The idea of using wings as a solution to climbing walls is based on research done by Kenneth Dial on wing-assisted incline running--a natural behavior exhibited by chukar partridges.
Click here to see video of wing-assisted incline running

• Related stuff: PerchingPapers

Propellers

Early trials investigating the potential for adapting this idea for robotic use were concieved by Moto and involved a propeller mounted at 45 degrees to a platform matted with a rubber backing.

Initial prototyping has shown that using a 400 speed motor and simple hobby shop propeller, significant normal force may be generated to hold the prototype on a board at an 80 degree angle. Further development of this idea was based on improving the thrust to weight ratio. Aside from obtaining a better motor (possibly an IC engine?) our initial thought was to build a duct to direct the thrust, since specs of manufactured propellers with ducts indicate that such ducts improve thrust values by 50 percent. Yet, the duct we built for our propeller decreased thrust. Due to the design of the propellor, instead of eliminating vortices at the edge of the slipstream, our duct was merely constricting flow. While industrially manufactured ducts eliminate this problem, there is often a large trade off due to their large weight. A compairison of attributes of existing motors and fans is presented below.

Ornithopters

A new direction suggested by Prof. Cutkosky involves the use of wings rather than propellers. Ornithopters are not only more biomimetic than model planes, but when adapted for wall climbing they may take advantage of ground effects, creating forces directed into the climbing wall.

Toys

	The Original Tim Flying Bird	Kinkade RC Ornithopter
Images
Weight	16g	425g
Wing span	14 in	48in
Max flight time	7sec	9min
Power source	rubber band	Speed 300 motor & 8-cell, 720 mah NiMH? battery
Manufacturer	Schylling	Sean Kinkade

Existing Research

• Birds
  • Flight Laboratory, Dial (U of Montana)
• Insects
  • Micromechanical Flying Insect (MFI) Project, Fearing (Berkeley, CA)
• Ornithopter Design
  • Microbat: A Palm-Sized Electrically Powered Ornithopter

Objectives

• Study dynamics of flight in insects, bats, and birds and its applications in ornithopters
• Use research to devise "thrust backpack" for GumbyBot
• Optimize thrust source for weight and energy constraints

Experiments

• What is the dynamic variance of thrust over time?
  • What direction does thrust need to be in order to maintain flight, and how is this manifested through linkage system/wing membrane?

Quantification of thrust via load cell
	order load cell construct setup install motor in Tim Bird measure periodic variance in thrust, overall force compare vertical, horizontal components how might thrust be optimized for climbing walls by increasing complexity of wing movement? how is wing movement coordinated with foot movement? (email Dial/Full?)

Interaction between Thrust and Drive
	measurements performed with and without wing thrust on pull-back motor driven vehicle average velocity over flat surface max angle without slipping

Load Cell Ordering Info

• Futek Fr1020 Planar Beam Force Sensor
  • item number: FP10006-00005-C
  • load capacity: 0.06 lb
  • price: $90
• FR1020 Mounting Kit
  • item number: F1020
  • price: $35.00
• Company info
  • FUTEK Advanced Sensor Technology--10 Thomas, Irvine, CA 92618 USA
  • Phone: (949) 465-0900  Fax: (949) 465-0905 Email: futek@futek.com

-- TiffanyCard? - 23 Jun 2003

Regarding ground effects, etc. -- what we want is sort of like an inverse hovercraft or a high-efficiency vacuum cleaner. Most vacuum cleaners use a centrifugal impeller, rather than fan. I suspect that is for compactness as opposed to efficiency. It might be worthwhile to see what a high-end (industrial?) Dustbuster uses. This might be designed for efficiency given that battery life is always a problem...
So here's one that claims superior battery life (look at impeller design in cross section)

A second point is that we may ultimately want to use wings so that we can have periodic thrust that is timed with front foot placement. Wings also benefit from ground effects (large transient suction as you lift an airfoil up from a flat surface). -- MarkCutkosky - 24 Jun 2003

-- MarkCutkosky - 13 Aug 2003
The closest functional equivalent to the Partridge is now: Lego Guy Plus movie (.avi) on LegPlatformDevelopment page.

• BiomimSumm.ppt: Summary of Tiffany's summer research and analysis