Download MAV Lecture - Fulton Student Organizations

MAE 598 – Special
Topics
Micro Air Vehicles
Lecture 2
Dr. Armando Rodriguez, Professor
Department of Electrical Engineering
Fulton School of Engineering
Arizona State University
Tempe, AZ
http://www.eas.asu.edu/∼aar/
[email protected]
Contributors
Michael Thompson, Graduate Student, School of Engineering Matter, Transport, and Energy, AIAA member
John S Burnett, Graduate Research Engineer-Vehicle designer
Ivan Ramirez, Undergraduate Student, School of Civil, Environmental and Sustainable Engineering,
Deyzi Ixtabalan, Undergraduate Student, School of Engineering Matter, Transport, and Energy, AIAA member
Outline
Motivation
State of The Art: Prior and Current Efforts
Fundamental Issues and Challenges
― Sample CFD Dynamic Mesh Model for Dynamic Wing
―Equations of Motion and Free Body Diagrams
― Static and Dynamic Analysis
― Control Design
― Non-linear Issues
Summary and Conclusions
Motivation
Dynamic wing vehicles represent a leap in micro and nano-scale aerial vehicle
design due to their size, agility and ability to carry small payloads such as
surveillance equipment
Vehicles that have hovering capabilities and can move at high velocity to a
target efficiently are more desirable than the separate class vehicles such as
slow moving 4-rotor MAV’s and a flapping bird MAV’s that requires foreword
velocity to remain aloft
Emphasis: Omnithopter, Capabilities include high foreword velocity and hover
capability
Issue: Model stabilities in both hover and foreword flight. Requires
development of a suitable control system. PID controls for attitude stability are
most crucial. Torque from the rotor system needs to be available for forward
flight
State of The Art
State of the Art: Programs
1996-2000 – DARPA funding of Micro Air Vehicles
◦ DARPA Program initiative - develop and test technologies for
mission capable flight system
◦ Only requirement –dimension of vehicle should not exceed
15 cm
2004 – 2005 – DARPA’s Goals
◦ integrate MAV technologies into militarily back packable
systems for soldier, marine, and special-forces missions.
2009 – AeroVironment
◦ NAV program – Nano hummingbird, while not especially
small, was a huge breakthrough in MAV ornithopter research
because of its gyroscopically stabilized flight without any tail
surfaces.
◦ 19 gram, 16cm wing span
◦ “will stretch our understanding of flight at these small sizes
and require novel technology development.” Dr. Todd Hylton,
DARPA program manager.
2012 – The Netherlands-Delft University of Technology
◦ Delfly II. 16 gram, 28 cm wing span
2012 – ASU Omnithopter- Arizona State University
◦ Omnithopter. 90 gram, 39 cm wing span
Prior and Ongoing Work
1999- H. M. Blackburn, R.D. Henderson. "A study of two-dimensional flow past an oscillating
cylinder" J. Fluid Mech. Cambridge University.
2007 - Berman, Gordon J. and Z. Jane Wang. “Energy-minimizing kinematics in hovering insect
flight.” J. Cambridge University.
2007-Katherine Sarah Shigeoka, University of Utah, "Velocity and Altitude Control of an
Ornithopter Micro Aerial Vehicle.“
2009- Michael A. Bolender, U. S. Air Force Research Laboratory, "Rigid Multi-Body Equations of
Motion for Flapping Wing MAVs Using Kanes Equations“.
2011-2012- ASU MAV Research team
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Computational Dynamic Mesh for simulation of flapping wing & Control system dynamics for MAV’s.
6-DOF ornithopter,
Electric motor driven axial wing articulation system,
Aileron/elevator (ailevator) control within the advancing wing rotor system,
CG shifting (pendulum) for roll stability.
Sample Engineering Model
Overview of Model
Demonstrating the effects of
the oscillating cylinder with
an amplitude of 0.25,
frequency is 0.89 Hz.
Video of the Oscillating cylinder CFD
simulation
https://www.youtube.com/watch?v=gJ23DopzUc&feature=player_embedded
Drag Profile for Oscillating Cylinder
Drag coefficient Vs. Time
Trend lines for the oscillating
cylinder.
Drag coefficient Vs. Time for the
oscillating cylinder from Blackburn
and Henderson.
Dynamic Mesh
Dynamic mesh of the oscillating cylinder moving up and down
• Amplitude ratio of 0.5
• Amplitude ratio = ymax/D,
• D is the diamter = 1, ymax = maximum displacement of the simple harmonic crossflow oscillation = 0.5
• Frequencies, fo, approximately 0.2.
• F is the frequency ratio, F= fo/fv
• fv is the fixed-cylinder vortex shedding frequency
• fo is the frequency of the cylinder cross-flow oscillation
Boundary Conditions
Wind Tunnel Testing
Wind Tunnel Testing of Avitron
https://www.youtube.com/watch?v=ccpLl4Uoj5w
Wind Tunnel Test Data Analysis
Drag versus Velocity of Avitron
Bird. Zero degrees and five
degrees AOA Gliding and Flapping
mode
Velocity vs. Lift of Avitron Bird.
Zero degrees and five degrees
AOA Gliding and Flapping mode
Wing geometry in Matlab and the actual wing of
Avitron and Omnithopter
• AVITRON AREA= 9.69 CM2 , WING SPAN =33CM
• OMNITHOPTER WING AREA = 8.9 CM2 ,WING SPAN =39CM
Equations of Motion and Free Body Diagrams
Fundamentals of hovering for Omnithopter
Velocity of wing (Linear)

Drag due to mass of the vehicle
and area of the wing

Resistive force of wing

Lift due to resistive force

Power Required to produce Lift 
1D Control Motion in the vertical direction:
FW=Thrust
F1=Force of wing
By= vertical damping of the ornithopter
Y=displacement
F2=Accel force of vehicle in space
Mg=Weight of vehicle