Proxflyer

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Proxflyer refers to a family of micro R/C helicopter prototypes based on a dual coaxial counter-rotating rotor concept developed and patented by Norwegian Petter Muren. The concept differs from the swashplate designs in conventional helicopter flight controls and enables a helicopter to be passively stable in hover. Elimination of the conventional cyclic and collective pitch controls allows for simpler and lighter helicopters to be developed. A helicopter based on this design achieves stability without the use of gyroscopes or any form of active stabilization and thus is made up of much fewer parts than other model helicopters. The two counter-rotating rotors keep the helicopter very stable relative to the surrounding air. Altitude control is performed by varying the speed for both main rotors while Yaw control is achieved by increasing the speed of one rotor and reducing the speed of the other rotor by the same amount. A horizontally oriented tail rotor controls the helicopter’s forward or backward movement by shifting its center of lift with respect to the center of gravity (CG).

Contents

Features and function

The Proxflyer co-axial rotor system utilize the combination of 3 features to achieve passive stability:

This combination of features enables the rotor to respond to aerodynamic forces and tilt in any direction without introducing mechanical bending forces between the rotor and the rotor shaft. At the same time it is possible to control the rotor by tilting the rotor shaft (helicopter) in the desired direction of flight. The forward speed is however limited because the rotors have a high tendency to tilt up to counteract any horizontal movement. The rotors increased tilting tendency is an important part of achieving passive stability but it at the same time makes it almost impossible to use this rotor system in a helicopter flying in anything but calm weather. The Proxflyer rotor system is designed for indoor use only and it is claimed to be the rotor system that enables the most stable yet controllable indoor helicopters.

The main benefits are believed to be:

The main limitations are:

Proxflyer Prototypes

DescriptionSizeWeightFlight DurationRadio ControlFirst Flight
Mosquito Twin-Tail
Rotor Dia. 360 mm130 grams20 mins4 Channel22 Jul 2004
Mosquito
Rotor Dia. 360 mm110 grams30 mins3 Channel1 Feb 2003
Microflyer
Rotor Dia. 128 mm7.8 grams10 mins3 Channel ; uses 210 Nov 2003
Nanoflyer
[]
Rotor Dia. 85 mm2.7 grams10 mins2 Channel IR4 Sep 2004
Picoflyer
Rotor Dia. 60 mm3.3 grams1 min3 Channel7 Aug 2005

Commercial products

The helicopters shown above are one-off prototypes built by Petter Muren. None of these helicopters are for sale, however, the Proxflyer rotor system is licensed to Interactive Toy Concepts. [1] The company’s R/C helicopters, which include Bladerunner and Micro Mosquito, [2] are all based on the Proxflyer rotor design. The Bladerunner is considered by some to be the first successful indoor R/C helicopter. Up until the beginning of 2007, the total number of toy helicopters produced using the Proxflyer rotor system is estimated to be about one million. Helicopters utilizing the Proxflyer rotor system are also used in some science projects around the world. [3] Petter Muren's designs were showcased as part of the 1st US-European MAV event in Garmisch Germany (MAV-05). [4] [5] [6]

See also

Related Research Articles

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References

  1. Interactive Toy Concepts
  2. Micro Mosquito from Gizmodo website
  3. UltraSwarm from University of Essex Archived October 8, 2006, at the Wayback Machine
  4. "@ero-mav.......all informations about MAV's for all users !".
  5. "Archived copy" (PDF). Archived from the original (PDF) on 2012-10-16. Retrieved 2013-01-08.{{cite web}}: CS1 maint: archived copy as title (link)
  6. "Proxflyer contents". Archived from the original on 2013-01-21. Retrieved 2013-01-08.