3rd US-European Competition and Workshop on Micro Air Vehicle Systems (MAV07) & European Micro Air Vehicle Conference and Flight Competition (EMAV2007), 17-21 September 2007, Toulouse, France
Advancement of the pedagogic mini-UAV project “Drone Cigogne” Renaud KIEFER Laboratoire des Systèmes Photoniques, INSA Strasbourg and Eric DESCOURVIERES Laboratoire d’Automatique de Besançon INSA de Strasbourg, 24 Bd de la victoire 67000 Strasbourg (France)
This paper presents the pedagogic project on a mini UAV system. It has begun in 2002 with the mini UAV competition organized by the DGA (general direction of armament) and the ONERA (National office of aerospace studies and research). We would like to present the new concept of our team which involves three parts: firstly The wing structure studies, moulds and structure conception, secondly the on-board electronic and Human Machine Interface (HMI) and at last a 3D with augmented reality system vision.
I.
Introduction
T
HIS student project began in September 2002 with the engineer students of Mechatronic. The “Drone cigogne” project was born by the annual project included in the Mechatronic section of the INSA de Strasbourg. The 2005 promotion of students obtain a subvention of 40000euros from the selection jury of university competition “Mini UAV” organized by the DGA and the ONERA. This subvention has made the very take of the project which becomes transversal within the different specialties of the school INSA de Strasbourg. The first prototype had an incline cylindrical wing shape and a central thermal motor (Figure 1). It is very stable even when it roll (without losing altitude) and flies at about 100 km/h and its design made its trajectory difficult to appreciate (Figure 2). The “Drone Cigogne” and its unexpected design brought back the first price of the contest “Drones Miniatures” to our team (first price ex-aequo with both teams of the Central Polytechnique de Paris and the INP Grenoble). Our team has bean prized on six mentions and was the best on two of them. For those reasons we won 8000 euros to continue the UAV development.
Figure 1: First prototype of our inclined cylindrical wing in fly
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3rd US-European Competition and Workshop on Micro Air Vehicle Systems (MAV07) & European Micro Air Vehicle Conference and Flight Competition (EMAV2007), 17-21 September 2007, Toulouse, France
Figure 2: Lateral view of our unusual UAV in flight during the competition In 2006 we have decided to develop a new structure with an elliptical shape and two electrical motors which could allow obtaining classical and VTOL flies. Electrical, Mechatronic, Plasturgy and Topography students work mainly on three different aspects that we would present in this article: Moulds and composite structure conception of a new structure, HMI and on board electronic, and the 3D vision with augmented reality.
II.
Moulds and composite structure conception
The necessity to produce a light and very resistant structure involves the plasturgy field of the school. They help us to develop the composite structure of the UAV. With regards to the fly results of the first prototype, we have decided to develop a new wing with an elliptical shape (Figure 3) but always incline as a biplane airplane. This shape would allow obtaining a best stability and handling, and reduce the vortex effect [1,2] due to the two lateral wings (Figure 4). We have design our wing by inspiring of a « pou du ciel airplane with jointed wings to reduce vortex. After that, the first thing was to validate our concept by using specific FEM simulation on CFDesign.
Figure 3: CAD view of the new prototype
Figure 4: Example of simulation allow to show on the cylindrical wing the reduce of Vortex effect without lateral small wings. After that validation we are actually developing the moulds by using MDF wood. The moulds, which include eight different parts, are conceived entirely in our school by the students. To obtain the final wing we have to proceed to several steps:
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3rd US-European Competition and Workshop on Micro Air Vehicle Systems (MAV07) & European Micro Air Vehicle Conference and Flight Competition (EMAV2007), 17-21 September 2007, Toulouse, France
- Master fabrication in MDF (numerical machining of the MDF, primer coating and sanding) - Moulds realization with fiber and carbon glass (Figure 5, 6 and 7) - Each part moulding - Positioning and assembling with precision Of course our UAV have a central fuselage which contain the main of electronic parts and the cameras system (for acquisition of a 3D video). Those parts are manufacturing with thermoforming plastic technology.
Figure 5: Fabrication steps of the wing
Figure 6: View of master of the top wing in MDF
Figure 7: Fiberglass moulds of the top wing before polishing
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3rd US-European Competition and Workshop on Micro Air Vehicle Systems (MAV07) & European Micro Air Vehicle Conference and Flight Competition (EMAV2007), 17-21 September 2007, Toulouse, France
III.
HMI and on board electronic
A. On board electronic In order to make, in the long term, the UAV totally autonomous we are developing the electronic associates with several sensors: Speed, altitude, positioning with GPS, inertial sensor. At the beginning, the heart of the drone was a microprocessor "ROVINTM". It had the advantage of an environment of development in C language, as well as a real time OS (up to 10 simultaneous tasks). Despite this fact, it has been proved that the "ROVIN" was not sufficient. Moreover, its limited input-outputs obliged us to use a PIC16F876 (Figure 8) from Microchip to manage the reception and the ordering of servomotors and a DSPic (Figure 9) to do the calculation for fly stabilization.
Figure 8: First CMS prototype of sensor card using a PIC16F876
Figure 9: Top and bottom views of the mother board card with the DSPic, serial and I2C interfaces and servos connectors In the future, two DSPic from Microchip would be in charge of the sensors and autonomous flight control respectively. DSPic allows us to centralize the data, as well as to reduce considerably the embarked electronics. The first and principal DSPic will recover information of the inertial power station and do the calculation of the stabilization parameters, and the other will managed the altitude, velocity and GPS sensors and send those different parameters to the ground station by a high power module of emission and to the principal DSPic by I2C protocol. B. Human machine interface
At the beginning of the project, all the information sent by the emission module was treated by a Labview interface (Figure 10). We are actually developing a specific HMI in C++/open GL (Figure 11), which allows to supervise the UAV attitude and space positioning. 4
3rd US-European Competition and Workshop on Micro Air Vehicle Systems (MAV07) & European Micro Air Vehicle Conference and Flight Competition (EMAV2007), 17-21 September 2007, Toulouse, France
Figure 10: The first Labview HMI interface
Figure 11: The new versatile HMI in C++/open GL
IV.
3D with augmented reality system vision
In order to facilitate the piloting, we have decided to conceive a 3D display system (Figure 12) using electronic glasses of 3D vision for video games. Used in an original manner, those could enable us to post what the UAV “sees” with 3D reconstruction by using two cameras which could move like eyes. We have also in optic to add different fly informations retransmitted such as the HUD (Head Up Display) systems by using the augmented reality that we work on at the LSP (Photonic Systems Laboratory).
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3rd US-European Competition and Workshop on Micro Air Vehicle Systems (MAV07) & European Micro Air Vehicle Conference and Flight Competition (EMAV2007), 17-21 September 2007, Toulouse, France
Figure 12: View of the pilot equipped of the 3D system vision with augmented reality
V.
Conclusion
This five years old pedagogic project have still being develop by more than one hundred students and more than ten teachers. The new team count forty students who are ambitious and really motivate. Therefore we will made everything we can to help them to go to the next session of the competition in order to confirm our first result. But the way is long until there. To allow our partners to follow our story, we often update our Website : http://www.insastrasbourg.fr/fr/drone-miniature/
References 1.« les tourbillons de sillage d’avions from Laurent Jacquin » on the Website : http://www.onera.fr/conferences/tourbillons-sillage/ 2. Joël Reneaux from Applied Aerodynamics Department of the ONERA, « OVERVIEW ON DRAG REDUCTION TECHNOLOGIES FOR CIVIL TRANSPORT AIRCRAFT », ECCOMAS, 24-28 July 2004, European Congress on Computational Methods in Applied Sciences and Engineering
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