Robohub.org
 

Using 3D snapshots to control a small helicopter

by
30 September 2012



share this:

In the latest article in the Autonomous Robots journal, researchers from the Australian Defense Force Academy present a new control strategy for small flying robots that uses only vision and inertial sensors.

To control a flying robot, you usually need to know the attitude of the robot (roll, pitch, yaw), where it is in the horizontal plane (x,y), and how high it is from the ground (z). While attitude measurements are provided by inertial sensors on board the robot, most flying robots rely on GPS and additional range sensors such as ultra-sound sensors, lasers or radars to determine their position and altitude. GPS signal however is not always available in cluttered environments and can be jammed. Additional sensors increase the weight that needs to be carried by the robot. Instead Garratt et al. propose to replace position sensors with a single small, low cost camera.

By comparing a snapshot taken from a downward pointing camera and a reference snapshot taken at an earlier time, the robot is able to calculate its displacement in the horizontal plane. The loom of the image is used to calculate the change in altitude. Image loom corresponds to image expansion or contraction as can be seen in the images below. By reacting to these image displacements, the robot is able to control its position.

Grass as seen from altitudes of 0.25 m, 0.5 m, 1.0 m and 2.0 m (from left to right).

Using this strategy, the researchers were able to show in simulation that a helicopter could perform take-off, hover and the transition from low speed forward flight to hover. The ability to track horizontal and vertical displacements using 3D snapshots from a single camera was then confirmed in reality using a Vario XLC gas-turbine helicopter.

In the future, the authors intend to further test the 3D snapshot control strategy in flight using their Vario XLC helicopter before moving to smaller platforms such as an Asctec Pelican quadrotor. Additional challenges include taking into account the shadow of the robot, which might change position from snapshot to snapshot.

Source: Matthew A. Garratt, Andrew J. Lambert and Hamid Teimoori (2012) Design of a 3D snapshot based visual flight control system using a single camera in hover, Autonomous Robots.




Sabine Hauert is President of Robohub and Associate Professor at the Bristol Robotics Laboratory
Sabine Hauert is President of Robohub and Associate Professor at the Bristol Robotics Laboratory





Related posts :



Robot Talk Episode 64 – Rav Chunilal

In the latest episode of the Robot Talk podcast, Claire chatted to Rav Chunilal from Sellafield all about robotics and AI for nuclear decommissioning.
31 December 2023, by

AI holidays 2023

Thanks to those that sent and suggested AI and robotics-themed holiday videos, images, and stories. Here’s a sample to get you into the spirit this season....
31 December 2023, by and

Faced with dwindling bee colonies, scientists are arming queens with robots and smart hives

By Farshad Arvin, Martin Stefanec, and Tomas Krajnik Be it the news or the dwindling number of creatures hitting your windscreens, it will not have evaded you that the insect world in bad shape. ...
31 December 2023, by

Robot Talk Episode 63 – Ayse Kucukyilmaz

In the latest episode of the Robot Talk podcast, Claire chatted to Ayse Kucukyilmaz from the University of Nottingham about collaboration, conflict and failure in human-robot interactions.
31 December 2023, by

Interview with Dautzenberg Roman: #IROS2023 Best Paper Award on Mobile Manipulation sponsored by OMRON Sinic X Corp.

The award-winning author describe their work on an aerial robot which can exert large forces onto walls.
19 November 2023, by

Robot Talk Episode 62 – Jorvon Moss

In the latest episode of the Robot Talk podcast, Claire chatted to Jorvon (Odd-Jayy) Moss from Digikey about making robots at home, and robot design and aesthetics.
17 November 2023, by





©2024 - Association for the Understanding of Artificial Intelligence


 












©2021 - ROBOTS Association