scholarly journals Velocity dependence of optic flow strategy for steering and obstacle avoidance

2010 ◽  
Vol 2 (7) ◽  
pp. 430-430
Author(s):  
P. W. Fink ◽  
W. Warren
Keyword(s):  
Obstacle Avoidance ◽  
Optic Flow ◽  
Velocity Dependence

scholarly journals Budgerigars adopt robust, but idiosyncratic flight paths

2019 ◽  
Author(s):  
Debajyoti Karmaker ◽  
Ingo Schiffner ◽  
Mandyam V. Srinivasan
Keyword(s):  
Detailed Analysis ◽  
Obstacle Avoidance ◽  
Optic Flow ◽  
High Speed ◽  
Care Needs ◽  
Maximum Value ◽  
High Propensity ◽  
Avoidance Manoeuvre ◽  
Minimal Deviation ◽  
Flight Trajectories

AbstractWe have investigated the paths taken by Budgerigars while flying in a tunnel. The preferred flight trajectories of nine Budgerigars (Melopsittacus undulatus) were reconstructed in 3D from high speed stereo videography of their flights in an obstacle-free tunnel. Individual birds displayed highly idiosyncratic flight trajectories that were consistent from flight to flight over the course of several months. We then investigated the robustness of each bird’s trajectory by interposing a disk-shaped obstacle in its preferred flight path. We found that each bird continued to fly along its preferred trajectory up to a point very close to the obstacle before veering away rapidly, making a minimal deviation to avoid a collision, and subsequently returning to its original path. Thus, Budgerigars show a high propensity to stick to their individual, preferred flight paths even when confronted with a clearly visible obstacle, and do not adopt a substantially different, safer route. Detailed analysis of the last-minute avoidance manoeuvre suggests that a collision is avoided by restricting the magnitude of the optic flow generated by the obstacle to a maximum value of about 700 deg/sec. The robust preference for idiosyncratic flight paths, and the tendency to pass obstacles by flying above them, provide new insights into the strategies that underpin obstacle avoidance in birds. It could also have wide-ranging implications for conservation efforts to mitigate collisions of birds with man-made obstacles – especially obstacles that are poorly visible, such as wind turbines or buildings with glass facades. Our findings indicate that care needs to be exercised to ensure that newly planned structures are not located near major bird flyways, wherever possible, and to ensure that the positioning takes into consideration the cues and behaviours that birds use to avoid such obstacles.

scholarly journals Through hawks' eyes: reconstructing a bird's visual field in flight to study gaze strategy and attention during perching and obstacle avoidance

2021 ◽  
Author(s):  
Sofia Minano ◽  
Graham K Taylor
Keyword(s):  
Visual Field ◽  
Visual Attention ◽  
Obstacle Avoidance ◽  
Motion Capture ◽  
Optic Flow ◽  
Visual Cues ◽  
Small Subset ◽  
Depth Information ◽  
Motion Capture Data ◽  
Full Dataset

We present a method to analyse visual attention of a bird in flight, that combines motion capture data with renderings from virtual cameras. We applied it to a small subset of a larger dataset of perching and obstacle avoidance manoeuvres, and studied visual field stabilisation and gaze shifts. Our approach allows us to synthesise visual cues available to the bird during flight, such as depth information and optic flow, which can lead to novel insights into the bird's gaze strategy in flight. This preliminary work demonstrates the method and suggests several new hypotheses to investigate with the full dataset.

Adjustable linear models for optic flow based obstacle avoidance

2013 ◽  
Vol 117 (6) ◽  
pp. 603-619 ◽  
Author(s):  
Manuela Chessa ◽  
Fabio Solari ◽  
Silvio P. Sabatini
Keyword(s):  
Obstacle Avoidance ◽  
Optic Flow ◽  
Linear Models

scholarly journals Optic Flow Contribution to Locomotion Adjustments in Obstacle Avoidance

Motor Control ◽  
2012 ◽  
Vol 16 (4) ◽  
pp. 506-520 ◽  
Author(s):  
Marcos Rodrigo Trindade Pinheiro Menuchi ◽  
Lilian Teresa Bucken Gobbi
Keyword(s):  
Obstacle Avoidance ◽  
Optic Flow

scholarly journals Optic Flow Based Autopilots: Speed Control and Obstacle Avoidance

2009 ◽  
pp. 29-50 ◽  
Author(s):  
Nicolas Franceschini ◽  
Franck Ruffier ◽  
Julien Serres
Keyword(s):  
Obstacle Avoidance ◽  
Optic Flow ◽  
Speed Control

Vision-based navigation using multi-rate feedback from optic flow and scene reconstruction

2011 ◽  
Vol 115 (1169) ◽  
pp. 411-420 ◽  
Author(s):  
A. R. Arvai ◽  
J. J. Kehoe ◽  
R. Lind
Keyword(s):  
Path Planning ◽  
Obstacle Avoidance ◽  
Optic Flow ◽  
Slow Rate ◽  
Fast Rate ◽  
Autonomous Systems ◽  
Computational Cost ◽  
Scene Reconstruction ◽  
Wide Range ◽  
Switch Element

AbstractVision-based control is being aggressively pursued for autonomous systems. Such control is particularly valuable for path planning to achieve mission objectives like target tracking and obstacle avoidance. This paper presents a multi-rate strategy that utilises a fast-rate optic flow approach and a slow-rate scene reconstruction approach. The vehicle uses scene reconstruction to generate an accurate map for path planning; however, optic flow is used to avoid obstacles while the scene reconstruction is computed. A switch element is used in the feedback path to determine whether information relating to the reconstructed map or the optical flow should be used for navigation. The resulting controller is able to generate flight trajectories and perform obstacle avoidance within a computational cost which is reasonable given performance demands and computational resources on a wide range of aircraft. A simulation demonstrates the performance of an aircraft that uses the multi-rate controller to avoid an obstacle which is only observed after a turn. Essentially, the fast-rate optic flow indicates the presence of the obstacle during the time that slow-rate scene reconstruction is being performed. The resulting flight path is able to follow mission objectives and avoid a collision.

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