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This SAE Aerospace Standard (AS) defines the requirements for polytetrafluoroethylene (PTFE) lined, metallic reinforced, hose assemblies suitable for use in aerospace hydraulic, fuel, and lubricating oil systems at temperatures between -67 and 450 °F for Class I assemblies, -67 and 275 °F for Class II assemblies, and at nominal pressures up to 1500 psi. The hose assemblies are also suitable for use within the same temperature and pressure limitations in aerospace pneumatic systems where some gaseous diffusion through the wall of the PTFE liner can be tolerated. The use of these hose assemblies in pneumatic storage systems is not recommended. In addition, installations in which the limits specified herein are exceeded, or in which the application is not covered specifically by this standard (for example, oxygen), shall be subject to the approval of the procuring activity.
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
This SAE Standard provides general and dimensional specifications for beaded ends and hose fittings. These connections are intended for general applications in low-pressure automotive and hydraulic systems on automotive, industrial, and commercial products. The fittings shown are designed to be used with hoses that are intended to be retained by hose clamps. It is recommended that where step sizes or additional types of fittings are required they be designed to conform with the specifications of this document insofar as they may apply. The following general specifications shall supplement the dimensional data contained in the tables with respect to all unspecified detail.
Hydraulic Hose and Hose Fittings Committee
This work aims to investigate how disturbance-aware, robustness-embedding reference trajectories translate into actual driving performance when executed by professional drivers in a dynamic driving simulator. The study compares three planned reference trajectories against a free-driving baseline (NO-REF) to assess the trade-offs between lap time (LT) performance and steering effort: NOM, the nominal time-optimal trajectory; TLC, a track-limit-robust, time-optimal trajectory obtained by tightening margins to the track edges; and FLC, a friction-limit-robust, time-optimal trajectory obtained by tightening against axle/tire saturation. All reference trajectories share the same minimum LT objective with a small steering-smoothness regularizer, and are evaluated with two professional drivers driving a high-performance car on a virtual track. The reference trajectories stem from a disturbance-aware minimum-LT framework recently proposed by some of the authors, where worst-case disturbance
Masoni, MatteoPalermo, VincenzoGabiccini, MarcoGulisano, MartinoPreviati, GiorgioGobbi, MassimilianoComolli, FrancescoMastinu, GianpieroGuiggiani, Massimo
This document contains information and guidance on assessment of the risk posed by observed tin whiskers for aerospace, defense, and high-performance (ADHP) products or other products that demand high reliability.
G-24 Pb-free Risk Management Committee for ADHP
In the context of the accelerating development of an aging society, the inconvenient mobility of the elderly conflicts with the design of existing vehicles. The promotion and development of autonomous vehicles can provide solutions to this conflict to a certain extent. But existing autonomous vehicles lack a systematic age-friendly design. This study is based on a service design idea and employs the KJKANO hybrid model. The KJ method is used to construct a three-tier demand framework of “safety-function-emotion.” The KANO method is applied to identify the priority classification of each demand within the tiered framework. The study derives an aging-friendly design strategy for autonomous buses that prioritizes safety demands as the foundation, with functionality and emotional demands balanced accordingly. These strategies are then implemented in design practice. This study provides a user-centered systematic solution for the age-friendly design of autonomous buses, offering insights
Li, WangyanJi, Yuanyuan
This study looks into the performance traits of a pure electric car that has a continuously variable transmission (CVT) system by doing careful simulations. The research is mostly about checking how well it performs dynamically and how much better its energy efficiency is compared to regular designs. With the help of AVL Cruise software, a detailed drivetrain model was made to test things like how fast it can accelerate, its top speed, how well it climbs hills, and how much energy it uses when driven in standard ways. The simulation results show some big improvements: the CVT car can go from 0 to 100 km/h in 12.92 seconds, which is 14% quicker than expected; it can reach a top speed of 179 km/h, 15% higher than planned; and it can climb really steep hills at a 41.33% gradient. The energy efficiency analysis also found that it uses less power, consuming just 15.88 kWh per 100km under NEDC conditions and 13.72 kWh per 100km in UDC cycles, which are 21% and 24% less than before. These
Chen, HaishanGong, NaifaPan, YulongCai, ZhichengGao, YujieShen, XiaobingFu, XianlanChen, Keren
Vehicle vibrations during precision instrument transport can cause damage and failure. Existing vibration isolators often lack reliability, mass production feasibility, and easy maintenance. In this paper, we design and analyze a quasi-zero-stiffness vehicle-mounted isolator with an inerter, decreasing dynamic stiffness while raising the effective mass. Theoretical, simulation, and experimental results show improved isolation performance, lower isolation frequency, and a broader isolation bandwidth.
Li, KaiLv, SiboSun, NingDai, Shijie
Hemisphere resonant gyroscope (HRG) is a new type of vibration gyroscope with high precision, high reliability, and long lifespan. Improving the temperature stability of a hemispherical resonant gyroscope (HRG) has profound implications for navigation and guidance systems as well as airborne sensor technology. By optimizing temperature compensation algorithms or improving material thermal properties, the angular velocity measurement error caused by temperature drift can be significantly reduced, thereby improving the long-term positioning reliability of navigation systems in extreme temperature fluctuation scenarios. This article starts with the structure of the hemispherical resonant gyroscope, studies the temperature characteristics of the hemispherical resonator through formula theory, verifies and analyzes the temperature characteristics of the hemispherical resonant gyroscope through experiments, and designs a temperature compensation scheme. Through experimental data analysis
Wang, JiachenChen, PuYao, ZhiqiangZhang, YiBai, Fan
Traffic flow prediction is of great significance for improving the operation efficiency of the transportation system, optimizing travel experience and reducing traffic congestion. Traditional traffic flow prediction methods are difficult to capture the spatio-temporal nonlinear characteristics of traffic flow due to its simple model and insufficient feature extraction ability. Therefore, an intelligent traffic flow prediction system based on deep learning is proposed, constructs a deep learning model based on graph convolution and fusion of attention mechanism LSTM. Based on this, a traffic flow prediction system is implemented. Experiments show that, on the PeMSD4 and PeMSD4 datasets, the error of the model in RMSE and Mae indicators is significantly reduced compared with the traditional methods, which provides an efficient solution for traffic flow prediction and congestion analysis, and has both theoretical innovation and engineering practical value.
Tang, ZhanLu, XiaoyuYang, NianXiang, XiaohongHou, XiangPeng, Xiaoli
The technology of autonomous vehicles has become the bellwether for the next transportation evolution. Based on the system of level 5 autonomous vehicles (fully autonomous vehicles), there will be space released from the existing urban context, including linear space, nodular space, and intersected space because of the enhancement of transportation efficiency and organization. The study took Beijing as an example to explore the linear space releasing potential under fully Autonomous Vehicles system to provide a reference for future urban planning. Considering saturation flow rate, speed, parallel throughput, vehicle occupancy, and safe headway, we quantitatively analyzed the potential release from various types of urban roads. The results shows that the expressways, arterial roads, secondary arterial roads, and branch roads could release up to 50%, 66% 50%, and 75% of the road space, respectively. The study verified that fully AV system can release great amount of public space, and
Ding, YufeiHou, Shuyu
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
Tian, YananPi, Zhengyang
Series hybrid electric vehicles (HEVs) employ an electric motor for propulsion, while the internal combustion engine operates solely as a generator under energy-efficient speed and load conditions. Owing to this architecture, series HEVs can achieve high fuel efficiency with a relatively simple control structure. However, conventional energy management systems (EMSs) often prioritize battery state-of-charge (SOC) stabilization, which can lead to frequent engine start–stop operations and unnecessary fuel consumption, particularly in short-trip driving. This study aims to enhance energy management performance in series HEVs by optimizing engine power generation timing based on predicted short-trip duration. A computationally efficient, rule-based prediction model is developed using real-world driving data, in which short-trip duration is estimated from vehicle speed and acceleration. Due to its low computational load, the proposed model is suitable for implementation in an onboard
Mizushima, NorifumiSato, AkiraKuboyama, TatsuyaMoriyoshi, Yasuo
This document defines the test procedures and performance limits of steady state and transient voltage characteristics for 12 V, 24 V, or 48 V electrical power generating systems used in commercial ground vehicles.
Truck and Bus Electrical Systems Committee
With the development of domestic vessel traffic service (VTS) systems, China has established a comprehensive maritime traffic management infrastructure. Marine sensing equipment, including radar, the automatic identification system (AIS), and electro-optical (EO) systems, provides diverse sources of ship information. In recent years, data fusion technology has attracted increasing attention for its potential to improve the accuracy and completeness of ship perception. This paper introduces key ship information sensing technologies and examines the distinct characteristics of each approach. It then reviews recent advances in three main areas: vision-based ship feature recognition, multi-source data association analysis, and ship motion prediction. Finally, the paper outlines prospective research directions, including the integration of additional data sources, real-time data processing, enhanced data security, and intelligent maritime decision-making.
Zhao, KuiSong, ZhemingHuang, Yuantao
To explore the impact of guiding and warning visual combination factors at the entrance sections of highway tunnels on drivers’ visual characteristics and driving behavior, this study recruited 16 drivers to conduct on-road vehicle experiments at the entrance sections of the Yunling Tunnel’s left bore (with visual combination factors) and right bore (without visual combination factors). Seven visual characteristics and driving behavior indicators, including pupil diameter and vehicle speed, were collected and statistically analyzed. Representative indicators such as pupil diameter, standard deviation of fixation point position, and vehicle speed were selected to establish a trend surface model of visual characteristics and driving behavior. The results indicate that when driving at the entrance section of the left bore, drivers’ pupil diameter and fixation duration were significantly lower than those at the entrance section of the right bore. With the increase in the sweeping view
Ma, YanpengHuang, HeHuang, YongYuan, Chen
As high-speed train technology advances, the demands on braking system performance have intensified. Known for their efficiency, reliability, and eco-friendliness, Linear Eddy Current Brakes (LECB) have become a focal point in the research and development of high-speed train braking systems. This paper presents an innovative Orthogonal Excitation Eddy Current Brake (OEECB), which enhances the braking force without modifying the overall dimensions of the conventional LECB. By adding a set of longitudinal excitation coils parallel to the rail surface, the OEECB creates an orthogonal excitation structure that augments the braking force. Initially, this paper outlines the design concept of the OEECB and then analyzes its working principle based on electromagnetic field theory. Subsequently, a finite element solver is employed to numerically model the electromagnetic characteristics of the OEECB. Finally, by comparing the performance differences between the conventional LECB and OEECB, the
Huang, LiuwenZuo, JianyongZhang, Yu
Traditional mechanical continuously variable transmission (CVT) has a complicated structure. During the transmission process, the master and slave wheels rub against each other to produce chattering and heat loss, and the master and slave wheels are seriously worn. In order to improve the transmission efficiency and reliability of continuously variable transmission, Automotive magnetic CVTs (Manetti Continus, Livaria, Breitlans, Mack) were used as research objects. By establishing the efficiency model of key parts, the relationship between the efficiency of each component and different parameters is transformed and calculated, and then it is optimized using Matlab. The finite element analysis of a permanent magnet eddy current speed regulating device is carried out by using finite element Ansys Maxwell, and the relationship curve between the average meshing area and each parameter is analyzed. The results show that the volume of the optimized gear train is reduced by about 51.7
Zhou, DanZhang, Bolin
The magnetic field modeling methodology for ships based on magnetic dipole arrays demonstrates heightened sensitivity to input data. When addressing overdetermined systems characterized by numerous variables and constrained measurement points, the coefficient matrix frequently develops pathological ill-conditioning, leading to solution divergence and compromised result accuracy. This research reformulates the ship magnetic field inversion challenge as a non-convex quadratic programming problem, employing the Successive Convex Approximation (SCA) algorithm as the computational solver. Rigorous comparative validation was performed against conventional stepwise regression algorithms and experimental datasets acquired from scaled ship model measurements. Results substantiate that while the modeling precision of the SCA algorithm remains comparable to that achieved by stepwise regression methods, SCA exhibits demonstrably superior solution stability. This enhanced robustness positions SCA
Chen, HaoPan, Xun
This study addresses the challenges of communication delays and system stability in autonomous obstacle avoidance (AOA) systems under next-generation vehicular electronic/electrical architectures. A centralized PON-based architecture is proposed, leveraging XGSPON technology to enhance bandwidth capacity and reduce electromagnetic interference, while rigorously analyzing worst-case in-vehicle communication (IVOC) delays. To mitigate latency impacts, a Software-Defined Networking (SDN)-driven dynamic scheduling strategy prioritizes safety-critical data streams (e.g., environmental perception, motion control) through adaptive resource allocation. Further integrated with a robust H-infinity LQR controller, the co-design framework ensures precise trajectory tracking and suppresses steering oscillations under communication uncertainties. Simulation tests validate the framework's efficacy, demonstrating significant reductions in loop delays and improved dynamic stability in complex scenarios
Wang, WenweiHan, MuchenCao, Wanke
In order to improve the transportation efficiency of high-speed trains, reduce the operational energy consumption and ensure the on-time arrival of trains, the operation curve optimization is regarded as a key way to achieve the above objectives. In this paper, a distributed control method and system for grouped trains based on multi-objective running curve optimization is introduced. Firstly, the train dynamics equations are established by considering the combined forces during train operation and the train driving maneuvering strategy, combining with the line conditions, and dividing the train operating conditions; secondly, combining with the virtual grouping technology, the train units are kept in a high safety and smooth tracking operation with small intervals between the train units; and then the constraints, such as setting up safety protection distance and Then, the constraints of safety protection distance and space-time safety protection are set, and with energy-saving and
Jiang, QiqiChen, GuangwuShi, JianqiangWang, DongSi, YongboLi, PengZhang, WentaoYang, Yang