Browsing by Author "Trani, Antonio"

Now showing 1 - 6 of 6
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    A Demand Driven Airline and Airport Evolution Study
    Seshadri, Anand (Virginia Tech, 2009-05-11)
    The events of September 11,2001 followed by the oil price hike and the economic crisis of 2008, have lead to a drop in the demand for air travel. Airlines have attempted to return to profitability by cutting service in certain unattractive routes and airports. Simultaneously, delays and excess demand at a few major hubs have lead to airline introducing service at reliever airports. This dissertation attempts to capture the changes in the airline network by utilizing a supply-demand framework.
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    Micro-macroscopic modeling and simulation of an Automated Highway System
    Nagarajan, Ramakrishnan (Virginia Tech, 1996)
    Intelligent Transportation Systems (ITS), which uses modem electronics and communications technology to guide or control the operation of vehicles holds great promise for increasing the capacity of existing roads. reducing congestion and accident losses, and contributing to the ease and convenience of travel. The most sophisticated of all the ITS technologies that may ultimately yield the largest benefits is the Automated Highway Systems (AHS). The AHS approach to enhance the performance of our highways is to apply automation techniques to vehicles and roadways to increase the capacity and efficiency of existing facilities, while retaining the advantages of individual mobility. The idea is to have a system with instrumented highways and vehicles which allows the automation of the driving function. The overall objective of this research study involves the modeling and analysis of an AHS system, using a simulation tool specifically developed for this purpose. A multi-layer control system architecture that conforms to the one developed at the University of California, Berkeley, provides a framework for the micro and macroscopic modeling of the system. The focus of the system modeling is towards the lower layers of this control system architecture, involving a comprehensive modeling of the regulation and physical layers and a simple, yet realistic modeling of the functionalities of the link layer. The regulation and physical layer design incorporates a complete power train modeling of the vehicle that includes one-wheel rotational dynamics, linear vehicle dynamics, engine dynamics and actuator dynamics.
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    Taxi Event Extraction from ASDE-X Surveillance for Surface Performance Evaluation
    Mirmohammadsadeghi, Navid; Hotle, Susan; Trani, Antonio; Gulding, John (AIAA, 2018-06)
    Unimpeded taxi times can be used to quantify a flight’s taxiing delay when compared with its actual taxi time. Currently, flight unimpeded taxi times are calculated by the Federal Aviation Administration using a regression method where flights in the Aviation System Performance Metrics (ASPM) data are clustered on the season of operation, airline, airport, and calendar year. It utilizes the airline-reported gate-Out, wheels-Off, wheels-On, gate-In (OOOI) times reported in ASPM, rounded to the nearest minute. For non-reporting airlines, these times are estimated from similar flights. The purpose of this paper is to evaluate the unimpeded time using a surveillance-based approach by identifying the time a flight spent waiting in the system (i.e. traveling slower than 3 m/s) and comparing it to the total taxi time. This study specifically focuses on analyzing both arrivals and departures for 6 top U.S. airports (ATL, CLT, DEN, IAH, JFK, ORD) during the month of July 2015. Airport Surface Detection Equipment-Model X (ASDE-X) surveillance data was matched with ASPM data in order to have a complete coverage of the taxiing phase of airplanes between the gate and runway for taxi out and in procedures. Results show the benefits of a spatial analysis, which allows for a quick identification of which locations on the taxiways were the most susceptible to cause. This study also evaluates changes in the unimpeded metric when compared to the current method and other proposed methods, such as the 5th-to-15th clustering, that is present in literature.
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    Taxi Event Extraction from Surveillance for Surface Performance Evaluation
    Mirmohammadsadeghi, Navid; Hotle, Susan; Trani, Antonio; Gulding, John (AIAA, 2020-06)
    Estimated unimpeded taxi times can be used to quantify a flight’s taxiing delay when compared with its actual taxi time. Currently, flight unimpeded taxi times are calculated by the Federal Aviation Administration using a regression method where flights in the Aviation System Performance Metrics data are clustered on the season of operation, airline, airport, and calendar year. The method uses the airline-reported gate-Out, wheels-Off, wheels-On, gate-In (OOOI) times rounded to the nearest minute. For nonreporting airlines, these times are estimated from similar flights. The purpose of this paper is to evaluate the unimpeded time using a surveillance-based approach by identifying the time a flight spent waiting in the system and comparing with the total taxi time. This study focuses on analyzing both arrivals and departures for six U.S. airports (Atlanta, Charlotte, Denver, Houston, New York Kennedy, and Chicago O'Hare) during themonth of July 2015. Thestudy results showhowthe non-surveillance-based andsurveillance-based metrics compare, with nonsurveillance methods including the current regression method and the 5th-to-15th clustering method described in current literature. The benefits of using surveillance information for surface performance are explored, as spatial analyses allow for quick identification of taxiway locations that were the most susceptible to delays.
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    Urban Air Mobility: Airport Ground Access Demand Estimation
    Rimjha, Mihir; Hotle, Susan; Trani, Antonio; Hinze, Nick; Smith, Jeremy; Dollyhigh, Samuel (AIAA, 2021-08)
    This study aims to estimate passenger demand of Urban Air Mobility (UAM) for airport ground access trips while considering airspace restrictions in the Dallas-Fort Worth region. UAM is a concept mode of transportation designed to bypass ground congestion for time-sensitive, price-inelastic travelers using autonomous, electric aircraft with Vertical Takeoff and Landing (VTOL) capabilities. Airport ground access trips constitute a trip purpose that can utilize this mode. This study analyzes originating ground access trips for two major airports in the Dallas-Fort Worth region: Dallas-Fort Worth International Airport (DFW) and Dallas Love Field Airport (DAL). First, a mode choice model is calibrated on the existing airport ground access behavior. UAM demand is then estimated using the developed model, airspace restrictions, and the results from UAM demand stated-preference surveys in literature. Airspace restrictions consist of unusable pieces of airspaces based on current air traffic patterns, where the placement of UAM vertiports and overflying of UAM vehicles are prohibited. The demand model considers the trajectories of the UAM vehicles, which navigate on pre-defined routes inside Class-B airspace to prevent Air Traffic Control (ATC) involvement requirements. This study includes sensitivity analyses of UAM demand to the cost per passenger mile (CPM), number of vertiports placed in the region, and other secondary factors like vertiport location, intermodal cost, fixed cost, and average speed. Corridors with significant UAM demand are identified from the spatial distribution of demand and potential bottlenecks in the UAM network. The findings predict up to 4% market share of UAM for trips to the airport at the optimistically lower fare of $2 per passenger mile (in addition to the fixed cost of $23) and a 50-vertiport UAM network. Average Value of Times (VOTs) for business and non-business travelers are estimated to be around $57/hr and $36/hr, respectively. Business travelers comprise three-quarters of the total UAM demand because of relatively higher VOTs. Airport access trips in Dallas-Fort Worth region have considerable potential for UAM if the trip's price is below $4 per passenger mile (in addition to the fixed cost of $23).
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    Urban Air Mobility: Preliminary Noise Analysis of Commuter Operations
    Rimjha, Mihir; Trani, Antonio; Hotle, Susan (AIAA, 2021-08)
    This study aims to estimate potential noise levels generated due to Urban Air Mobility (UAM) commuter operations in the Northern California and the Dallas-Fort Worth regions. UAM is a concept aerial transportation mode designed to bypass ground congestion using an electric vehicle with Vertical Take-Off and Landing (VTOL) capabilities. UAM vehicles are expected to be significantly quieter than traditional helicopters, but operate on a much larger scale. Commuter travel demand will not be uniformly distributed with operations concentrated in a small geographical area such as Central Business Districts (CBD) and short time windows such as morning or evening peak periods. The objective of this study is to evaluate the aircraft noise annoyance generated by commuter UAM operations using flight trajectories developed in a previous study estimating UAM commuter demand. This study estimates the noise level from overflying UAM vehicles in a full day of operation (24 hours) and identifies areas where the noise levels may pose a challenge to future UAM operations. Noise estimation is performed at the Census Block group level using the Day-Night Level (DNL) metric. We run a parametric analysis considering two scenarios in each region: the UAM vehicle has a 10 dBA and 15 dBA noise reduction compared to the Robinson R-44 helicopter. The findings indicate a considerable difference between the 10 dBA and 15 dBA reduction scenarios. Although challenging, achieving a 15-dBA reduction compared to a 10-dBA reduction could reduce land area with DNL value above 50 dBA by 94% and highly-annoyed population by 91% in Northern California. Similarly, in Dallas-Fort Worth, achieving a 15-dBA reduction compared to a 10-dBA reduction could reduce the land area with DNL value above 50 dBA by 80% and a highly annoyed population by 85%. Lastly, we analyze the high-demand vertiport in the San Francisco Financial District in the Aviation Environmental Design Tool (AEDT) to observe the DNL contours for the varying noise performance scenarios.