Search NASASearch

SEARCH · Search NASA

Results for “sUAS”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2

Predictive Model for Workload in Remote Operators During sUAS Contingency Scenarios

The increase in automated capabilities of small Uncrewed Aerial Systems (sUAS) has enabled the human operators to manage larger numbers of vehicles simultaneously. As this happens, the operational paradigm shifts to an m:N configuration where multiple operators (m) are managing multiple vehicles (N) together. However, many questions about how operators will interact with each other and share interaction across the vehicle pool are yet unanswered. Therefore, stakeholders from government and industry have partnered to develop ground control station concepts for such operations. The work presented in this paper aims to identify factors that contribute to operator workload. A supervised machine learning-based method built using Support Vector Machines and K-fold cross-validation was used to create workload prediction models for various NASA TLX subscales by leveraging features related to interactions and their relative timings during m:N operations. Results show that the models yielded fairly high predictive accuracies ranging from ~60-75%.

workload prediction

Comparison of Prediction Modeling Methodologies for Aeroacoustic Characterization of Hovering sUAS Rotors

This work compared artificial neural network and multivariate orthogonal function modeling methodologies for the prediction and characterization of isolated hovering sUAS rotor aerodynamics and aeroacoustics. Design of Experiments was used to create input feature spaces over 9 input features: the number of rotor blades, rotor size, rotor speed, the amount of blade twist, blade taper ratio, tip chord length, collective pitch, airfoil camber, and airfoil thickness. CAMRAD~II and AARON were executed at the points defined by the input feature space to predict aerodynamic and aeroacoustic quantities. These predicted aerodynamic and aeroacoustic data were then used to generate artificial neural networks and polynomial response surface models. The two prediction model methodologies were evaluated over test data previously unseen by the models, which showed good prediction capabilities for both model types, with slightly lower prediction error for the artificial neural networks. A characterization study was performed, which showed that input features correspondent to the spanwise sectional blade lift and drag were the most significant factors to the aerodynamic thrust and power, respectively. It was also shown that the aeroacoustic quantities were highly dependent on variations in rotor speed and size, which affect the Doppler factor for tonal noise and the spanwise Reynolds number for broadband noise.

Christopher S Thurman

Remotely Administered Psychoacoustic Test for sUAS Noise to Gauge Feasibility of Remote UAM Noise Study

The National Aeronautics and Space Administration (NASA) remotely administered a psychoacoustic test in fall of 2022 as the first of two phases of a cooperative Urban Air Mobility (UAM) vehicle noise human response study. The first phase, the Feasibility Test, described in this paper, determined the feasibility of the remote test method, in contrast to a previous in-person psychoacoustic test that found an annoyance response difference between small unmanned aerial system (sUAS) noise and ground vehicle noise. This paper discusses the Feasibility Test online layout, sound calibration method, remote test software development, stimuli selection, test subject recruitment, and test administration. Test performance is measured through comparison of annoyance response data with the previous in-person test results. The paper also investigates if providing a contextual cue to test subjects influenced their annoyance response. Response differences between test subjects in geographically distinct areas are analyzed. Administrative challenges that were encountered during the test are discussed. The second phase of this study, the implementation phase, will use a remote (web-based) test method and leverage the cooperation of multiple government agencies, academia, and industry to gain human response insights from a wide range of UAM vehicle sounds that would be challenging for a single organization to acquire. Improvements to administering a remote test for the implementation phase of the UAM vehicle noise human response study are recommended.

Remote Psychoacoustic Test

Remotely Administered Psychoacoustic Test for sUAS Noise to Gauge Feasibility of Remote UAM Noise Study

The National Aeronautics and Space Administration (NASA) remotely administered a psychoacoustic test in fall of 2022 as the first of two phases of a cooperative Urban Air Mobility (UAM) vehicle noise human response study. The first phase, the Feasibility Test, described in this paper, determined the feasibility of the remote test method, in contrast to a previous in-person psychoacoustic test that found an annoyance response difference between small unmanned aerial system (sUAS) noise and ground vehicle noise. This paper discusses the Feasibility Test online layout, sound calibration method, remote test software development, stimuli selection, test subject recruitment, and test administration. Test performance is measured through comparison of annoyance response data with the previous in-person test results. The paper also investigates if providing a contextual cue to test subjects influenced their annoyance response. Response differences between test subjects in geographically distinct areas are analyzed. Administrative challenges that were encountered during the test are discussed. The second phase of this study, the implementation phase, will use a remote (web-based) test method and leverage the cooperation of multiple government agencies, academia, and industry to gain human response insights from a wide range of UAM vehicle sounds that would be challenging for a single organization to acquire. Improvements to administering a remote test for the implementation phase of the UAM vehicle noise human response study are recommended.

Remote Psychoacoustic Test

Semi-Autonomous Transportation of Emergency Supplies via sUAS

Over the past several decades, the extent and severity of wildfires in the United States has increased dramatically. This, accordingly, has put ever-increasing pressure on wildland firefighters to mitigate the effects of fire damage. Wildland firefighters have exceptionally dangerous and strenuous jobs. The United States Forest Service has an interest to develop an autonomous sUAS logistics payload delivery system to transport supplies to crews on the fireline. A design reference mission which includes the transportation of portable drinking water from a helicopter drop site closer to crews on the fire line was developed. Two delivery methods were designed and prototyped within this project, with one of them tested in flight.

Wildfire UAS Logistics

Automated sUAS Inspection Capability for NASA’s Mission Critical Testing Facilities

The wind tunnels at Ames are crucial to NASA and industry but pose unique inspection challenges. Current inspection processes are highly manual, and as such are labor and schedule intensive. These needs can be better met with emerging technology such as sUAS (drones), computer vision, and machine learning. This work seeks to bring the drone based inspection workflow into production-ready status and integrate into existing facility inspections. This includes operation of a drone platform, establishing a photogrammetry pipeline, development of procedures and streamlining flight approval processes, and establishing a base of experience at Ames for this work. We have worked with the NFAC, unitary, and Arcjet facilities to identify use cases and have performed test flights at Ames (both indoors and outdoors). The system is being readied for incorporation into routine inspection operations.

David Daisuke Murakami

Effects of Autonomous sUAS Separation Methods on Subjective Workload, Situation Awareness, and Trust

The Unmanned Aircraft System (UAS) Traffic Management (UTM) concept was designed to support autonomous small UAS operations at a large-scale and without direct human intervention. However, human-autonomy interactions will be impacted by situation awareness, workload, and trust in the autonomy. Method: Nine participants monitored live small UAS operations in a representative UTM system during a series of traffic conflict scenarios and then provided subjective responses regarding situation awareness, workload, and trust in the autonomous separation method. The study employed a 3 (Separation Method: Autonomous Sense and Avoid, Geofence, Manual) × 2 (Incursion: High, Medium) within subjects design. Results: Situation awareness ratings for both autonomous separation methods were significantly lower than the manual condition. An interaction indicated differential workload ratings for the Autonomous Sense and Avoid separation ratings. Trust ratings significantly dropped when the Geofencing separation method failed. Conclusion: Subjective responses of remote operators in the UTM system are affected by the vehicle separation methods. Operators’ understanding of decisions made by the autonomous systems onboard the vehicle likely influence this effect

UAS

Measurements of TRACER pre-convective conditions and mesoscale circulations using small unmanned aircraft systems (sUAS)

Improved comprehension of the physical processes governing convective cloud formation and lifecycle are of critical importance for understanding and predicting future climate states. The influence of these clouds on the planetary energy budget, including on precipitation, is significant. Things are particularly complex in coastal regimes, where gradients in aerosol particle properties, localized circulations such as sea breezes, and large population centers are found. To date, numerical models struggle to accurately represent these critical clouds and are therefore challenged to provide a realistic view on the planetary energy budget. Through the proposed research, we deployed two uncrewed aircraft systems (UAS) equipped with a variety of instruments alongside sensors deployed by the US Department of Energy Atmospheric Radiation Measurement (ARM) program for the TRACER (Tracking Aerosol Convection Interactions Experiment) field campaign. The two small UAS platforms consisted of a CU RAAVEN fixed-wing airplane and an OU CopterSonde system, with the copter collecting frequent vertical profiles of thermodynamic and kinematic variables such as temperature, pressure, wind and humidity. At the same time, the fixed-wing captured horizontal gradients of these quantities and aerosol size distribution. These systems were deployed south of the Houston metro area, in an area that is impacted by the Gulf of Mexico sea breeze on a daily basis. These observations offer enhanced and complementary perspectives to those provided by the DOE ARM Mobile Facility (AMF) which is was deployed in southeast Houston, and an ancillary site in a more rural location west of the urban Houston area. Quality-controlled versions of the UAS data were collected and posted on the DOE ARM data archive after the conclusion of the campaign where they are accessible by the research community and general public. The UAS perspective offers revolutionary insight into key spatial and temporal effects that have not been evaluated previously.

54 ENVIRONMENTAL SCIENCES

Sua Pan surface bidirectional reflectance: a validation experiment of the Multi-angle Imaging SpectroRadiometer (MISR) during SAFARI 2000

The Southern Africa Regional Science Initiative (SAFARI 2000) dray deason campaign was carried out during August and September 2000 at the peak of biomass burning. The intensive ground-based and airborne measurements in this campaign provided a unique opportunity to validate space sensors, such as the Multi-angle Imaging SpectroRadiometer (MISR), onboard NASA's EOS Terra platform.

SAFARI

On the Use of Acoustic Wind Tunnel Data for the Simulation of sUAS Flyover Noise

Acoustic measurements of a small, unmanned aerial system were recently acquired during a ground test campaign. The purposes of the ground test, conducted in the NASA Langley Low Speed Aeroacoustic Wind Tunnel, were to characterize the source noise in terms of its tonal and broadband content, and to identify conditions under which multirotor and rotor-airframe interactions are present. The focus of this work is to assess the effectiveness of using those data for the simulation of flyover noise at a ground observer. The assessment is made at two levels of fidelity using different sets of tools. In the first, 1/3 octave band spectra at a ground receiver will be simulated in a frequency domain approach using the NASA Aircraft NOise Prediction Program. In the second, the pressure time history at a ground receiver is simulated in a time domain approach using the NASA Auralization Framework. Various objective measures are used to verify the simulation process. Acoustic wind tunnel and flight test data are used to gain insight into perceptually important effects.

Rizzi, Stephen A.