bluuebunny/crossref_metadata_2025_split huggingface dataset:
High frequency attitude determination of micro satellites based on FPGA
Authors: Yin Chengjin , Meng Tao 
Published: May 2024

Abstract
The accuracy and speed of satellite attitude calculation algorithms are one of the key factors affecting the performance of satellite attitude control. This article proposes a high-performance attitude calculation algorithm for micro satellites based on Field Programmable Gate Array (FPGA). This algorithm is designed and simplified based on the parallel characteristics and abundant computing resources of FPGA. The algorithm fully utilizes the parallel computing power of FPGA and designs a multi-stage pipeline for complex matrix operations in Kalman filtering. It can simultaneously complete data collection and final attitude determination result output, greatly improving the output frequency of attitude information and reducing output delay. The experimental results show that compared to traditional embedded processors, FPGA based attitude calculation has significant advantages in terms of speed.
Equivalent modeling of LSTS and frequency calculation based on dynamic stiffness method
Authors: Li Hongming , Ma Wenlai , Zhao Yang 
Published: May 2024

Abstract
Large space truss structures (LSTS) are quickly becoming a vital type of space structure due to the fast expansion of the outer space field. The equivalent modeling approach has recently attracted the attention of researchers and engineers due to the finite element method’s limitations. In order to solve the equivalent beam model (EBM) in terms of frequency, the Wittrick-Williams algorithm based on dynamic stiffness matrix and the equivalent modeling procedure of large space truss structure are introduced in this study. The frequencies obtained by the equivalent model are good agreement with that obtaied by the finite element model, demonstrating the efficiency of the frequency solution method and equivalent modeling.
Process identification of laser powder bed fusion anomalies based on process-monitored melt pool radiation intensity data
Authors: Yao Chenguang , Zhang Ting , An Zhibin , Dang Mengxiang 
Published: May 2024

Abstract
Laser powder bed fusion (LPBF)) has great application prospects in aerospace and other fields, but low process stability and difficult quality assurance in the process of Laser Powder Bed Fusion are the key problems that restrict its extensive development at present. One of the important ways to solve this problem is to realize online monitoring of molten pool and closed-loop quality control. In this paper, the photodiode sensor is used to collect the radiation signal of the molten pool in real time, and the characteristics of the radiation intensity signal of the molten pool in time domain and frequency domain are extracted. The most appropriate modeling features are selected by comparing and analyzing different features, and XGBoost classical integration algorithm is used to model, and the relationship between the radiation intensity signal of the molten pool and process parameters is established, which provides a new method for abnormal process identification and quality control.
Mechanical property analysis and experimental validation of composite honeycomb sandwich radome considering perforation and impact damage
Authors: Chen X Y , Feng Y W , Song Z C , Zhou C P 
Published: May 2024

Abstract
To carry out the experimental verification of the mechanical properties analysis of the radome considering the damage factors, the test matrix design is carried out according to the finite element analysis method of the equivalent elastic theory and the idea of building block test verification. Firstly, the necessity and basic principle of equivalent elasticity theory in the performance analysis of complex curvature products considering damage factors are explained. Then, combined with the theory, a modular test matrix design is carried out, which should be able to test the correctness of the equivalent elastic modulus. Finally, a case study is carried out, and the difference between the test results and the simulation results is analyzed with the damaged radome as the research object. The results show that the development of the equivalent elasticity theory and the design of the test matrix can make the analysis results meet the engineering requirements.
Global adaptive event-triggered output feedback control for p-normal feedforward nonlinear systems with uncertain output function
Authors: Liu Ce , Zhai Junyong , Li Zeyu 
Published: May 2024

Abstract
This paper concentrates on the global adaptive event-triggered output feedback controller design for a class of p-normal feedforward nonlinear systems with uncertain output function. Due to the existence of unknown growth rate and uncertain output function, the considered uncertain nonlinear systems contain more uncertainties. To overcome this difficulty, a dynamic gain technique is introduced and an elaborate adaptive law of the gain is designed. Then, a completely time-varying event-based strategy is presented, which can effectively eliminate the effects caused by event-triggered errors. Since the presented event-triggered controller is not differentiable, a new analysis manner is developed to prove that the system is Zeno-free. Meanwhile, the closed-loop system(CLS) states are asymptotically convergent with the proposed strategy. Finally, a simulation example is given to illustrate the effectiveness of the proposed control scheme.
Adaptive adjustable performance function based direct prescribed performance control for spacecraft flying around mission
Authors: Wang Kun , Meng Tao , Lei Jiakun 
Published: May 2024

Abstract
The control for spacecraft flying around mission is investigated in this paper based on the prescribed performance control (PPC). Considering the challenges in the traditional PPC framework, we design an adaptive adjustable performance function, which can self-adjust the performance requirement according to the saturation of the control input. Besides, a combined switching controller is designed and the controller behaves as a PPC in the convergence stage, and gradually switches to a nonlinear controller after entering a steady state, which can avoid the over-control problem caused by high-gain PPC after entering the steady state. Finally, the numerical simulations illustrate the effectiveness of the proposed control method.
Artificial potential field-based method for multi-spacecraft loose formation control
Authors: Guan Yue , Zhang Xiang , Chen Danhe , Fan Shuhui 
Published: May 2024

Abstract
This study presents a control strategy based on artificial potential fields to maintain loose formation flying of satellites without a fixed formation, ensuring collision avoidance and stability under various conditions. The approach employs artificial potential fields for obstacle evasion and maintaining relative distances between satellites. Comprehensive simulations validate this method, with Monte Carlo techniques confirming control stability despite variations in initial conditions. The strategy effectively manages the integration of external satellites, maintaining optimal formation even as operational demands increase.
PID controller tuning based on PSO and dominant pole placement
Authors: Kim Yong Su , Hong Kwang Hyok , Yu Hun , Pak Se Yang 
Published: May 2024

Abstract
This paper proposed a new approach for proportional integral derivative (PID) controller tuning. particle swarm optimization (PSO) algorithm and dominant pole placement were used for PID controller tuning. Minimizing the estimation criterion with integral of absolute error (IAE) and overshoot by PSO algorithm, we determined the dominant pole and crossover frequency satisfying the maximum sensitivity and phase margin. This dominant pole and crossover frequency were used in order to design the PID controller. It satisfied robust stability and improves the control effect of the system to balance the trade-off between overshoot and settling time. We simulated this approach for SOPDT model. A simulation results were given to demonstrate the effectiveness of this approach.
Asymptotic consensus tracking control of robotic manipulators with disturbance and dead-zone via adaptive sliding mode control
Authors: Li Zeyu , Zhai Junyong , Liu Ce 
Published: May 2024

Abstract
This article aims at solving the difficulties of robotic manipulator systems with unknown disturbance and dead-zone in consensus trajectory tracking. For the purpose of accelerating the tracking process of leader and follower manipulators, a novel sliding mode control strategy is proposed. For compensating the influence of unknown lumped disturbance and control dead-zone, a novel adaptive law is designed for the construction of controller. With the help of adaptive sliding mode controller, based on the Lyapunov stability theory, the over-estimation is alleviated and the tracking errors converge to zero asymptotically. The simulations demonstrate the validity of the proposed strategy for consensus asymptotic trajectory tracking.
Numerical study on altitude-compensating mechanism of a permeable nozzle
Authors: Xue Yuqin , Bu Yuzhe , Wang Shuai , Guan Ben , Wang Ge 
Published: May 2024

Abstract
A conceptual adaptive altitude compensation nozzle with a permeable wall (permeable nozzle for short) is proposed in the present study. The typical operating states of the nozzle are demonstrated using numerical methods and the underlying mechanism of its altitude compensation is interpreted. The numerical results show that, at low nozzle pressure ratios, the external atmosphere enters the nozzle through its permeable wall section, which inhibits the backflow at the nozzle wall, weakens the strength of the separated oblique shock, thus improves the low-altitude thrust performance of the nozzle. However, at high nozzle pressure ratios, the exhaust gas leaves the nozzle through its permeable wall, which weakens the expansion of the exhaust gas and reduces the thrust performance. The permeable nozzle is considered to possess altitude compensation ability when the enhancement in its low-altitude thrust performance surpasses the deterioration in high-altitude thrust performance. The thrust composition analysis of the permeable nozzle reveals that its altitude compensation ability derives from the internal pressure rise due to the atmospheric air penetration into the nozzle at low nozzle pressure ratios.
A Spacecraft design for mars water survey
Authors: Zhang Yiwen , Huang Hulin , Chen Tiantian , Chen Yulong 
Published: May 2024

Abstract
To probe the possibility of water sources on Mars and research the surface environment of Mars, a Martian spacecraft was designed in detail in this study. Camera PIXL was selected as the payload. The service platform includes an orbit control system, communication system, thermal control system, main computer, energy system, and structure system, which was designed to support the operation of the spacecraft to complete required space missions. The consequence of this research furnishes some guidance for the design of the Martian spacecraft, which discovers water sources on Mars.
Simulation and experiment of the aerodynamic performance of a vane compressor damaged by a bird strike
Authors: Sun Hao , Wang Zhiqiang 
Published: May 2024

Abstract
Based on the purpose of studying the impact of bird strike on compressor aerodynamic performance, this paper takes a single-stage low-speed axial flow compressor as an object to establish a blade model damaged by bird strike, and on this basis, it carries out a three-dimensional full-loop numerical simulation and experiments on the compressor model with damaged blades. Through comparison with the experimental data of undamaged compressors, the results show that after the rotor blades are damaged, the rotor blades are damaged. The aerodynamic performance and stability of the compressor have significantly decreased, which accords with our understanding. The reliability of the numerical simulation method is verified by analyzing the detailed flow field structure of typical working conditions and comparing the experimental data of the compressor, which lays a foundation for the relevant calculation of damaged blades in the future.
The design of a novel two-dimensional deployable mechanism for large-aperture planar antennas
Authors: Liu Xianyi , Zhang Jiarui , Zhang Shuai , Li Wei 
Published: May 2024

Abstract
Large-aperture planar antennas are essential in applications like satellite communication and Earth observation. In order to accommodate them within the constrained storage space of rockets during launch, the development of high-folding-ratio mechanisms becomes imperative. However, most of the existing planar antennas rely on one-dimensional deployable mechanisms, limiting their width and impeding the development of planar antennas with larger apertures. The lack of two-dimensional deployable planar antennas is primarily due to their stringent requirements, including the need for flat reflecting surfaces, regular panel shapes to accommodate electronic devices on the panels’ rear sides and minimal inter-panel gaps. In this paper, we introduce a novel two-dimensional deployable mechanism for the development of large-aperture planar antennas, capable of simultaneously meeting these requirements. Firstly, the architecture of the proposed mechanism and its two-step deployment procedure are described; next, the kinematics on the displacement level are conducted; moreover, a case study is presented to demonstrate its folding performance and frequency response. These studies indicate that the antenna thus obtained can achieve efficient two-dimensional folding while offering a reasonable frequency response, which can be a practical solution for the development of large-aperture planar antennas.
Optimal design of water immersion sensor layout for helicopter emergency flotation system based on the nsgaII algorithm
Authors: Wang Bingqian , Wang Zhe , Sun Zhi , Hou Bin 
Published: May 2024

Abstract
Aiming at the problem of sensor layout in an emergency flotation system, a sensor layout scheme design method based on the NSGAII method is proposed. The ALE method is used to simulate the water landing process of the helicopter on different pitch angles. The logic relationship of the 4/5 voting system is used to improve the sensor module reliability. Further, a mathematical model of layout scheme is established to maximize the detection coverage and minimize the force acting on the water immersion sensors when helicopter emergent water landing as the objective functions. Based on the mathematical model of water immersion sensor layout optimization constructed in this paper, NSGAII is used to solve this problem. The results show that the proposed method can realize the optimization of the layout of the water immersion sensor, the detection coverage of optimized schemes is increased by 3.26% on average compared with the value under the original scheme, and the force acting on the water immersion sensors is reduced by 61.86%.
Parameter identification of disk-gap-band parachute during steady descent
Authors: Jiang Tian , Ge Sicheng 
Published: May 2024

Abstract
In light of the challenges associated with acquiring the display model for identifying parachute aerodynamic parameters, this study aims to establish a correlation model for the aerodynamic parameters of a specific type of disk-gap-band parachute during the steady drop stage of transonic and subsonic speeds. This will be achieved by employing the genetic algorithm and utilizing observed data from airdrop experiments. The findings indicate that the genetic algorithm can accurately calculate the aerodynamic parameters in dynamic simulation with a high level of precision. Additionally, the numerical distribution state of the parameters to be identified exhibits similarity in the multiple disk-gap-band parachute airdrop experiments, thereby confirming the accuracy of the model and methodology. Finally, the numerical ranges for the drag coefficient and the stable equilibrium angle of attack of this particular type of disk-gap-band parachute are provided. The results are compared with both the airdrop experiments and the wind tunnel experiment. The errors in question satisfy the criteria of engineering precision, and the verification process confirms the accuracy of the identification outcomes.
Effects of fuselage shape on helicopter aerodynamic performance in case of intermeshing-rotor interference
Authors: Ma Cunwei , Li Jingyang , Yu Hao , Baoyin Hexi 
Published: May 2024

Abstract
To study the influence of fuselage shape on the aerodynamic performance of a helicopter under the interference of an intermeshing-rotor, a numerical simulation method of flow field under the forward flight state of Synchropter is established based on the lattice Boltzmann method. Firstly, the Maryland helicopter was calculated to verify the scientific validity of the method. Then, the simplified S-97 fuselage was used as the object of analysis to analyze the aerodynamic data such as surface pressure, friction, and lift resistance of the fuselage with different head curvature, cross-section shapes, and transition segments under Synchropter interference with different attack angles in forward flight. The results show that increasing the radius of curvature of the nose can reduce the total drag of the fuselage; the fuselage with a circular cross-section shape has better aerodynamic characteristics of lift resistance, and the fuselage with rhombic cross-section shape has better transverse stability; the transition section with backward position, smaller upward dihedral angle, and smooth transition can avoid serious airflow separation and achieve the purpose of drag reduction.
Strength performance simulation and testing of pontoon component cabin
Authors: Yang Li , Sun Libing , Zhu Yuanchun , Feng Zhijie , Zhang Dongxiao 
Published: May 2024

Abstract
The helicopter emergency flotation system consists of a buoy installation mechanism, a high-pressure gas bottle, and an electronic control starting device. The buoy assembly cabin is an important part of the buoy installation mechanism. During the flotation test, openings and cracks appeared in the pontoon assembly cabin due to insufficient strength. To avoid the occurrence of openings and cracks, methods such as rounding corners at the locations of openings and cracks, carbon fiber cross-laying technology, and changing cross-sections at stress concentration locations are adopted. The improved method was applied to the buoy cabin of the emergency flotation system, and the damage coefficient in the front and back states was simulated. The simulation results showed that the damage coefficient was reduced by 59%. After the improved cabin was subjected to the emergency flotation system flotation test, the openings and cracks in the pontoon assembly cabin disappeared, indicating that the improvement method was effective and could improve the strength and performance of the cabin.
Parameters design for feel system of aircraft active inceptor controller
Authors: Wei Hongwei , Liu Xiaoyu , Cui Haiwei , Xu Shuting , Tan Wenqian 
Published: May 2024

Abstract
To provide the pilot with feedback on flight states, aircraft active inceptor controllers deliver appropriate tactile feedback through the feel system. Current research on the feel system often relies on conventional models, with limited analysis of its unique characteristics. Investigating the dynamic properties of the feel system and their impact on flying quality can inform the parameters design of the feel system. In this paper, we designed various feel system parameters with different natural frequencies and damping ratios and selected three typical aircraft dynamic models. A human-vehicle closed-loop system model is established, including the pilot model, feel system model, and aircraft dynamic model. Combining different flying quality criteria, including bandwidth criterion, Neal-Smith criterion, and Open-Loop Onset-Point (OLOP) criterion, the flying qualities of Type I and Type II pilot-induced oscillations (PIO) are evaluated separately. The influence of aircraft configuration, feel system natural frequency and damping ratio on flying quality is explored. Finally, design recommendations for the feel system are proposed, aiming to reduce the adverse aircraft pilot coupling and improve flying quality.
Aerodynamic optimization design of low reynolds number aerofoils based on induced laminar separation
Authors: Liu Haoji , Di Weicheng , Wei Zixing , Li Daochun , Xiang Jingwu , Tu Zhan 
Published: May 2024

Abstract
At low Reynolds numbers, the design of aerofoils with a high lift-to-drag ratio (RLD) is crucial for enhancing the aerodynamic performance of Micro Air Vehicles (MAVs). However, the transition from laminar to turbulent flow plays a dominant role in the aerodynamic performance of aerofoils at Low-Reynolds-Numbers (LRN). The laminar separation bubbles formed in laminar flow alter the effective aerofoil shape, reducing aerodynamic efficiency. Additionally, predicting the shape and location of the laminar separation bubbles becomes challenging due to its sensitivity to the flight environment. To design aerofoils suitable for low Reynolds number MAV applications, we optimize a high RLD aerofoil by inducing transition to improve the effective aerofoil shape in the flow field. The study reveals that excessive curvature can suppress the formation of laminar separation bubbles at the leading edge, redirecting separation to the midsection. This results in reduced aerofoil drag and enables a high lift distribution at the leading edge.
Structural response analysis of a solid rocket motor charge under temperature and internal pressure loads
Authors: Liu Fangyi , Ba Shuhong 
Published: May 2024

Abstract
To study the structural integrity of a solid rocket motor under low temperature load, internal pressure load, and two combined loads, based on the linear viscoelastic model, the structural response of a solid rocket motor under low temperature load, internal pressure load and two combined loads were analyzed by ANSYS finite element software, and the temperature field and strain field of charge loading were obtained. The Von Mises strain distribution of the solid rocket motor along the axial characteristic line is obtained. The results are: Under the combined action of low temperature load, internal pressure load, and two kinds of loads, the maximum Von Mises strain appears at the transition position between the blade joint and the barrel section, which is the most dangerous position for charging.
Non-geodesic winding design method for the composite shell of unequal-pole-hole solid rocket motor
Authors: Sun Xiaoliang , Ma Hu , Li Jing 
Published: May 2024

Abstract
Advanced composite materials have the advantages of high specific strength, high specific modulus, good fatigue resistance, good shock absorption performance, and strong designability. They are widely used in the fields of national defense science and technology and civil engineering. To make a more accurate winding design of the composite shell of the non-equidistant solid rocket motor, based on the ANSYS ACP composite structure design and analysis software, this paper uses the cubic spline function method to design the fiber winding thickness of the shell head section for a solid rocket motor. The Runge-Kutta method is used to calculate the changing winding angle of the non-geodesic line, and the changing winding angle and winding thickness on the head are simulated based on the look-up table interpolation table module in ACP. Finally, the mechanical properties of the designed shell under certain internal pressure are simulated and analyzed. Through the simulation analysis of the designed engine model, it is found that the connection between the front head and the barrel section is a weak profit, and the follow-up study should reinforce this area.