Browse Topic: Public transportation systems

Items (1,172)
The advent of the low-altitude economy represents a novel economic paradigm that has emerged in recent years in response to technological advancement and an expanding social demand. The low-altitude economy is currently undergoing a period of rapid development, which underscores the importance of ensuring the safety of airfield operations. To enhance operational efficiency, unmanned aerial vehicles (UAVs) can be utilized for the inspection of the surrounding area, runway inspection, environmental monitoring, and other tasks. This paper employs TurMass technology, the TurMass gateway is miniaturised as the communication module of FT24, and the TK8620 development board replaces the LoRa RF module in the ELRS receiver to achieve the communication transmission between the remote control and the receiver. Additionally, a TurMass chip is integrated into the UAV to transmit beacons, while an airfield management aerial vehicle is employed to receive nearby UAV data, thereby preventing
Zhang, XiaoyangChen, Hongming
This equipment specification covers requirements for airfield liquid anti-icing/deicing equipment for airfield snow removal purposes. The unit shall include a combination of a carrier vehicle, liquid product tank, and dispensing system. This vehicle as a unit shall be an integrated chemical dispensing deicing/anti-icing application system. Primary application is for the liquid chemical application for cleaning of ice and snow from airfield operational areas such as runways, taxiways, and ramp aprons. The term “carrier vehicle” represents the various self-propelled prime movers that provide the motive power necessary to move snow and ice control equipment during winter operations. The airport operator may require this specified piece of equipment in order to maintain the airfield during large and small snow events. When necessary, the airfield liquid anti-icing/deicing chemical applicator (ALAD) shall be a central and critical element in the winter pavement maintenance fleet in the
G-15 Airport Snow and Ice Control Equipment Committee
Autonomous vehicle technologies have become increasingly popular over the last few years. One of their most important application is autonomous shuttle buses that could radically change public transport systems. In order to enhance the availability of shuttle service, this article outlines a series of interconnected challenges and innovative solutions to optimize the operation of autonomous shuttles based on the experience within the Shuttle Modellregion Oberfranken (SMO) project. The shuttle shall be able to work in every weather condition, including the robustness of the perception algorithm. Besides, the shuttle shall react to environmental changes, interact with other traffic participants, and ensure comfortable travel for passengers and awareness of VRUs. These challenging situations shall be solved alone or with a teleoperator’s help. Our analysis considers the basic sense–plan–act architecture for autonomous driving. Critical components like object detection, pedestrian tracking
Dehghani, AliSalaar, HamzaSrinivasan, Shanmuga PriyaZhou, LixianArbeiter, GeorgLindner, AlisaPatino-Studencki, Lucila
US transportation infrastructure is dominated by the automobile form factor. Alternative modalities of movement, such as bikes, golf carts, and other micromobility options, have existed but are decidedly at a lower tier of importance. Even pedestrian access ways are not overly emphasized in the US transportation system. This lack of prioritization matches the reality that the vast majority of people and commerce moves through the motor vehicle infrastructure, with micromobility sitting in the periphery. Additionally, given the current lack of commercial applications, there are limited direct fee-based funding mechanisms connected to micromobility form factors. Micromobility and the Next Infrastructure Wave discusses how recent technological innovations in electrification, e-commerce, and autonomy are enabling a new class of micromobility devices which offer palpable value to consumers and enable significant commercial applications. Unlike the past, these micromobility devices now have
Razdan, Rahul
A challenge of public transportation GPS data is the frequent utilization of monitoring systems with low sampling rates, primarily driven by the high costs associated with cellular data transmission of large datasets. Altitude data is often imprecise or not recorded at all in regions without large elevation changes. The low data quality limits the use of the data for further detailed investigations like a realistic energy consumption forecast for assessing the electrical grid load resulting from charging the vehicle fleet. Modern research often reconstructs speed data only, or uses additional GPS loggers, which is associated with increased costs in the vehicle fleet. The importance of precise and high-quality altitude data and specialized expertise in mountainous regions are frequently overlooked. This paper introduces an efficient new route matching method to reconstruct speed and respective road slope data of a GPS signal sampled at low frequency for a public transportation electric
Hitz, ArneKonzept, AnjaReick, BenediktRheinberger, Klaus
A bearing is a mechanical component that transmits rotation and supports load. Depending on the type of rotating mechanism, bearings are categorized into ball bearings and tapered-roller bearings. Tapered-roller bearings are superior to ball bearings in load-bearing capabilities. They are used in applications where high loads, such as, the wheel bearings for commercial vehicles and trucks, aircraft, high-speed trains, and heavy-duty spindles for heavy machinery must be supported. The demand for reducing the friction torque in automobiles has recently increased owing to carbon-emission regulations and fuel-efficiency requirements. Therefore, research on the friction torque of bearings is essential; studies have been conducted on lubrication, friction, and contact in tapered-roller bearings. There have also been studies on lip friction, roller misalignment, and so on; however, research on the influence of roller geometries and material properties is scarce. This study investigated the
Lee, SeungpyoAn, Hyun Gyu
To identify the influences of various built environment factors on ridership at urban rail transit stations, a case study was conducted on the Changsha Metro. First, spatial and temporal distributions of the station-level AM peak and PM peak boarding ridership are analyzed. The Moran’s I test indicates that both of them show significant spatial correlations. Then, the pedestrian catchment area of each metro station is delineated using the Thiessen polygon method with an 800-m radius. The built environment factors within each pedestrian catchment area, involving population and employment, land use, accessibility, and station attributes, are collected. Finally, the mixed geographically weighted regression models are constructed to quantitatively identify the effects of these built environment factors on the AM and PM peak ridership, respectively. The estimation results indicate that population density and employment density have significant but opposite influences on the AM and PM peak
Su, MeilingLiu, LingChen, XiyangLong, RongxianLiu, Chenhui
In the evolving landscape of automated driving systems, the critical role of vehicle localization within the autonomous driving stack is increasingly evident. Traditional reliance on Global Navigation Satellite Systems (GNSS) proves to be inadequate, especially in urban areas where signal obstruction and multipath effects degrade accuracy. Addressing this challenge, this paper details the enhancement of a localization system for autonomous public transport vehicles, focusing on mitigating GNSS errors through the integration of a LiDAR sensor. The approach involves creating a 3D map using the factor graph-based LIO-SAM algorithm, which is further enhanced through the integration of wheel encoder and altitude data. Based on the generated map a LiDAR localization algorithm is used to determine the pose of the vehicle. The FAST-LIO based localization algorithm is enhanced by integrating relative LiDAR Odometry estimates and by using a simple yet effective delay compensation method to
Kramer, MarkusBeierlein, Georg
The winged body reusable launch vehicle needs to be tested and evaluated for its functionality during the pre-flight preparation at the runway. The ground based checkout systems for the avionics and the actuator performance testing during pre-flight evaluation are not designed for rapid movement. This new kind of launch vehicle with solid rocket first-stage and winged body upper-stage demands the system testing at Launchpad and at the runway. The safety protocol forbids the permanent structure for hosting the checkout system near runway. The alternative is to develop a rapidly deployable and removable checkout system. A design methodology adopting conventional industrial instrumentation systems and maintaining mobility is presented. This paper presents the design and development of a mobile checkout system for supporting the ground pre-flight testing during autonomous flight landing trials
V, Vivekanand
The impending deployment of automated vehicles (AVs) represents a major shift in the traditional approach to ground transportation; its effects will inevitably be felt by parties directly involved with vehicle manufacturing and use (e.g., automotive original equipment manufacturers (OEMs), public transportation systems, heavy goods transportation providers) and those that play roles in the mobility ecosystem (e.g., aftermarket and maintenance industries, infrastructure and planning organizations, automotive insurance providers, marketers, telecommunication companies). The focus of this chapter is to address a topic overlooked by many who choose to view automated driving systems and AVs from a “10,000-foot perspective:” the topic of how AVs will communicate with other road users such as conventional (human-driven) vehicles, bicyclists, and pedestrians while in operation. This unsettled issue requires assessing the spectrum of existing modes of communication—both implicit and explicit
Beiker, SvenRazdan, RahulFavaro, FrancescaTaiber, JoachimSell, Raivo
The study emphasizes transitioning school buses from diesel to electric to mitigate their environmental impact, addressing challenges like limited driving range through predictive models. This research introduces a comprehensive control-oriented model for estimating auxiliary loads in electric school buses. It begins by developing a transient thermal model capturing cabin behavior, divided into passenger and driver zones. Integrated with a control-oriented HVAC model, it estimates heating and cooling loads for desired cabin temperatures under various conditions. Real-world operational data from school bus specifications enhance the model’s practicality. The models are calibrated using experimental cabin-HVAC data, resulting in a remarkable overall Root Mean Square Error (RMSE) of 2.35°C and 1.88°C between experimental and simulated cabin temperatures. A lateral powertrain model has been developed that encompasses vehicle dynamics, electric machinery, transmission, and electrical loads
Nawaz, MuneebullahAlsharif, KhaledHanif, AtharAhmed, Qadeer
Given the growing interest in improving the efficiency of the bus fleet in public transportation systems, this paper presents an analysis of the energy consumption of a battery electric bus. During the experimental campaign, a battery electric bus was loaded using sand payloads to simulate the passenger load on board and followed another bus during regular service. Data related to the energy consumed by various bus utilities were published on the vehicle’s CAN network using the FMS standard and sampled at a frequency of 1 Hz. The collected experimental data were initially analyzed on a daily basis and then on a per-route basis. The results reveal the breakdown of energy consumption among various utilities over the course of each day of the experiment, highlighting those responsible for the highest energy consumption. Subsequently, the relationship between the energy consumption of the traction motor and the climate control system was investigated concerning environmental parameters
Belloni, MattiaTarsitano, DavideSabbioni, Edoardo
When the aircraft towing operations are carried out in narrow areas such as the hangars or parking aprons, it has a high safety risk for aircraft that the wingtips may collide with the surrounding aircraft or the airport facility. A real-time trajectory prediction method for the towbarless aircraft taxiing system (TLATS) is proposed to evaluate the collision risk based on image recognition. The Yolov7 module is utilized to detect objects and extract the corresponding features. By obtaining information about the configuration of the airplane wing and obstacles in a narrow region, a Long Short-Term Memory (LSTM) encoder-decoder model is utilized to predict future motion trends. In addition, a video dataset containing the motions of various airplane wings in real traction scenarios is constructed for training and testing. Compared with the conventional methods, the proposed method combines image recognition and trajectory prediction methods to describe the relative positional relationship
Zhu, HengjiaXu, YitongXu, ZiShuoJiYuan, LiuZhang, Wei
This document includes recommendations of installations of adequate landing and taxiing lighting systems in aircraft of the following categories: a Single engine personal and/or liaison type b Light twin engine c Large multiengine propeller d Large multiengine turbojet e Military high-performance fighter and attack f Helicopter g Electric Vertical Takeoff and Landing (EVTOL) and Urban Air Mobility (UAM
A-20B Exterior Lighting Committee
This specification covers runway deicing and anti-icing products in the form of a liquid. Unless otherwise stated, all specifications referenced herein are latest (current) revision
G-12RDP Runway Deicing Product Committee
This specification covers a runway deicing and anti-icing product in the form of a solid. Unless otherwise stated, all specifications referenced herein are latest (current) revision
G-12RDP Runway Deicing Product Committee
The use of appropriate loads and regulations is of great importance in weld fatigue assessment of rail on-track maintenance equipment and similar vehicles for optimized design. The regulations and available loads, however, are often generalized for several categories, which proves to be overly conservative for some specific categories of machines. EN (European Norm) and AAR (Association of American Railroads) regulations play a pivotal role in determining the applicable loads and acceptance criteria within this study. The availability of track-induced fatigue load data for the cumulative damage approach in track maintenance machines is often limited. Consequently, the FEA-based validation of rail track maintenance equipment often resorts to the infinite life approach rather than cumulative damage approach for track-induced travel loads, resulting in overly conservative designs. The work presented in this article evaluates and compares the weld fatigue damage of track maintenance
Patil, DipakPetersen, Michael
Prime concern for electric vehicle where the application of the vehicle is public transport, is the charging of vehicle and operation of its infrastructure. Such an example of operating the EV buses is under the GCC (gross cost contract) model, with high operation time and comparatively lesser time for charging. It is challenging to meet these requirements. To counter this situation in fleet operated busses it is proposed to adapt an automated charging method which involves minimum man power intervention and automated mechanism to connect & disconnect the charging connectors. This paper proposes an automated pantograph mechanism based method of charging EV buses, meeting requirements as per SAE J3105 & ISO 15118 standards, which would be an ideal way to resolve the current situation. In the above mentioned pantograph type charging, the charging station or depot will have an infrastructure including charger whose input will be from grid, and the charging dispenser will be pantographs
Gullyal, AvinashAhmed, YasirAmancharla, Naga ChaithanyaKinjalkar, Milind
The transport sector in all domains like personal vehicles, public transport and logistics has seen a tremendous growth over the past decade, more so in the last 5 years. The main reasons for this rapid growth is the development of new energy storage systems in battery technology (Lithiumion, sodium ion, aluminum air etc.), hydrogen fuel cells, super capacitors etc. On the other hand there has been tremendous development in the motor drive technology with the availability of brushless dc motors (BLDC Motors), induction motors, Permanent magnet synchronous motors (PMSM, IPMSM). Each motor having its own special characteristics and usage suited for a very specific application in terms of torque and load bearing capacities. In this paper we describe a unique platform with twin motor drive system electric vehicle which is powered by an artificial intelligence (AI) enabled electronic module DuoPackR. The basic platform is described with the help of a bicycle which has two BLDC motors on the
Pratiwadibhayankaram, Ashwini Kumar KrishnaswamyK A, RakeshSangam, Manjunath
The advent of autonomous vehicles promises to revolutionize the transportation sector globally, and India, as one of the world's fastest-growing economies, stands at the forefront of this transformative technology. This paper presents a brief overview of the current state and potential implications of autonomous vehicles in the Indian context. With its densely populated cities, diverse traffic conditions, and complex road infrastructure, India presents unique challenges and opportunities for the deployment of autonomous vehicles. This technology has the potential to address critical issues such as road safety, congestion, and pollution while transforming the mobility experience for millions of people. However, several hurdles must be overcome to fully harness its benefits. The paper explores key considerations for the implementation of autonomous vehicles in India. These include adapting the technology to navigate chaotic traffic scenarios, addressing infrastructure limitations, and
Shetty, Sharan Harish
A bus is integral part of public transportation in both rural and urban areas. It is also used for scheduled transport, tourism, and school transport. Buses are the common mode of transport all over the world. The growth in economy, the electrification of public transport, demand in shared transport, etc., is leading to a surge in the demand for buses and accelerating the overall growth of the bus industry. With the increased number of buses, the issue of safety of passengers and the crew assumes special importance. The comfort of driver and passenger in the vehicle involves the vibration performance and therefore, the structural integrity of buses is critically important. Bus safety act depicts the safety and comfort of bus operations, management of safety risks, continuous improvement in bus safety management, public confidence in the safety of bus transport, appropriate stakeholder involvement and the existence of a safety culture among bus service providers. In order to provide
Bijwe, Vilas B.Mahajan, RahulVaidya, RohitPatel, KaustubhHiwale, DiwakarWalke, Abhijit Ashok
India is a highly populous country. The traffic problems faced by the people here are not uncommon. The increase in traffic leads to increase in accidents, pollution, inconvenience and frustration. It also comes with costs of additional fuel and time. Though public transport is extensively available in India, still it isn't sufficient for the population of India. Especially in Metro cities, public transport services are often crowded. So, to travel peacefully people are opting for commuting in their own vehicles. And as a result, more vehicles are coming on roads. Other major reasons for increasing traffic are lack of proper implementation of traffic rules and traffic signals out of sync. In addition to city traffic, congestion is also seen on highways, mainly at toll plazas. Although implementation of FASTag has reduced it to some extent, some toll plazas still face traffic congestion issues. This paper provides an idea to ease the traffic problems in the city and on the highways too
Jain, Pritesh
The battery electric buses (BEB) are set as key tools to enable cities to meet their challenging transport environmental targets, i.e. the reduction of Greenhouse gas (GHG) emissions, improvement of local air quality, as well as to provide a quieter system for both passengers and the urban community. The recent evolutions of the traction battery technology, with increasing battery energy and power densities, battery durability and dynamic performance, driven by both the light and heavy duty vehicles segment, has opened the way for a series of transit bus electrification initiatives, focused on the evaluation of the feasibility of the BEB technology for the zero local emission bus fleet targets, already set by transit authorities in some important cities worldwide. In this context, as important as the onboard electric traction technology itself, currently already mature for BEB test trials, is the required electric charging infrastructure and its inherent operational effects, which
Barbosa, Fábio C.
Nowadays, the rapid growth of civil aviation transportation demand has led to more frequent flight delays. The major problem of flight delays is restricting the development of municipal airports. To further improve passenger satisfaction, and reduce economic losses caused by flight delays, environmental pollution and many other adverse consequences, three machine learning algorithms are constructed in current study: random forest (RF), gradient boosting decision tree (GBDT) and BP neural network (BPNN). The departure flight delay prediction model uses the actual data set of domestic flights in the United States to simulate and verify the performance and accuracy of the three models. This model combines the visual analysis system to show the density of departure flight delays between different airports. Firstly, the data set is reprocessed, and the main factors leading to flight delays are selected as sample attributes by principal component analysis. Secondly, the mean absolute error
Qi, XinyueQian, PinzhengZhang, Jian
Transporting baggage is critical in airport ground support services to ensure smooth flight operations. However, the scheduling of baggage transport vehicles faces challenges related to low efficiency and high costs. A multi-objective optimization vehicle scheduling model is proposed to address these issues, considering time and space costs, vehicle utilization, and passenger waiting time. An improved genetic algorithm (IGA) based on the large-scale neighborhood search algorithm is proposed to solve this model. The simulation experiment is conducted using actual flight data from an international airport. The IGA algorithm is compared with the standard genetic algorithm (SGA) based on experimental results, revealing that the former achieves convergence in a significantly shorter time. Moreover, the scheduling paths of baggage cars that violate flight service time window requirements are significantly lower in the final scheduling scheme under the IGA algorithm than in SGA. Additionally
Jiang, HanZhang, JianZhang, HaiyanQian, Pinzheng
Given the rapid advancement of connected and automated transportation, its applications have significantly increased. They are being studied worldwide to shape the future of mobility. Key promises are a more comfortable, efficient and socially adapted kind of mobility. As part of the EU Horizon2020 project SHared automation Operating models for Worldwide adoption (SHOW), the Karlsruhe Test Site in the Test Area Autonomous Driving Baden-Württemberg (TAF-BW) addresses aspects of scalability to overcome challenges, which have so far hindered market penetration of this future-oriented kind of mobility. The explored services, including passenger and cargo transport, are closely linked to the daily travel requirements of road users, particularly in peri-urban areas, to cover the last mile of their journeys, connecting them to public transport. The provided high-definition maps and the smart and intelligent roadside infrastructure of TAF-BW facilitate the testing and evaluation of automated
Ochs, SvenFleck, TobiasOrf, StefanSchotschneider, AlbertGontscharow, MartinPolley, RupertZofka, Marc RenéViehl, AlexanderZöllner, J. MariusSimon, KevinFrey, Michael
Ground vibration testing (GVT) is an important phase of the development, or the structural modification of an aircraft program. The modes of vibration and their associated parameters extracted from the GVT are used to modify the structural model of the aircraft to make more reliable dynamics predictions to satisfy certification authorities. Due to the high cost and the extensive preparations for such tests, a new method of vibration testing called taxi vibration testing (TVT) rooted in operational modal analysis (OMA) was recently proposed and investigated by the German Institute for Aerospace Research (DLR) as alternative to conventional GVT. In this investigation, a computational framework based on fully coupled flexible multibody dynamics for TVT is presented to further investigate the applicability of the TVT to flexible airframes. The time domain decomposition (TDD) method for OMA was used to postprocess the response of the airframe during a TVT. The framework was then used to
Al-bess, LohayKhouli, Fidel
More airports are starting to adopt and test the use of radio frequency (RF) mitigation techniques to counter the operation of unmanned aircraft systems (UAS) in violation of civilian airspace rules. While civilian aviation regulatory agencies are welcoming the integration of more commercially operated UAS into civilian airspace, airports are responding to the growing number of incidents in recent years with counter measures to ensure drones do not interfere with regular operations. In the U.S., the Federal Aviation Authority (FAA) now receives more than 100 reports per month from pilots that have observed UAS operating near airports or within a restricted area of civilian airspace. The problem is a unique one for the FAA and other civilian aviation regulatory agencies who want to unleash as much commercial UAS innovation as possible within civilian airspace, but simultaneously recognize rogue operators are a problem. The FAA's method for addressing the operation of drones near
The goal of the automated mobility platforms (AMPs) initiative is to raise the bar of service regarding equity and sustainability for public mobility systems that are crucial to large facilities, and doing so using electrified, energy efficient technology. Using airports as an example, the rapid growth in air travel demand has led to facility expansions and congested terminals, which directly impacts equity (e.g., increased challenges for Passengers with Reduced Mobility [PRMs]) and sustainability—both of which are important metrics often overlooked during the engineering design process. Therefore, to evaluate systems and inform critical near- and long-term decisions more effectively, a holistic evaluation framework is proposed focused on four key areas: (1) mobility, with emphasis on travel time and accessibility within an airport, (2) environment, focused on energy consumption and greenhouse gas (GHG) emissions associated with intra-airport mobility, (3) equity, specifically to the
Young, StanleyGrahn, RickDuvall, Andrew
An extensive evaluation of the Deep Image Prior (DIP) technique for image inpainting on Synthetic Aperture Radar (SAR) images. Air Force Research Laboratory, Wright Patterson Air Force Base, OH Synthetic Aperture Radar (SAR) images are a powerful tool for studying the Earth's surface. They are radar signals generated by an imaging system mounted on a platform such as an aircraft or satellite. As the platform moves, the system emits sequentially high-power electromagnetic waves through its antenna. The waves are then reflected by the Earth's surface, re-captured by the antenna, and finally processed to create detailed images of the terrain below. SAR images are employed in a wide variety of applications. Indeed, as the waves hit different objects, their phase and amplitude are modified according to the objects' characteristics (e.g., permittivity, roughness, geometry, etc.). The collected signal provides highly detailed information about the shape and elevation of the Earth's surface
The upcoming regulations to achieve zero-emission passenger transport present challenges for designing new ferry powertrains. The proposed work investigates the feasibility of using a Proton Exchange Membrane Fuel Cell (PEMFC) power system to power a long-haul ferry. The paper describes the zero-order cell model as well as the method for estimating cell degradation. The stack modeling, heat balance equations, and auxiliary modeling are also presented. The proposed model enables the simulation of the fuel cell under different operating conditions and includes the use of air or oxygen as an oxidizer. A thermal management strategy for the overall PEMFC system is also proposed. The model was calibrated on the characteristic curves of the PEMFC Ballard FCvelocity™ HD6 (150 kW) and validated by reproducing experimental results. Then, a real load profile of a ferry, as well as the proposed powertrain is considered as case study. The presented results are related to a single daily mission and
Saponaro, GianmarcoStefanizzi, MicheleFranchini, EmanueleTorresi, MarcoCamporeale, Sergio
Electrification of public transport in cities puts lots of stress onto the vehicle's traction batteries and the power grid during charging. The authors present a self-learning operating strategy to improve the battery life and reduce stress on the power grid by lengthening charging operations as long as possible and avoiding extreme states of charge. During regular service operation, the operating strategy observes the vehicle state and energy flows inside of the vehicle and between vehicle and charging infrastructure. Based on these observations, the operating strategy plans a guidance state of charge trajectory for the trip and dispatches recommendations for charging and discharging the traction battery to the vehicle's ECU. Additionally, the operating strategy ensures reliable service trips by checking if the current state of charge matches the estimated energy consumption for a fixed range laying ahead. The operating strategy can detect and mitigate a situation in which the vehicle
von Kleist, HermannSaroch, LarsBeims, Martin
With the law on autonomous driving and the associated ordinance, it has been possible in Germany since June 2022 to grant operating permission to vehicles with automated driving function and to admit them to road traffic. For public transport, automated shuttle buses offer the opportunity to maintain the existing service despite a shortage of personnel and to close gaps in supply. The safety of vehicle occupants, other road users and third parties is a key concern in the operation of automated shuttle buses. As part of the project RABus “Real laboratory for automated bus operation in public transport in urban and rural areas”, which is funded by the Ministry of Transport Baden-Württemberg, the operational reliability of automated shuttle buses (SAE Level 4) in public transport is being scientifically investigated. In the implementation of automated driving, obstacle detection/avoidance is a safety-critical driving function. The number of possible scenarios in the real world is almost
Gao, KunWeinrich, UlrikeRiemer, ThomasReuss, Hans-Christian
One of the most significant challenges for the aviation industry in the winter is the deicing operations on runways. As a result, deicer chemicals can pollute the environment if used in a large amount. A mathematical model could help optimize the use of deicer chemicals. Road deicing models exist to predict pavement temperature covered by snow/ice during deicing operations. However, the specificity of airport operations requires a model for the runway deicing to simulate the mass of ice melted with usage of deicing agents. Here we propose a model for runway deicing and validate it against experimental results. Our model considers temperature, diffusive flux, and time changes in a normal direction. It also calculates the mass and heat transfer in three regions (liquid, mushy, and solid). We used the enthalpy method to determine the temperature and the interface location at each time step. In the liquid and solid, the deicer concentration is obtained by Fick’s law and updated at each
Maroufkhani, AidaCharpentier, ClaireMorency, FrancoisMomen, Gelareh
Measurements in snow conditions performed in the past were rarely initiated and best suited for pure and extremely detailed quantification of microphysical properties of a series of microphysical parameters, needed for accretion modelling. Within the European ICE GENESIS project, a considerable effort of natural snow measurements has been made during winter 2020/21. Instrumental means, both in-situ and remote sensing were deployed on the ATR-42 aircraft, as well as on the ground (ground station at ‘Les Eplatures’ airport in the Swiss Jura Mountains with ATR-42 overflights). Snow clouds and precipitation in the atmospheric column were sampled with the aircraft, whereas ground based and airborne radar systems allowed extending the observations of snow properties beyond the flight level chosen for the in situ measurements. Overall, five flight missions have been performed at different numerous flight levels (related temperature range from -10°C to +2°C) beyond the ‘Les Eplatures’ airport
Jaffeux, LouisSchwarzenboeck, AlfonsCoutris, PierreFebvre, GuyDezitter, FabienAguilar, Borisbillault-Roux, Anne-claireGrazioli, JacopoBerne, AlexisKöbschall, KilianJorquera, SusanaDelanoe, Julien
Surveillance cameras are becoming more commonplace in public environments, as well as finding use in private security and military operations. We are particularly interested in scenarios where a single pan-tilt-zoom (PTZ) camera is used to perform surveillance in large outdoor environments, which may include 360-degree horizontal coverage and depths out to 1 km or more. These scenarios exist in many environments such as security for building exteriors, airports, highways, parking lots, and property perimeters; anomaly detection in dense urban environments; and surveillance in military overwatch missions. In environments with many vertical obscurations (e.g., trees and buildings), ground-based cameras will need to be carefully located to provide long-range views. As the elevation of the camera is increased above the ground level, by placement on tall poles or building rooftops, for example, obtaining views of distant regions becomes easier
This SAE Recommended Practice establishes uniform Installation Parameters for desiccant Air Dryers for vehicles with compressed air systems
Truck and Bus Brake Supply and Control Components Committee
With the rapid development of the Internet and intelligent control technology, intelligent transportation has become a research hotspot in building a smart city. Under the background of intelligent transportation, it is particularly important to effectively evaluate the rail transit as the framework of urban public transport in this study, and fuzzy mechanism is introduced to optimize the support vector machine (SVM), and on this basis, analytic hierarchy process (AHP) and SVM are combined to improve the classification accuracy and improve the rail transit operation safety evaluation index system. The experimental results show that the classification accuracy of the fuzzy SVM combined with AHP is above 85% on all the datasets, and it can effectively eliminate the less-relevant indicators. In the actual evaluation of Shanghai Rail Transit safety, the prediction accuracy exceeded 80% and the highest reached 94.51%. Among them, the accuracy of management level and infrastructure were
Shi, XiuhongWu, Kaixin
Challenges that persons with disabilities face with current modes of transportation have led to difficulties in carrying out everyday tasks, such as grocery shopping and going to doctors’ appointments. Autonomous vehicles have been proposed as a solution to overcome these challenges and make these everyday tasks more accessible. For these vehicles to be fully accessible, the infrastructure surrounding them need to be safe, easy to use, and intuitive for people with disabilities. Thus, the goal of this work was to analyze interview data from persons with disabilities, and their caregivers, to identify barriers to accessibility for current modes of transportation and ways to ameliorate them in pick up/drop off zones for autonomous vehicles. To do this, interview subjects were recruited from adaptive sports clubs, assistive living facilities, and other disability networks to discuss challenges with current public transit stops/stations. Responses to questions were recorded and later
Scott, JustinD'Arcangelo, MicahOlness, BenjaminGrimm, MicheleBush, Tamara
This paper proposes the use of an on-demand, ride hailed and ride-Shared Autonomous Vehicle (SAV) service as a feasible solution to serve the mobility needs of a small city where fixed route, circulator type public transportation may be too expensive to operate. The presented work builds upon our earlier work that modeled the city of Marysville, Ohio as an example of such a city, with realistic traffic behavior, and trip requests. A simple SAV dispatcher is implemented to model the behavior of the proposed on-demand mobility service. The goal of the service is to optimally distribute SAVs along the network to allocate passengers and shared rides. The pickup and drop-off locations are strategically placed along the network to provide mobility from affordable housing, which are also transit deserts, to locations corresponding to jobs and other opportunities. The study is carried out by varying the behaviors of the SAV driving system from cautious to aggressive along with the size of the
Meneses Cime, KarinaGuvenc, LeventAksun Guvenc, Bilin
The towbarless aircraft taxiing system (TLATS) consists of the towbarless towing vehicle (TLTV) and the aircraft. The tractor realizes the towing work by fixing the nose wheel. During the towing process, the tractor driver may cause the aircraft to collide with an obstacle because of the blind spot of vision leading to the accident. The special characteristics of aircraft do not allow us to modify the structure of the aircraft to achieve collision avoidance. In this paper, three degrees of freedom (DOE) kinematic model of the tractor system is established for each of the two cases of pushing and pulling the aircraft, and the relationship between the coordinates of each danger point and the relatively articulated angle of the TLATS and the velocity of the midpoint of the rear axle is derived. Considering that there is an error between the velocity and relatively articulated angle measured by the sensor and the actual one, the effect of velocity and relatively articulated angle
Zhu, HengjiaXu, ZiShuoZhang, BaizhiZhang, Wei
This SAE Aerospace Information Report (AIR) summarizes prior empirical findings (AIAA 2018-3991; Chati, 2018) to recommend a modified baseline fuel flow rate model for jet-powered commercial aircraft during taxi operations on the airport surface that better reflects operational values. Existing standard modeling approaches are found to significantly overestimate the taxi fuel flow rate; therefore, a modified multiplicative factor is recommended to be applied to these existing approaches to make them more accurate. Results from the analysis of operational flight data are reported, which form the basis for the modeling enhancements being recommended
A-21 Aircraft Noise Measurement Aviation Emission Modeling
This equipment recommended practice defines the requirements for a permanent vehicle-mounted or slip-in accessory device designed to transport and distribute aggregate de-icing, anti-icing, or friction modifying solid materials or wetted solid materials onto runways, taxiways, ramp, and terminal areas and other paved surfaces on an airport. It is not intended for liquid material spreaders which are addressed in ARP5559. The material spreader may be permanently mounted on a carrier vehicle, trailer, or semi-trailer, or temporarily installed on a carrier vehicle trailer, or semi-trailer for seasonal use only. The carrier vehicle may be dedicated to material spreading applications only, or provide additional functions such as a plow vehicle, flat bed or dump body. Carrier vehicles are self-propelled prime movers, generally a commercial or purpose-built truck that provides the mobility to move the material spreader on these paved surfaces. Carrier vehicle recommended practices may be found
G-15 Airport Snow and Ice Control Equipment Committee
This SAE Aerospace Recommended Practice (ARP) covers the requirements for a Stationary Runway Weather Information System (referred to as the system) to monitor the surface conditions of airfield operational areas to ensure safer ground operations of aircraft. The system provides (1) temperature and condition information of runway, taxiway, and ramp pavements and (2) atmospheric weather conditions that assist airport personnel to maintain safer and more efficient airport operations. The system can be either a wired system or a wireless system
G-15 Airport Snow and Ice Control Equipment Committee
Items per page:
1 – 50 of 1172