Tuesday, December 23, 2014

‘BOTS: The Insectothopter – The First Miniature Unmanned Aerial Vehicle

4 September 2014


The Insectothopter

THE RUMOR

            There is rumor about a flying robot.  At recent political events in Washington D.C. and New York, several people said they saw something that they described as a cross between a slightly over-sized dragonfly and a miniature helicopter.  Maybe these reporters mistook real insects for robots . . . or maybe not.  [1]

            There are no insect-sized UAV’s.  The smallest is a bird-sized 'bot -- the Nano Hummingbird.  Formally named, the “Nano Air Vehicle” (“NAV”), this bird 'bot was developed, in 2011, by AeroVironment, Inc. under the direction of DARPA


"Nano Air Vehicle" or Robo-Hummingerbird

THE PROBLEM IS FLIGHT

            So, if you want an insect-sized robot, why not just shrink Robo-Hummer down to the size of an insect? 

            The problem is flight.

            With robotic insects, flight itself is the biggest challenge.  While bird-sized flying drones are now being developed with relative success, flying insect ‘bots present a special aerodynamic problem.  It’s the size.  If you shrink a bird-sized drone down to the size of an insect -- it won’t fly. 

            A roboticist at the University of California at Berkeley, Ronald Fearing, told the Washington Post that “the rules of aerodynamics change” with an object as small as an insect.  [2] Unlike bird wings, insect-sized wings must move with amazing precision. 

            Replicating these precise wing movements is a major engineering challenge.  In fact, scientists only recently came to understand how insects fly at all.  Compounding the problem, these precision wing movements require yet larger supplies of portable power.  [3]

SOME HISTORY

            While robotic insect flight, in reality, has yet to be mastered by modern technologists, in science fiction, the technology was mastered in 1936 in Raymond Z. Gallun’s The Scarab.  Gallun’s robotic beetle flew like any other insect, but transmitted to its “manipulator” what it heard and saw through its “ear microphones” and “minute vision tubes.”

            Philip K. Dick refers to a commercial robotic fly in his novel, The Simulacra.

            Fast forward to the 1970’s.  America’s CIA (Central Intelligence Agency) had developed an eavesdropping (listening) device, but needed a way to use it.  In other words, the agency needed a way to “deliver” it to a target location.  Needless to say, the delivery had be unnoticed if the device was to serve its purpose.


Insectothopter

THE FIRST MINI UAV

            An insect-sized mini UAV seemed ideal.  And, of course, making the UAV look like an actual insect solved another problem - camouflage.  It wasn't enough to get the listening device to the target.  The target must, also, not know that the device was there.  

            At first, the bumblebee was to be the model for the mini UAV, but this insect was rejected due to its erratic flight.  One project member, reasonably familiar with insects, suggested the dragonfly.  This proved to be the almost perfect solution.

            One has to admire the simple ingenuity that went into the construction of what would become the Insectothopter.  Even with all the grants and theoretical computer models of today, the development of an insect sized drone remains in the future.   Yet, in the 1970’s, a group of project technologists just did it – in rather short order. 

            Today, we are just learning exactly how insects manage to fly.  But the CIA technologists of the 1970’s didn’t bother with the science true insect flight.  Instead, they just designed a set of wings with up and down movements that gave the Insectothopter both lift and thrust.

            Today, the development of a light, yet powerful, propulsion system for small drones remains a daunting task.  But in those far off days of the 1970’s, the CIA technologists simply used a gasoline engine to power the Insectothopter.  Certainly, the engine was loud, but the project members had selected their "model" insect well.  Have you ever heard a dragonfly in flight?  The gasoline engine probably made less noise than the real flying dragonfly. 

            But how could you design a gasoline (or any other kind of) engine that small?  Today, it would require a staggering amount of dollar grants and a consortium of research facilities to design a computer simulated prototype.  But, in the 1970’s, you just found a good watchmaker.  And project did just that. 

            The result was a miniature oscillating engine that would make the wings beat.  A fuel bladder carried the engine's liquid propellant.  Not only did the liquid propellant power the engine, but the excess gas was vented out the rear of the mini UAV, giving the Insectothopter added thrust.  The Insectothopter was directed using a laser beam and, finally, was hand-painted to look like a dragonfly.


Insectothopter

            But the insectothopter never made it into the field.  It’s downfall was its inability to withstand cross-drafts.  Real insects can drift a bit with the wind, but the operator of a surveillance drone must be able to direct it to a target if any meaningful surveillance is to take place.  Only a five mile per hour crosswind would throw the insectothopter off course.

            Today, the smallest operational UAV is AeroVironment’s “Nano Air Vehicle” (“NAV”).  With the story of the Insectothopter in mind, it’s easier to understand why DARPA’s project specifications for that project required that the “Nano Air Vehicle” demonstrate the ability to hover in a 5 mph side-wind without drift of more than one meter.


"Nano Air Vehicle" or Robo-Hummingerbird

THE END?

            So, with the retirement of the Insectothopter, the development of robotic insects ended -- only reappearing with the modern resurgence of robotic research. 

            But remember those recent political events in Washington D.C. and New York, at which several persons said they saw something that they described as a cross between a slightly over-sized dragonfly and a miniature helicopter.  Maybe these reporters mistook real insects for robots . . . or maybe not.

            Is it possible that the CIA secretly continued to develop insect drones?

            Has some U.S. Government agency developed a secret, advanced version of the Insectothopter?  Sources at the CIA have declined to comment.  When questioned about the possibility of the secret development of flying drone insects, an “expert in unmanned aerial vehicles,” retired Colonel Tom Ehrhard, simply said, "America can be pretty sneaky.”  [4]

 

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