Micro Air Vehicles
Micro Air Vehicles (MAVs) are a relatively new class of flying craft that are attracting interest from a broad spectrum of users spanning soldiers to children.
The Wright brothers maintained that the most difficult obstacle to powered flight wasn't generating sufficient lift or propulsion, but that maintaining control of a craft in 3 dimensions was the real challenge. Their solution was to incorporate aerodynamic devices (rudder, elevator and wing warping), whose modern day equivalents can be found on virtually all subsequent airplanes, controlled by a pilot.
The relentless pace of electronic and software advances have allowed pilots to leave the cockpit and control airplanes, known as Unmanned Aerial Vehicles (UAVs), from the safety of the ground. The real story of increased electronic processing power is about miniaturization, aptly summarized by Moore's Law, whereby the number of transistors on a chip doubles every 18 months – although in reality it's more like 24 months. The miniaturization of avionic controls has encouraged a new class of flying craft to be viable known as Micro Air Vehicles (MAVs), which are typically considered to be less than 6 inches (150mm) in length and weight just a few ounces (100s of grams).
The low Reynolds number, laminar flow aerodynamics of MAVs resembles that of insects and birds more than the traditional human piloted craft we are familiar with. Therefore it should come as no surprise that the designers of MAVs have used nature for inspiration. So alongside traditional fixed wing and helicopter derived MAVs you'll also see flapping winged MAVs known as ornithopters. Control of ornithopters in flight is difficult and is an ongoing area of research.
As is the tradition for aerial vehicle development dating back to the Wright brothers, competition is also viewed as a catalyst for MAV innovation. A joint US-European MAV workshop and competition is held annually with university teams competing for honors in indoor and outdoor flying tests with an emphasis on maneuverability. The International Micro Air Vehicle Competition is another competition that has attracted mainly US university teams to push the frontiers of MAV design and construction.
Incorporating mini cameras into MAVs makes them ideal for surveillance operations in small, confined spaces and hazardous environments. With this in mind the military, already keen backers of larger UAVs, are also keen to exploit MAVs.
The other major opportunity for MAVs is as radio-controlled (RC) toys. Aerial vehicles have a long history of fascinating children and adults. The latest MAV toys incorporate automatic stabilizers that make them much easier to fly than previous generations of RC airplanes and helicopters.
Build Your Own
The design and manufacture of MAVs is relatively inexpensive so it is prime territory for ingenuous hobbyists armed with imagination. While wind tunnels and Computational Fluid Dynamics (CFD) are useful tools to perfect the aerodynamic performance of MAVs, they are not essential, as full scale flight tests can be performed in the average living room – best to put the ornamental glassware away first.