bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electric tractor dual motor coupling drive system structure design and simulation experimental research
Authors: Zhang Xin , Qi Huijun , Wang Wei , Ge Hongen 
Published: August 2023

Abstract
Electric tractors as a kind of green agricultural machinery, in reducing carbon emissions, saving resources, and other aspects have outstanding advantages. Therefore, the development and research of electric tractors are of great significance. In this paper, a new dual-motor coupled drive system applicable to electric tractors is proposed, and the structure and transmission characteristics of the system are analyzed in conjunction with the tractor operation requirements. At the same time, the drive system model is built in MATLAB/Simulink environment for simulation and verification. Finally, hardware-in-the-loop experiments were conducted using the Speedgoat platform. The simulation and experimental results prove that the electric tractor with this dual-motor coupled drive system has better power performance. The economic performance is better compared with the single-motor drive system, and the whole vehicle range can be extended by 1.23 h.
Hardware design of electrostatic levitation accelerometer control system
Authors: Liu Jianhe , Huang Wenhao , Chen Yuqi 
Published: August 2023

Abstract
The electrostatic levitation accelerometer is a high-precision inertial instrument for measuring small displacement and acceleration, and it plays a very important role in global gravity field measurement, space gravitational wave detection, and other space missions as a key payload for satellites. It can realize the measurement of three-axis linear acceleration and three-axis angular acceleration. The open loop is unstable, and the control system needs to control six degrees of freedom at the same time so that the test mass can be stably suspended in the center position of the capacitive pole plate. For the demand of multi-channel simultaneous control of electrostatic levitation accelerometer, this paper designs an eight-channel digital control system hardware circuit with DSP as the core and FPGA as the co-processor, which can realize the data acquisition and feedback control of six degrees of freedom, writes the driver using hardware description language (Verilog), and simulates and analyzes the driver timing by the timing simulation software Modelsim. Finally, the hardware circuit was tested for the onboard drive. The results show that the system can work normally, the average sampling error of ADC is 0.00198 V, and the output error of DAC is 0.004 V, which is small enough to meet the system requirements.
LEO Small-Scale Experimental Regional Navigation Constellation Design and Optimization
Authors: Liu Jialu , Wang Shuquan 
Published: August 2023

Abstract
In order to demonstrate the key functionalities of large-scale LEO navigation constellations, this paper investigates the small-scale LEO experimental constellation design problem. The major requirements include achieving quadruple coverage of specific ground target areas. The regional navigation constellation consists of four satellites distributed on two orbit planes. Considering the sustainable regional navigation, it is expected that the orbits of the satellites are regressional such that it takes little effort for the constellation to cover the designated region. In this way, the structure of the optimization problem is set up, which is constrained by the quadruple coverage and accuracy requirements. It takes the maximum task time as the objective function. The differential evolution algorithm (DE) is utilized to solve the optimization problem. The optimal regional navigation constellation design scheme satisfying the constraints is obtained. The simulation results show that the regional navigation constellation designed by this method can meet the predetermined requirements.
Integrated System of Spacecraft Impact Monitoring and Shape Reconstruction
Authors: Luo Yuxiang , Zhang Qingzhi , Wang Dingding , Sun Geng , Wu Yanxi , Cao Jian , Du Xuan , Sun Zhaoxiong , Zhang Tao 
Published: August 2023

Abstract
When the spacecraft is in orbit, there is a risk of high-speed impact by space debris. After the spacecraft is impacted, it is of great significance to determine the exact location of the spacecraft and the structural changes caused by the impact. However, the conventional impact monitoring methods are mainly realized by sticking sensors on the surface of spacecraft structures. Such contact measurement methods generally have one or more of the problems of large size, heavy mass, complex system, easy to fall off, and do not have the function of reconstructing the shape of the impacted part of the spacecraft. This study proposes an integrated system of spacecraft impact monitoring and shape reconstruction, which realizes the organic integration of positioning and shape reconstruction and can help astronauts and ground technicians to timely know the impact location and shape changes after spacecraft damage.
The Demand for Satellite Attitude Error for High-Resolution Spaceborne SAR Image Quality
Authors: Guo Xin , Yao Yuying , Fu Weida , Shi Sihan , Wang Zhonghui 
Published: August 2023

AbstractBecause of the prominent problem of insufficient index decomposition of satellite-earth integration indicators and attitude control demand analysis for spaceborne SAR, this paper made studies on the effect of attitude measurement error and attitude pointing error for spaceborne SAR images. The attitude error model of azimuth and range antennae was constructed. The quantitative transfer relationships, which contain the attitude measurement error model determined by azimuth Doppler parameters and the attitude pointing error model determined by ambiguity and system sensitivity, were analyzed. Theoretical analysis and simulation results are shown as follows: for the X-band SAR satellite, the attitude measurement error should be better than 0.01° for 0.5 m azimuth resolution, and the attitude pointing error should be better than 0.03°. The research results can provide theoretical support for the error allocation phase of the satellite scheme and the analysis of attitude control requirements.
Design and Analysis of Buffer Device for Interstage Pyrotechnic Separation
Authors: Yang Yifan , Lin Sanchun , Luo Yanshou , Yu Yubing , Yang Heng 
Published: August 2023

Abstract
Buffer device for interstage pyrotechnic separation is the key part to achieving electrical connector plug separation. This paper carries out research on the buffer structure in different working conditions and finally designs two kinds of buffer devices, which are respectively applied to the stage separation structure of large mass SLMB (Shingle-Like Mass Blocks) and the stage separation structure of the small mass SLMB. Both can control the energy absorption size of the device through structural parameters to adapt to different working conditions. Compared with the original structure, the buffer effect after optimization is very obvious. The time domain peak value and frequency domain peak value of the buffering device suitable for small mass SLMB are reduced by 79.90% and 85.67%, respectively. The buffering device suitable for large mass SLMB changes the energy absorption mode of the buffering structure, and the steel cable structure will not break. Compared with the original structure loaded with small mass SLMB, the response in the time domain and frequency domain also decreased. The application range of buffer devices for interstage pyrotechnic separation is greatly expanded.
Pipe Routing Design for Aero-Engine Using Monte Carlo Tree Search Method
Authors: Xu Hongbin , Fan Jiang , Meng Qingze , Su Yuming 
Published: August 2023

Abstract
Pipe routing design (PRD) is a complex process that involves a large search space and requires experienced professionals. Despite advancements in aero-engine design, PRD remains a stage that is not completely automated. In this article, we present a new approach to PRD by formulating it as a Markov decision process and proposing a pipe routing design method based on Monte Carlo Tree Search (PRD-MCTS). Firstly, this paper uses an intelligent algorithm to look for enough paths for each pair of joints. Secondly, PRD-MCTS regards each path as a candidate choice, and then PRD-MCTS randomly chooses a path and calculates the probability of collision-free routing until the set time. The method selects the path with the highest probability and updates the environment for the next selection. A simplified environment from the aero engine verifies the correctness of the methods.
Aerodynamic Stability Study of Turbojet Engine During Unmanned Aerial Vehicle Assisted Taking Off Stage
Authors: Du Yufei , Wu Jiang , Wang Gerui , Du Farong 
Published: August 2023

Abstract
Rocket Assisted Take Off (RATO) technology is utilized for the takeoff phase of various types of UAVs. RATO creates heavy axial overload for a UAV system, which consequently increases the inlet pressure of the fuel pump of the UAV’s turbojet engine. This situation leads to an abrupt change in fuel supply for its combustor, eventually causing drastic changes in the operating state of the compressor system. In addition, it may potentially induce compressor surge. To resolve this problem, through an experimental investigation, this study delves into the dynamic response of the fuel system during the RATO phase. A two-zone dual-wave coupled compressor model has been established for the intake-turbojet engine system to scrutinize the aerodynamic stability of the turbojet engine during the RATO phase. The findings reveal that when the increase of fuel pump inlet pressure causes changes in the fuel flow rate, it is essential for the engine to re-establish aerodynamic equilibrium in order to mitigate the impacts of abrupt fuel flow step increases. Moreover, it has been observed that the more the ratio of the length of the intake and the cross-section area, the greater the contribution of the inertial force of airflow in the pipe it brings within the passage. This results in a stronger suppression of combustion chamber pressure and flow rate fluctuations induced by fuel step supply, thereby rendering the compressor less susceptible to surge. In summary, this research contributes valuable insights for appropriate matching of intakes, enhancing the ability of the turbojet engine against fuel step supply in the combustion chamber during the takeoff stage and augmenting the aerodynamic and thermodynamic overload resistance capability of the engine.
A high-precision synchronization system based on custom benchmarks
Authors: Shi Xiaoxia , Wang Yu , Li Xindong 
Published: August 2023

Abstract
In order to meet the requirements of high synchronization of information flow for the cooperation among subsystems of spacecraft and of autonomous operation and management of spacecraft, this article proposes a synchronization system design based on a custom synchronization benchmark. This plan provides a custom synchronization benchmark design method and design constraints and proposes synchronization strategies for different system requirements. On this basis, a high-precision synchronization system design scheme is proposed. By conducting tests, the synchronization error compliance of the synchronization system is verified based on custom benchmarks. This design does not rely on the availability of GPS signals, and the synchronization system design is triggered by the requirement for synchronization accuracy. This method can be applied to spacecraft onboard systems and ground testing systems with extensive application value.
Analysis of Pressure Fluctuation of Pumped Storage Units
Authors: Li Yao , Ma Zhijie , Sun Bozhi 
Published: August 2023

Abstract
In pump turbines, the observation in the engineering field shows that pressure fluctuation has become one of the most serious hydraulic instability phenomena. The pressure pulsation will cause vibration and fatigue failure of the unit, even vibration of the plant, which greatly affects the safe operation of the power station. In this paper, the research on pressure fluctuation by domestic and foreign researchers is introduced and discussed. It includes the characteristics of pressure pulsation in various regions of pump turbines under various operating conditions, existing research methods, and the possibility of improving pressure pulsation problems with variable-speed pumped storage units, which will serve as the basis for further research and improvement of pressure pulsation.
A New Type of Oxidation Air Bubble Breaking and Detention Device with Wing Span Baffle Structure Numerical simulation research
Authors: Zhang Qilong , Wu Dehua , Guo Junhai , Wu Bin , Qi Zhenyu , Wang Peng 
Published: August 2023

Abstract
Taking the limestone gypsum wet desulfurization oxidation air duct of a 660 MW coal-fired unit in a power generation enterprise as the research object, a new type of oxidation air bubble crushing and retention device with a wing span baffle structure was simulated and optimized using CFD numerical simulation technology. The results showed that the retention time of bubbles in the slurry in the final design scheme was about 10.4 seconds, significantly better than the initial scheme’s 8.5 seconds and the comparison scheme 1’s 6.5 seconds. The new oxidation air bubble crushing and retention device significantly increases the retention time of oxidation air bubbles in the slurry, reduces the size of oxidation air bubbles, and improves the distribution uniformity of oxidation air in the slurry pool.
UCAV situation assessment based on SAE-ELM
Authors: Xie Lei , Huang Changqiang , Tang Shangqin , Li Yintong , Han Bo 
Published: August 2023

Abstract
A Stacked Autoencoder Extreme learning machine (SAE-ELM) assessment model is proposed to study the weight of an Unmanned Combat Air Vehicle (UCAV) situation assessment. On the basis of the existing air combat situation description parameters and their optimized situation advantage function weights, the mapping relationship between the air combat situation description parameters and the situation advantage function weights is established by using the SAE-ELM to achieve a more accurate evaluation. From the four error indicators of MAE, RMSE, MAPE, and R-Squared, the simulation experiment shows that the SAE-ELM evaluation error is the smallest and can effectively achieve accurate situation assessment.
Evaluation Indicators of Space Frontier Technology Based on D-ANP
Authors: Zheng LeiXin , Wang WeiJun 
Published: August 2023

Abstract
With the rapid development of aerospace frontier technology and the gradual improvement of its application impact, it is particularly necessary to track and analyze the development and evaluation of frontier technology. In the process of a comprehensive evaluation, the rationality and weight of evaluation indicators determine whether the evaluation is effective. In this paper, the relevant evaluation index system is constructed through a comprehensive analysis of various factors of aerospace frontier technology. The weight of the index is calculated by the combination of DEMATEL and ANP to judge the interaction and importance of the indexes and make the evaluation results more accurate and reliable.
Study on the aerodynamic performance of nacelle inlet under crosswind
Authors: Lin Weibin , Wu Xing , Shao Yanan , Meng Tianyu , Zhang Han 
Published: August 2023

Abstract
Flow separation will occur in the nacelle inlet under crosswind operation, which will result in engine intake distortion and even engine surge. To study the reference characteristics of the flow field of the short tank inlet separation under the influence of crosswind, this paper observed the cloud map of the total price loss coefficient by changing the flow deflection Angle and flow velocity, made a qualitative analysis of the total pressure distortion degree, then calculated the average total pressure loss coefficient and distortion index, and conducted a quantitative analysis to explore the improvement of the total pressure distortion under different flow field factors. The results show that the degree of total pressure distortion is improved with the increase of incoming flow velocity at a small inlet deflection Angle, but with the increase of incoming flow deflection Angle, the ability of incoming flow velocity to improve the total pressure distortion gradually weakens until it disappears. The inlet deflection Angle plays a decisive role in the improvement effect of incoming flow velocity on the total pressure distortion.
Numerical study of aerodynamic characteristics and particle motion in square cylinder vortex flow with different void ratios
Authors: Xiong Feng , Yin Kang , Sun Ke 
Published: August 2023

Abstract
In actual production practice, blunt block structures usually exist in multiple forms simultaneously, such as buildings, bridges, and offshore platforms. Flow around multi-cylinder structures is often accompanied by complex phenomena, including separation and reattachment of shear layers, vortex-structure interactions, and the evolution of wake vortex streets. These phenomena can worsen fatigue damage or local accumulation of harmful substances on bluff block structures. The main purpose of this study is to analyze the complex flow phenomena of square cylinders with different void ratios and the distribution of particulate matter in the flow. The results show that the drag forces applied to the square cylinder under different void conditions will be very different, the flow will also vary greatly, and the location of particle deposition will also change significantly with the change of void ratio conditions.
Numerical analysis of the effect of different V-winglets on the aerodynamic performance of wind turbines
Authors: zhang Pengyu , Ma Jianlong 
Published: August 2023

Abstract
The aerodynamic characteristics and flow field distribution of wind turbines with the addition of V-flat winglets and V-winglets are investigated to investigate the effects of power, blade surface pressure, and flow field distribution of wind turbines with different V-winglets at rated operating conditions. The results show that the installation of V-winglets at the blade tip can increase the total power of the wind turbine. The V-winglets have better aerodynamic performance, and the total power is 1.57% higher than that without the winglets at rated operating conditions. The presence of V-winglets increases the pressure difference on the blade tip surface, and the pressure difference on the blade tip surface is more significant for flat V-winglets than for V-winglets. The V-winglets weaken the intensity of the blade tip disturbance, which makes the blade tip vortex V-shaped airfoil reduce the intensity of leaf tip disturbance and makes the vortex nucleus position far away from the leaf tip area. This can reduce the adverse effect of the leaf tip vortex on the main body of the blade.
Numerical Study on the Aerodynamic Characteristics of High Bypass Ratio Engine Exhaust System
Authors: Cai Beijing , Chao Xiao , Liu Kaili , Wang Lei 
Published: August 2023

Abstract
Research using numerical simulation methods on the aerodynamic performance of the high bypass ratio civil engine exhaust system for civil aircraft has been launched in this paper. The influence of flight conditions and aircraft integration on the aerodynamic performance of the exhaust system is systematically analyzed. The result shows that flight Mach number manifests an inhibition influence on the mass flow of the exhaust system and a positive impact on the thrust of the exhaust system. Flight altitude has a negative influence on the mass flow and the thrust of the exhaust system. Aircraft body integration represents a gain on the exhausting flow and an opposite influence on the thrust.
Torque Ripple Suppression Research of V-Shaped External Rotor Permanent Magnet Motor
Authors: Liang Jianwei , Guo Peiyao , Wang Xinhua , Yin Liying 
Published: August 2023

Abstract
Aiming at the problems of large torque ripple and poor output torque performance of external rotor permanent magnet synchronous motors, this paper took a three-phase 24-slot 19-pole external rotor motor as the research object, uses the magnetic circuit method and Lorentz theorem to analyze and calculate the motor torque, and improved the output torque by optimizing the position parameters of the V-shaped permanent magnet. The output torque was further optimized by a circular groove on the side of the stator teeth. The finite element simulation results show that the output performance of the motor can be improved by selecting the proper permanent magnet position. Stator tooth chooses slot position for Z = 1.2 mm, R = 3.5 mm torque ripple when dropped by 81.9%, up 7.6% on the output torque, motor performance is improved.
Hydraulic Systems Fault Diagnosis Based on Random Forests Recursive Feature Elimination and XGBoost
Authors: Song Zixiong , Wang Junle , Wang Mingxian , Yang Bingjian , Cui Langfu , Zhang Qingzhen , Xiang Gang , Lin Ruishi 
Published: August 2023

Abstract
This paper proposes an RFRFE-XGBoost method for fault mode recognition in hydraulic systems. The proposed method combines random forests-based recursive feature elimination (RFRFE) and extreme gradient boosting (XGBoost) to effectively identify important features and improve fault diagnosis efficiency and accuracy. The method is validated on relevant datasets and compared with existing methods, demonstrating its effectiveness and superiority. The results show that RFRFE-XGBoost can accurately recognize various fault modes and outperforms other methods in terms of classification accuracy and computational efficiency. The proposed method provides a promising approach for fault diagnosis in complex systems.
Adaptive Super-Twisting Sliding Mode Forward Tracking Guidance Law Considering Missile Body Characteristics
Authors: Liu Xiang , Ding Xutuo , Wang Yunlong , Li Yahui , Wang Yukai 
Published: August 2023

Abstract
Aiming at the problem of forward tracking guidance munitions with missile body characteristics intercepting maneuvering targets, and to improve the hit accuracy of forward tracking guidance system, this paper proposes an adaptive super-twisting sliding mode forward tracking guidance algorithm considering the impact of first-order overload characteristics of missile body and input saturation limitation. Firstly, the nonlinear model of the guidance system is made by the kinematic relation for projectile-target, the principle for the forward tracking interception, the overload characteristic of the missile body, and the input saturation limitation. Secondly, a finite time interference observer (FTIO) is adopted to accurately estimate the nonlinear interference in the guidance system, furthermore, an adaptive super-twisting algorithm for slide mode control is used to design the forward tracking guidance algorithm considering the characteristics of the projectile body. Finally, the results by simulation indicate the adaptive super-twisting slide mode for forward tracking guidance algorithm considering characteristics of the projectile body designed in this paper has better-hit accuracy.