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This briefing discusses the constraints of the Northeast Corridor (NEC), the increasing predictability that can be achieved by leveraging digital assets (e.g., EOBT), and the challenges of a multi-airport scenario and the use of TOS alternative routes. It further describes the potential of near-term digital asset expansion and near real-time predictive analytics to generate innovative solutions.
The modern day National Airspace System (NAS) is powered by System Wide Information Management (SWIM) which is a real-time digital data sharing infrastructure that provides a high fidelity view of the lifecycle of a flight. The newly available data within the SWIM feeds can be leveraged to help drive efficiencies in the NAS. In this talk, we investigate the gate conflict prediction problem as a concrete use case which could help drive efficiencies. We begin with a high level description of NASA's Airspace Technology Demonstration 2 which is built upon the real-time SWIM feeds and produces the data used in our investigation. We model gate conflicts as a regression problem and describe the iterative process of model building, model validation, and evaluation used to assess the efficacy of our approach.
The NASA Airspace Technology Demonstration 2 Phase 1 and 2 Field Evaluations have successfully demonstrated new technologies developed to manage the Integrated Arrival, Departure, and Surface traffic flows at a single airport. The Phase 3 Field Evaluation extends the capabilities to a Metroplex environment where multiple airports are interacting and sharing resources along the terminal boundary. This paper describes the scheduling algorithm enabling the coordinated scheduling and describes the interaction between airports within the Metroplex and the terminal boundary. We describe the metrics developed to inform flight operators about reroute opportunities and discuss the potential benefits to the rerouted flight and the system-wide aggregate benefits of a single reroute. We believe that the capabilities developed and the lessons learned during the Phase 3 Field Evaluation will set up the National Airspace System for future success.
NASA is conducting the Airspace Technology Demonstration-2 to evaluate an Integrated Arrival, Departure, and Surface (IADS) traffic management system. The IADS system is powered by real-time System Wide Information Management feeds which provide an accurate and high fidelity view of the lifecycle of a flight. This data can be leveraged to drive efficiencies in the National Airspace System. For non safety critical applications there is opportunity for third party service providers to offer this type of data-driven prediction service in near real-time. This paper investigates the gate conflict prediction problem as a concrete use case which could help drive efficiencies. We model gate conflicts as a regression problem and describe the iterative process of model building, model validation, and evaluation used to assess the efficacy of our approach. We quantify our predictive accuracy and identify paths for improvement. Through this iterative process we hope to evolve our models and methods to a near real-time prediction service.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
The THOR anthropomorphic test device (ATD) has been developed and continuously improved by the National Highway Traffic Safety Administration to provide automotive manufacturers an advanced tool that can be used to assess the injury risk of vehicle occupants in crash tests. Recently, a series of modifications were completed to improve the biofidelity of THOR ATD [1]. The updated THOR Modification Kit (THOR-K) ATD was employed at Wright-Patterson Air Base in 22 impact tests in three configurations: vertical, lateral, and spinal [2]. Although a computational finite element (FE) model of the THOR had been previously developed [3], updates to the model were needed to incorporate the recent changes in the modification kit. The main goal of this study was to develop and validate a FE model of the THOR-K ATD. The CAD drawings of the THOR-K ATD were reviewed and FE models were developed for the updated parts. For example, the head-skin geometry was found to change significantly, so its model was re-meshed (Fig. 1a). A protocol was developed to calibrate each component identified as key to the kinematic and kinetic response of the THOR-K head/neck ATD FE model (Fig. 1b). The available ATD tests were divided in two groups: a) calibration tests where the unknown material parameters of deformable parts (e.g., head skin, pelvis foam) were optimized to match the data and b) validation tests where the model response was only compared with test data by calculating their score using CORrelation and Analysis (CORA) rating system. Finally, the whole ATD model was validated under horizontal-, vertical-, and lateral-loading conditions against data recorded in the Wright Patterson tests [2]. Overall, the final THOR-K ATD model developed in this study is shown to respond similarly to the ATD in all validation tests. This good performance indicates that the optimization performed during calibration by using the CORA score as objective function is not test specific. Therefore confidence is provided in the ATD model for uses in predicting response in test conditions not performed in this study such those observed in the spacecraft landing. Comparison studies with ATD and human models may also be performed to contribute to future changes in THOR ATD design in an effort to improve its biofidelity, which has been traditionally based on post-mortem human subject testing and designer experience.
NASA spacecraft design requirements for occupant protection are a combination of the Brinkley Dynamic Response Criteria and injury assessment reference values (IARV) extracted from anthropomorphic test devices (ATD). For the ATD IARVs, the requirements specify the use of the 5th percentile female Hybrid III and the 95th percentile male Hybrid III. Each of these ATDs is required to be fitted with an articulating pelvis (also known as the aerospace pelvis) and a straight spine. The articulating pelvis is necessary for the ATD to fit into spacecraft seats, while the straight spine is required as injury metrics for vertical accelerations are better defined for this configuration. Sled testing of the Hybrid III 5th Percentile Female Anthropomorphic Test Device (ATD) was performed at Wright-Patterson Air Force Base (WAPFB). Two 5th Percentile ATDs were tested, the Air Force Research Lab (AFRL) and NASA owned Hybrid III ATDs with aerospace pelvises. Testing was also conducted with a NASA-owned 95th Percentile Male Hybrid III with aerospace pelvis at WPAFB. Testing was performed using an Orion seat prototype provided by Johnson Space Center (JSC). A 5-point harness comprised of 2 inch webbing was also provided by JSC. For suited runs, a small and extra-large Advanced Crew Escape System (ACES) suit and helmet were also provided by JSC. Impact vectors were combined frontal/spinal and rear/lateral. Some pure spinal and rear axis testing was also performed for model validation. Peak accelerations ranged between 15 and 20-g. This range was targeted because the ATD responses fell close to the IARV defined in the Human-Systems Integration Requirements (HSIR) document. Rise times varied between 70 and 110 ms to assess differences in ATD responses and model correlation for different impact energies. The purpose of the test series was to evaluate the Hybrid III ATD models in Orion-specific landing orientations both with and without a spacesuit. The results of these tests were used by the NASA Engineering and Safety Center (NESC) to validate the finite element model (FEM) of the Hybrid III 5th Percentile Female ATD. Physical test data was compared to analytical predictions from simulations, and modelling uncertainty factors have been determined for each injury metric. Additionally, the test data has been used to further improve the FEM, particularly in the areas of the ATD preload, harness, and suit and helmet effects.
In an effort to develop occupant protection standards for future multipurpose crew vehicles, the National Aeronautics and Space Administration (NASA) has looked to evaluate the test device for human occupant restraint with the modification kit (THOR‐K) anthropomorphic test device (ATD) in relevant impact test scenarios. With the allowance and support of the National Highway Traffic Safety Administration, NASA has performed a series of sled impact tests on the latest developed THOR‐K ATD. These tests were performed to match test conditions from human volunteer data previously collected by the U.S. Air Force. The objective of this study was to evaluate the THOR‐K finite element (FE) model and the Total HUman Model for Safety (THUMS) FE model with respect to the tests performed. These models were evaluated in spinal and frontal impacts against kinematic and kinetic data recorded in ATD and human testing. Methods: The FE simulations were developed based on recorded pretest ATD/human position and sled acceleration pulses measured during testing. Predicted responses by both human and ATD models were compared to test data recorded under the same impact conditions. The kinematic responses of the models were quantitatively evaluated using the ISO‐metric curve rating system. In addition, ATD injury criteria and human stress/strain data were calculated to evaluate the risk of injury predicted by the ATD and human model, respectively. Results: Preliminary results show well‐correlated response between both FE models and their physical counterparts. In addition, predicted ATD injury criteria and human model stress/strain values are shown to positively relate. Kinematic comparison between human and ATD models indicates promising biofidelic response, although a slightly stiffer response is observed within the ATD. Conclusion: As a compliment to ATD testing, numerical simulation provides efficient means to assess vehicle safety throughout the design process and further improve the design of physical ATDs. The assessment of the THOR‐K and THUMS FE models in a spaceflight testing condition is an essential first step to implementing these models in the computational evaluation of spacecraft occupant safety. Promising results suggest future use of these models in the aerospace field.
NASA spacecraft design requirements for occupant protection are a combination of the Brinkley criteria and injury metrics extracted from anthropomorphic test devices (ATD's). For the ATD injury metrics, the requirements specify the use of the 5th percentile female Hybrid III and the 95th percentile male Hybrid III. Furthermore, each of these ATD's is required to be fitted with an articulating pelvis and a straight spine. The articulating pelvis is necessary for the ATD to fit into spacecraft seats, while the straight spine is required as injury metrics for vertical accelerations are better defined for this configuration. The requirements require that physical testing be performed with both ATD's to demonstrate compliance. Before compliance testing can be conducted, extensive modeling and simulation are required to determine appropriate test conditions, simulate conditions not feasible for testing, and assess design features to better ensure compliance testing is successful. While finite element (FE) models are currently available for many of the physical ATD's, currently there are no complete models for either the 5th percentile female or the 95th percentile male Hybrid III with a straight spine and articulating pelvis. The purpose of this work is to assess the accuracy of the existing Livermore Software Technology Corporation's FE models of the 5th and 95th percentile ATD's. To perform this assessment, a series of tests will be performed at Wright Patterson Air Force Research Lab using their horizontal impact accelerator sled test facility. The ATD's will be placed in the Orion seat with a modified-advanced-crew-escape-system (MACES) pressure suit and helmet, and driven with loadings similar to what is expected for the actual Orion vehicle during landing, launch abort, and chute deployment. Test data will be compared to analytical predictions and modelling uncertainty factors will be determined for each injury metric. Additionally, the test data will be used to further improve the FE model, particularly in the areas of the ATD neck components, harness, and suit and helmet effects.
Urban transportation is currently evolving from traditional ground-based vehicles (cars, taxis, and buses) to include air-based electric vertical take-off and landing (eVTOL) vehicles which can be utilized for on-demand transportation, cargo transport, and emergency services. These new eVTOL vehicles are designed to be small, lightweight, and able to operate autonomously without user intervention. Safety is a big part of eventual eVTOL adoption, however gaps in the consideration of safety features exist. Anthropomorphic test devices (ATDs) are used in aerospace crashworthiness standards to quantify occupant injury risk and develop improved safety designs for emergency landing situations, but the ATDs currently used in aircraft certification requirements were developed many decades ago. Developments have occurred over the years involving ATD technology, which includes a host of newer and more biofidelic ATDs such as the Test Device for Human Occupant Restraint (THOR). Increased computing power has also allowed for detailed computational human body models (HBMs) to be created, such as the Global Human Body Model Consortium (GHBMC). This study aims to assess the capability of both HBMs and new ATD designs to identify injury mechanisms within eVTOL relevant emergency landing conditions. Finite element (FE) analysis was used to expand upon full-scale and seat level impact testing conducted by researchers at the National Aeronautics and Space Administration (NASA) to look at effects of occupant model configurations on prediction of injury. The GHBMC HBM and THOR ATD models were simulated in the seat level test conditions to characterize differences between these advanced assessment tools and traditional ATDs in the isolated seat loading environment. Results identified key differences in the responses from each of the models utilized and compared their impact response in head, neck, and spinal injury metrics. The THOR model identified potential risks for head injuries due to head impacts on the seat, however it predicted lower spinal loads than the other occupant surrogates. The GHBMC showed distinctly different biomechanical responses compared to the ATD. The GHBMC model is much more deformable than the ATDs and it exhibited higher distribution of forces and increased sensitivity to the duration of acceleration pulses. Both models incorporated into this study identified key mechanisms for injury that should be considered for passenger safety in the development of these novel aircraft. In addition, this study demonstrated the value of FE modeling for running a variety of complex human surrogates to identify potential injury mechanisms for consideration in regulation and development of new aircraft. Continued research in this field to improve validation these models will only lead to safer aircraft and more comprehensive safety measures.
Urban transportation is currently evolving from traditional ground-based vehicles (cars, taxis, and buses) to include air-based electric vertical take-off and landing (eVTOL) vehicles which can be utilized for on-demand transportation, cargo transport, and emergency services. These new eVTOL vehicles are designed to be small, lightweight, and able to operate autonomously without user intervention. Safety is a big part of eventual eVTOL adoption, however gaps in the consideration of safety features exist. Anthropomorphic test devices (ATDs) are used in aerospace crashworthiness standards to quantify occupant injury risk and develop improved safety designs for emergency landing situations, but the ATDs currently used in aircraft certification requirements were developed many decades ago. Developments have occurred over the years involving ATD technology, which includes a host of newer and more biofidelic ATDs such as the Test Device for Human Occupant Restraint (THOR). Increased computing power has also allowed for detailed computational human body models (HBMs) to be created, such as the Global Human Body Model Consortium (GHBMC). This study aims to assess the capability of both HBMs and new ATD designs to identify injury mechanisms within eVTOL relevant emergency landing conditions. Finite element (FE) analysis was used to expand upon full-scale and seat level impact testing conducted by researchers at the National Aeronautics and Space Administration (NASA) to look at effects of occupant model configurations on prediction of injury. The GHBMC HBM and THOR ATD models were simulated in the seat level test conditions to characterize differences between these advanced assessment tools and traditional ATDs in the isolated seat loading environment. Results identified key differences in the responses from each of the models utilized and compared their impact response in head, neck, and spinal injury metrics. The THOR model identified potential risks for head injuries due to head impacts on the seat, however it predicted lower spinal loads than the other occupant surrogates. The GHBMC showed distinctly different biomechanical responses compared to the ATD. The GHBMC model is much more deformable than the ATDs and it exhibited higher distribution of forces and increased sensitivity to the duration of acceleration pulses. Both models incorporated into this study identified key mechanisms for injury that should be considered for passenger safety in the development of these novel aircraft. In addition, this study demonstrated the value of FE modeling for running a variety of complex human surrogates to identify potential injury mechanisms for consideration in regulation and development of new aircraft. Continued research in this field to improve validation these models will only lead to safer aircraft and more comprehensive safety measures.
Orion Spacecraft water landing environments have necessitated the design and testing of a novel Helmet Support Assembly (HSA) as part of the NASA Orion Crew Survival Systems (OCSS) launch and re-entry spacesuit. A series of development sled tests using 5 th female, 50th male, and 95th male Hybrid III Anthropometric Test Devices (ATDs) simulated worst case water landings and identified the need for an integrated suit countermeasure to control the helmet during dynamic loading. Initial prototype countermeasures rigidly restrained the helmet keeping the helmet in place as desired, but led to large force and moment transmission to the upper neck. Further development led to a flexible HSA which used high-strength steel wire contoured to the size-matched ATD thorax and attached to both the front and rear of the neck ring. The selected wire diameter and contoured shape provided some ability to flex under the expected worst-case dynamic loads. The existing shoulder harness was used to restrain the helmet motion during “eyeballs out/down” loading while also attempting to prevent head-to-helmet contact in “eyeballs down” spinal-axis loading. A new small prototype helmet was also developed and tested for the 5th and 50th ATDs with both HSA devices. Dynamic impact tests were conducted on the HIA (Horizontal Impulse Accelerator) at Wright Patterson Air Force Base (WPAFB) under simulated off-nominal landing conditions using a representative Orion seat and 5-point harness. For each ATD size, peak Neck Injury Criteria (Nij) were compared to equivalent sled tests with an unsuited ATD configuration. Adding a helmet without attempting to control motion increased peak Nij values for all ATD sizes. The use of the rigid countermeasure showed decreased peak Nij results for the 5th female, but increased peak Nij values for both 50th configurations and the 95th male ATDs. By comparison, the flexible HSA showed reduced peak Nij values for all ATD sizes. Overall, this series of dynamic impact tests identified a risk of increased crew neck loading when under- or over-restraining the helmet during simulated Orion water landings and also demonstrated an effective strategy to mitigate those loads with a compliant HSA design.
United States (U.S.) crewed vehicles are being designed to support the National Aeronautics and Space Administration’s (NASA’s) human spaceflight programs. Vehicles must be designed to meet NASA’s occupant protection requirements including landing injury assessment with anthropomorphic test devices (ATDs) and analytical models. However, these tools are limited in capturing all injuries that might occur during spacecraft landings. A NASA study of injuries during Soyuz vehicle landings has shown that analytical models are underpredicting occupant injury. Because of the inherent limitations with our analytical tools, human volunteer impact testing was employed to validate the safety of U.S. crewed vehicles. A total of 84 human volunteer tests in 11 different test orientations and g-levels were completed as part of this effort in collaboration with the Air Force Research Laboratory (AFRL) at Wright-Patterson Air Force Base and the vehicle development companies. Human subjects were tested at various realistic landing loads and in the highest fidelity seat and suit components that were available at the time of testing for two U.S. vehicles. Matched-pair ATD tests in the same test conditions were also conducted with small female and midsized male Hybrid III ATDs. ATDs were fully instrumented. Head accelerations and subjective responses were recorded in human subjects. In some cases, chest accelerations were captured. Responses of the ATDs and humans in matched-pair tests were compared. No ATD tests showed evidence for risk of injury based on NASA occupant protection requirements. Human subjects reported 17 cases of discomfort or pain, 1 human subject was diagnosed with a minor injury that was not evident in the ATD tests. These results provide evidence that ATDs do not capture all potential injury risks, namely lower severity injuries, discomfort, pain, and fit issues. Overall, human testing is beneficial to understanding the true risk of injury to crewmembers during Earth landings.
United States (U.S.) crewed vehicles are being designed to support the National Aeronautics and Space Administration’s (NASA’s) human spaceflight programs. Vehicles must be designed to meet NASA’s occupant protection requirements including landing injury assessment with anthropomorphic test devices (ATDs) and analytical models. However, these tools are limited in capturing all injuries that might occur during spacecraft landings. A NASA study of injuries during Soyuz vehicle landings has shown that analytical models are underpredicting occupant injury. Because of the inherent limitations with our analytical tools, human volunteer impact testing was employed to assess flight-like landing conditions of U.S. crewed vehicles. A total of 84 human volunteer tests in 11 different test orientations and g-levels were completed as part of this effort in collaboration with the Air Force Research Laboratory (AFRL) at Wright-Patterson Air Force Base and U.S. vehicle development companies. Human subjects were tested at various realistic landing loads and in the highest fidelity seat and suit components that were available at the time of testing for two U.S. vehicles. Matched-pair ATD tests in the same test conditions were also conducted with small female and midsized male Hybrid III ATDs. ATDs were fully instrumented. Head accelerations and subjective responses were recorded for human subjects. In some cases, chest accelerations were captured. Responses of the ATDs and humans in matched-pair tests were compared. No ATD tests showed evidence for risk of injury based on NASA occupant protection requirements. Human subjects reported 17 cases of discomfort or pain, and 1 human subject was diagnosed with a minor injury that was not evident in the ATD tests. These results provide evidence that ATDs do not capture all potential injury risks, namely lower severity injuries, discomfort, pain, and fit issues. Overall, human testing is beneficial to understanding the true risk of injury to crewmembers during Earth landings.
United States (U.S.) crewed vehicles are being designed to support the National Aeronautics and Space Administration’s (NASA’s) human spaceflight programs. Vehicles must be designed to meet NASA’s occupant protection requirements including landing injury assessment with anthropomorphic test devices (ATDs) and analytical models. However, these tools are limited in capturing all injuries that might occur during spacecraft landings. A NASA study of injuries during Soyuz vehicle landings has shown that analytical models are underpredicting occupant injury. Because of the inherent limitations with our analytical tools, human volunteer impact testing was employed to assess flight-like landing conditions of U.S. crewed vehicles. A total of 84 human volunteer tests in 11 different test orientations and g-levels were completed as part of this effort in collaboration with the Air Force Research Laboratory (AFRL) at Wright-Patterson Air Force Base and U.S. vehicle development companies. Human subjects were tested at various realistic landing loads and in the highest fidelity seat and suit components that were available at the time of testing for two U.S. vehicles. Matched-pair ATD tests in the same test conditions were also conducted with small female and midsized male Hybrid III ATDs. ATDs were fully instrumented. Head accelerations and subjective responses were recorded for human subjects. In some cases, chest accelerations were captured. Responses of the ATDs and humans in matched-pair tests were compared. No ATD tests showed evidence for risk of injury based on NASA occupant protection requirements. Human subjects reported 17 cases of discomfort or pain, and 1 human subject was diagnosed with a minor injury that was not evident in the ATD tests. These results provide evidence that ATDs do not capture all potential injury risks, namely lower severity injuries, discomfort, pain, and fit issues. Overall, human testing is beneficial to understanding the true risk of injury to crewmembers during Earth landings.
United States (U.S.) crewed vehicles are being designed to support the National Aeronautics and Space Administration’s (NASA’s) human spaceflight programs. Vehicles must be designed to meet NASA’s occupant protection requirements including landing injury assessment with anthropomorphic test devices (ATDs) and analytical models. However, these tools are limited in capturing all injuries that might occur during spacecraft landings. A NASA study of injuries during Soyuz vehicle landings has shown that analytical models are underpredicting occupant injury. Because of the inherent limitations with our analytical tools, human volunteer impact testing was employed to assess flight-like landing conditions of U.S. crewed vehicles. A total of 84 human volunteer tests in 11 different test orientations and g-levels were completed as part of this effort in collaboration with the Air Force Research Laboratory (AFRL) at Wright-Patterson Air Force Base and U.S. vehicle development companies. Human subjects were tested at various realistic landing loads and in the highest fidelity seat and suit components that were available at the time of testing for two U.S. vehicles. Matched-pair ATD tests in the same test conditions were also conducted with small female and midsized male Hybrid III ATDs. ATDs were fully instrumented. Head accelerations and subjective responses were recorded for human subjects. In some cases, chest accelerations were captured. Responses of the ATDs and humans in matched-pair tests were compared. No ATD tests showed evidence for risk of injury based on NASA occupant protection requirements. Human subjects reported 17 cases of discomfort or pain, and 1 human subject was diagnosed with a minor injury that was not evident in the ATD tests. These results provide evidence that ATDs do not capture all potential injury risks, namely lower severity injuries, discomfort, pain, and fit issues. Overall, human testing is beneficial to understanding the true risk of injury to crewmembers during Earth landings.