetic data. The performance of other sensors and their combinations indicate that there are additional possibilities to obtain low estimation error. These findings are promising as they can be used to inform the design of a wearable robot aimed at assisting users in dynamic motions, while in environments with oncoming threats. Copyright © 2021 by ASME.

关键词： Dynamics

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mechanical, Tribological, and Anti-corrosion Properties of Nitrogen-Doped AlCrNbSiTiMoW High-Entropy Coatings

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Journal of Materials engineering and Performance 2024年第12期33卷 6092-6110页

作者： Kao, W.H. Su, Y.L. Lin, Y.J. Department of Automation Engineering & Institute of Mechatronoptic Systems Chienkuo Technology University Changhua Taiwan Department of Mechanical Engineering National Cheng Kung University Tainan Taiwan

(AlCrNbSiTiMoW)N high-entropy alloy (HEA) coatings with various nitrogen-to-argon gas flow ratios (RN = N2/Ar) in the range of RN0 to RN1.25 were deposited on WC and Si substrates using a radio-frequency magnetron sputtering system. The as-sputtered coatings were then annealed at 950 °C for 1 hour in a vacuum. The effects of the nitrogen flow ratio on the composition, microstructure, mechanical properties, tribological properties, and corrosion resistance of the various coatings were systematically explored. The as-deposited RN0, RN1.0, and RN1.25 coatings exhibited FCC structures, while the RN0.5 and RN0.75 coatings had amorphous structures. Following the annealing process, all of the coatings showed an FCC structure. The annealing process had no significant effect on the hardness of the coatings. Thus, they were inferred to have excellent thermal stability. Among the coatings, the HRN1.0 coating showed the highest hardness (37.4 GPa), adhesion strength, and tribological properties, with a wear depth and wear rate of 0.07 μm and 0.41 × 10-6 mm3/Nm, respectively. The wear depth and wear rate of the HWC substrate were 0.28 μm and 1.67 × 10-6 mm3/Nm, respectively. Thus, compared with the HWC substrate, the HRN1.0 coating improved the wear depth and wear rate by 75.0 and 75.4%, respectively. The tribological performance of the annealed HRN1.0 coating was enhanced as a result of the formation of a greater amount of MoO3 and WO3 solid lubricant phases and a higher hardness and hardness-to-elastic modulus ratio. The RN1.0 coating exhibited the best corrosion resistance among all the coatings. The corrosion current density of the RN1.0 coating was 1.8 × 10-7 A/cm2, while that of the WC substrate was 2.2 × 10-7 A/cm2. In other words, the RN1.0 coating improved the corrosion resistance by 18.1%. However, the corrosion resistance reduced following the annealing process due to a greater surface roughness. © ASM International 2023.

关键词： Thermodynamic stability

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Force perception -based active breath-following control of a puncture ablation surgery robot end effector

Force perception -based active breath-following control of a...

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2023 IEEE International Conference on robotics and Biomimetics, ROBIO 2023

作者： Yong, Tao Han, Dongming Wang, Tianmiao Zhang, Yufan Duan, Lian Wang, Yiru Beihang University School of Mechanical Engineering & Automation Research Institute of Aero-Engine China School of Mechanical Engineering & Automation Beihang University Robotics Institute of School of Mechanical Engineering and Automation China Beihang University Research Institute of Aero-Engine China

ISBN: (纸本)9798350325706

During the process of remote microwave puncture ablation surgery in areas such as the liver and thoracic cavity, there are accompanying physiological movements due to the body's respiratory motion, as well as possible spasms and twitching of the body's muscles caused by factors like anesthesia and temperature. These physiological activities can easily lead to skin lacerations near the rigid percutaneous puncture ablation needle due to relative motion. To prevent this secondary harm to the surrounding skin caused by such movements, we designed a robot end-effector active respiration tracking method based on fuzzy variable admittance control of a robotic arm and sliding window half-wave analysis debounce algorithm. This method not only enables smooth zero-force tracking but also monitors real-time end-effector motion information to adjust the admittance parameters, thus avoiding the occurrence of potential oscillations. Finally, we conducted experiments by applying a random step-like oscillation to simulate spasms and twitching phenomena. The robot not only achieved zero-force tracking with forces less than 1.5N but also demonstrated excellent resistance to oscillations, showcasing remarkable flexibility and stability. © 2023 IEEE.

关键词： Breath Following Debounce Algorithm Muscle Cramps Variable Admittance Control

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Numerical Study of Plate-Fin Heat Exchanger for Cryogenic Application 9th

Numerical Study of Plate-Fin Heat Exchanger for Cryogenic Ap...

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9th International and 49th National Conference on Fluid Mechanics and Fluid Power, FMFP 2022

作者： Ramprasad, Margam Moharana, Manoj Kumar Thermal Systems Laboratory Department of Mechanical Engineering National Institute of Technology Rourkela Rourkela India

ISBN: (纸本)9789819957545

Among different types of plate-fin heat exchangers, offset-strip fin heat exchangers are widely used for cryogenic applications. Though many correlations are available in literature for plate-fin heat exchangers, still there is a requirement to sort out more accurate correlation through parametric analysis. In view of this, the present study is focused on thermo-fluidic analysis involving numerical analysis of periodically sectioned 3-D geometry with 12 offset fins. The outcome of the numerical simulation is presented in the form of Nusselt number, overall efficiency, j factor, and f factor by considering temperature-dependent fluid properties for varying Prandtl number, thermal conductivity of solid, and fluid flow rate. Five different fin materials and nitrogen (at three different states) as the working fluid with Re in the range of 50–1000 have been considered in the numerical analysis. The results indicate that there are no significant variations in considered parameters concerning temperature difference ranges of 1, 2, and 3 K. The f factor is independent of the thermal conductivity of fin material and the Prandtl number of working fluids. As thermal conductivity increases, the increment of j factor for working fluid with Pr > 1 is more rapid than Pr 1, as Reynolds number increases. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024.

关键词： Prandtl number

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Conjugate Heat Transfer Analysis of U-Bend/Turn Microchannel: A Computational Approach 9th

Conjugate Heat Transfer Analysis of U-Bend/Turn Microchannel...

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9th International and 49th National Conference on Fluid Mechanics and Fluid Power, FMFP 2022

作者： Mohapatra, Jyoti Ranjan Moharana, Manoj Kumar Thermal Systems Laboratory Department of Mechanical Engineering National Institute of Technology Rourkela Rourkela India

ISBN: (纸本)9789819971763

To examine the fluid flow and heat transfer properties of a U-shaped bend microchannel, a three-dimensional single-phase numerical study involving the conjugate effect of heat transfer is analyzed. The hydraulic diameter of the geometry was constant (0.4 mm) and the radius of curvature was varied from 2 to 4 mm. The constant heat flux boundary condition was applied at the bottom of the substrate and a comparative study with a straight conventional microchannel design is presented in terms of the performance evaluation factor. Different flow rates were considered to evaluate the effect of secondary flow in the form of Dean Vortices. Non-dimensional heat transfer parameter such as the average Nusselt number and frictional losses in terms of pressure drop was evaluated and the contours of temperature and velocity were analyzed to elaborate the effect of heat transfer enhancement in the bend microchannel. Higher radii of curvature improved the overall performance of the bend channel. At a lower radius of curvature, the performance of the bend microchannel can be improved with increased pumping power. Due to unavoidable pressure loss in the case of microchannel, it is advisable to use U-bend microchannel at relatively low flow rates and higher radius of curvature. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024.

关键词： Nusselt number

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