Stereo Matching Method and Height Estimation for Unmanned Helicopter

The research and development of autonomous unmanned helicopters has lasted for more than one decade. Unmanned aerial vehicles (UAVs) are very useful for aerial photography, gas pollution detection, rescue or military applications. UAVs could potentially replace human beings in performing a variety of tedious or arduous tasks. Because of their ubiquitous uses, the theory and applications of UAVs systems have become popular contemporary research topics. There are many types of UAVs with different functions. Generally UAVs can be divided into two major categories, fixed-wing type and rotary-wing type. The fixed-wing UAVs can carry out long-distance and high-altitude reconnaissance missions. However, flight control of fixed-wing UAVs is not easy in low-altitude conditions. Conversely, rotary-wing UAVs can hover in low altitude while conducting surveys, photography or other investigations. Consequently in some applications, the rotary-wing type UAVs is more useful than the fixed-wing UAV. One common type of rotary-wing type UAVs is the AUH (Autonomous Unmanned Helicopter). AUHs have characteristics including of 6-DOF flight dynamics, VTOL (vertical taking-off and landing) and the ability to hover. These attributes make AUHs ideal for aerial photography or investigation in areas that limit maneuverability.