Browse Topic: Interiors, Cabins, and Cockpits

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Heterogeneous multi-operator GEO-LEO satellite networks serve as key infrastructure for next-generation global broadband communications. However, existing routing and security frameworks fail to resolve two fundamental challenges. First, orbital layers display inherent topological asymmetry: LEO intra-domain topologies suit fixed routing, while GEO-LEO links change dynamically. This dynamism makes pre-planned SR paths across the GEO layer unfeasible. Second, multi-operator networks introduce cross-domain trust boundaries without pre-established PKI. Centralized packet authentication is impractical for large constellations with intermittent ground contact. Existing solutions either use uniform SR or ground-assisted authentication, neither maintaining correctness in unstable polar regions. This paper proposes H-SID, a hybrid routing and authentication framework for multi-operator GEO-LEO networks. H-SID adopts a dual-layer architecture: SRv6 uSID enables deterministic routing in LEO domains, and a lightweight dynamic protocol handles real-time GEO forwarding. We design uSec, a 16-bit uSID instruction with VER and AuthType fields, allowing GEO nodes to adjust forwarding independently in polar instability. BG nodes perform SR-to-IP conversion and IBC-based authentication for cross-domain flows. GEO satellites act as offline IBE PKGs, issuing long-lived keys to BG nodes without data-plane operations. H-SID concentrates overhead at boundaries and works without cross-operator PKI, ensuring deployability.
Gao, Yuan, Li, Congcong, Ma, Hongxiao, Zhang, Shuo, Yan, Jingshan, Liu, Huiyong
Large-scale UAV clusters make real-time reconstruction of joint spatio-temporal-frequency (STF) situations difficult because the monitored state is high-dimensional and strongly coupled. This paper proposes a lightweight reconstruction algorithm based on Kronecker Compressive Sensing (KCS). First, a Multi-Channel Random Demodulation (MCRD) sensing model is built, and a Spatio-Temporal-Frequency 5D Grid (STF-5D Grid) is used to represent space, frequency, and time resources in a unified form. Next, a Tensor Orthogonal Matching Pursuit (T-OMP) algorithm is developed under the KCS framework. By using the separability of Kronecker products, the method replaces storage and multiplication of a global high-dimensional sensing matrix with dimension-wise operations. Two simulation studies are conducted to evaluate computational feasibility and reconstruction quality. In the city-scale case with 62.91 million grid cells, the factorized implementation avoids constructing the global sensing matrix and completes the tested reconstruction in 9.44 s. The reported memory value is interpreted as additional algorithmic storage for the factorized operators rather than total process peak memory, and should be rechecked with full tensor input/output and runtime overhead included. In noise-free, highly sparse proxy tests, several reconstruction errors approach the numerical precision floor; these results are therefore treated as ideal upper-bound evidence rather than practical field accuracy. The simulations suggest that KCS-based T-OMP can reduce storage and computational pressure for STF reconstruction, while its engineering performance still requires validation under noisy observations and realistic platform constraints.
Tian, Jinghao, Wang, Qianzhe, Di, Shen, Wei, Tan, Song, Bowen
Automotive Engineering: October 202626AUTP1010/8/2026
Why cars need hearing before they need more vision An engineering perspective on faster intent, lower compute, and better in-cabin UX. Improved laser welding for automotive seat structures and recliners When it comes to automotive seats, regulatory pressures aren't the only challenge. Of ladders and limits Why supply chain leaders still can't scale their warehouse technology. Lidar at $200: The competitive inflection point Western OEMs can't ignore Chinese suppliers Hesai and Robosense show one way to make rapid advances in sensor technology. Accelerating air suspension development with a deep-learning surrogate for FEA A bespoke AI tool compressed a typical air spring development cycle from several weeks to around an hour and uncovered a feasible design solution that manual iteration had previously ruled out. Trailblazing innovators: Meet Rising Star winner Qiang Li Meet the winner of the third annual SAE Media Group's Women in Engineering: Rising Star Awards program, which proudly honors women engineers who are driving innovation and making significant contributions to the engineering profession. Editorial AI, Automechanika, and a Rising Star The Navigator 2027 could be the Year of the EREV in America Automechanika Frankfurt: re-thinking automotive materials with INDRA Clarios' battery management system for fleets now in 2,000 trucks Advanced Manufacturing Commercialization Center holds open house for potential partners Designing flash storage platforms with an eye to SDVs LGES opens first-of-its-kind battery plant in Michigan Mercedes Maybach S-Class first drive: V12 pampering for all occupants Product Briefs Spotlight: Plastics & composites; electrification technology Q&A Faster than anyone else thanks to H2 ICE
Concealed HVAC air duct and vent systems are increasingly adopted in modern electric vehicles due to their improved cockpit integration capability and compatibility with intelligent airflow management strategies. However, the complex internal geometry and distributed airflow characteristics of concealed vent configurations often introduce increased broadband aeroacoustic noise, particularly at middle and high frequencies, where cabin masking effects are significantly reduced in electric vehicles. In this work, a high-fidelity aeroacoustic methodology based on the Lattice Boltzmann Method (LBM) was applied using PowerFLOW to investigate concealed HVAC vent aeroacoustic mechanisms and design sensitivities. Detailed vent geometry was preserved using the Precise Wrap tessellation approach, while acoustic porous media and wall absorption treatments were incorporated to represent the acoustic behavior of foam materials inside the duct system. Numerical predictions were correlated with semi-anechoic chamber measurements under representative test conditions. The study hypothesized that concealed vent cavity structures and flap–louver interaction dominate broadband aeroacoustic generation above 1000 Hz and that high-fidelity LBM simulation with detailed geometric representation can capture these mechanisms within engineering-level prediction accuracy. Good agreement between simulation and experiment was achieved for both overall sound pressure level (SPL) and narrow-band spectrum distribution. The average OASPL deviation was approximately 2 dB, with a maximum deviation of 3.3 dB among the investigated microphone locations, while the narrow-band SPL deviation mainly remained within 5 dB for frequencies below 5000 Hz. The predicted broadband hump near 1500–2500 Hz was shown to correlate strongly with vent cavity characteristics and flap–louver interaction. Flow field analysis identified pronounced vortex shedding within concealed vent branches and localized flow separation near the flap leading edge and louvers. Parametric investigations further demonstrated that suppressing leading-edge vortex impingement reduced the broadband hump near 1500 Hz, while removal of flap–louver interaction significantly reduced high-frequency broadband noise above 1500 Hz. The present work demonstrates that high-fidelity LBM simulation can provide reliable engineering-level aeroacoustic prediction for concealed HVAC vent development during the early design stage. The study also provides practical design guidance for developing low-noise concealed HVAC systems for electric vehicle applications.
Hu, Liangbo, Xiong, Fei, Pan, Aicheng, Song, Jinxiang, He, Jianfeng
This technical report provides minimum requirements for subordinate technical reports that define the specifics for retrofitting refrigerants in various mobile thermal management applications.
ICTMS Service Committee
Certain aspects of cognitive state, such as attention, are known to oscillate and exhibit time-varying dynamics. This has strong implications for future human-system integration since, across domains, there is often a cost to interrupting ongoing processes. However, to date there is little knowledge about the cost of such disruption when considering cognitive resources. We have constructed a predictive model that captures these oscillations and predicts future cognitive state using only a finite history of prior state. We use this model to investigate what happens when ongoing cognitive dynamics are interrupted. We use data in which participants perform an unrestricted visual search task, while an auditory side task is randomly injected. The results show that when the timing of the side task causes a disruption, the participants’ physiology display patterns that have been previously associated with increased cognitive load. This indicates that it is not only the nature of the task that must be considered but also the onset time of the task. When task demands are out of phase with ongoing dynamics there is a cost to this timing error in addition to the challenge of the task itself.
Gordon, S. M., Touryan, J.
This document recommends criteria for the layout and for the design, installation, and operation of flight deck facilities for transport aircraft.
S-7 Flight Deck Handling Qualities Stds for Trans Aircraft
This SAE Standard applies to new refrigerant used in vehicle air-conditioning and thermal management systems designed to use R-290. Refrigerant for use in hermetically sealed, refrigerated cargo systems is not covered by this document.
ICTMS Fluids Committee
The provisions of this SAE Aerospace Recommended Practice (ARP) cover minimum performance requirements and design parameters for preconditioned air (PCA) devices supplying air to the aircraft cabin. It identifies the need for interim and future performance improvement for ground equipment delivery systems, to meet industry requirements for reducing airborne compounds or particulates (“source types”) in the aircraft cabin and flight deck. This ARP will guide SAE, IATA, airline operators, and airframe and PCA manufacturers to meet new requirements. This ARP defines: Minimum performance and maintenance requirements for filtration, hose assemblies, operations, and maintenance. Level of humidity supplied by the ground equipment to the aircraft cabin. Minimum performance and maintenance requirements for digital communication of cabin parameters between the cabin and the PCA. Installation of the sensor unit within the aircraft cabin. The data collected by these sensors is not intended to assess impacts on aircraft occupant health and shall not be used to make a finding of airworthiness.
AGE-3 Aircraft Ground Support Equipment Committee
This document covers information concerning the use of oxygen when flying into and out of high elevation airports for both pressurized and non-pressurized aircraft. Oxygen requirements for pressurized aircraft operating at high altitudes have for decades emphasized the potential failures that could lead to a loss of cabin pressurization coupled with the potential severe hypoxic hazard that decompressions represent. This document is intended to address the case where the relationship between cabin and ambient pressures are complicated by operations at high terrestrial altitudes. Operators who fly into these high-altitude airports should address the issues related to this environment because it carries the potential for insidious hypoxia and other conditions which can affect safety. It provides information to consider in developing operational procedures to address hypoxia concerns consistent with regulatory mandates. In some sections, procedures are discussed that may mitigate the deleterious effects of hypoxia in a non-flight regime yet still have the potential to represent risk factors associated with flight operations. All the information is provided as a framework for potential oxygen management and other procedures to facilitate responsible practices and facilitate compliance with existing regulatory requirements. This document cannot address every type of aircraft pressurization system, oxygen system, or operational condition the flight may encounter. Any threat or hazard not discussed in AIR6829 should be brought to the attention of the OEM, the regulatory authority, and the flight operations department for proper guidance.
A-10 Aircraft Oxygen Equipment Committee
In the forward development process of civil aircraft, traditional configuration management, which primarily focuses on the physical implementation end, often leads to inconsistencies between functions, requirements, design configurations, and physical realizations. This study optimized the principles of configuration item identification by refining the logic, timing, and sequence for identifying different types of configuration items. It proposed a product structure centered on the Logical Identification Number (LIN), which explicitly represents the mapping relationships from functional to physical elements. Additionally, the research established the logic for change propagation and validity calculation. Using an air-conditioning refrigeration system as a case study, the model was validated, demonstrating its advantages for improving the efficiency of change-impact analysis, enhancing compliance verification, and ensuring scenario reproducibility.
Xie, Xiang, Meng, Xu, Zhang, Xinyuan, Wu, Binbin
In order to solve the problems of long preheating time and high energy consumption caused by the traditional resistance heating track deicing technology and large power supply load, this paper presents a track deicing and road maintenance method based on electromagnetic induction heating. This paper studies the operational bottlenecks of the resistance heating system in a certain marshalling yard. It explains the eddy current heating from the principle of electromagnetic induction heating and designs an appropriate coil for turnouts and derives its power calculation formula. A mathematical model for the 'solid-liquid' phase transformation in the melting of snow is created and the melting parameter α = 0.623. In comparative experiments, compared to a 4kW electromagnetic induction heating device with no preheating time which melts snow up to 5cm in 40 minutes and consumes 40kW · h of energy in 1 hour, a 13kW resistance heating device needs 150 minutes to preheat, 180 minutes to melt, and consumes 130kW · h of energy. Use 70% less energy and help with track and road de-icing and upkeep with this technology.
Song, Zongying, Li, Zhongming, Wei, Dong, Yang, Jin, Wang, Xingzhong, Liu, Jingwei, Zhang, Xiaoyu
After an investigation into a fruit and vegetable storage compartment on a ship, this paper proposes a method for creating different temperature zones within a single storage unit. To perform this approach, a top perforated plate air supply system should be implemented, and storage panels should act as partitions to make temperature control more accurate in different zones within the same compartment. This method ensures that fruits and vegetables can be stored for the best flavor at suitable temperatures, enabling fewer separate storage units on the ship. According to the experimental results, this solution can preserve various types of fruits and vegetables under different conditions during long trips, deal with the challenge of chilling or freezing injury due to mixed storage, and save the cold storage capacity on the ship. The proposed method has significant value in engineering applications.
Xie, Zhihao, Cui, Yonglong, Duan, Wenli, Li, Kun, Li, Qi, Wei, Shuaiju
With the continuous and in-depth advancement of automotive lightweighting, the quality issues of automotive components have become increasingly prominent. Copper tubes, as an important component of automotive air conditioners, also need to ensure their quality level. In the production process of copper tubes, the multi- pass moving core head disc drawing process is one of the commonly used processing techniques. The relevant drawing dies determine the drawing effect and the quality of the finished copper tubes, so it is necessary to make a reasonable combination of drawing dies. At present, many copper tube processing enterprises overly rely on manual experience for mold matching work. Moreover, mold inventory information, usage records of matching molds, and mold size measurements are all completed by different operators. The operation procedures are not standardized, the standardization of mold matching operations is insufficient, there are too many uncertain factors, and the degree of human influence is too high. The intelligent mold library system for copper tube drawing process is designed to address the problems of weak stability, poor reproducibility, and insufficient precision in the existing manual mold matching. It facilitates accurate computation and control of process parameters. Compared with the estimation and rough adjustment based on manual experience, it can more accurately achieve the best parameter combination required by the process, thereby improving product quality and production efficiency. By integrating the mold matching methods of drawing pass process parameters such as the double decreasing method, the minimum pass method, the empirical pass method, the ZBL method, and the KD-KS coefficient method, and combining the inventory information in the system, it is ensured that the mold matching scheme generated by the algorithm is the best one, thereby improving the production level of the production process.
Yue, Fengli, Meng, Dezhi, Cui, Haitao, Zhang, Jiakun, Sun, Hongyun
As a critical component in thermal management systems, copper tubes are widely used in automotive radiators, condensers, and other parts. In copper tube production, the drawing process is essential for achieving target dimensions and performance specifications. However, as the copper tube industry evolves, nowadays manual drawing process design and traditional drawing algorithms struggle to meet increasingly diverse finished product specifications and complex manufacturing requirements. To address this issue, this study developed an intelligent drawing process design algorithm suitable for automotive copper tube production. This algorithm builds upon existing drawing without plug algorithms, floating plug drawing algorithms, and manually compiled drawing process sheets. It first learns the fundamental principles of drawing without plug algorithms, then derives the relationship between wall thickness changes before and after drawing using mathematical formulas. Subsequently, by analyzing the enterprise’s existing 297 drawing process sheets, the design principles of the drawing without plug algorithm were extracted. This established the number and positioning of required drawing without plug processes within different drawing procedures as the design principles for drawing without plug. Then, using the ‘Double decrement method’ from the floating plug drawing algorithm as an example and integrating the design principles of drawing without plug processes, we developed an intelligent drawing process design algorithm suitable for automotive copper tube production. Furthermore, we selected a typical drawing process sheet for comparison. Through comparative analysis of key parameters such as processing rate and relative wall thickness reduction coefficient, we validated that this algorithm yields more rational results compared to traditional methods. Utilizing this algorithm not only significantly reduces the workload for drawing process designers but also produces more optimal drawing process design outcomes. Compared to other floating plug drawing algorithms, this algorithm also demonstrates greater universality.
Yue, Fengli, Zhang, Jiakun, Liu, Jinsong, Meng, Dezhi
This paper investigates the crashworthiness of freight vehicles under frontal impact based on the C-NCAP (China New Car Assessment Program) standard. Explicit dynamics and finite element methods were employed to conduct simulation analyses of the impact event, with the aim of offering references for improving vehicle crashworthiness. The findings indicate that the vehicle cabin remains largely intact, providing sufficient survival space for occupants. However, increased load amplifies the impact impulse and reduces crashworthiness. Additionally, the use of an enhanced anti-collision beam helps distribute impact forces and lowers the peak impact load.
Liu, Zihan, Jiang, Yi, Wang, Pu
Different commercial vehicles, such as the sunflower harvester, tracked vehicle, and vibratory roller, operate across off-road and on-road environments, often encountering rough and poorly maintained surface conditions. Thus, their comfort and working efficiency are very low. To solve this problem, a quasi–zero stiffness structure (QZSS) is investigated and added to traditional seat suspensions in the sunflower harvester, tracked vehicle, and vibratory roller to improve their comfort and working efficiency. From their established dynamic models, the isolating efficiencies and stabilities of QZSS are then analyzed in detail under different conditions of speed and seat mass. Reducing the root-mean-square values of the seat acceleration (aw) and displacement (zw) is used to evaluate the results. The research shows that the comfort of the sunflower harvester and vibratory roller is very poor compared with the tracked vehicle under the same simulation conditions. By adding QZSS to their seat suspension system, the values of {aw and zw} in the sunflower harvester, tracked vehicle, and vibratory roller are strongly reduced by {67.9% and 38.8%}, {54.7% and 23.9%}, and {65.4% and 34.3%} in comparison without QZSS. Therefore, the comfort of the three vehicle models is greatly improved in comparison without QZSS. Besides, QZSS improves the vibratory roller’s comfort better than the tracked vehicle, while QZSS improves the sunflower harvester’s comfort to be the best. These study results further strengthen the isolation efficiency of QZSS on different commercial vehicles. This contributes to providing more applicability of QZSS in real vehicle conditions.
Nguyen, Vanliem, Zhang, Li, Liu, Yaxi
This SAE Standard applies to: Recycled R-134a refrigerant, used in servicing of motor vehicle air-conditioning (A/C) systems Recycled R-1234yf refrigerant, used in servicing of motor vehicle air-conditioning (A/C) systems Hermetically sealed, refrigerated cargo systems are not covered by this document.
ICTMS Fluids Committee
Assembly sequence planning is a crucial part of process preparation in aircraft final assembly. A scientifically designed assembly sequence can significantly improve assembly efficiency and reduce costs in aircraft production. Efficient planning not only streamlines the workflow but also minimizes potential errors and rework, which are critical in high-stakes aviation manufacturing. This paper examines the constraint relationships in aircraft assembly from the perspectives of cabin constraints and system constraints, covering both spatial layout restrictions and functional logical dependencies to ensure the comprehensiveness of constraint analysis. It establishes a directed graph for the aircraft assembly outline and generates the corresponding adjacency matrix, which converts the complex constraint relationships into a structured mathematical expression for easier subsequent algorithmic processing. The Warshall algorithm and Johnson algorithm are used to check and extract contradictory constraints from the directed graph. The adjacency matrix is then employed to calculate the reachability matrix, which helps identify redundant constraints and reduces the computational effort in assembly sequence planning. Finally, the optimized constraint relationships are used to calculate the aircraft’s final assembly sequence, which generates a Gantt chart for assembly sequence planning, guiding the on-site assembly order and accelerating aircraft development efficiency. The integrated approach effectively addresses the key challenges in complex aircraft assembly sequence planning.
Guo, Jingjing, Cun, Wenyuan, Zhao, Jiong, Yu, Yang, Yang, Rui, Yu, Long
This SAE Aerospace Recommended Practice (ARP) provides a framework for establishing methods and stakeholder responsibilities to ensure that seats with integrated electronic components (e.g., actuation system, reading light, inflatable restraint, in-flight entertainment equipment, etc.) meet the seat technical standard order (TSO) minimum performance standards (MPS). These agreements will allow seat suppliers to build and ship TSO-approved seats with integrated electronic components. The document presents the roles and accountabilities of the electronics manufacturer (EM), the seat supplier, and the TC/ATC/STC applicant/holder in the context of AC 21-49, Section 7.b (“Type Certification Using TSO-Approved Seat with Electronic Components Defined in TSO Design”). This document applies to all FAA seat TSOs C39( ), C127( ), etc. The document defines the roles and responsibilities of each party involved in the procurement of electronics, their integration on a TSO-approved seat, and the seat’s installation on an aircraft. Requirements for design and quality control and the methods for communicating design and change data between EMs and seat suppliers are defined such that standardization is possible across the industry to ensure continued airworthiness of TSO-approved seats with integrated electronic components. This document primarily focuses on correspondence between the seat supplier and the EM. Appendix A: Presents key characteristics of electronic components and guidance on how changes are classified per the requirements of Table 1 of AC 21-49. Appendix B: Provides an outline of a typical data approval process and the change management process between EMs and seat suppliers. Appendix C: While the responsibility rests solely with the seat supplier to ensure all TSO attributes identified in Table 1 of AC 21-49 are acceptable, Appendix C has been included to outline the process for delegating EMs authorization to assess the impact of changes on their equipment with respect to seat TSO attributes. This authorization will allow the classification of the change and the appropriate administration of the change by the EM via seat supplier delegation. Appendix D: Given the mix of business arrangements that can exist in the seat, in-flight, and aircraft procurement life cycle (buyer-furnished equipment, supplier-furnished equipment, customer-furnished equipment), there is discussion on the potential need for separate agreements between the EMs and seat suppliers to ensure binding flow down of design and quality control requirements. As such, a working together agreement (WTA) template is provided as Appendix D.
Aircraft Seat Committee
The heating, ventilation, and air-conditioning (HVAC) systems are one of the main factors that contribute to the building’s energy usage. Achieving an effective balance between reducing energy use and maintaining acceptable thermal comfort is the key challenge in conventional HVAC systems. To overcome this challenge, integrating the occupant-centric controls coupled with digital twins into HVAC systems is another potential technique for this effective balance. For this purpose, computational fluid dynamics (CFD) offers the potential, in combination with other surrogate models for real- time applications to enhance the system's performance further. In general, the CFD is applied to investigate indoor airflow/temperature distributions. These are essential for occupant health, comfort, and energy optimisation for the HVAC design state. The objective of this study is to propose an initial step toward building an occupant-centric HVAC digital twin by validating a CFD model of an office against dense in-situ sensing data. The model has been used to resolve airflow and temperature stratification under conventional HVAC operations, using ANSYS Fluent. The boundary conditions have been derived from measured supply parameters, internal gains, and local weather conditions. The results from this study show that the air velocity and temperature at selected durations follow the same trend with low errors, compared to the sensing and measurement data. The model validation from this study establishes the basis for a weather- aware, occupant-feedback digital twin for larger floorplates and multi-zone systems. To achieve the target of the energy and comfort co-optimisation in Industry 4.0-ready buildings, the future work will focus on surrogate modelling to enable near-real-time inference for closed-loop occupant-centric controls, which will directly support dynamic set-point adjustments and multi-zone system ventilation.
Larpruenrudee, Puchanee, Hellany, Ali, Famakinwa, Tosin, Shrestha, Surendra, Attwater, Roger, Calheiros, Rodrigo Neves
It's near that time of year again when early-career and well-established engineers alike gather in Schaumburg, Illinois, for the annual SAE COMVEC conference (www.sae.org/events/comvec). From September 29 to October 1, attendees will listen to experts on a range of topics - from “Right Sizing Hybrid Powertrains” to “AI for Efficient Engineering Development” - walk the exhibit floor to witness the latest technologies and of course converse with one another over coffee or other beverages. KPIT Technologies is providing the executive leadership for this year's COMVEC and has a significant presence on the agenda, including the opening keynote by Omkar Panse, KPIT's chief technology officer (CTO). Panse and Satish Kumar, senior VP at KPIT, offered their insights on the engineering challenges and opportunities that next-generation commercial vehicles present in this issue's feature story on page 16.
Gehm, Ryan
In recent years, driven by increasing consumer demands for vehicle aesthetics and perceived quality, automotive instrument panels (IPs) have extensively adopted materials with poor friction compatibility, such as chrome-plated strips and synthetic leather. Concurrently, the engineering requirement for tighter matching gaps between components has significantly escalated the risk of friction noise. Traditional mitigation strategies—such as material substitution, increasing gap clearances, or applying physical isolation—are often difficult to implement due to design constraints, rendering the IP a critical high-risk zone for abnormal noise. This paper proposes a methodology to mitigate squeak noise between polycarbonate/acrylonitrile butadiene styrene (PC/ABS) and its mating counterparts by modifying the viscoelastic characteristics of the PC/ABS base material through the addition of a specialized polymer. Furthermore, a neural network model was established to objectively determine the noise compatibility of these materials. Evaluations of the material compatibility before and after modification demonstrate that adding a specific proportion of the special polymer to PC/ABS significantly improves its friction compatibility with materials such as polyvinyl chloride (PVC) skin. The efficacy of this solution was confirmed through application and verification in a mass-production vehicle.
Liu, Zubin, Cao, Chunyu, Hou, Hangsheng
In view of the practical problem that the air-conditioner outdoor units in the spacecraft test workshops of coastal launch sites are severely damaged under the influence of super typhoon, this paper employs the finite-element simulation method to establish a finite-element model of the outdoor units. The implicit Euler solution method is used to calculate the stress conditions of each component of the unit under the influence of typhoons with wind speeds of 50.9 m/s and 61.2 m/s respectively. By combining with the material yield strength, the weak links in the design are identified, and targeted improvement measures are proposed. The simulation results demonstrate good agreement with the actual impact of the typhoon, which can effectively guide the typhoon-resistance optimization design of subsequent air-conditioning units.
Gu, Yufei, Chen, Shaojiang, Shi, YunShan, Fu, Yuanming, Chen, Xi, Yang, Degang
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, Li, Feng, Yanpeng, Ding, Keqin
In this paper, the simulation software was used to conduct a thermal analysis of the design scheme of a certain type of forced air-cooled display and control console, and the results were compared with the experimental results. The results show that in an environment of 50 °C, the maximum temperature of the chip on this strong display control console does not exceed 98 °C, meeting the usage requirements of the chip and the thermal reliability requirements of the display control console. The thermal design scheme of the display and control console proposed in this paper has the advantages of a simple structural form, good heat dissipation effect, low fan noise, and consideration of the heat dissipation of multiple heat sources. It can provide a good reference for the thermal design of similar display and control consoles.
Li, Yun
The cabins of ships are mainly made of steel. When a fire breaks out, the temperature inside the cabin rises rapidly, and an extensive body of heat spreads through the bulkheads to adjacent cabins. Understanding the variation law of the temperature field in adjacent compartments after a fire occurs in the compartments is of great significance for the research on the thermal safety of ship compartments. This paper designs an L-shaped cabin test system. We conduct fire tests of different scales and obtain the temperature distribution of adjacent compartments. The test results show that as the fire area in the pool keeps rising, the temperature in the adjacent compartments keeps rising. Due to the fact that an extensive body of high-temperature smoke produced by combustion is suspended at the ceiling of the compartment of fire, the temperature of the vertically adjacent compartments is higher than that of the horizontally adjacent compartments.
Hu, Wei-guo, Hu, Yang, Wei, Jin, Yuan, Ya-long
A car seat is one of the most critical components of passive safety. On the basis of the safety of car seats, this paper focuses on optimizing the design of the seat frame and achieving a lightweight design under various dynamic and static loading conditions. The optimization results are verified through physical experiments, which demonstrate the correctness and feasibility of the proposed design method. These experiments also provide research ideas for the optimization design of the seat structure and a certain reference value for the engineering application of the seat.
Shao, Youlin, Ni, Weiyu, Chen, Daojiong
The filter seat of diesel engine fuel filters is a key load-bearing component in the engine fuel system. Its structural integrity directly affects the reliability and safety of fuel delivery. In actual operation, the filter seat is subjected to random vibration loads generated by engine operation and vehicle dynamics, which may cause fatigue failure over time, even when static stresses are below the yield strength. This study employs finite element modeling (FEM) to investigate the structural strength and fatigue life of the diesel engine filter seat under random vibration conditions. The CAD model is simplified and meshed to reflect the main load paths, and boundary conditions, including bolt preload, gravity, and measured vibration PSD spectra are applied. Modal and harmonic response analyses are performed using Abaqus, and the Tovo-Benasciutti frequency-domain method is used in fe-safe to predict fatigue life. The results identify the most fatigue-sensitive areas and reveal that the minimum fatigue life is 10^3.067 cycles under realistic conditions, with the most critical regions located near the bolt connection. The simulation methodology and results provide a reliable basis for structural optimization and life prediction of similar components under random vibration environments.
Gu, Kexuan, Zhu, Yi, Xie, Liang, Wang, Wei
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
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, Kai, Wu, Bin, Li, Guolin, Yue, Chaoyu, Zeng, Tai, Su, Zhengliang
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
This specification covers the installation of aircraft interior lighting for military aircraft.
A-20C Interior Lighting
The vehicles often accompanied by a huge impact in the collision process, high-quality and high-strength car-seats can better protect the safety of passengers. However, in the call for vehicle energy saving and emission reduction, the lightweight design of car-seats is imminent. Therefore, it is necessary to achieve lightweight seat weight while ensuring vehicle safety. Based on the dynamic condition of vehicle collision, this paper takes the rear seat of a certain model as the research object, takes multiple responses of the seat skeleton system as the target, establishes a multi-objective optimization model of the seat skeleton, determines the optimization result with the greatest comprehensive satisfaction, verifies the optimization result of the seat skeleton. The correctness and feasibility of the design method are proved.
Shao, Youlin, Ni, Weiyu, Chen, Daojiong, Cheng, Zhiqing
This paper uses a structured evaluation framework to study the ergonomics of electric pilot seats in modern civil aircraft. We have established a multi-level indicator system to examine the adjustability, pressure distribution, dynamic response and, fatigue relief effect of the seat. All experimental data were obtained from a full-scale cockpit simulator environment, where a ground-based mock-up and motion-free simulated cockpit were used to replicate real operational posture, control-reach conditions, and long-duration mission loads. This framework combines experimental measurement and fuzzy evaluation techniques to quantify the quality of human-computer interaction. Test results show that compared with ordinary seats, the prototype seat has a wider adjustment range, a more uniform pressure distribution, and a smoother dynamic response. It is particularly worth mentioning that it can delay the emergence of fatigue during long-term operation, which proves the advantages of the electric adjustment mechanism. The simulated-cockpit test conditions ensure that these results are reproducible and representative of actual cockpit usage scenarios. This findings not only provide theoretical guidance and engineering basis for optimizing the cockpit seat system, but also provide methodological reference for applying fuzzy analysis in aerospace ergonomics research.
Tian, Yanan, Pi, Zhengyang
Zero-gravity seats alleviate prolonged sitting fatigue by optimizing human body pressure distribution, but the correlation mechanism between body size parameters and pressure distribution remains unclear. This study proposes a deep learning model based on multimodal data fusion, combining pressure matrices and postural angle data to construct a convolutional neural network (CNN) with a height prediction error ⩽3 cm. Experiments collected pressure and posture data from 100 participants with diverse anthropometric percentiles. Through the fusion of features and the optimization of the model, the study managed to quantify how height and weight impact pressure gradients. The results indicate that the model achieved a prediction R2 value of 0.73, which confirms that there is a strong correlation between pressure distribution and body size parameters. The findings offer theoretical and technical support for the adaptive adjustment systems within intelligent cabins.
Bi, Tengfei, Nie, Jiacheng, Du, Changjiang, Ji, Yuechen, Wang, Song, Sun, Jiawei
The goal of reducing global CO2 emissions requires actions especially for the transportation sector. To achieve the goal, electric traction motors are frequently implemented in passenger vehicles, as well as in commercial vehicles like heavy-duty trucks or buses. Particularly electric city buses have the potential to reduce the local emissions in urban areas and provide local exhaust-emission-free mobility. While their number of registrations rises, research focusses on the improvement of the overall system in order to increase energy efficiency. High importance is gained by the thermal management of the whole system. This research investigates a simulative approach to improve the thermal management and therefore the energy efficiency of an electric city bus. The different thermal components of an electric city bus like drive system, battery system and heating, ventilation and air conditioning system (HVAC system) are modelled. Their thermal behavior has been validated in previous research. Based on the validated model, this study proposes an improved thermal management that, state-dependent, combines the thermal circuits of the single components to reduce the overall energy demand. Cooling or heating is provided by the HVAC system. Furthermore, the simulation utilizes real driving cycles of a city bus in the Hamburg area. Measurement data from an entire year are examined by a cluster analysis that results in typical application profiles for urban bus traffic. These profiles are used as basis for further research. An operating strategy for the thermal management of an electric city bus under real driving conditions is developed using the simulation model. Results are presented, which show that the overall energy demand decreases due to an improved, application profile-dependent thermal management system.
Schäfer, Henrik, Hellberg, Tobias, Meywerk, Martin
This standard covers oronasal type masks which use a continuous flow oxygen supply. Each such mask comprises a facepiece with valves as required, a mask suspension device, a reservoir, or rebreather bag (when used), a length of tubing for connection to the oxygen supply source, and a means for allowing the crew to determine if oxygen is being delivered to the mask. The assembly shall be capable of being stowed suitably to meet the requirements of its intended use.
A-10 Aircraft Oxygen Equipment Committee
This SAE Aerospace Information Report (AIR) provides an orientation regarding the general technology of chemical oxygen generators to aircraft engineers for assistance in determining whether chemical oxygen generators are an appropriate oxygen supply source for hypoxia protection in a given application and as an aid in specifying such generators. Information regarding the details of design and manufacture of chemical oxygen generators is generally beyond the scope of this document.
A-10 Aircraft Oxygen Equipment Committee
Passive fatigue can cause accidents with automated and regular vehicles. A proof-of-concept prototype [made with light-emitting diode (LED) matrices and white LED (WLED)] and a preliminary comparative usability test (N = 7) are used to study whether the active manipulation of simulated weather cues can be a potential countermeasure to passive fatigue. Participants rated system suitability, system impression, and their fatigue level similarly when they viewed a weather windshield heads-up display (HUD) versus a speedometer windshield HUD [no significant differences found and relatively small 95% confidence interval (CI) ranges around 0]. Qualitative analysis of interviews found that participants saw the potential value of the weather display and that display placement, dynamic graphics, and user activation were commonly mentioned themes. These results suggest the concept is theoretically possible, though further work is needed to prove the concept in practice.
Ensafjoo, Mohsen, Li, Jamy
Humanoid robots are moving beyond hype-driven prototypes toward early commercial deployment, with automotive manufacturing emerging as the first scalable adoption market, according to IDTechX’s recent report Humanoid Robots 2026-2036: Technologies, Markets, and Opportunities.
The automotive air-conditioning service ports task force conducted a field survey with MACS (Mobile Air Climate Systems Association) in June 2021. The scope of this survey was to determine the types of failures reported primarily at member service shops related to automotive air-conditioning service ports.
ICTMS Supplier Committee
Electric vehicles (EVs) and internal-combustion-engine vehicles (ICEVs) differ fundamentally in their in-cabin acoustics, notably the attenuation or absence of engine-order content. Prior work reports associations between reduced engine sound, speed underestimation, and poorer speed maintenance; however, research on how EVs’ new sound affects speed perception and control is scarce, and most newer studies focus on comfort and subjective pleasantness rather than speed perception. Addressing this gap, the present study uses a two-interval, two-alternative forced-choice (2AFC) paradigm to directly measure just-noticeable differences (JNDs) in speed under ICEV, EV, and silent conditions. Thirty participants performed a 2AFC task in which, on each trial, they viewed two first-person highway clips (reference vs. comparison) and indicated which appeared faster. Results from ANOVA and post-hoc tests indicate that at the 40 km/h reference speed participants showed no clear differences across sound conditions, whereas at 100 km/h there were marked differences in JND: mean values were 1.93 km/h (ICEV), 3.48 km/h (EV), and 5.15 km/h (silence). A psychoacoustic parameter analysis suggests that this effect is not explained by speed-dependent changes in loudness or sharpness; we interpret that RPM-related, clearly audible frequency shifts in ICEV provide the primary contributory cue. For EV NVH or artificial sound design, enhancing speed-contingent, trackable spectral cues while respecting comfort may help maintain drivers’ ability to discriminate speed differences.
Li, Zhenxian, Parizet, Etienne, Colangeli, Claudio
As acoustic requirements for NVH trim components become increasingly constrained by mass, cost, and sustainability targets, traditional approaches to inner dash design based on spatially averaged Transmission Loss (TL) metrics are reaching their practical limits. In fully built vehicles, the acoustic performance of the inner dash is governed by its global insulation capability but also by strong spatial heterogeneity and its interaction with spatially distributed noise sources such as the power unit, gearbox, and tyre-road excitation. This paper presents a test-based methodology for the spatial optimisation of inner dash acoustic performance using reciprocal holography. By applying a calibrated sound power source within the vehicle cabin and measuring the reciprocal response in the engine bay and wheel-arch regions, a high-resolution spatial Transmission Loss “hologram” of the inner dash is obtained under in-situ conditions. The resulting spatial data enables the identification of localised acoustic weak points that are not observable using conventional testing methods. To bridge the gap between passive component characterisation and real-world vehicle operation, the spatial TL hologram is subsequently evaluated using representative operational source sound power data to prioritise acoustically relevant regions. This enables the transmitted acoustic energy to be evaluated under realistic driving conditions. The holographic data is then coupled with a parametric acoustic model of the inner dash system, allowing localised mass redistribution to be optimised using a genetic algorithm while respecting packaging and manufacturing constraints.
Harry, Evan, Eandi, Giacomo
The increasing electrification of vehicles means that heating, ventilation and air conditioning systems have a broader range of tasks and a different priority assessment. In electric cars, air conditioning systems are not only responsible for cooling the passenger compartment, but also for controlling the battery temperature, particularly during rapid charging, which represents a high-load operating point. Furthermore, achieving high thermodynamic efficiency is desirable, as this directly impacts the range of electric cars. The elimination of the combustion engine as a major source of noise prioritizes the noise, vibration and harshness behavior of the refrigerant compressor for product selection. To investigate the vibration and acoustic behavior, as well as the fluid dynamic forces resulting from the cyclic compression principle of an electric refrigerant compressor, a test rig was developed that allows compressors to be operated and measured in isolation in an anechoic chamber under various defined operating conditions. This test rig has been expanded in two ways within the scope of this work. Firstly, the compressor can be either rigidly attached to a dead mass using a VDA mount or measured while suspended freely. Secondly, a new R744-compatible refrigeration circuit has been added to the test rig, enabling compressors operating with the environmentally friendly refrigerant CO₂, which has so far only been used by a few manufacturers in selected models, to be tested. Measurement results obtained using this test rig provide valuable insight into the vibration behavior and sound spectra of the refrigerant compressor's fluid, structural, and airborne noise when operating at different points.
Beer, Gabriel, Saur, Lukas, Schwarz, Manuel, Zemsch, Stefan, Becker, Stefan
Realistic seat vibration reproduction is essential for delivering authentic haptic cues and enhancing driver immersion in driving simulators. Unlike direct playback of road recordings, simulator applications require vibration synthesis that responds interactively to driver inputs and vehicle dynamics. Reproducing these vibrations at the seat is often complicated by actuator bandwidth limitations and the dynamic behaviour of the seat structure itself, which can alter the intended target response. This work presents vibration synthesis and seat dynamics compensation strategies implemented on a single-axis seat vibration reproduction system equipped with a vertical actuator. Frequency Response Functions (FRFs) were measured to characterise the system dynamics under single-axis excitation. Run-up and coast-down tests were conducted on the seat and compared to target responses measured on an actual vehicle under operational conditions. Several seat dynamics compensation strategies were evaluated, including inverse FRF filtering, energy-based matching, and manual frequency-domain equalisation. The results indicate that single-input single-output (SISO) compensation approaches can achieve reasonable performance under independent single-axis excitation when compared to alternative methods. The study presents a comparative evaluation of these methodologies and highlights their respective challenges and limitations.
Muthu Chaiphas, Joshua Daniel, Cuenca, Jacques, Bianciardi, Fabio, Colangeli, Claudio, Deckers, Elke, Denayer, Hervé, Janssens, Karl
In vehicles with electrified powertrains, high-frequency tonal noise components have become increasingly prominent and can be perceived as particularly annoying by the driver. While recent advancements in international standardization — such as ECMA-74 [1] and ECMA-418 [2] — have led to powerful new algorithms for tonal noise visualization and analysis, including Tonality-Heatmaps, the measurement side still lacks sensor setups that adequately reflect the spatial sensitivity of noise, especially for tonal components. This challenge is amplified in enclosed vehicle cabins, where room modes create local minima and maxima that become increasingly dense at higher frequencies. As a result, even small head movements can lead to noticeable differences in perceived tonal noise. Current measurement approaches do not sufficiently account for this spatial variability. This contribution addresses the absence of tailored solutions for the driver’s position by introducing an improved microphone arrangement that significantly reduces the uncertainty of measured noise levels. The proposed setup considers spatial variability without compromising comfort or crash safety requirements. By enhancing the precision of tonal noise quantification, this approach provides noise-vibration-harshness (NVH) engineers with a valuable complement to modern software-based tonal analysis methods. The paper discusses the technical implementation constraints and demonstrates the comparability of the new measurement technique with conventional setups.
Schecker, Daniel, Rittenschober, Thomas
Acoustic user interfaces and audio experiences are among the leading comfort factors in new vehicle interior designs. OEMs are more and more focusing on loudspeaker design and positioning, to provide the most immersive experience to the customers. The industrial target is to be able to predict the performance of an audio system in early design phases. This paper presents an integrated vibro-acoustic methodology enabling early-stage prediction of loudspeaker performance in real vehicle conditions. The approach combines electromechanical characterization, a hybrid loudspeaker calibrated model valid across the audible range and coupled FEM/BEM/SEA simulations to capture the loudspeaker response in the vehicle’s cabin considering door-installation effects and cabin acoustics. The method is validated experimentally on a rear-door loudspeaker installed in a production vehicle, showing strong correlation with measured SPL. A final application case demonstrates its capability to assess the impact of alternative speaker mounting positions during the design phase.
Zerrad, Mehdi, Errico, Fabrizio, Mordillat, Philippe
The intent of this standard is to establish a framework to assure that all evaporators conforming to its requirements demonstrate an acceptable health and safety environment for vehicle occupants as determined from the completed risk assessment. R-744 and low pressure (i.e., non-transcritical refrigerants with a critical temperature between 85 and 120 °C) mobile air conditioning (MAC) refrigerant evaporators shall meet the testing and labeling requirements of this standard. SAE J639 contains a list of all refrigerants considered acceptable for use in mobile thermal systems for which this standard applies when the refrigerant is used in a direct expansion architecture. SAE J639 also requires an assessment to be performed to minimize reasonable risks in MAC systems. The evaporator (as designed and manufactured) shall be part of that risk assessment, and it is the responsibility of the vehicle manufacturer to ensure all relevant aspects of the evaporator are included. It is the responsibility of all vehicle or evaporator manufacturers to comply with the standards of this document at a minimum. (Substitution of specific test procedures by vehicle manufacturers that correlate well to field return data is acceptable.) As appropriate, this standard can be used as a guide to support risk assessments. With regard to certification, most vehicle manufacturers have established formal production part approval processes (PPAP) where compliance certification is established and formally documented. For an evaporator manufacturer of non-original equipment parts (or a vehicle manufacturer that does not have a formal part compliance certification process), then the certification described in this standard is the requirement to which those evaporators shall comply. In this case, the evaporator manufacturer or an independent institution shall complete the evaporator certification according to SAE J2911. An example of the latter would be the completion of witness testing by the evaporator manufacturer with the submission of certification documents by the witness organization. This standard originated for the introduction of R-1234yf. The content is based upon the associated 2011 Risk Assessment with input from five OEM evaporator manufacturers. R-744 was included as its requirements were understood in 2011. Refrigerant R-152a was excluded from this standard because a single secondary loop refrigerant system is required. This standard also does not apply to R-134a refrigerant evaporators because it is proven in use.
ICTMS Supplier Committee
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