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a vision based automatic landing method fro fixed wing uavs

Nov 18, 2014

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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

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Automatic landing method for fixed wing UAVs

Introduction A system for small-size, fixed-wing unmanned aerial vehicles (UAVs). 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.Department of EC 2

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.Department of EC 3

Automatic landing method for fixed wing UAVs

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 UAVs more accurately.

Department of EC

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Automatic landing method for fixed wing UAVs

Unmanned aerial vehicles(UAVs) 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.

Department of EC

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Automatic landing method for fixed wing UAVs

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).Department of EC 6

Automatic landing method for fixed wing UAVs

Description on the proposed approach

Department of EC

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Automatic landing method for fixed wing UAVs

Airframe and Avionics In this research we make use of BWB-based UAVs. 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.

Department of EC

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Automatic landing method for fixed wing UAVs

Blended-wing body (BWB) UAV Test bed

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Avionics hardware architecture

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Automatic landing method for fixed wing UAVs

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.

Department of EC

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Automatic landing method for fixed wing UAVs

Vision AlgorithmsThe proposed vision algorithm consists of: A color-based detection, A moment-based detection, and Visual servoing.

Proposed landing dome and recovery netDepartment of EC 12

Automatic landing method for fixed wing UAVs

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 domes color is the strongest visual cue. By making use of the moment invariant, specific target can be found.

Department of EC

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Automatic landing method for fixed wing UAVs

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 Hus method for high rate-detection for visual-based landing. Four image moments are used for detection Hus moment approach is applied to various red objects seen from space.Roof Hus moment 1 Hus moment 2 Hus moment 3 Hus moment 4 0.48560 0.18327 0.01701 0.00911 Road sign 0.20463 0.00071 0.00009 0.00028 Automobile 0.27423 0.04572 0.00193 0.00098 Landing Dome 0.21429 0.01806 0.00106 0.000

Hus moment value of various shapesDepartment of EC 14

Automatic landing method for fixed wing UAVs

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.15

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Automatic landing method for fixed wing UAVs

Visual servoing scheme:

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Automatic landing method for fixed wing UAVs

Sequence of images during landing to dome

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Fig. 4

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Automatic landing method for fixed wing UAVs

Sequence of images during landing to the recovery net

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Automatic landing method for fixed wing UAVs

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.

Department of EC

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Automatic landing method for fixed wing UAVs

References: www.wikipedia.org http://ieeeexplore.ieee.org/stamp/stamp.jsp?tp=&a rnumber=1057692 Intelligent robots and systems, 2007, IROS 2007. IEEE/RSJ international conference on. www.springerlink.com/index/80660XH9678W 1810 www.sciencedirect.comDepartment of EC 20

Thank you!

Department of EC

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