Engineering topics

Barreiro, Javier

Publications and source records attributed to Barreiro, Javier.

3 records

NASA NTRS2014

Intelligent UAS Sense-and-Avoid Utilizing Global Constraints

Sense-and-avoid (SAA) is a critical research topic for enabling the operation of Unmanned Aircraft Systems (UAS) in civilian airspace. SAA involves two planning related problems: 1) plan-recognition to predict the future trajectory of nearby aircraft, and 2) path planning to avoid conflicts with nearby aircraft that pose a threat. We have designed and built components of a novel intelligent sense-and-avoid (iSAA) reasoning framework that takes into account information about aircraft type, transponder code, communications, local routes, airports, airspace, terrain, and weather to more accurately predict near- and medium-term trajectories of nearby aircraft. By using this additional information both the on-board control software and the ground-based UAS operator can make more informed, intelligent decisions to effectively predict and avoid conflicts and maintain separation. While this capability benefits all categories of UASs operating under both Instrument Flight Rules (IFR) and Visual Flight Rules (VFR), it is absolutely essential for allowing smaller UASs to operate VFR at low altitude in uncontrolled airspace for operations such as survey work, wildlife tracking, aerial photography, utilities inspection, crop dusting, and package delivery.

unmanned aircraft systems↗

NASA NTRS2009

Peer-to-Peer Planning for Space Mission Control

Planning and scheduling for space operations entails the development of applications that embed intimate domain knowledge of distinct areas of mission control, while allowing for significant collaboration among them. The separation is useful because of differences in the planning problem, solution methods, and frequencies of replanning that arise in the different disciplines. For example, planning the activities of human spaceflight crews requires some reasoning about all spacecraft resources at timescales of minutes or seconds, and is subject to considerable volatility. Detailed power planning requires managing the complex interplay of power consumption and production, involves very different classes of constraints and preferences, but once plans are generated they are relatively stable.

Barreiro, Javier↗

NASA NTRS2008

ATHLETE's Feet: Mu1ti-Resolution Planning for a Hexapod Robot

ATHLETE is a large six-legged tele-operated robot. Each foot is a wheel; travel can be achieved by walking, rolling, or some combination of the two. Operators control ATHLETE by selecting parameterized commands from a command dictionary. While rolling can be done efficiently with a single command, any motion involving steps is cumbersome - walking a few meters through difficult terrain can take hours. Our goal is to improve operator efficiency by automatically generating sequences of motion commands. There is increasing uncertainty regarding ATHLETE s actual configuration over time and decreasing quality of terrain data farther away from the current position. This, combined with the complexity that results from 36 degrees of kinematic freedom, led to an architecture that interleaves planning and execution at multiple levels, ranging from traditional configuration space motion planning algorithms for immediate moves to higher level task and path planning algorithms for overall travel. The modularity of the architecture also simplifies the development process and allows the operator to interact with and control the system at varying levels of autonomy depending on terrain and need.

Smith, Tristan B.↗