Search NASASearch

SEARCH · Search NASA

Results for “detect and avoid”

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 127 records · Page 7

Procedures for the interpretation and use of elevation scanning laser/multi-sensor data for short range hazard detection and avoidance for an autonomous planetary rover

An autonomous roving science vehicle that relies on terrain data acquired by a hierarchy of sensors for navigation was one method of carrying out such a mission. The hierarchy of sensors included a short range sensor with sufficient resolution to detect every possible obstacle and with the ability to make fast and reliable terrain characterizations. A multilaser, multidetector triangulation system was proposed as a short range sensor. The general system was studied to determine its perception capabilities and limitations. A specific rover and low resolution sensor system was then considered. After studying the data obtained, a hazard detection algorithm was developed that accounts for all possible terrains given the sensor resolution. Computer simulation of the rover on various terrains was used to test the entire hazard detection system.

Troiani, N.

Test and Evaluation Metrics of Crew Decision-Making And Aircraft Attitude and Energy State Awareness

NASA has established a technical challenge, under the Aviation Safety Program, Vehicle Systems Safety Technologies project, to improve crew decision-making and response in complex situations. The specific objective of this challenge is to develop data and technologies which may increase a pilot's (crew's) ability to avoid, detect, and recover from adverse events that could otherwise result in accidents/incidents. Within this technical challenge, a cooperative industry-government research program has been established to develop innovative flight deck-based counter-measures that can improve the crew's ability to avoid, detect, mitigate, and recover from unsafe loss-of-aircraft state awareness - specifically, the loss of attitude awareness (i.e., Spatial Disorientation, SD) or the loss-of-energy state awareness (LESA). A critical component of this research is to develop specific and quantifiable metrics which identify decision-making and the decision-making influences during simulation and flight testing. This paper reviews existing metrics and methods for SD testing and criteria for establishing visual dominance. The development of Crew State Monitoring technologies - eye tracking and other psychophysiological - are also discussed as well as emerging new metrics for identifying channelized attention and excessive pilot workload, both of which have been shown to contribute to SD/LESA accidents or incidents.

Bailey, Randall E.

Windshear detection and avoidance - Airborne systems perspective

The generalized windshear hazard index presently defined is derived from aircraft-position wind data and remotely sensed data obtained along the extended flight path by such candidate sensor technologies as microwave Doppler radar, Doppler lidar, and IR radiometry. Attention is given here to the results of a comparative evaluation of CO2 and Ho:YAG lidar sensor-employing windshear-detection systems, over a range 1-3 km ahead of the aircraft (corresponding to 15-45 sec of warning time). While the technology for a 10.6-micron CO2 lidar system is available, an optimum 2-micron REE laser crystal-based system remains to be developed.

Bowles, Roland L.

Constraints on the Progenitor of SN 2010jl and Pre-existing Hot Dust in its Surrounding Medium

A search for the progenitor of SN 2010jl, an unusually luminous core-collapse supernova of Type IIn, using pre-explosion Hubble/WFPC2 and Spitzer/IRAC images of the region, yielded upper limits on the UV and near infrared (IR) fluxes from any candidate star. These upper limits constrain the luminosity and effective temperature of the progenitor, the mass of any pre-existing dust in its surrounding circumstellar medium (CSM), and dust proximity to the star. A lower limit on the CSM dust mass is required to hide a luminous progenitor from detection by Hubble. Upper limits on the CSM dust mass and constraints on its proximity to the star are set by requiring that the absorbed and reradiated IR emission not exceed the IRAC upper limits. Using the combined extinction-IR emission constraints, we present viable M(sub d)-R(sub 1) combinations, where M(sub d) and R(sub 1) are the CSM dust mass and its inner radius. These depend on the CSM outer radius, dust composition and grain size, and the properties of the progenitor. The results constrain the pre-supernova evolution of the progenitor, and the nature and origin of the observed post-explosion IR emission from SN 2010jl. In particular, an eta Car-type progenitor will require at least 4 mag of visual extinction to avoid detection by Hubble. This can be achieved with dust masses greater than approximately equal to 10(exp -3) solar mass (less than the estimated 0.2-0.5 solar mass around eta Car), which must be located at distances of greater than approximately equal to 10(exp 16) cm from the star to avoid detection by Spitzer.

Dwek, Eli

Lidar windshear detection and avoidance: Performance and technical assessment

The objective of this study is to evaluate competing lidars for use in an airborne forward-looking system to enable aircraft to avoid the hazards of low altitude wind shear. Information is presented in vugraph form on lidar general requirements, tentative technical requirements, comparison of velocity errors and signal to noise ratios in clear weather for 2.1 and 10.6 micron lidars, a wind shear display, and preliminary results.

Targ, Russell

The Autonomous Precision Landing and Hazard Detection and Avoidance Technology (ALHAT)

As NASA plans to send humans back to the Moon and develop a lunar outpost, technologies must be developed to place humans and cargo safely, precisely, repeatedly, on the lunar surface with the capability to avoid surface hazards. Exploration Space Architecture Study requirements include the need for global lunar surface access with safe, precise landing without lighting constraints on terrain that may have landing hazards for human scale landing vehicles. Landing accuracies of perhaps 1,000 meters for sortie crew missions to 10 s of meters for Outpost class missions are required. The Autonomous precision Landing Hazard Avoidance Technology (ALHAT) project will develop the new and unique descent and landing Guidance, Navigation and Control (GNC) hardware and software technologies necessary for these capabilities. The ALHAT project will qualify a lunar descent and landing GNC system to a Technology Readiness Level (TRL) of 6 capable of supporting lunar crewed, cargo, and robotic missions. The (ALHAT) development project was chartered by NASA Headquarters in October 2006. The initial effort to write a project plan and define an ALHAT Team was followed by a fairly aggressive research and analysis effort to determine what technologies existed that could be developed and applied to the lunar landing problems indicated above. This paper describes the project development, research, analysis and concept evolution that has occurred since the assignment of the project. This includes the areas of systems engineering, GNC, sensors, sensor algorithms, simulations, fielding testing, laboratory testing, Hardware-In-The-Loop testing, system avionics and system certification concepts.

Epp, Chirold D.

Joint Detect and Avoid Flight Testing

This presentation gives insight into a joint flight testing effort that included participation from NASA, Honeywell, and General Atomics. The presentation includes roles and responsibilities, test flow, and encounter requirements and summary.

flight tests

Implicitly Coordinated Detect and Avoid Capability for Safe Autonomous Operation of Small UAS

As the airspace becomes increasingly shared by autonomous small Unmanned Aerial Systems (UAS), there would be a pressing need for coordination strategies so that aircraft can safely and independently maneuver around obstacles, geofences, and traffic aircraft. Explicitly coordinating resolution strategies for small UAS would require additional components such as a reliable vehicle-to-vehicle communication infrastructure and standardized protocols for information exchange that could significantly increase the cost of deploying small UAS in a shared airspace. This paper explores a novel approach that enables multiple aircraft to implicitly coordinate their resolution maneuvers. By requiring all aircraft to execute the proposed approach deterministically, it is possible for all of them to implicitly agree on the region of airspace each will be occupying in a given time interval. The proposed approach lends itself to the construction of a suitable feedback mechanism that enables the real-time execution of an implicitly conflict-free path in a closed-loop manner dealing with uncertainties in aircraft speed. If a network infrastructure is available, the proposed approach can also exploit the benefits of explicit information.

Balachandran, Swee

UAS Integration in the NAS Project: Detect and Avoid Display UNITED Demo

This demo shows the UAS-NAS project's Vigilant Spirit Control Station developed in partnership with the U.S. Air Force Research Lab. Attendees will be able to view encounters and see how the DAA and TCAS II alerting and guidance displays are used to avoid simulated aircraft.

Roberts, Zachary

Detect and Avoid Timeline

This brief presentation provides a timeline for the steps taken by an unmanned aerial system (UAS) pilot when maneuvering to avoid a conflicting aircraft. This talk also provides time estimates for each step in the timeline utilizing 'measured response' data from previous Human Systems Integration Division simulation research.

Fern, Lisa

UAS Integration in the NAS Detect and Avoid Subproject: Kitty Hawk - NASA Collaboration Discussion

NASA is conducting research under the UAS Integration in the NAS Project to develop standards that will enable mid-size and large unmanned aircraft to fly unrestricted in the National Airspace System. As these efforts move into its second phase, NASA is planning a series of flight tests and demonstrations, integrating industry partners' technologies. These events will not only provide valuable data to inform the RTCA Special Committee 228 DAA and C2 MOPS, but also provide an opportunity for the UAS community to test their technologies in a realistic environment. An overview of NASA UAS-NAS research will be presented touching on human systems integration, modeling and simulation and guidance and control. Plans for Flight Test 6 and Systems Integration Operationalization (SIO) will also be presented. The purpose of this meeting is to share with Kitty Hawk, at a high level, UAS-NAS research and discuss potential future collaboration between NASA and Kitty Hawk.

Shively, Jay