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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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Improving aircraft nose wheel steering stability based on control continuation method

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science China(Technological sciences) 2025年第3期68卷 258-277页

作者： Qiaozhi YIN Dexu KONG Jiawei WANG Hong NIE Xiaohui WEI National Key Laboratory of Helicopter Aeromechanics Nanjing210016China State Key Laboratory of Mechanics and Control for Aerospace Structures Nanjing210016China Key Laboratory of Fundamental Science for National Defense-Advanced Design Technology of Flight Vehicle Nanjing210016China AVIC Nanjing Engineering Institute of Aircraft Systems Nanjing211106China

Aircraft steering instability during the taxiing process sometimes occurs resulting from the unstable bifurcation phenomena of the nonlinear steering dynamic system,which may lead to severe *** this study,the control parameter design of an aircraft nose wheel steering control system based on the control continuation method is proposed to reduce the number of unstable bifurcation points and enlarge the system stable region area in a certain parameter ***,the aircraft turning performance can be improved ***,a nonlinear aircraft rollout dynamic model is constructed,and the aircraft ground steering bifurcation characteristics are obtained under the open-loop steering control ***,the bifurcation performances under three closed-loop nose wheel steering controllers based on the feedback control method are compared,and the control parameter of the quadratic nonlinear controller with a better bifurcation control effect is selected as a second bifurcation parameter to analyze the directional system stability via two-parameter bifurcation ***,the influence of a crosswind on the aircraft ground steering bifurcation performance is studied for various control parameter ***,the control effects of a traditional proportional-integral-derivative(PID)nose wheel steering control law and the designed feedback controller are compared and ***,a semi-physical experiment of the aircraft nose wheel steering system is carried out,and different control parameter values are selected for test verification,which can further verify the control effect of the designed nonlinear feedback *** results indicate that the feedback control method is unable to vary the system bifurcation types,but appropriate control parameter design can effectively shrink the system instability region and even eliminate the unstable Hopf bifurcation points under some specific working conditions,improving the aircraft ground turning stability re

关键词： aircraft taxiing dynamics and stability nose wheel steering control system control continuation steering bifurcation characteristics quadratic feedback control

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Integrated online identification of aerodynamic and thrust parameters for air-breathing aircraft 3

Integrated online identification of aerodynamic and thrust p...

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2024 3rd International Conference on aerospace and Control Engineering, ICoACE 2024

作者： Jiang, Zhenyu Li, Xiaodong Liu, Shuang College of Aerospace Science and Engineering National University of Defense Technology Hunan Changsha410073 China Hunan Provincial Key Laboratory of Aerospace Cross-Domain Flight Vehicle System and Control Technology Changsha410073 China

A method for integrated online identification of aerodynamic and thrust parameters has been proposed. Firstly, a motion model of an aircraft powered by a solid rocket ramjet engine was established in the longitudinal plane. Secondly, polynomial models of aerodynamic and thrust coefficients were established for the horizontal flight segment. Then, an integrated online identification simulation of aerodynamic and thrust parameters was carried out using the unscented Kalman filter method. The results indicate that the proposed method has high identification accuracy and efficiency. © 2025 Institute of Physics Publishing. All rights reserved.

关键词： Kalman filters

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Adaptive terminal super-twisting prescribed performance controller for near-space vehicle based on data-driven model

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ISA Transactions 2025年 160卷 1-18页

作者： Zhang, Tianchen Ding, Yibo Yue, Xiaokui Li, Naying School of Astronautics Northwestern Polytechnical University Xi'an710072 China Research & Development Institute of Northwestern Polytechnical University in Shenzhen Sanhang Science &Technology Buliding No. 45th Gaoxin South 9th Road Nanshan District Shenzhen518063 China National Key Laboratory of Aerospace Flight Dynamics Northwestern Polytechnical University Xi'an710072 China Beijing Electro-mechanical Engineering Institute Beijing100074 China

A data-driven adaptive terminal super-twisting prescribed performance controller (DASTPC) is designed for near-space vehicle (NSV) to satisfy transient and steady-state performance, and prevent scramjet choking. Firstly, a novel predetermined-time performance function is proposed to guarantee that tracking error can converge to a prescribed bound of small residual sets at the predetermined time. Compared with traditional performance functions, the predetermined-time performance function can achieve faster respond speed, realize more accurate convergence, and avoid overlarge initial value of actuators. Secondly, by combining the predetermined-time performance function with sliding mode control, a novel non-singular fast terminal sliding surface and an improved adaptive super-twisting reaching law are proposed to improve computational efficiency and accelerate convergent rate of system. The adaptive reaching law can avoid excessive gains and attenuate chattering by automatically tuning control gain. Thirdly, a deep recurrent neural network-based long-short term memory (LSTM) is employed to learn time-series historical flight dynamics data offline, so as to construct a data-driven LSTM training model. This data-driven model replaces nominal dynamics model of NSV in DASTPC, effectively suppressing model uncertainties. In addition, a homogeneous high-order sliding mode observer is utilized to compensate for external disturbances, avoiding excessive parameter estimation. Since boundary conditions of the predetermined-time performance function are fully satisfied, the DASTPC can effectively restrict amplitude of angle of attack, thus ensuring the intake condition of scramjet. Ultimately, to illustrate the superiority of DASTPC, several sets of simulations are performed on NSV subject to prescribed performance bound, external disturbances and parameter perturbations. © 2025 ISA

关键词： Long short-term memory

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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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Numerical simulation of the effect of Faraday cage on the inductively coupled plasma discharge

Numerical simulation of the effect of Faraday cage on the in...

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2024 International Conference on aerospace, Mechanical and Materials Engineering, AMME 2024

作者： Lei, Fan Zhang, Zhaoyang Wei, Xiaolong Han, Xinmin Wu, Hongzhi Liu, Zhiwei School of Electrical and Control Engineering Shaanxi University of Science and Technology Xi'an710016 China National Defense Key Laboratory of Aeronautical Plasma Dynamics Air Force Engineering University Xi'an710038 China China Academy of Aerospace Science and Innovation Beijing100032 China

Taking inductively coupled plasma (ICP) as the research object, a method of increasing the electron density of ICP by Faraday cage electromagnetic shielding is proposed. At the same time, the introduction of the Faraday cage can effectively prevent the electromagnetic interference caused by the discharge coil, which is helpful in reproducing the real near-space plasma environment in the laboratory. Based on COMSOL Multiphysics, a two-dimensional inductively coupled plasma discharge model was constructed, and the effect of the Faraday cage on ICP discharge parameters was comparatively studied. The simulation results show that the Faraday cage can effectively shield the electromagnetic interference caused by the discharge coil. At the same time, the Faraday cage can increase the electron density and the electron temperature of the plasma to a certain extent, and the plasma is evenly distributed in this case. With the increase of discharge power, the electromagnetic shielding effect of the Faraday cage is still effective, and the effect on the plasma electron density is more obvious. © 2025 Institute of Physics Publishing. All rights reserved.

关键词： Inductively coupled plasma

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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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Nonlinear flow control mechanism of two flexible flaps with fluid-structure interaction

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Acta Mechanica Sinica 2025年第2期41卷 116-131页

作者： Jiakun Han Chao Dong Jian Zhang Gang Chen College of Science Xi’an University of Science and TechnologyXi’an 710054China Beijing Institute of Space Long March Vehicle Beijing 100076China Science and Technology on Space Physics Laboratory China Academy of Launch Vehicle TechnologyBeijing 100076China State Key Laboratory of Strength and Vibration for Mechanic Structures Shaanxi Key Laboratory of Service Environment and Control for Flight VehiclesSchool of Aerospace EngineeringXi’an Jiaotong UniversityXi’an 710049China

The flow control at low Reynolds numbers is one of the most promising technologies in the field of aerodynamics,and it is also an important source of the innovation for novel *** this study,a new way of nonlinear flow control by interaction between two flexible flaps is proposed,and their flow control mechanism is studied employing the self-constructed immersed boundary-lattice Boltzmann-finite element method(IB-LB-FEM).The effects of the difference in material properties and flap length between the two flexible flaps on the nonlinear flow control of the airfoil are *** is suggested that the relationship between the deformation of the two flexible flaps and the evolution of the vortex under the fluid-structure interaction(FSI).It is shown that the upstream flexible flap plays a key role in the flow control of the two flexible *** FSI effect of the upstream flexible flap will change the unsteady flow behind it and affect the deformation of the downstream flexible *** flexible flaps with different material properties and different lengths will change their own FSI characteristics by the induced vortex,effectively suppressing the flow separation on the airfoil’s upper *** interaction of two flexible flaps plays an extremely important role in improving the autonomy and adjustability of flow *** numerical results will provide a theoretical basis and technical guidance for the development and application of a new flap passive control technology.

关键词： Nonlinear flow control Flexible flap Fluid-structure interaction Flow separation IB-LB-FEM

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