Browse Topic: Aircraft

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Aircraft assembly systems, as a critical phase in aerospace manufacturing, face significant challenges in maintaining production efficiency and ensuring product quality. This complex manufacturing system exhibits two distinct characteristics: (1) tightly coupled interactions among manufacturing elements involving process sequences, material flows, and equipment utilization; and (2) dynamic resource allocation and material distribution plans. The inherent variability in production element configurations often leads to operational instability and schedule deviations, which may result in abnormal production states. To address these challenges, this study proposes a data-driven predictive framework that integrates Long Short-Term Memory (LSTM) neural networks with multi-criteria evaluation. The developed LSTM-based model effectively forecasts two critical production indicators of cycle time and balance rate, achieving temporal prediction through historical operational data analysis. The proposed methodology facilitates timely anomaly detection and early warning, allowing proactive risk mitigation and ensuring sustained production system stability. This research contributes to advancing intelligent monitoring and control strategies for aircraft assembly operations within data-driven manufacturing environments.
Chen, BolinWu, JunjieSun, JinfengWang, Kai
To fulfill the multi-tube launch requirements for a specific folding-wing UAV, this study improves the structure of the existing storage-launch container. Based on the finite element method, a parametric model of the container is established, and a multi-condition mechanical analysis is carried out for various storage, transportation, and launch conditions. The difference between the first six natural frequencies of the free mode and the prestressed mode is compared and analyzed. The modal analysis model considering prestress is used to identify the optimization area of the container. The variable density method (SIMP) is used to optimize the topology of the container, with the volume of the container as the constraint condition and the minimum strain energy as the optimization goal. The optimization results show that the first-order modal natural frequency of the container is increased by 108%, and the first six natural frequencies are increased to a safe range, which effectively avoids the resonance risk. At the same time, the quality is reduced by 29%, and good optimization results are achieved.
Yuan, WeiyangJi, YuguoLiu, ZhipengYu, Wenxin
To facilitate the development and application of bulb-flat titanium alloys in aerospace and automotive industries, this study selects TC4 as the research material and employs finite element simulation software to simulate the hot rolling process of TC4 bulb flat titanium. The temperature field, strain field, and metal flow velocity in each rolling pass are analyzed, and rolling experiments are conducted after optimizing the roll pass system. The results indicate that during the rolling process of TC4 bulb flat titanium, the head undergoes relatively smaller deformation, resulting in a slower temperature decrease, whereas the waist experiences greater deformation and a faster temperature drop. A significant temperature difference exists between the core and surface, which can be mitigated by appropriately increasing the roll temperature to reduce heat transfer. Prior to the K4 pass, the billet temperature drops to a level that may affect rolling performance, necessitating furnace reheating. Strain increases progressively with each rolling pass, with higher values observed at the waist compared to the head. A gradual strain transition occurs at the interface between the head and waist. Furthermore, the irregular design of the roll pass leads to a considerable difference in metal flow velocity between the upper and lower surfaces. During the K1 pass rolling, this imbalance can cause the guide guard to be displaced upward and result in roll wrapping. Without altering the roll diameter, shifting the entire roll pass system toward the side with higher metal flow velocity effectively reduces the linear velocity and prevents these issues, ensuring stable billet rolling. Rolling experiments successfully produced the final TC4 bulb flat titanium, thereby validating the feasibility of the optimized roll pass system and the rationality of the selected rolling parameters. It provides the possibility for its development and application in fields such as aircraft and automobiles.
Wu, XiaojuanLiu, DongmingWen, Mingyue
Focusing on the requirements engineering activities, this study analyzed the problems in the implementation process of the forward design practice of commercial aircraft airframe, introduced the breakthrough methods, including the convergence and integration with the traditional design process, the supporting work organization model, process optimization, and specification, and proposed the airframe stakeholder need capture model based on the theory of systems engineering. Practice has shown that the requirements engineering implementation strategy introduced in this paper can effectively resolve conflicts and redundancies between the requirements system and the original top-level document system requirements. It ensures clear requirements sources, sufficient basis, reasonable allocation, controllable changes, adequate change assessments, clear design status, and controllable design risks. It effectively overcomes human resource bottlenecks during the early stage of requirements engineering implementation while cultivating talent reserves for systems engineering implementation, saving approximately 23.5 person-years in labor costs. It significantly optimizes non-value-added processes, reducing approximately 100 reports. It unifies the team’s understanding of requirements work, improves coordination efficiency, and significantly improves the requirements validation rate between aircraft-level and system-level requirements by an average of approximately 46%. It assists stakeholders and engineers in systematically and scientifically capturing product requirements during the design phase, with original product design specifications covering approximately 70% of subsystem specifications on average. Given its generality across the airframe forward design domain, the airframe requirement management paradigm established by this implementation strategy holds significant importance for the comprehensive and in-depth application of systems engineering methods in commercial aircraft development.
Sun, LuyanChang, Liang
The malfunction of the aircraft windshield electric heating system, particularly arc discharge, poses a serious threat to flight safety by causing glass breakage. A systematic study was conducted on the causes and effects of arc faults on windshield structural integrity, employing macroscopic observation, microscopic analysis, and energy dispersive spectroscopy (EDS) following a windshield fracture incident. The results indicate that arc discharge typically occurs at the interface between the heating film busbar and adjacent structures. Localized high temperatures cause the outer glass to fracture, generating radial cracks. The ablation of the busbar silver coating and the carbonization of the PVB interlayer are direct evidence of arc action, whereas the heating wire remains a passive component affected by the high-temperature environment. The fault is primarily attributed to local disbonding at the busbar interface and moisture ingress. Based on the findings, recommendations are proposed for process optimization and inspection method improvement, providing a basis for the safe design and maintenance of windshield structures.
Chen, LiFeng, YanpengDing, Keqin
With the advance of high-end manufacturing and the rise of green design, lightweight structures have become a central concern in aerospace. Topology optimization offers a principled route to shed mass while preserving performance, yet most additive manufacturing (AM) studies still emphasize process tuning and new materials rather than structural layouts constrained by AM realities. This work targets a representative wing rib from a specific unmanned aerial vehicle (UAV) and formulates a multi-objective topology optimization that explicitly embeds AM constraints. Using the Solid Isotropic Material with Penalization (SIMP) variable-density framework, we couple static stiffness and strength measures with modal objectives so that the optimized rib not only resists deformation and limits stress but also improves the first three natural frequencies, thereby mitigating adverse vibration interactions at the wing level. A compromise-programming strategy balances these competing objectives under volume and manufacturability requirements, including AM-driven minimum feature scales and related geometric restrictions. Finite-element analyses are used throughout the loop to evaluate displacement, von Mises stress, and eigenfrequencies, ensuring that the emerging material distribution is both efficient and physically meaningful. The resulting topology exhibits clearer load paths and smoother stress flow, reduces peak displacements, and delivers a marked rise in the first three natural frequencies. Overall mass is lowered by approximately 55% while meeting all imposed constraints, achieving the dual aims of structural optimization and lightweighting. The study demonstrates that integrating AM constraints directly into the optimization stage yields designs that are performance-robust and fabrication-ready, and it provides a reusable workflow for thin-walled aerospace components such as wing ribs where stiffness, strength, and vibration behavior must be jointly considered.
Zhao, FeiZhang, HeranLi, XiaotingShi, BowenKong, Xiangwei
Due to the inherent characteristics of large dimensions, complex curved surfaces, and densely distributed protrusions present in aerospace products, conventional offline programming and trajectory planning techniques for robots primarily prioritize the facilitation of uninterrupted grinding processes and the generation of points along trajectories on surfaces characterized by smoothness. However, these methods encounter challenges in identifying and proactively avoiding surface protrusions during the planning phase. The present paper puts forth a proposal for an automated robot trajectory planning method for grinding operations. This method is predicated on the integration of region partitioning and deformation correction. Specifically, this method first identifies protrusions based on curvature features and rule matching, followed by an analysis of the feasible workspace of a six-axis industrial robot equipped with an external axis. The product surface is discretized into multiple regional units according to the distribution characteristics of protrusions and the constraints of the feasible workspace. Subsequently, a parameter-optimized parallel sectioning method is employed to independently plan trajectories for each unit. The utilization of on-site measured point cloud data facilitates the analysis of contour deviations. In addition, grinding trajectories are dynamically corrected to meet high-precision process requirements. This approach effectively overcomes the challenge that trajectory planning for large-scale, complex-shaped products is easily affected by protrusions. According to the established methodology, the development of an offline programming software system for robotic automatic grinding was initiated. To this end, experiments were conducted on aircraft wall panels to plan and modify grinding trajectories using the proposed method. This process was undertaken to validate the effectiveness and engineering practicability of the proposed method.
Fan, ChanghaoWang, MingyangLv, RuiqiangZhou, Peng
Regarding the external sling load system of heavy-lift helicopters, the influence of the law of lifting point position on flight control stability characteristics has not been distinctly explained. To address this challenge, this paper constructs a sling load flight simulation model based on multi-body dynamics. Overall, the proposed model consists of four parts, including the rotor aeroelastic coupling model, the fuselage rigid body dynamics model, the flexible sling model, and the slung object rigid body model. Furthermore, through the hub six-degree-of-freedom rigid model and the flexible sling model, this paper realizes the dynamic coupling between the components. On this basis, taking the CH-53E heavy-lift helicopter as the research object, this paper utilizes real flight test data to validate the multi-body dynamic model. Subsequently, this paper systematically analyzes the influence of different lifting points’ lateral position, sling load mode, load-mass ratio, and forward flying speed on helicopter control stability characteristics. Simulation results indicate that the lifting point location exerts a significant impact on the helicopter’s trim attitude angles and dynamic stability. Of them, the lifting point location of the front center of gravity is the optimal in terms of trim characteristics and eigenvalue distribution. Furthermore, within a certain flight speed range, the lifting point of the front center of gravity demonstrates superior speed adaptability and system robustness. Apart from providing a solid theoretical basis for the lifting point layout design of the external sling load system of heavy-lift helicopters, the research results have important engineering application value for improving the safety of sling load flight of heavy-lift helicopters.
Wang, ZixinZhang, HonglinMeng, XiaoweiZhang, Yunrui
This Aerospace Information Report (AIR) addresses the subject of aircraft inlet-swirl distortion. A structured methodology for characterizing steady-state swirl distortion in terms of swirl descriptors and for correlating the swirl descriptors with loss in stability pressure ratio is presented. The methodology is to be considered in conjunction with other SAE inlet distortion methodologies. In particular, the combined effects of swirl and total-pressure distortion on stability margin are considered. However, dynamic swirl, i.e., time-variant swirl, is not considered. The implementation of the swirl assessment methodology is shown through both computational and experimental examples. Different types of swirl distortion encountered in various engine installations and operations are described, and case studies which highlight the impact of swirl on engine stability are provided. Supplemental material is included in the appendices. This AIR is issued to bring together information and ideas required to address the inlet-swirl problem for which common industry practice has yet to be established. This document should foster the tests and analyses necessary to mature the ideas proposed by the committee to a recommended practice. These tests and analyses must include information that justifies three main features of the proposed swirl methodology: (1) swirl descriptors for correlating inlet swirl and stability pressure ratio loss, (2) computational techniques for analyzing compression systems (inlets, fans, compressors), and (3) test protocols (instrumentation and test techniques). The committee anticipates serving the industry by using such information to establish the consensus necessary for issuance of an SAE recommended practice.
S-16 Turbine Engine Inlet Flow Distortion Committee
This study compares 4 representative tiltrotor platforms: Joby S4, Archer Midnight, Vertical Aerospace VX4, and Uber eCRM-001 in a typical UAM mission profile under standardized rotor and wing assumptions using an integrated OpenVSP-SUAVE-VSPAero framework. This work aims to isolate the influence of eVTOL configuration from proprietary optimizations on thrust generation and aerodynamic interaction by using standard wing airfoils and a consistent rotor design tool. Vehicle geometries were modeled in OpenVSP. Rotor Operating conditions were obtained from the SUAVE conceptual design platform. Mid-fidelity aerodynamic analysis was done using VSPAero. SUAVE results show a decrease in thrust requirements as the tilt angle decreases, with the most complexity occurring in the transition phase where lift shifts from rotors to wing. Archer Midnight and Vertical Aerospace VX4 show higher hover thrust requirements due to their high takeoff weights. They display localized thrust increase near mid transition due to numerical adjustments made to achieve solver convergence. Joby S4 and Uber eCRM-001 display a smoother thrust requirement trend. VSPAero simulations also show a gradual decrease in thrust from hover to cruise. Joby S4’s continuously active rotor configuration maintained more stable performance than the hybrid configurations, which deactivate lift-only rotors after takeoff. A comparative flight feasibility analysis was conducted, defined as the difference between VSPAero-predicted thrust and SUAVE-required thrust. This analysis reveals that Joby S4 maintains a positive margin across most flight phases. Archer Midnight and Vertical Aerospace VX4 show a marginal deficit in near-cruise phases. Uber eCRM-001 showed negative margins throughout the mission, indicating limited aerodynamic robustness under standardized assumptions. Rotor-wing interactions enhances rotor thrust across all mission segments, while creating periodic pressure oscillations on the wings. Rotor-rotor interactions provide limited near-field benefits that dissipate in forward flight. The findings of this study highlight the significance of eVTOL configuration in determining performance and aerodynamic efficiency.
Sawron, Md Sadat Shahrier
The implementation of the ground deceleration function in civil aircraft represents a critically complex process that deeply relies on the seamless collaboration of multiple onboard systems, including but not limited to braking, thrust reversal, spoiler, and steering systems. The operational logic governing these systems is highly intricate, characterized by tightly coupled interactions, stringent safety requirements, and a vast array of diverse physical and logical interfaces. This inherent complexity makes it exceptionally difficult to gain a thorough, system-level understanding of the implementation mechanisms and collaborative principles solely through traditional means of examining extensive, yet often fragmented, design documentation. The limitations of document-based analysis frequently lead to unforeseen integration conflicts, which are typically discovered late in the development cycle, resulting in substantial rework costs and project delays. To address this pervasive industry challenge, this paper selects the aircraft ground deceleration function as a representative case study and proposes an innovative, simulation-based validation methodology. This approach systematically utilizes model state machines to create a dynamic digital representation of the system-of-systems, enabling rigorous validation of aircraft deceleration requirements under various operational scenarios. By adopting this model-based systems engineering (MBSE) paradigm for mechanism representation, our approach effectively captures the nuanced coordination, timing dependencies, and dynamic interactions within the multi-system operational logic. It thereby facilitates the intuitive identification, analysis, and resolution of potential design flaws, including logical conflicts, deadlocks, race conditions, and uncovered or ambiguous requirements. Consequently, the method not only provides a robust framework for validating the aircraft’s function-related design requirements with greater confidence but also offers crucial, data-driven support for the iterative optimization and evolution of the overall functional architecture. The fundamental value proposition of this research lies in its transformative capability to convert implicit design knowledge and assumptions—originally scattered across voluminous documents, specifications, and expert minds—into an integrated set of executable, observable, and analyzable formal models. This digital thread enables systems engineers and designers to identify deep-seated integration and coordination issues proactively during the early conceptual and detailed design stages, rather than relying on discovery during the late, costly integration and testing phases. By shifting validation left in the development V-cycle, this approach significantly reduces the risk of major design changes and associated cost overruns later in the project lifecycle. Ultimately, it effectively enhances the overall maturity, safety, certifiability, and operational reliability of complex aircraft function development, paving the way for more efficient and predictable engineering processes.
Wang, MingqianYu, QiaoYu, MiaoTang, Chao
This paper presents the design, implementation, and validation of an aerial-launch FPV (First-Person View) drone system that was developed to provide a complex environment with flexible deployment and precise delivery capabilities. The integrated system is composed of a hybrid VTOL carrier aircraft, a number of FPV drones, and an aerial mounting / release equipment. Using the AYK-250 platform, the carrier has a vertical take-off and landing function and long-time endurance. In terms of the FPV drones, it is built upon the high performance MARK4 5-inch frame that has high agility and high payload. The release module uses a single-hook point structure with a limit stop. The FPV drones are released stably, and the separation is reliable in flight. Comprehensive flight tests proved all workflows completely, involving carrier take-off, cruise with drones mounted, sequential aerial launch, and subsequent autonomous attitude recovery and route tracking by the FPV drones. The test results confirm the system’s capability for reliable launch from an aerial platform coupled with precise guidance, establishing a credible technical solution for expanding the practical applications of FPV drones in distributed tasks. Results show that our system can be launched via an aerial platform with an accurate guide and is a viable technological solution to spread FPF Drones for operational strategies in a more distributed way.
Wang, YujieXi, YangyangLu, YafeiWang, ChengyuanZhang, ZhiyongChen, Qingyang
The reliability verification of cargo door latches for civil aircraft requires a safe, accurate, and controlled method for simulating jamming failures in lab settings. We adopt a crank-rocker mechanism with a variable degree of freedom (DOF) to construct a novel jamming apparatus that may be dynamically constrained in order to meet this requirement. The apparatus maintains two DOFs when not in use, which permits the latch mechanism to move freely. Both the guiding shafts and the rotation shafts are simultaneously constrained for a jamming test, reducing the mechanism’s DOFs to zero. This operation creates a precise and passive lock that immobilizes the mechanism without the need for an active external load. This approach offers a more realistic simulation of the sudden jamming brought on by wear, foreign object intrusion, or manufacturing tolerances. A theoretical kinematic analysis is then conducted to calculate the mobility of the mechanism and determine the theoretical conditions and transition paths to reach the two functional states. Moreover, the apparatus implements a real-time computational model based on classical planar linkage force analysis and integrates a multi-sensor system. This model converts sensor data into the torques and jamming forces that are actually delivered to the latch. The findings demonstrate that the proposed design accurately simulates latch jamming conditions while allowing for real-time monitoring and quantification of important dynamic characteristics. Thus, by offering a dependable and effective verification solution for cargo door latches, the apparatus greatly improves testing safety and the value of the data gathered.
Ren, JieZeng, XiaohuQiu, XudongXie, Youshui
Urban railways are an important part of China’s rail transit “four network integration”. Their stations are typically situated in suburban regions, characterized by long lines and large station spacing. Traditional manual inspections entail a substantial workload and exhibit low efficiency; multi-rotor UAVs are constrained by limited endurance and airspeed, leading to low efficiency in daily long - range inspections. Fixed-wing UAVs have the advantages of long endurance and high altitude, and are more cost-effective for daily routine inspections when deployed in long areas. They complement the functions of multi-rotor UAVs in rail transit inspection applications. The flight control system of a fixed-wing UAV is a multi-channel, strongly coupled complex system. Based on its lateral and longitudinal dynamic models and navigation technology, this paper designs different types of PID control strategies for the control channels, such as roll angle, pitch angle, altitude, vertical velocity, and flight airspeed, and verifies the feasibility of the control algorithm through numerical simulation. Finally, through on-site test flights, the stability and reliability of the single aircraft flight control system were verified, providing technical support for the availability of fixed-wing unmanned aerial vehicles in the inspection of long sections of urban railways.
Lin, JingDeng, ZhixiangXu, JunWu, HuankunGuan, BinLiu, Lei
Aerodynamicists around the globe are developing mechanisms and structures inspired by nature that enable variable camber morphing (VCM) for aerodynamic surfaces. The implementation of the VCM mechanism in an airplane wing enhances the performance and stability during various flight segments. The present review article is focused mainly on the up-to-date VCM methods in a qualitative as well as quantitative approach that are specific to Aircraft/unmanned aerial vehicle (UAV) wing configurations. Initial literature discussions are confined to the conventional mechanisms that enable VCM in different aircraft configurations and the added aerodynamic advantages such as lift enhancement, drag reduction, boundary layer separation, and flow control. However, those designs need either external shape optimization or internal structural refinements to ensure the factor of safety (FoS). The modern aviation industry is also focused on bioinspired technology because of the adaptive flying capabilities and stall-delay characteristics. Therefore, a review of bioinspired VCM methods that are assessed based on the aerodynamic potentials is sequentially organized in the article. Additionally, considerations are motivated by the application of various compliant structural patterns for VCM in the aircraft industry. The discussion indicates the prospective benefits of morphing toward the future of the Green Aviation industry.
Manjunath, S. V.Jini Raj, R.
Corrosion critically damages structural strength and affects the structural safety, so there is an urgent need for a method that can accurately model and predict corrosion. Digital twin technology offers new methodologies for corrosion research. This study develops a digital twin-enabled virtual-reality mapping model for simulating aluminum alloy pitting corrosion. The model accounts for the effect of temperature on corrosion and establishes temporal correlations between field conditions and simulations through damage factor (DF) analysis coupled with detailed fatigue rating (DFR) methodology. Experimental validation using 7A04 aluminum specimens confirms the model’s reliability, with maturity analysis demonstrating its applicability in aircraft corrosion research. Through numerical simulation methods, this study simulates the evolutionary law of pitting corrosion development, reflecting the level of structural pitting corrosion damage. This investigation establishes a fundamental theoretical framework for condition monitoring and lifetime prediction of aircraft components affected by pitting corrosion.
Lv, ShengliLiu, ChenglongSun, Jingjue
At present, the aircraft arresting system in our country is the fixed water turbine type. This kind of equipment cannot achieve the arrestment of multiple aircraft types, and the arresting distance cannot be adjusted. According to these problems of the aircraft arresting system in our country, the eddy current retarding device is added, based on the water turbine braking device of the aircraft arresting system. It derives the differential equation for an aircraft arresting system with a water turbine brake and eddy current retarder using mathematical modeling. Four types of aircraft parameters are selected, and MATLAB is used as a simulation tool to verify the reliability of the arresting system after installing the eddy current retarder. This research can improve the arresting support ability and make the arresting device meet the arresting requirements of different types of aircraft.
Wei, YanFeng, ChunchunWang, JianwuLi, BinghongYang, Yang
In response to the current airworthiness regulations’ inability to cover the stall flight test requirements under icing conditions of civil aircraft with high-angle-of-attack restriction function and the lack of relevant flight test technologies in China, a study was conducted on the differences in airworthiness provisions for stall characteristics under icing conditions of such aircraft. Key technologies, including simulated ice accretion stall flight test methods, ice installation strategies, and data analysis techniques, are proposed and successfully applied to a specific civil aircraft. The results demonstrate that the methodologies proposed in this paper can effectively support simulated ice accretion stall tests, providing valuable insights for other similar aircraft.
Zhang, Haini
Due to the constraints of manufacturing costs and cycles, it is difficult to simulate the full-scale operating conditions of aircraft electrical power systems. Usually, scaled-down low-power systems are used for prototype development and experimental research. This paper puts forward a systematic framework for developing scaled physical models of aircraft electrical power systems by using similarity theory. In this paper, according to the general design principles of DC-DC converters, a 10-kW low-power DC-DC converter and a 250-kW high-power DC-DC converter are designed. Mathematical models for both systems are developed, and a time-domain performance index analysis is carried out using the per-unit dynamic equivalence principle. A metric conversion model is established and equivalently mapped to a high-power DC-DC converter simulation model. The waveform consistency between the converted model and the aforementioned 250-kW high-power model is verified, which shows the validity of the proposed conversion method.
Ma, HuanAi, FengmingBi, WenyanPei, XiaoningLiu, Liangliang
This research overcomes the serious problem of unregulated fastener substitution in aviation manufacturing, which is due to supply chain disruption, design modification, improved production, and permanent installation of substitute fasteners other than temporary installation substitutes. It can introduce potential risks, including the differences between designed and as-built configurations, and problems with the structural strength of parts. Analysis of a 20XX aircraft model that has been documented with 9 types of fasteners reveals that shortages of 4CE5 and 1CD6 remain constant manufacturing nonconformities and a major element causing long term quality erosion. We have developed an early warning system centered on data with the introduction of the Tolerable Substitution Ratio (TSR) and the non-substitution ratio (NSR). Empirical results show that after implementation, the substituted materials can save as much as 25%, which is approximately $534,000 on domestic sourcing costs and permanently revised drawing costs. We should consider both users’ specifications and the production facility’s actual capabilities when designing the degree of substitution tolerances; substitution deviating from the original specification would not be tolerated. For an extended cycle longer than one year, phase adaptive tolerance adjustments are critical for achieving the acceptable quality limit (AQL). Real-time alignment of the key trigger point in the process stream with supply chain analytics takes away the historical trade-off between operational efficiency and the quality of the final deliverable. The result of this process is that there were more than 1,600 fewer ad-hoc deployments but higher levels of system stability, even as the processes had become more unstable. The payoff in terms of verified protocols for mitigating risk was much greater.
Feng, Yu
With the advancement of the aviation industry, aircraft safety is a priority as closed cavities are susceptible to water infiltration during flight, which can lead to short circuits and operational problems. The current standard manual inspection is inefficient. Our paper describes an industrial vision inspection method that combines an enhanced channel attention mechanism with YOLOV9. 3,000 images generated by aircraft water penetration are replicated in a simulated environment, expanded to 6,000 by data enhancement techniques such as rotation and flipping, and then accurately annotated with targets for model training and validation. Feature extraction was improved on the standard YOLOV9 framework by adapting its weighting strategy to improve the SELayer channel attention mechanism to emphasize specific features of water infiltration. Experiments show a 4.7% improvement in accuracy on our dataset, with a single-frame inference time of 23 ms, which meets real-time requirements. This method provides a reliable automated solution for aircraft maintenance.
Ye, KaiyuanMiao, JunWang, JianqiaoHuang, YuLu, Panna
Because of the increasing requirement for frequent international traveling, developing a new generation of supersonic transport is critical for commercial aviation. The typical features of supersonic transport are a large swept-back wing and thin airfoil, potentially causing excessive tip deflection and triggering aeroelastic divergence. Hence, conducting evaluation, analysis, and optimization of the structures of an SST is essential. This study applied the finite element method to investigate the wing and fuselage structures under aerodynamic loads during cruise for a next-generation supersonic transport aircraft. Deformations and stress contributions were analyzed, showing the feasibility of the structure design and the stress concentration zones requiring reinforcement in the detailed design. Structural optimizations were also conducted, yielding significant weight reduction.
Ding, MenglongXu, ZhaoyangWang, YongqiangMeng, LiTan, JiaxinXuan, JintingBie, DaweiShao, Lintao
Generally, the allowable strain design is adopted for composite structures, which should ensure that the structure has sufficient strength and stiffness under the service load, and the safety margin should be greater than zero under the design load. The thesis develops a structured design for a stabilizer of civil aircraft based on standards and airworthiness requirements. The main task of this thesis is to compare the results of the all-mental structure and composite material structure of stabilizer on weight reduction at sufficient strength and stiffness.
Pi, RungeLv, BaoliangZhang, Liang
It is very hard to position helicopters in complex environments, and this severely limits their ability to navigate on their own. This paper proposes a navigation algorithm that uses a combination of different sensors and deep learning. It uses a special type of deep learning called ResNet50 and a special type of machine learning called LSTM. This algorithm extracts features of the environment and uses a Kalman filter to estimate the state of the system. The system is made more robust by merging information from multiple levels. The algorithm’s ability to maintain stable navigation in the face of faulty sensors is noteworthy, as is its use of an adaptive inference strategy that dynamically adjusts computational load. This strategy strikes a balance between performance and resource consumption. Experiments show that the plan works well in places where GPS is not available. This makes it much better for the helicopter to fly by itself, and it can be used in places like the army, for looking at places from the sky, and for helping people in danger.
Yang, Ming
This study develops an end-to-end load analysis scheme for flap and slat actuators, which comprise the aircraft’s high-lift system, and the analysis results are directly integrated into hardware optimization. Because they shoulder heavy responsibilities during the takeoff and landing phases, whether they can remain rock-solid under complex aerodynamic conditions or even remain unmoved in emergencies is directly related to their overall safety performance. This work process is closely linked and includes three major links. First of all, according to the CCAR-25.301 standard, the load envelope under normal working conditions is sorted out, and the limit cases of abnormal faults are exhausted. Subsequently, ANSYS Workbench pulled silk and peeled off the cocoons to capture the peak stress at the engagement between the output shaft and the gear. In the end, the closed-loop verification of the customized test bench made the theoretical calculations and the hardware-measured data exactly the same. The entire package provides designers with hardcore data support, and always uses airworthiness, not convenience, as the criterion when improving actuator performance.
Xu, Yuanze
Pollution in the oxygen system of civil aircraft may lead to fire accidents, and maintaining the cleanliness of oxygen equipment is the most effective measure to reduce the risk of fire. This paper introduces the cleanliness requirements, cleaning methods, and procedures of oxygen equipment, and combines the cleanliness level requirements of oxygen equipment for a certain type of civil aircraft. By detecting the total weight of Non-Volatile Residue and the size and quantity of particles on the surface of the parts, it verifies whether the specific cleaning process can meet the cleanliness level required by the design. In addition, the possible sources of pollutants are analyzed based on the first unqualified verification results, and targeted improvement directions for the process are provided. After re-performing the cleanliness verification test, the results passed successfully, indicating that the process improvement is effective and has passed the airworthiness certification of the reviewer.
Huang, Jingqi
To analyze flight test failures, ensure flight safety, and provide data support for the aerodynamic design of helicopters, it is necessary to conduct aerodynamic characteristic analysis of helicopter rotors based on flight test data. This article establishes a helicopter rotor aerodynamic model and an aerodynamic parameter identification method in level flight. In this article, we take the flight test data of a helicopter’s level flight performance as an example, and use the genetic algorithm and Particle Swarm Optimization for parameter identification calculation. We obtain aerodynamic parameters such as rotor angle of attack and rotor lift-to-drag ratio in the helicopter’s level flight state, and so on, and analyze the aerodynamic characteristics of the helicopter’s rotor. The results show that the method established in this paper can accurately and effectively obtain the aerodynamic parameters of the helicopter rotor through flight tests. It can also evaluate the aerodynamic characteristics of the helicopter rotor and meet the requirements of the American standard ADS40 for obtaining the aerodynamic characteristics of the helicopter through flight tests. Thus, it has great engineering application value.
Zhao, Jingchao
With CFD technology, a numerical simulation method based on the Navier-Stokes (NS) equations with slip boundary conditions was established. For the flow conditions at altitudes of 60 km and 70 km with a Mach number of 20, the calculation convergence problem of slip flow was analyzed through a flat plate. The research shows that as the altitude increases, the degree of rarefaction increases, and the frictional drag decreases. Without slip, the viscous drag decreases from 17.8 N at an altitude of 60 km to 9.97 N at 70 km. With a slip, it decreases from 17.5 N to 9.63 N. After adding the slip condition, the calculation convergence is slower compared with that of the non-slip attached flow. The difference between the calculation results with and without slip increases as the altitude increases. During the iteration process, the difference between the cases with and without slip gradually decreases. The difference in viscous force between the cases with and without slip is 1.76% at 60 km and reaches 3.47% at 70 km.
Hu, JunlinWang, YapingGao, YunguangWan, LvPan, Sha
Folding wing mechanisms are widely applied in aircraft structural design. This design reduces the size of the aircraft, making it easier to store and transport. Whether the foldable wing can successfully deploy determines the completion of the flight mission. Therefore, it is crucial to study the kinematic and dynamic parameters of the mechanism during the deployment process. The deployment of the folding wing typically occurs within milliseconds. The flow field imposes aerodynamic loads on the mechanism, causing it to move, while the large deformation motion of the mechanism, in turn, affects the aerodynamic loads from the flow field. This is a typical fluid-structure interaction (FSI) process. Traditional CFD methods for solving the deployment process in a decoupled manner often result in large errors and cumbersome procedures. To investigate the aerodynamic loads and deformation of the folding wing mechanism during deployment, the ALE algorithm in LS-DYNA was selected to directly solve the kinematic and dynamic parameters of the mechanism in unsteady flow fields, guiding the design of foldable wing mechanisms.
Wei, TingTong, ZongkaiLi, Naitian
Against the backdrop of accelerating urbanization and diversifying social demands, aerospace technology has extensively permeated numerous fields such as logistics and transportation, emergency and disaster relief, environmental monitoring, and urban transportation. Its application scope is expanding from traditional reconnaissance and surveillance to complex scenarios like material transportation, manned operations, and precision maintenance. Within this trend, high-payload, vertical take-off and landing (VTOL), and high-safety aircraft have become key equipment for enhancing operational efficiency across multiple sectors. Among these, high-payload ducted fan aircraft, with their high safety, excellent low-speed performance, and outstanding VTOL capability, demonstrate unique advantages in tall building fire suppression, power lines and towers maintenance, and personal flight experiences. This paper first outlines the diversified application prospects of aerospace technology, then focuses on high-payload ducted fan aircraft. It discusses the technical requirements specific to such aircraft in the aforementioned key scenarios and analyzes the critical technical bottlenecks hindering their broader application, along with potential viable solutions.
Lou, BinLi, ZhuoyuanZhang, YuansongZhou, HaoyuLi, ChengLuo, ZiniuTian, ConglingYang, Chengchuan
This study analyzed the evacuation process of aircraft cabin personnel, with a focus on the impact of emergency exit configuration on evacuation efficiency. The research results indicated that the number and location of emergency exits are key factors determining evacuation time. In the case of only one exit, the evacuation time was significantly longer than that of multiple exit configurations. Utilizing three exits could reduce the evacuation time to 76 seconds. Additionally, the age and gender distribution of passengers, as well as priority rules, also had a significant impact on the evacuation process. The study further demonstrated that the activation of emergency exits and rear cabin doors could significantly enhance evacuation efficiency, while the opening of the front cabin door had a relatively smaller effect.
Wang, KaiWu, BinLi, GuolinYue, ChaoyuZeng, TaiSu, Zhengliang
Aiming at the problems of traditional physical model methods in aircraft endurance prediction, an end-to-end prediction model based on depth deterministic policy gradient (DDPG) is proposed. The model realizes continuous mapping from flight parameters to range index through Actor-Critic dual network architecture, and combines experience playback mechanism and soft update strategy of target network to effectively suppress training oscillation and improve convergence stability. UAV Delivery Aircraft Versus hybrid dataset was used to verify model performance in test samples. The results show that the MAE of the model is 9.2 km, which is 42.1% lower than that of DQN; the prediction accuracy of the model is the best (MAE 7.3 km) in cruise phase, which is due to the dynamic compensation of time series difference error to wind speed disturbance; in environmental disturbance test, the error increment (50.0%) is significantly lower than that of DQN (78.0%) at low temperature (-5 ° C), which highlights its robustness to battery voltage sag. The model provides real-time and reliable decision support for aircraft endurance management in high-dynamic airspace.
Bai, RongqiangChen, Li
Quadrotors (UAVs) are widely used in intelligent inspection, environmental monitoring, and logistics due to their simple structure, strong maneuverability, and vertical take-off and landing capabilities. However, their highly nonlinear, strongly coupled, and highly constrained dynamic characteristics make trajectory tracking control a challenging task. To improve trajectory tracking accuracy and control robustness, this paper proposes a quadrotor trajectory tracking method based on model predictive control (MPC). First, a six-degree-of-freedom dynamic model of the quadrotor is established and linearized with small disturbances to transform it into a state-space model suitable for MPC design. An MPC optimization controller is then constructed, with an objective function that minimizes state error and imposes an input energy penalty, while explicitly considering the system's input and state constraints. Simulation results demonstrate that this method exhibits good tracking accuracy and control smoothness for typical trajectory tracking tasks (such as circular and spiral trajectory tracking). Compared with traditional PID and LQR controllers, the proposed method significantly improves maximum error, mean square error, and interference rejection. This study provides an engineering-feasible optimization control framework for UAV trajectory control.
Peng, FeiTao, ZhongGao, QiangJia, Bobo
Civil aircraft, as typical complex product systems, exhibit characteristics such as a high concentration of high-tech technologies, strong interdisciplinarity, a high level of system integration, long development cycles, substantial project investments, and complex management. During the R&D process of civil aircraft projects, there are often high risks in performance, cost, and schedule. Delays in the schedule can lead to losses in project manpower and material resources, as well as project failure. A mature objective criteria system for maturity assessment provides a reference basis for determining whether the project has reached its optimal state at a specific stage, thereby reducing project management risks and increasing the probability of project success. This research will adopt a research approach combining theoretical studies with practical case analysis. First, it will conduct extensive and in-depth investigations into various maturity models and their applications across the entire product lifecycle within relevant fields. A requirement maturity model and requirement maturity KPI (Key Performance Indicator) indicators will be established to clarify the maturity status of requirements at different development stages, enabling judgment of whether the project is ready to proceed to the next development phase. Concurrently, by developing a KPI statistical system platform integrating application servers and data processing tools, a scientific and quantitative inspection mechanism will be implemented to visualize project development progress, status, and risk data. This will provide actionable insights for project decision-making and achieve effective project management and control.
Wang, YiHuang, JunkaiZhang, Xinyu
With the increasing demand for multi-unmanned aerial vehicle (UAV) cooperative operations, the design of guidance laws with time and angle synchronization constraints has become a critical technology to enhance strike precision. This paper focuses on a UAV-launched multi-missile cooperative attack scenario, proposing a composite guidance law that integrates the advantages of existing optimal time/angle control guidance laws. By introducing a time error feedback term and an angle constraint term, combined with an adaptive disturbance observer to compensate for aerodynamic errors and target maneuvers, the proposed guidance law ensures a terminal miss distance of less than 0.5 m while achieving a time error ≤0.6 s and an incidence angle deviation ≤2° among multiple missiles. Simulation and test results both demonstrate that the four-missile cooperative attack achieves time dispersion within 1s, satisfying engineering practicality and anti-interference requirements.
Xie, LijunWang, DeshuangYang, XiaodongZhang, TingtingLi, Yang
The rapid advancement of Unmanned Aerial Vehicles (UAVs) has imposed increasingly demanding requirements on aerodynamic force testing. Ground vehicle-mounted testing provides a safe, relatively accurate, and cost-effective experimental method for testing UAV aerodynamic forces. This paper focuses on a ducted fan as the research object and presents a ground vehicle-mounted testing system designed to investigate its aerodynamic characteristics. The testing process includes building a testing platform, ground static testing, vehicle-mounted testing, and systematic data analysis. Comparative results between experimental tests and Computational Fluid Dynamics (CFD) simulations demonstrate that the vehicle-mounted testing method can accurately provide the aerodynamic force of the ducted fan, with errors in aerodynamic force and moment measurements being less than 5%. This approach could provide important technical support for the design and optimization of ducted UAVs.
Mao, SenZhao, ChuangxinWu, ShuangFeng, YupengZhang, YanwuChen, Lin
To reduce the drag and intense heating faced by the hypersonic vehicle during flight, a novel spike–dual-disk–channel configuration is proposed, featuring a slotted channel at the head and exhaust at the second aerodisk. Numerical simulations were conducted using Fluent at 30 km and 5 Ma in free-flow. The new configuration's comprehensive aerodynamic performance were evaluated and compared to those of the single-disk and dual-disk configurations. The simulation results indicate that the new configuration exhibits superior comprehensive aerodynamic performance compared to the single-disk configuration. In contrast to the dual-disk configuration, the new configuration slightly compromises drag reduction (by approximately 1%), but achieves significantly better thermal protection (by approximately 10%).
Luo, ShenxingFang, ShuzhouYe, Chen
Terminal guidance is critical for ensuring strike precision in the final phase of flight. However, traditional methods, such as proportional navigation and optimal guidance laws, face significant challenges regarding real-time performance and adaptability to dynamic targets. To address these issues, neural networks offer a promising solution by enabling adaptive adjustments to guidance parameters, thereby improving performance under various constraints.
Ma, HengweiWang, YongfengWen, HongLiu, DiWei, YuanhangDong, LonghaoLuo, Ying
Flexible cables are widely used in aircraft and are essential for ensuring the proper functioning of critical systems and flight safety. The design and validation of these cables represent a foundational technology in enabling the transmission of electrical power and signals throughout the entire aircraft. To achieve their intended service life, appropriate protective measures and experimental verification must be implemented. Drawing on the development experience of flexible cables for a specific domestic aircraft model, this paper proposes a combined protection method designed to extend the service life of flexible cables. Experimental analysis demonstrates the practicality and reference value of this approach.
Shi, LiqingHu, HuanghuaGe, Zengwen
In recent years, drone technology has seen widespread application in both civilian and military fields. By 2025, China will introduce supportive policies from multiple dimensions, including industrial development, technological innovation, and application promotion, to significantly increase the number of UAVs in use and their frequency. However, drones are prone to malfunctions due to factors such as bad weather and electromagnetic interference, which may result in serious consequences, including property damage and casualties. Therefore, improving the accuracy of fault detection and the response time of drones is of great significance. Although current research has made progress, there are still deficiencies: First, most of them rely on a single or limited data source, resulting in incomplete information and vulnerability to interference, which leads to low detection accuracy and reliability; Second, traditional methods are mostly based on fixed thresholds or simple rules, lacking real-time dynamic monitoring and adaptive analysis capabilities, making it difficult to issue timely warnings of potential faults. To this end, this study proposes a multi-scale time series prediction model based on multimodal and multi-branch, integrating multimodal data, constructing a dual-branch architecture, and combining deep learning and attention mechanisms to enhance the anomaly detection effect of unmanned aerial vehicles. A dual-branch anomaly detection model based on 1DCNN-BiLSTM and continuous wavelet transform is proposed, including a trajectory prediction difference branch and a full time series data branch. In the dual-branch output stage, the attention gating mechanism is utilized to fuse features and improve the detection performance. The experimental results show that this model performs excellently in both normal trajectory prediction and anomaly detection, providing an effective solution for drone anomaly detection.
Pu, ZhenglinZhang, Lin
This paper, for the first time, applies the Divine Religions Algorithm (DRA) to three-dimensional UAV path planning. Targeting the complex terrain of urban-mountain mixed environments, we propose a novel method that incorporates multiple enhancements, including A* initialization, single-point disturbance mutation, and adaptive weighting. First, the A* algorithm is employed to generate high-quality initial paths, serving as the skeleton of the population. Innovative mechanisms such as terrain-adaptive disturbances and dynamic weight adjustment are integrated to achieve both efficiency and robustness in path optimization. Comparative experiments with Genetic Algorithm (GA) and Crowned Porcupine Optimization (CPO) show that the improved DRA algorithm exhibits significant advantages in terms of path length, safety margin, average altitude variation, average turning angle, and overall cost function. It consistently obtains superior paths and achieves faster convergence. The results demonstrate that the proposed approach provides an efficient, adaptive, and practical intelligent optimization tool for UAV path planning in urban-mountain mixed or similarly complex environments, offering promising prospects for engineering applications.
Fang, LianyuYi, Wenjun
A comprehensive solution integrating advanced sensor technology, structural dynamics models, and intelligent control algorithms is proposed to address the shortcomings of traditional flight testing techniques in monitoring and controlling aircraft structures under complex flight conditions. By establishing precise aircraft structural dynamic equations through fiber optic sensors, an accurate description of the dynamic characteristics of the aircraft structure can be achieved. A distributed structural monitoring system is constructed through FBG to monitor the physical quantities, such as strain and temperature, of key parts of the aircraft in real time during flight testing. Based on the real-time monitoring data, the structural state of the aircraft can be predicted, and the structural response can be actively adjusted by controlling the actuator. The experimental results show that this technology system effectively improves the accuracy of structural monitoring and the effectiveness of control during aircraft flight testing, providing strong guarantees for the safety and reliability of aircraft flight testing, and laying a solid foundation for aircraft structural design optimization and flight performance improvement.
Gao, Sheng
Since the concept of low-altitude economy was included in the national plan, many application scenarios have continuously promoted the innovation of low-altitude technology. This paper presents a design scheme for low-altitude intelligent logistics air-supported membrane service stations, analyzes their technical advantages over traditional logistics service stations, conducts investment estimates for trial operation projects, and demonstrates their scientificity and economy, providing a new solution for intelligent logistics.
Li, XingChen, PanpanQing, QiangShang, MingZhu, LiliWang, Shuai
This paper proposes a multi-source dynamic error compensation algorithm for the transfer alignment of airborne optoelectronic payloads. This method addresses performance limitations of micro-inertial navigation systems (micro-INS) in complex dynamic environments, specifically those arising from accumulated device noise and the inability to perform static alignment due to installation errors. The algorithm’s core is the Extended Kalman Filter (EKF) technology. By constructing a “velocity + attitude” matching model between the UAV’s master inertial navigation system (MINS) and the optoelectronic payload’s slave inertial navigation system (SINS), it leverages high-precision MINS navigation information to correct SINS errors. Utilizing a 21-dimensional state space equation and measurement equation, the algorithm achieves real-time estimation and compensation of various errors, including attitude misalignment angles, sensor biases, installation errors, and flexure deformation. Simulation results demonstrate significant alignment accuracy improvement. Post-lever arm effect compensation, velocity errors are stably controlled within 0.01 m/s. Concurrently, flexure deformation angle compensation substantially reduces misalignment angle fluctuations across all directions, enhancing system stability and maintaining low misalignment angles. These findings validate the proposed error compensation strategy’s effectiveness.
Zhang, LuLi, MaoWang, ShiyongLei, Chao
This paper proposes a UAV combat simulation method integrating AFSIM and DoDAF to address the complexity of UAV combat systems. DoDAF establishes a multi-view architecture mode to clarify logical relationships between UAVs and weapon systems, laying a structured foundation. AFSIM implements dynamic simulation of combat processes by mapping DoDAF’s static architecture to its dynamic elements, simulating UAV maneuver, situation awareness, and strikes. A UAV search-and-strike mission scenario test shows the method accurately simulates collaborative behavior in target searching, tracking, and engaging. This method features a high degree of standardization and normalization, providing a foundation for the evaluation of UAV combat effectiveness and strategy optimization.
Sun, ZhenleiYang, Longquan
This study focuses on a compact-layout propeller aircraft, investigating how its powerplant influences stall characteristics via combined theoretical analysis of aerodynamic principles and validation with flight test data. Special attention is paid to the effects of propeller slipstream, appropriate evaluation criteria are selected to assess the aircraft’s high-angle-of-attack performance and stall behavior, and the Weissman chart criteria are further adopted to analyze its lateral-directional departure tendencies. A theoretical analysis of the stall characteristics of compact-layout propeller aircraft is conducted. Through flight test data analysis, the stall characteristics of compact-layout propeller aircraft are studied, with an emphasis on understanding how slipstream effects influence their longitudinal and lateral-directional stall characteristics.
Fang, ShengyouYang, XiaoliJiang, TianjunFu, Yi
Analysis of cabin depressurization is key to ensuring civil aircraft airworthiness safety. In this study, we use a comprehensive approach to analyze depressurization scenes under regulations such as CCAR 25.841. For cases with and without cabin altitude warnings, we calculated critical leakage areas using an orifice flow model and iterative numerical methods. This combines inputs like emergency descent envelopes, air supply rates, and cabin parameters. In our analysis, we evaluate system failure impact and structural breaches on cabin pressure dynamics. For cases where the critical leakage area failed to meet the limits, we use an equivalent safety analysis based on the Depressurization Exposure Index (DEI). This combines pressure and exposure duration to measure physiological risks. We validated this approach through Simulink simulations and case studies, and found that it supports airworthiness verification, emergency descent optimization, and structural design improvements. This method provides a robust framework for enhancing civil aircraft depressurization safety.
Zheng, Bian
Efficient optimization of aerodynamic shapes is a critical challenge in aircraft design. Traditional CFD-based optimization workflows suffer from high computational costs and low efficiency, which severely restricts their practical engineering application. In this paper, a novel aerodynamic optimization method based on a hierarchical neural network with adaptive activation functions is proposed. The network adopts learnable B-spline activation functions and is hierarchically constructed in accordance with the sharing status of B-spline control points. After being trained to achieve fast and accurate prediction of aerodynamic performance, the network can effectively replace the traditional CFD module in the optimization loop. The primary advantage of the proposed method is that it significantly reduces the computational cost during the optimization process while ensuring that the prediction accuracy is not compromised. This work thereby presents a novel strategy and technical framework for streamlining the design process of hypersonic vehicles.
Liu, DiWang, YongfengWen, HongWei, YuanhangMa, HengweiZhao, Runhui
This paper investigates the high-precision landing control problem of carrier-based aircraft. An Active Disturbance Rejection Control (ADRC) technique is employed to design longitudinal and lateral-directional landing control laws. The landing process is simulated by incorporating an airwake model, and the results are compared with those of a PID control law. The analysis demonstrates that the proposed ADRC controller reduces lateral deviation errors and significantly improves landing accuracy and success rate.
Yu, JiayangYin, Yong
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