a vision based automatic landing method fro fixed wing uavs
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A Vision-Based Automatic Landing Method For Fixed-Wing Unmanned Aerial Vehicles
Name:
Sahana Sridhar
1SG06EC064
Guided by:
Mrs.Shobha.K
Mrs.Padmavathi.H
Department of EC 1
Introduction
• A system for small-size, fixed-wing unmanned aerial
vehicles (UAV’s).
• Based on vision in front of the vehicle.
• Visual servoing algorithm is used to improve accuracy
of the landing
• Color- and moment-based target detection.
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Automatic landing method for fixed wing UAVs
Manual landing
• Landing is the most accident-prone stage airplanes.
• Pilot obtains visual info by naked eyes live images taken by onboard cameras.
• Piloting outside needs lot of practice.
• Nearly 70% of mishaps and 50% of fixed-wing UAVs such as Hunter and Pioneer suffer accidents during landing.
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Automatic landing method for fixed wing UAVs
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Vision-based Automatic landing
• A camera and a vision processing unit onboard.
• Detects the runway or other visual markers.
• Guide the vehicle to the touchdown point with good accuracy.
• Automatic landing systems control velocity of UAV’s more accurately.
Automatic landing method for fixed wing UAVs
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• UAVs fly without onboard pilots.
• They have become increasingly popular in military operations.
• UAVs use energy-absorption technique.
• These are simple and they use high rate of survivability.
Unmanned aerial vehicles(UAVs)
Automatic landing method for fixed wing UAVs
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System Description
• Proposed landing system consists of three
major components:
Inflated dome as a visual marker,
A vision processing unit,
Flight controller using visual servoing algorithm.
• Vision system is integrated with an MEMS based inertial
measurement unit (IMU).
Automatic landing method for fixed wing UAVs
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Description on the proposed approach
Automatic landing method for fixed wing UAVs
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Airframe and Avionics
• In this research we make use of BWB-based UAV’s.
• BWB has only 2 control surfaces at the trailing edge know as elevons.
• The fuselage houses the flight computer, IMU, battery and radio receiver, also vehicle has a DC motor.
•The vehicle is resistant to shocks and crashes.
Automatic landing method for fixed wing UAVs
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Blended-wing body (BWB) UAV Test bed
Automatic landing method for fixed wing UAVs
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Avionics hardware architecture
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Landing equipment
• An arresting device is needed.
We propose a dome-shaped air bag.
• The dome is constructed with sturdy nylon of red color.
• The vehicle would simply fly into the dome at low speed with a reasonable incident angle.
• Dome serves as visual cue and recovery net is responsible for arresting the vehicle.
Automatic landing method for fixed wing UAVs
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Vision Algorithms The proposed vision algorithm consists of:A color-based detection,A moment-based detection, and Visual servoing.
Proposed landing dome and recovery net
Automatic landing method for fixed wing UAVs
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Color-based target detection
• Color can provide an efficient vision.
• It can identify the target color regions with faster speeds.
• Good results are obtained under good lighting conditions.
• The dome’s color is the strongest visual cue.
• By making use of the moment invariant, specific target can be
found.
Automatic landing method for fixed wing UAVs
Roof Road sign Automobile Landing Dome
Hu’s moment 1 0.48560 0.20463 0.27423 0.21429
Hu’s moment 2 0.18327 0.00071 0.04572 0.01806
Hu’s moment 3 0.01701 0.00009 0.00193 0.00106
Hu’s moment 4 0.00911 0.00028 0.00098 0.000
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Moment based target detection:
• Multiple red objects are found by color based detection.
• Now it is required to determine whether the object is the landing dome or not.
• We use Hu’s method for high rate-detection for visual-based landing.
Four image moments are used for detection
Hu’s moment approach is applied to various red objects seen from space.
Hu’s moment value of various shapes
Automatic landing method for fixed wing UAVs
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Visual servoing:
• Is a method to control a robot using computer vision.
• Can be applied to the fixed-wing UAV.
• Landing dome from the center of the image represents the heading
and pitch deviation.
• When the heading and pitch angle errors are zero the vehicle flies
directly to the landing dome.
• The heading and pitch angle deviations are sent to the heading and
pitch angle controllers.
Automatic landing method for fixed wing UAVs
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Visual servoing scheme:
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Fig.1 Fig. 2
Fig. 3 Fig. 4
Sequence of images during landing to domeAutomatic landing method for fixed wing UAVs
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Sequence of images during landing to the recovery netAutomatic landing method for fixed wing UAVs
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Conclusion
• The domes distinctive color and shape provides a visual cue to
vision system without any mistakes.
• The vision algorithm detects the landing dome.
• Navigation sensors cannot provide accurate solutions, visual
servoing is implemented.
• The idea shows that the system is a viable approach for landing.
Automatic landing method for fixed wing UAVs
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References:
• www.wikipedia.org
• http://ieeeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=1057692
• Intelligent robots and systems, 2007, IROS 2007. IEEE/RSJ international conference on.
• www.springerlink.com/index/80660XH9678W1810
• www.sciencedirect.com
Automatic landing method for fixed wing UAVs
Thank you!
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