bluuebunny/crossref_metadata_2025_split huggingface dataset:
Remaining Useful Life Prediction Of Precision Bearing Based on Multi-Head Attention Mechanism
Authors: Guo Fan , Niu Hongwei , Li Ming 
Published: June 2024

Abstract
The high-precision bearing is the core component of the space actuator, whose remaining useful life (RUL) prediction is an essential issue of constructing condition-based maintenance (CBM) system. To address the current challenges of establishing traditional physical failure models for high-precision bearings and dealing with long time-series vibration data, this paper proposes a precision bearing remaining useful life prediction model based on multi-head attention mechanism. The model utilizes a one-dimensional convolutional neural network (CNN) to compress the input features along the time dimension, then, an encoder-decoder architecture with a multi-head attention mechanism for further feature exploration. Experiments are conducted using vibration signals from the IEEE PHM 2012 Challenge dataset for training and validation. The results indicate that this algorithm exhibits relatively smaller relative errors compared to other algorithms, demonstrating good accuracy and strong stability. This approach shows promise in accurate and reliable precision bearing life prediction.
MCSA-based fault diagnosis for rotary parts in servo motion system: Approach and experimental study
Authors: Liu Hanyang , Sheng Feng , Lu Xinyu , Lin Jing 
Published: June 2024

Abstract
Motor current signature analysis (MCSA), as a non-invasive diagnostic method, is robust to environmental noise and of less sensor cost than vibration-based monitoring. Although large amount of progress has been achieved, little attention is paid to the MCSA-based diagnosis task in the Servo motion systems (SMS). An approach using Park vector demodulation, comb filtering and the ensemble empirical mode decomposition (EEMD) is proposed for cyclic fault event detection in this paper. Experiment studies reveal that the MCSA approach could extract the fault signature under extremely low-speed or noisy working condition, which has potential in the scenarios where the accelerometers placement is limited or affected by interferences.
Research on bearing fault diagnosis based on laser vibrometer
Authors: Chen Xueying , Jiang Zhaoxiang , Zhou Chengning , Liu Caixue , Yang Taibo 
Published: June 2024

Abstract
As general components in machinery, rolling bearings are also fault prone components. And unexpected faults will bring immeasurable loss to economy, personnel, etc. Therefore, fault detection and diagnosis are of paramount importance. As the carrier of fault information, component response signal is the most concerned part in fault diagnosis researches. The detection methods for response signal can be divided into contact and non-contact detection. Compared with the contact detection, laser Doppler vibrometer has the advantage of no contact, no damage and dynamic measurement. Thus, this paper progresses theoretical and experimental researches on non-contact detection of bearing wear fault based on laser Doppler vibrometer. Firstly, the vibration measurement principle of laser Doppler vibrometer is analyzed in this paper. On account of the principle, the internal optical path and signal flow of the single point laser vibrometer is established and analyzed. Secondly, in order to carry out the non-contact detection test, an optical measuring system based on a single point laser vibrometer is built to collect signals. Also, a bearing wear fault simulated test rig is built to provide fault response signals. Based on the above built test devices, the detection tests of the intact and faulty bearings are carried out. Lastly, through the analysis of collected signals of bearings with wear of different parts in time domain and frequency domain, the characterizations of the corresponding fault are obtained so as to implement the fault diagnosis, which prove the effectiveness of laser vibration detection method for fault detection.
A Method for Continuous Observation of Sea Surface Moving Targets Based on Multi Point Trajectory Prediction
Authors: Ren Xupu , Cheng Yao , Li Yuqing 
Published: June 2024

Abstract
The detection and tracking of sea surface sensitive targets are challenging due to their high manoeuvrability and the limited field of view of low-orbit remote sensing satellites. This paper presents a prediction model for the trajectory of moving targets on the sea surface, which utilizes a dynamic and variable potential target area and transition probability density function by using prior information, such as the position, speed, and course of a moving target when observed. When a moving target is observed multiple times, its velocity is estimated using the least squares method and the Kalman filtering algorithm, while its course is predicted using Hermite interpolation polynomials. Simulation examples are used to validate the feasibility and effectiveness of the proposed approach.
An Analytical Method for Accuracy Analysis of Close Proximity Rendezvous in Space Based on an Improved C-W Equation under Perturbation Effects
Authors: Duan Qinzheng , Gao Yu , Li Yuqing 
Published: June 2024

Abstract
In order to address the issue of quantitatively solving the impact of perturbation forces and initial errors on rendezvous accuracy, traditional analytical methods are not suitable, and the calculation steps for statistical methods based on Monte Carlo simulation analysis are complex and computationally time-consuming. To overcome these challenges, this paper proposes a method for analysing rendezvous accuracy based on an improved relative motion dynamics model. Describing the relative motion between a sub-spacecraft and a target spacecraft by an improved Clohessy-Wiltshire (C-W) equation. By employing the derived state transition matrix from the model, it is possible to calculate the error propagation during the rendezvous process and express the rendezvous accuracy analytically. Through simulation examples, the proposed method proves to be both accurate and efficient in analysing the influence of perturbation forces and random errors such as initial position and velocity on rendezvous accuracy. This study verifies the correctness and effectiveness of the approach.
Research on Spacecraft Fault Diagnosis and Recovery Architecture
Authors: Cheng Yao , Gong Ying , Wang Jingyan , Xiong Xiao 
Published: June 2024

Abstract
Fault diagnosis and recovery system is designed to monitor on-orbit state of spacecraft and handle exception, which provides spacecraft security and missions succeed. This report studies the design of spacecraft fault diagnosis and recovery system from technology and architecture two respects. Technical system and modules design from top level for spacecraft fault diagnosis and recovery is proposed. And the architecture of comprehensive fault diagnosis system is also proposed, which supports spacecraft to diagnose and recover on-orbit faults.
A Multi-satellite Scheduling Method for Emergency Observation Mission Based on Hierarchical Planning Strategy
Authors: Huang Lixia , Zhao Xuemei , Zhang Qiang , Li Qunzhi 
Published: June 2024

Abstract
Emergency observation tasks involve Earth imaging activities by satellites to aid in emergency scenarios like disaster relief, emphasizing promptness and unpredictability. Multi-satellite collaborative planning for several emergency tasks faces issues like high computational complexity, slow processing, and numerous optimization considerations. This paper introduces a hierarchical planning approach and designs an algorithm for collaborative task planning across multiple emergencies and satellites. The algorithm’s computational efficiency and planning effectiveness are later confirmed through a case study.
Attitude control of combined spacecraft with fuzzy neural network disturbance observer
Authors: Sun Yicheng , Li Xiaoyue , Fu Yichuan , Lyu Yueyong 
Published: June 2024

Abstract
A finite-time control strategy based on a fuzzy neural network disturbance observer (FNNDO) and nonsingular terminal sliding mode (NTSM) is proposed for the attitude control system of a combined spacecraft in the presence of non-cooperative targets with competitive torque output. First, a mathematical model of the combined spacecraft attitude is established with the service spacecraft as the reference. Then, the external disturbances and competitive torque output from non-cooperative targets are treated as generalized disturbances, and FNNDO is employed for tracking and compensation. Subsequently, a NTSM controller is designed to achieve finite-time attitude takeover control of non-cooperative targets. The stability of the disturbance observer and controller is proven using Lyapunov stability theory. Simulation results demonstrate that this control strategy effectively handles the competitive actions of non-cooperative targets while rapidly stabilizing the combined spacecraft’s attitude at the desired values.
Design of Improved Ground Closed-loop Test System Based on Variable-stability Flight Control Computer
Authors: Yahui Hu , Wei Fang , Ertai Cao 
Published: June 2024

Abstract
With the development of civil aviation, ground simulation test has gradually become a key link in the transformation of basic theory to engineering application. By forming a closed-loop link between the variable stability aircraft (VSA) dynamics model and the aircraft rudder surface, sensors, etc., the variable-stability ground closed-loop test system can simulate the aircraft flight state and response characteristics in the ground environment. However, the current ground test system suffers from a wide range of signals, complex signal simulation methods, and low system integration. In this study, an improved modular ground closed-loop test system for VSA is designed from three aspects: signal acquisition and simulation of airborne equipment, parameter monitoring and data processing, and fault simulation subsystem, which improves its compatibility and integrates with the software hardware of the variable-stability flight control computer and other air-borne equipment. After the system interconnection test, the generalized ground closed-loop test system designed in this study can replace the original system more efficiently, and its signal connection has inheritability, and provides a design method reference for other related researches of the variable-stability flight control computer.
Model Predictive Control with Gaussian-Process-Enhanced Dynamics for Spacecraft Attitude Takeover Maneuvers
Authors: Liu Yuhan , Wang Pengyu 
Published: June 2024

Abstract
This paper aims to deal with the attitude takeover control for combined spacecraft with unknown dynamics and attitude maneuverability of the target. Generally, the dynamics of combined spacecraft executing an on-orbit servicing task is highly nonlinear and costly to identify. To address this issue, a sparse variational Gaussian process (GP)-based model predictive control (MPC) strategy is proposed to achieve efficient attitude takeover maneuvers under multiple constraints and target attitude maneuverability. The GP regression performs a model completion behavior, where the unknown dynamics is compensated by the sparse variational GP with a low computational load. This enhances the control performance of the combined spacecraft during the takeover task execution. Numerical simulations are used to demonstrate the effectiveness of the proposed strategy.
Air-Ground Characteristic Test and Analysis on Fan Blade Vibration Stress of Turbofan Engine
Authors: Tao Ye 
Published: June 2024

Abstract
Obtaining the vibration stress of fan rotor blades under actual working conditions through flight tests is a necessary means to carry out design verification and optimization improvement of turbofan engine. Taking the high bypass ratio turbofan engine as research object, installed ground and flight tests were carried out. The vibration characteristics and stress distribution of the fan blade were obtained by direct measurement means of strain gauge, and the air-ground characteristics of the test data were compared and analyzed. The results show that under the steady state, the vibration stress level of fan blade in ground test is significantly higher than that in flight test; There is a significant difference in frequency distribution of excitation factors on fan blade in the ground and flight tests.
A Framework for FDM-based DFAM: Key Enabling Technologies for Knowledge-based Design
Authors: Haruna Auwal , Noman Khandaker , Li Yongbo , Shah Intizar Ali 
Published: June 2024

Abstract
The booming and evolution of additive manufacturing (AM) technologies call for robust key enabling technologies and solutions to the ongoing advancement of AM. However, there are limitations to the fused deposition modeling-based design for AM (FDM-based DFAM), including an inadequate understanding of the process activities and the progressive industrialization, which make the concept generation operations unreliable, inconsistent, and of limited influence. This paper proposes a principle knowledge-based framework for enabling technologies in FDM-based DFAM to provide solutions to the abovementioned engineering problems to increase the viability of industrial applications. Consequently, a case study application is used to verify the feasibility and effectiveness of our approach.
A boundary condition-damping spring for simulating the acoustoelastic effects of Lamb waves
Authors: Tao Tang , Zhigao Xu , Jiazhao Chen , Yuxiang Zhang 
Published: June 2024

Abstract
Physical field simulation is considered an efficient and economical method to study the acoustoelastic effect. Therefore, many researchers thirst for a suitable boundary condition for effectively absorbing incoming waves and reducing echoes while applying pre-stress to the study object, so that the acoustoelastic effects can be more clearly observed by time-domain information of simulation results. However, the existing boundary conditions in physical field simulation software perform helplessly. For this reason, a boundary condi-tion named “damping spring” is proposed in this paper and the corresponding parameter setting scheme is given, effectively solving the above contradiction. Then the feasibility of this boundary condition is verified in 2D and 3D models. In addition, the damping spring boundary condition is applied in this paper to the simulate the acoustoelastic effect of S0-mode Lamb waves in metal plate structures, whose rule shows a good consistency with that of the known literature [5], further verifying the feasibility of the damping spring boundary condition applied to simulate the acoustoelastic effects.
Research on Simulation Technology of Excitation Response of Aircraft Structural Based on Finite Element Model in Flutter Flight Test
Authors: Ming Lei 
Published: June 2024

Abstract
To simulate excitation response of the aircraft structural of flutter test aircraft under different excitation methods. A simulation method for excitation response of flutter flight tests based on finite element models has been proposed. This method is based on the finite element model of the aircraft structure. Establish aerodynamic and excitation force models for flutter flight tests. Obtain a simulation model for the excitation response of aircraft flutter flight tests. Solve the model and simulate various excitation methods for flutter flight tests. Firstly, a detailed introduction was given to the excitation modeling method for aircraft flutter flight tests, including two excitation models: external excitation and control surface excitation. Then, the finite element model of the structural dynamics of a single wing with ailerons is taken as the research object. Establish a single wing flutter flight test excitation response model. Implemented simulation of control surface sweep excitation, control surface pulse excitation, and small rocket excitation. The feasibility of this method has been verified. Finally, based on the finite element model of the entire aircraft, a flutter flight test excitation response simulation model was established. We have conducted analysis and research on sensor position optimization, excitation method optimization, excitation response amplitude prediction, and flutter boundary prediction. And the simulation optimization analysis results were compared with the flight test results. Analyzed the promoting effect of flutter flight test excitation response simulation on flight tests.
Honeycomb Elastic Metasurfaces for Broadband Control of Flexural Waves
Authors: Cheng Jiali , Li Bing 
Published: June 2024

Abstract
Elastic metasurfaces are artificial planar structures endowed with unique properties that natural materials do not possess. They exhibit significant potential in the realm of wave control. Despite the widespread attention garnered by metasurfaces due to their ultrathin profile, ease of design and fabrication, and enhanced physical characteristics, they still grapple with the challenge posed by their narrow operational bandwidth. In this study, a structurally compact, subwavelength-scale honeycomb metasurface is proposed for broadband manipulation of flexural waves. Through modulation of the unit cell dimensions, precise control over the phase is achieved, enabling a series of remarkable wavefront manipulations, including anomalous refraction, energy concentration, self-bending beam, and source illusion. Results indicate that compared to conventional localized resonance metasurfaces, the introduced approach offers advantages in terms of broad bandwidth, compactness, and high efficiency. This endeavor holds the potential to provide more comprehensive methods for vibration attenuation, noise reduction, and wave control.
Modulation of flow, heat, and mass transfer in turbulent double-diffusive convection
Authors: Kenjereš S. , Roovers R. 
Published: June 2024

Abstract
The present study addresses numerical simulations of the double-diffusive convection in a turbulent regime. The characteristic concentration and temperature Prandtl numbers (PrC
= 700 and PrT
= 7) correspond to the typical seawater properties. Here, we applied the Large-Eddy Simulation (LES) approach, with relatively simple subgrid turbulence closures of momentum, concentration, and temperature for the unresolved scales. The wall-resolved LES approach proved to work well on significantly coarser numerical mesh than used in recent Direct Numerical Simulation (DNS) studies of Yang et al. (2016) in the intermediate range of working parameters, 107 ≤ RaC
≤ 109, 0 ≤ RaT
≤ 106, which covers the quasi-Rayleigh-Bénard, fingering, and damping flow regimes. A good agreement between concentration and temperature Nusselt numbers is obtained. The instantaneous Nusselt numbers distribution revealed a significant impact of the imposed strong thermal stratification (RaT
= 106) in comparison to the neutral case (RaT
= 0).
Stagnation point heat transfer under a free-surface jet
Authors: Harnik R S , Haustein H D 
Published: June 2024

Abstract
Laminar free-surface jet impingement is a crucial configuration for heat transfer processes. Focusing on the link between stagnation-point heat transfer and near-axis radial acceleration, its dependence on jet width and profile is studied. Thus, heat transfer depends on: fluid properties, flow rate, nozzle length, nozzle-to-plate spacing, surface tension and gravity (Pr, Re, L/d, H/d, We & Fr, accordingly). As existing theory is limited to specific cases, a new general description is developed from analogy to submerged jets. Validated by two-phase flow simulations, this description captures key jet dynamics evolution (centerline velocity, profile curvature). It reveals significant property changes during jet flight due to relaxation (L dependence) and contraction (Re/Fr dependence). Unlike submerged jets, contraction raises arrival Reynolds number, leading to additional dependencies Nu ∝ L and Nu ∝ H/Fr, and further deviations at low-We and -Re. The theory successfully predicts heat transfer across diverse conditions and converges to negligible gravity (horizontal jet) as expected.
Comparison between DNS and RANS approaches for liquid metal flows around a square rod bundle
Authors: Trane D , Grespan M , Angeli D 
Published: June 2024

Abstract
The thermal-hydraulic characteristics of liquid metal flows around rod bundles are of great interest for the research and design of fourth generation nuclear reactors. Currently, a large research effort is aimed at the development of accurate numerical models for low Prandtl number fluid flows, since the data available in the literature are quite scarce. Direct Numerical Simulation (DNS) is undoubtedly the most accurate approach, but its large requirements of computational resources and time make it less practical than other simplified methods such as the Reynolds-Average Navier Stokes (RANS) approach. The present paper provides a comparison between numerical results of a flow of liquid Lead-Bismuth Eutectic (LBE) at Pr=0.031 around four vertical cylindrical rods arranged in a square lattice, obtained by DNS and RANS. Several turbulence models are considered, including the standard k−ε, k−ω SST, and two Reynolds stress models, namely the ones by Launder, Reece and Rodi (LRR), and Speziale, Sarkar and Gatski (SSG). The accuracy of these models is assessed by comparing the mean Nusselt number, the pressure drop, and local field distributions with those obtained by DNS.
Structured illumination with infrared imaging for measuring thermal conductivity
Authors: Bhat Ashwath , Dames Chris 
Published: June 2024

Abstract
With developments in advanced manufacturing and materials by design comes the need for high-throughput thermal characterization and inspection. Towards this end, Structured Illumination with Thermal Imaging (SITI) is an all-optical pump-probe thermal characterization technique recently developed by our group. In the first generation [Zheng et al., Appl. Phys. Rev. 9, 021411 (2022)] SITI uses an LED with a digital micromirror device (DMD) to “structurally illuminate” and heat the sample with dynamic patterns, a visible light camera for thermoreflectance based “thermal imaging” [leveraging a Microsanj MTIR120], and the resultant temperature response was fit with a thermal model to characterize the sample’s thermal properties. This represents a novel approach to dynamic and flexible spatial mapping of thermal properties by virtue of being a non-contact technique and having a simpler scanning means (computer control only) than conventional pump-probe laser methods. SITI also can tolerate rough samples with diffuse reflections. This talk presents the second generation of SITI. The pumping is now based on a lower cost off-the-shelf digital projector. The thermometry is now performed using an infrared (IR) camera, which we find is a more flexible and accessible hardware approach compared to the thermoreflectance microscopy used previously. With these updates the setup can deliver higher heating power and a broader range of frequencies, allowing an extended range of samples that can be studied. We have demonstrated SITI’s ability to measure the thermal conductivity of a microscope glass slide.