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Distributed predefined-time estimator-based affine formation target-enclosing maneuver control for cooperative underactuated quadrotor UAVs with fault-tolerant capabilities

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Chinese Journal of Aeronautics 2025年第1期38卷 471-490页

作者： Yang XU Yuanfang QU Delin LUO Haibin DUAN Zhengyu GUO School of Civil Aviation Northwestern Polytechnical UniversityXi’an 710072China Research&Development Institute Northwestern Polytechnical UniversityShenzhen 518057China School of Marine Science and Technology Northwestern Polytechnical UniversityXi’an 710072China School of Aerospace Engineering Xiamen UniversityXiamen 361005China School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China National Key Laboratory of Air-based Information Perception and Fusion Luoyang 471000China

The paper presents a two-layer,disturbance-resistant,and fault-tolerant affine formation maneuver control scheme that accomplishes the surrounding of a dynamic target with multiple underactuated Quadrotor Unmanned Aerial Vehicles(QUAVs).This scheme mainly consists of predefinedtime estimators and fixed-time tracking controllers,with a hybrid Laplacian matrix describing the communication among these *** the first layer,we devise predefined time estimators for leading and following QUAVs,enabling accurate estimation of desired *** the second layer,we initially devise a fixed-time hybrid observer to estimate unknown disturbances and actuator *** translational tracking controllers are then proposed,and the intermediary control input from these controllers is used to extract the desired attitude and angular velocities for the fixed-time rotational tracking *** employ an exact tracking differentiator to handle variables that are challenging to differentiate *** paper includes a demonstration of the control system stability through mathematical proof,as well as the presentation of simulation results and comparative simulations.

关键词： Affine formation maneuver control Target tracking Fixed-time control Quadrotor unmanned aerial vehicle Target enclosing Predefined-time estimation

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Research on Silicon based multi-layer 2.5D Integration for MOS Switch Modules

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IEEE Transactions on Components, Packaging and Manufacturing Technology 2025年第5期15卷 894-904页

作者： Zhang, Xiangou An, Ning Wang, Yuexing Cao, Linwei Xu, Pan Deng, Zejia Pu, Yingdong Sun, Xiangyu Li, Bofeng China Academy of Engineering Physics Microsystem and Terahertz Research Center Chengdu610200 China China Academy of Engineering Physics Institute of Electronic Engineering Mianyang621999 China Northwestern Polytechnical University School of Mechanics Civil Engineering and Architecture China

Integrated microsystems, owing to their remarkable performance and scalability, have garnered increasing popularity within the realm of high-value electronic equipment. Despite this, a prevailing approach in the integration of power devices continues to involve the use of wire bonding, primarily due to concerns over the thermal and mechanical risks associated with power devices. In this study, we introduce a novel multi-layer 2.5D structure designed to incorporate a double-sided cooling (DSC) packaging technology into silicon-based power device integration. This innovative structure is applied to MOS switch modules, which consist of eight p-type MOSFETs (pMOS) and eight n-type MOSFETs (nMOS). The module's architecture relies on through silicon vias (TSV), micro bumps, and redistribution Layer (RDL) for device interconnection. The aim of this design is to ensure that the MOS switch module exhibits excellent electrical and thermomechanical performance. Electrical simulation results indicate that the parasitic inductance of the MOS switch module is 0.85nH, and the parasitic resistance is 8.04mΩ, demonstrating significant advantages among power chip integration solutions. To further investigate the thermal mechanical properties and reliability of the proposed structure, we conducted a comparative analysis focusing on thermal management efficiency and reliability under different power losses and temperature conditions. Additionally, the temperature-dependent characteristics of the solder within the structures were analyzed using the Anand viscoplasticity model. Parasitic resistance of the MOS switch module was measured to be 9mΩ by the static test under the conditions of 12V/0.5A, which consistent with the simulation results. © 2011-2012 IEEE.

关键词： Chip scale packages

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Nonsingular fast predefined time convergence sliding mode control for construction robot

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ISA Transactions 2025年 161卷 109-121页

作者： Yin, Chun-Wu Ding, Yun-Peng Sun, Hou-Jun College of Information and Control Engineering Xi'an University of Architecture and Technology Shaanxi Xi'an710055 China School of Computer Science Northwestern Polytechnical University Xi'an710072 China

To solve the practical engineering problem that the angle of a construction robot with an arbitrary initial value completely and accurately track the desired trajectory, this paper presents a control strategy for extending the desired trajectory, and a sliding mode controller with predefined time convergence is designed for an uncertain construction robot. Firstly, the special characteristics of the construction robot's trajectory tracking control are analyzed, an extended desired trajectory control strategy including the arrival phase and the precise tracking phase is proposed, and the design method of the extended desired trajectory in the arrival stage is given. Then, based on the improved non-singular fast sliding mode surface and a novel stability criterion of predefined time convergence, a predefined time convergence sliding mode controller based on a state observer was designed for the construction robot, which enables the angle tracking error of the construction robot to converge to zero within the specified time, ensures the angle completely and accurately tracking the original desired trajectory. Comparative simulation results show that the angle tracking error based on the proposed algorithm reaches 0.0004 rad, with an accuracy improvement of 33 %, and solves the problem of control torque chattering. © 2025 ISA

关键词： Sliding mode control

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Vibration Characteristics of Multilayer Airborne Equipment Integrated Platform 30th

Vibration Characteristics of Multilayer Airborne Equipment I...

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30th International Conference on Computational and Experimental engineering and Sciences, ICCES 2024

作者： Mu, Binjie Liu, Jun Chen, Yuanfang Li, Xin Chengdu Aircraft Design Institute Chengdu610091 China School of Mechanics Civil Engineering and Architecture Northwestern Polytechnical University Xi’an710129 China

ISBN: (纸本)9783031829062

Through vibration testing and simulation methods. The vibration characteristics of multi-layer airborne equipment integrated platform was analyzed. The experimental and simulation results indicate that the lower order modes of the platform are related to the stiffness of the shock absorber;In X-direction vibration, the first mode of the platform plays a major role;In the Y and Z direction vibration, the second and third order modes of the platform play a major role;The simulated RMS value of the equipment basically consistent with the experimental value, which can provide reference for subsequent virtual experimental models. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2025.

关键词： Shock absorbers

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Identification of mechanical responses of interconnect structures based on Bayesian regularization under board-level drop impact

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Microelectronics Reliability 2025年 170卷

作者： Long, Xu Hu, Yuntao School of Mechanics Civil Engineering and Architecture Northwestern Polytechnical University China

To address the challenge of directly measuring the mechanical response of critical interconnect structures in board-level packaging structures, which is complicated by the inherent complexity of electronic components, a load identification methodology is first proposed in this study. This methodology is established based on finite element (FE) analysis to accurately identify the critical failure points in the key interconnect structures of board-level packaging. Furthermore, an indirect measurement method based on Bayesian regularization is proposed for load identification to comprehensively capture the stress conditions of critical structural components in the board-level packaging structures subjected to drop impact. During the impact process, the solder joints at the corners beneath the edge areas experience the maximum stress and strain, making them more prone to failure. The normal stress in the Z-direction (S33) perpendicular to the printed circuit board (PCB), which is the maximum stress component, is the primary cause of damage to the interconnect structure. To address the ill-posed problem in load identification, such as the instability due to the inversion of ill-conditioned matrices and sensitivity to noise, an improved Bayesian method using augmented Tikhonov regularization is introduced. The proposed method incorporates a wavelet thresholding technique to solve the problem of poor load identification accuracy under high noise levels. It adaptively determines the optimal regularization parameters during the identification process and effectively removes the noise impact on load recognition. The established response identification methodology is capable of achieving relatively small relative error (RE) and high correlation coefficients when identifying the mechanical response of critical interconnections in board-level packaging structures. Furthermore, both the smoothness of the response curve and the accuracy of peak value identification are ensured. Th

关键词： Strain rate

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Mechanical response identification of local interconnections in board-level packaging structures under projectile penetration using Bayesian regularization

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Defence Technology 2025年

作者： Long, Xu Hu, Yuntao Ali, Irfan School of Mechanics Civil Engineering and Architecture Northwestern Polytechnical University Shaanxi 710129 China

Modern warfare demands weapons capable of penetrating substantial structures, which presents significant challenges to the reliability of the electronic devices that are crucial to the weapon's performance. Due to miniaturization of electronic components, it is challenging to directly measure or numerically predict the mechanical response of small-sized critical interconnections in board-level packaging structures to ensure the mechanical reliability of electronic devices in projectiles under harsh working conditions. To address this issue, an indirect measurement method using the Bayesian regularization-based load identification was proposed in this study based on finite element (FE) predictions to estimate the load applied on critical interconnections of board-level packaging structures during the process of projectile penetration. For predicting the high-strain-rate penetration process, an FE model was established with elasto-plastic constitutive models of the representative packaging materials (that is, solder material and epoxy molding compound) in which material constitutive parameters were calibrated against the experimental results by using the split-Hopkinson pressure bar. As the impact-induced dynamic bending of the printed circuit board resulted in an alternating tensile-compressive loading on the solder joints during penetration, the corner solder joints in the edge regions experience the highest S11 and strain, making them more prone to failure. Based on FE predictions at different structural scales, an improved Bayesian method based on augmented Tikhonov regularization was theoretically proposed to address the issues of ill-posed matrix inversion and noise sensitivity in the load identification at the critical solder joints. By incorporating a wavelet thresholding technique, the method resolves the problem of poor load identification accuracy at high noise levels. The proposed method achieves satisfactorily small relative errors and high correlation co

关键词： Projectiles

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Space Production by Migrants in China’s Urban Villages: The Case of Beijing by Shiyu Yang, Transcript, Bielefeld, Germany (2024), p. 236, ISBN: 978-3-8376-6914-5 (hbk), ISBN: 978-3-8376-6914-9 (ebk)

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Journal of Urban Management 2025年第2期14卷 615-617页

作者： Chen Yang School of Mechanics Civil Engineering and Architecture Northwestern Polytechnical University Xi'an 710129 China

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Surface micro-arrays enhancing electromagnetic interference shielding of polydimethylsiloxane/multiwalled carbon nanotubes nanocomposites

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Nano Research 2025年第1期18卷 508-519页

作者： Ke Jiang Zhi Chen Ji Yu Chen Zheng Shan Huang Ming Wang Chongqing Key Laboratory of Soft-Matter Material Manufacturing School of Chemistry and Chemical EngineeringSouthwest UniversityChongqing 400715China School of Mechanics Civil Engineering and ArchitecturesNorthwestern Polytechnical UniversityXi’an 710072China Jieyang Branch of Chemistry and Chemical Engineering Guangdong Laboratory(Rongjiang Laboratory) Jieyang 515200China

Herein,the electromagnetic shielding performance of surface concave-convex(SC)and zig-zag micro-arrays was studied by using a simulation prediction and a three-dimensional(3D)printing custom ***,surface stripe concaveconvex(SSC)and surface cylindrical concave-convex(SCC)micro-arrays with or without zig-zag micro-arrays are designed,and their shielding performance is simulated in multi-bands(C-,X-band).The multiwalled carbon nanotubes/polydimethylsiloxane composites(MWCNT/PDMS)with different SC structures and different electrical conductivity are molded in acrylonitrile-butadiene-styrene copolymer(ABS)molds which are printed by a 3D *** results show that the electromagnetic interference shielding effectiveness(EMI SE)of the samples can be enhanced by constructing the SC micro-arrays with zig-zag micro-arrays,and improving with the increase of conductivity and *** addition,the shielding mechanism of the SC-MWCNT/PDMS composites is investigated and discussed by an electromagnetic simulation.

关键词： surface micro-arrays electrical properties electromagnetic interference(EMI)shielding three-dimensional(3D)printing

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Non-contact overall 3D deformation measurement based on a multi-camera system for static testing of large aircraft wing structure

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Acta Mechanica Sinica/Lixue Xuebao 2025年第6期41卷 1-18页

作者： Zhu, Bingwei Liu, Yan Lian, Zongyuan Cai, Yiqiu Zhu, Hewei Gao, Liqiang Yu, Qifeng College of Physics and Optoelectronic Engineering Shenzhen University Shenzhen518060 China Institute of Intelligent Optical Measurement and Detection Shenzhen University Shenzhen518060 China School of Civil Aviation Northwestern Polytechnical University Xi’an710072 China

To obtain the certificate of airworthiness, it is essential to conduct a full-scale aircraft static test. During such test, accurate and comprehensive wing deformation measurement is crucial for assessing its strength, stiffness, and bearing capability. This paper proposes a novel and cost-effective videogrammetric method using multi-camera system to achieve the non-contact, high-precision, and 3D measurement of overall static deformation for the large-scale wing structure. To overcome the difficulties of making, carrying, and employing the large 2D or 3D target for calibrating the cameras with large field of view, a flexible stereo cameras calibration method combining 1D target and epipolar geometry is proposed. The global calibration method, aided by a total station, is employed to unify the 3D data obtained from various binocular subsystems. A series of static load tests using a 10-meter-long large-scale wing have been conducted to validate the proposed system and methods. Furthermore, the proposed method was applied to the practical wing deformation measurement of both wings with a wingspan of 33.6 m in the full-size civil aircraft static test. The overall 3D profile and displacement data of the tested wing under various loads can be accurately obtained. The maximum error of distance and displacement measurement is less than 4.5 mm within the measurement range of 35 m in all load cases. These results demonstrate that the proposed method achieves effective, high-accuracy, on-site, and visualized wing deformation measurement, making it a promising approach for full-scale aircraft wing static test. © The Chinese Society of Theoretical and Applied Mechanics and Springer-Verlag GmbH Germany, part of Springer Nature 2025.

关键词： Aircraft static testing Large wing Multi-camera system Non-contact 3D deformation measurement Videogrammetric technique

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Revisiting Parametric Identification in Johnson–Cook Constitutive Equation Based on Multi-objective Optimization and 3D Metal Cutting Process Simulation

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Journal of Materials engineering and Performance 2025年 1-21页

作者： Liu, Yupeng He, Jinhu Cao, Yan Li, Xiaoxia Shen, Qiang Long, Xu Chang, Chao School of Applied Science Taiyuan University of Science and Technology Taiyuan030024 China Shanxi Diesel Engine Industry Co. Ltd Datong037036 China School of Mechanics Civil Engineering and Architecture Northwestern Polytechnical University Xi’an710072 China

The Johnson–Cook (J–C) constitutive model is extensively used in numerical simulations. Traditional parameter-fitting methods often prioritize a single objective, which can compromise parameter applicability across diverse working conditions. Multi-objective fitting methods account for multiple mechanical behaviors concurrently, thereby improving both model accuracy and generalizability. In this study, mechanical tests covering strain rates from 0.001 to 1900/s and temperatures ranging from 20 to 310 °C were performed, along with microstructural observations under varying strain rates. Three parameter sets, derived using traditional methods and the multi-objective optimization approach, were applied in finite element tensile simulations. Model suitability was assessed through comparisons of the correlation coefficient (R), average absolute relative error, and prediction relative error. Their accuracy was further validated through cutting simulation. The results demonstrated that the multi-objective optimization method substantially reduced discrepancies between simulated and experimental cutting forces, achieving prediction errors below 20%. © ASM International 2025.

关键词： Multiobjective optimization

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