6,949 research outputs found
PIXHAWK: A micro aerial vehicle design for autonomous flight using onboard computer vision
We describe a novel quadrotor Micro Air Vehicle (MAV) system that is designed to use computer vision algorithms within the flight control loop. The main contribution is a MAV system that is able to run both the vision-based flight control and stereo-vision-based obstacle detection parallelly on an embedded computer onboard the MAV. The system design features the integration of a powerful onboard computer and the synchronization of IMU-Vision measurements by hardware timestamping which allows tight integration of IMU measurements into the computer vision pipeline. We evaluate the accuracy of marker-based visual pose estimation for flight control and demonstrate marker-based autonomous flight including obstacle detection using stereo vision. We also show the benefits of our IMU-Vision synchronization for egomotion estimation in additional experiments where we use the synchronized measurements for pose estimation using the 2pt+gravity formulation of the PnP proble
Towards High-Performance Solid-State-LiDAR-Inertial Odometry and Mapping
We present a novel tightly-coupled LiDAR-inertial odometry and mapping scheme
for both solid-state and mechanical LiDARs. As frontend, a feature-based
lightweight LiDAR odometry provides fast motion estimates for adaptive keyframe
selection. As backend, a hierarchical keyframe-based sliding window
optimization is performed through marginalization for directly fusing IMU and
LiDAR measurements. For the Livox Horizon, a newly released solid-state LiDAR,
a novel feature extraction method is proposed to handle its irregular scan
pattern during preprocessing. LiLi-OM (Livox LiDAR-inertial odometry and
mapping) is real-time capable and achieves superior accuracy over
state-of-the-art systems for both LiDAR types on public data sets of mechanical
LiDARs and in experiments using the Livox Horizon. Source code and recorded
experimental data sets are available on Github.Comment: 15 page
Index to 1984 NASA Tech Briefs, volume 9, numbers 1-4
Short announcements of new technology derived from the R&D activities of NASA are presented. These briefs emphasize information considered likely to be transferrable across industrial, regional, or disciplinary lines and are issued to encourage commercial application. This index for 1984 Tech B Briefs contains abstracts and four indexes: subject, personal author, originating center, and Tech Brief Number. The following areas are covered: electronic components and circuits, electronic systems, physical sciences, materials, life sciences, mechanics, machinery, fabrication technology, and mathematics and information sciences
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