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Enhancement of Quality Factor in Gain-Assisted Acoustic Resonance Systems

Acta Mechanica Solida Sinica 2025年第1期38卷 25-32页

作者： Lei Zhang Linlin Geng Yonghui Zhang Youdong Duan Jinbo Yuan Xiaoming Zhou Key Laboratory of Dynamics and Control of Flight Vehicle of Ministry of Education School of Aerospace EngineeringBeijing Institute of TechnologyBeijing100081China

Damped acoustic systems have a limited quality factor due to intrinsic *** introducing gain elements,a method to enhance the quality factor of damped systems is proposed based on the concept of bound states in the continuum(BICs).The acoustic model under study is a two-port waveguide system installed with two side Helmholtz resonators connected by a coupling *** on the temporal coupled-mode theory,a Hamiltonian matrix with both intrinsic and radiation losses is used to characterize the resonance behavior of the coupled *** achieve a high quality factor,acoustic gain is introduced to compensate the intrinsic loss,leading the Hamiltonian parameters toward a quasi-BIC *** simulation demonstrates a gain-assisted and quasi-BIC-supported extremely high quality factor in damped acoustic *** concept is further utilized to design a sensor model for particle size *** enhanced sensing performance due to high quality factors is numerically *** findings suggest potential applications in acoustic sensing and detection devices.

关键词： Acoustic resonance Quality factor Bound states in the continum Coupled-mode theory

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Deployment dynamics and experiments of a tendon-actuated flexible manipulator

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Chinese Journal of Aeronautics 2025年第2期38卷 459-477页

作者： Benteng ZHANG Jialiang SUN Haiyan HU State Key Laboratory of Mechanics and Control for Aerospace Structures Nanjing University of Aeronautics and AstronauticsNanjing 210016China MOE Key Laboratory of Dynamics and Control of Flight Vehicle School of Aerospace EngineeringBeijing Institute of TechnologyBeijing 100081China

The quantity of space debris on Earth orbit has escalated tremendously in recent years, presenting a significant hazard to human space operations. It is urgent to develop effective measures to capture and remove various space debris. For this purpose, this paper presents a tendon-actuated flexible deployable manipulator. The flexible manipulator consists of several deployable units connected by Cardan joints and actuated by tendons. Compared with the present technologies for capturing space debris such as rigid robotic arm or flying net, this flexible manipulator is deployable, reusable, lightweight and applicable to the capture of large space debris. In order to investigate its deployment dynamics, an accurate dynamic model of the flexible manipulator is established based on the natural coordinate formulation (NCF) and the absolute nodal coordinate formulation (ANCF). Subsequently, numerical simulations are carried out to study the effects of system parameters and the base satellite on its deployment dynamics. Finally, ground experiments for both deployment and bending of the flexible manipulator are conducted to verify its effectiveness and feasibility.

关键词： Flexible manipulator Tendon-actuated Dynamic modeling Deployment dynamics Ground experiments

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Optimization of Impact Load Reduction for Cross-Medium Multirotor During High-Speed Water Entry 7th

Optimization of Impact Load Reduction for Cross-Medium Multi...

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7th China Aeronautical Science and Technology Conference, CASTC 2024

作者： Zhang, Tao Long, Teng Zhang, Baoshou Ye, Nianhui Liang, Jinming School of Aerospace Engineering Beijing Institute of Technology Beijing100081 China Key Laboratory of Dynamics and Control of Flight Vehicle Ministry of Education Beijing100081 China

ISBN: (纸本)9789819797646

Recently, cross-medium flight vehicles have attracted much attention due to their capacity to operate underwater and in the air. However, the significant impact load during high-speed water entry poses a great challenge for the cross-medium flight vehicle design. To alleviate the extreme impact load, a novel parabolic configuration for cross-medium multirotors is proposed in this paper and parameterized via cabin bottom curve shape and model length. The Structured Arbitrary Lagrange-Eulerian (S-ALE) method is employed to analyze the characteristics of impact loads during high-speed water entry. An optimization problem for the multirotor configuration is then formulated to minimize the impact load, considering several constraints, i.e., the volume of the payload cabin, bottom curve height, and minimum curvature. The Kriging-assisted Constrained Differential Evolution (KRG-CDE) algorithm is utilized to improve the optimization efficiency. The optimization results demonstrate that compared to the cylindrical and initial parabolic configurations, the maximum impact load of the optimized configuration is reduced by 20.78% and 9.46%, respectively. This study validates the effectiveness and practicality of the proposed cross-medium multirotor configuration and optimization framework in reducing impact loads upon water entry. © Chinese Society of Aeronautics and Astronautics 2025.

关键词： Lagrange multipliers

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Optimization of Hypersonic Vehicle Configuration Design for Wide-speed-range Morphing flight

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Yuhang Xuebao/Journal of Astronautics 2025年第3期46卷 414-425页

作者： Long, Teng Zhang, Yao Shi, Renhe Ye, Nianhui Zhang, Baoshou School of Aerospace Engineering Beijing Institute of Technology Beijing100081 China Key Laboratory of Dynamics and Control of Flight Vehicle Ministry of Education Beijing Institute of Technology Beijing100081 China National Key Laboratory of Land and Air Based Information Perception and Control Beijing100081 China

The fixed-configuration waverider often fails to deliver optimal performance across a wide range of flight speeds. Research is conducted on the configuration design optimization of a morphing hypersonic waverider vehicle. Initially，the corresponding optimization framework for the morphing vehicle is established. A class function/shape function transformation（CST）parameterization method for the morphing waverider configuration，which accounts for leading edge variation，is proposed. Subsequently，the Kriging-assisted constrained differential evolution algorithm is employed to efficiently determine the optimal waverider configuration under various conditions，based on an aerodynamics-aerothermodynamics-trajectory morphing assessment model. Compared to the initial fixed configuration，the morphing strategy utilizing optimal configurations significantly enhances wide-speed range flight performance. On average，the lift-to-drag ratio is increased by 4. 82%，and the range is improved by 4. 13%. These results demonstrate the effectiveness of the morphing configuration optimization and offer valuable insights for the design of hypersonic morphing aircraft. © 2025 Chinese Society of Astronautics. All rights reserved.

关键词： Linear transformations

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Learning for predictive control: A Dual Gaussian Process approach

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Automatica 2025年 177卷

作者： Liu, Yuhan Wang, Pengyu Tóth, Roland Control Systems Group Department of Electrical Engineering Eindhoven University of Technology Eindhoven Netherlands Flight Dynamics and Control Laboratory Department of Aerospace Engineering Korea Advanced Institute of Science and Technology Daejeon Korea Republic of Systems and Control Laboratory Institute for Computer Science and Control Budapest Hungary

An important issue in model-based control design is that an accurate dynamic model of the system is generally nonlinear, complex, and costly to obtain. This limits achievable control performance in practice. Gaussian Process (GP) based estimation of system models is an effective tool to learn unknown dynamics directly from input/output data. However, conventional GP-based control methods often ignore the computational cost associated with accumulating data during the operation of the system and how to handle forgetting in continuous adaption. In this paper, we present a novel Dual Gaussian Process (DGP) based Model Predictive control (MPC) strategy that enables efficient use of online learning based predictive control without the danger of catastrophic forgetting. The bio-inspired DGP structure is a combination of a long-term GP and a short-term GP, where the long-term GP is used to keep the learnt knowledge in memory and the short-term GP is employed to rapidly compensate unknown dynamics during online operation. A novel recursive online update strategy for the short-term GP is proposed to successively improve the learnt model during online operation without a "dictionary" update and re-computation of the Gram matrix at each time step. Effectiveness of the proposed strategy is demonstrated via numerical simulations. © 2025

关键词： Predictive control systems

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Entire aerial-aquatic trajectory modeling and optimization for trans-medium vehicles

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Defence Technology 2025年

作者： Long, Teng Ye, Nianhui Zhang, Baoshou Sun, Jingliang Shi, Renhe School of Aerospace Engineering Beijing Institute of Technology Beijing100081 China Key Laboratory of Dynamics and Control of Flight Vehicle Ministry of Education Beijing100081 China National Key Laboratory of Land and Air Based Information Perception and Control Beijing100081 China

Trans-medium flight vehicles can combine high aerial maneuverability and underwater concealment ability, which have attracted much attention recently. As the most crucial procedure, the trajectory design generally determines the trans-medium flight vehicle performance. To quantitatively analyze the flight vehicle performance, an entire aerial-aquatic trajectory model is developed in this paper. Different from modeling a trajectory purely for the water entry process, the constructed entire trajectory model has integrated aerial, water entry, and underwater trajectories together, which can consider the influence of the connected trajectories. As for the aerial and underwater trajectories, explicit dynamic models are established to obtain the trajectory parameters. Due to the complicated fluid force during high-velocity water entry, a computational fluid dynamics model is investigated to analyze this phase. The computational domain size is adaptively refined according to the final aerial trajectory state, where the redundant computational domain is removed. An entire trajectory optimization problem is then formulated to maximize the total flight range via tuning the joint states of different trajectories. Simultaneously, several constraints, i.e., the max impact load, trajectory height, etc., are involved in the optimization problem. Rather than directly optimizing by a heuristic algorithm, a multi-surrogate cooperative sampling-based optimization method is proposed to alleviate the computational complexity of the entire trajectory optimization problem. In this method, various surrogates cooperatively generate infill sample points, thereby preventing the poor approximation. After optimization, the total flight range can be improved by 20%, while all the constraints are satisfied. The result demonstrates the effectiveness and practicability of the developed model and optimization framework. © 2025 China Ordnance Society

关键词： Maneuverability

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Deployment dynamics and experiments of a tendon-actuated flexible manipulator

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Chinese Journal of Aeronautics 2025年第02期 463-481页

作者： Benteng ZHANG Jialiang SUN Haiyan HU State Key Laboratory of Mechanics and Control for Aerospace Structures Nanjing University of Aeronautics and Astronautics MOE Key Laboratory of Dynamics and Control of Flight Vehicle School of Aerospace EngineeringBeijing Institute of Technology

The quantity of space debris on Earth orbit has escalated tremendously in recent years,presenting a significant hazard to human space operations. It is urgent to develop effective measures to capture and remove various space debris. For this purpose, this paper presents a tendon-actuated flexible deployable manipulator. The flexible manipulator consists of several deployable units connected by Cardan joints and actuated by tendons. Compared with the present technologies for capturing space debris such as rigid robotic arm or flying net, this flexible manipulator is deployable,reusable, lightweight and applicable to the capture of large space debris. In order to investigate its deployment dynamics, an accurate dynamic model of the flexible manipulator is established based on the natural coordinate formulation(NCF) and the absolute nodal coordinate formulation(ANCF). Subsequently, numerical simulations are carried out to study the effects of system parameters and the base satellite on its deployment dynamics. Finally, ground experiments for both deployment and bending of the flexible manipulator are conducted to verify its effectiveness and feasibility.

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Differential Flatness-Based Fast Trajectory Planning for Fixed-Wing Autonomous Aerial Vehicles

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IEEE Transactions on Systems, Man, and Cybernetics: Systems 2025年

作者： Li, Junzhi Sun, Jingliang Long, Teng Zhou, Zhenlin Beijing Institute of Technology Beijing100081 China Key Laboratory of Dynamics and Control of Flight Vehicle Ministry of Education Beijing100081 China Beijing Institute of Technology Chongqing Innovation Center Chongqing401121 China National Key Laboratory of Land and Airbased Information Perception and Control Beijing100081 China

Due to the strong nonlinearity and nonholonomic dynamics, despite the various general trajectory optimization methods presented, few of them can guarantee efficient computation and physical feasibility for relatively complicated fixed-wing autonomous aerial vehicles (AAVs) dynamics. Aiming at this issue, this article investigates a differential flatness-based trajectory optimization method for fixed-wing AAVs (DFTO-FW). The customized trajectory representation is presented through differential flat characteristics analysis and polynomial parameterization, eliminating equality constraints to avoid the heavy computational burdens of solving complex dynamics. Through the design of integral performance costs and derivation of analytical gradients, the original trajectory optimization is transcribed into a lightweight, unconstrained, gradient-analytical optimization with linear time complexity to improve efficiency further. The simulation experiments illustrate the superior efficiency of the DFTO-FW, which takes subsecond CPU time (on a personal desktop) against other competitors by orders of magnitude to generate fixed-wing AAV trajectories in randomly generated obstacle environments. © 2013 IEEE.

关键词： Aerobraking

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Fast low-energy halo-to-halo transfers between Sun–planet systems

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Chinese Journal of Aeronautics 2014年第2期27卷 338-348页

作者： Shang Haibin Wang Shuai Cui Pingyuan Key Laboratory of Dynamics and Control of Flight Vehicle Ministry of Education Beijing Institute of Technology

In this paper, the problem of fast low-energy halo-to-halo transfers between Sun-planet systems is discussed under ephemeris constraints. According to the structure of an invariant man- ifold, employing an invariant manifold and planetary gravity assist to save fuel consumption is ana- lyzed from the view of orbital energy. Then, a pseudo-manifold is introduced to replace the invariant manifold in such a way that more transfer opportunities are allowed. Fast escape and cap- ture can be achieved along the pseudo-manifold. Furthermore, a global searching method that is based on patched-models is proposed to find an appropriate transfer trajectory. In this searching method, the trajectory is divided into several segments that can be designed under simple dynamical models, and an analytical algorithm is developed for connecting the segments. Earth-Mars and Earth Venus halo-to-halo transfers are designed to demonstrate the proposed approach. Numerical results show that the transfers that combine the pseudo-manifolds and planetary gravity assist can offer significant fuel consumption and flight time savings over traditional transfer schemes.

关键词： Astrophysics Halo orbit Low-energy Planetary gravity assistPseudo-manifold

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Experiments on pilot visibility from a V/STOL in overwater Hover

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Journal of the American Helicopter Society 1971年第4期16卷 19-28页

作者： KURYLOWICH G RITTER A Stability and Control Group Flight Control Division Air Force Flight Dynamics Laboratory Dayton Ohio

11 refs. 31750

关键词： AIRCRAFT, VTOL-STOL

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