Autonomous Hovering Flight of a Small Helicopter

Abstract

During the 20th century, aircraft were only used for transportation. If aircraft can be made small and lightweight, however, they can become tools to assist in everyday life. We developed a small, lightweight co-axial helicopter with a rotor diameter of about 30 cm. The mechanisms for varying cyclic pitch of the upper and lower rotors, which are used in the coaxial helicopter for entertainment, are adopted in our develop helicopter. Our developed helicopter is equipped with a flight control system for the attitude and position, which is composed of a micro computer and some sensors. And the helicopter can make autonomous hovering flight just measuring the height and the distances from the walls. The weight of the helicopter is no more than 200 g and this helicopter is the lightest helicopter for an autonomous hovering flight among the helicopters where all control systems are onboard, as far as the authors know.

Navigation of Small and Lightweight Helicopter

“…Autonomous hovering flight near walls [4][5][6] Three IR range finders (GP2D12 by Sharp) mounted on the helicopter measure the height of the helicopter above the ground, and the distance from two walls. The microcomputer contains a pre-programmed flight plan comprised of the required time variations in height and distances from two walls.…”

“…If the receiver gets no signals from an operator, flight is autonomous defined as take off, hover for 1 minute, and land. Figures 4(a) and (b) show 4) the position of the center of gravity (pink circles) viewed from the top and side, respectively, during autonomous flight. In flight, variation from the target hovering position was less than 30 cm.…”

“…Such small and lightweight aircraft will be tools assisting everyday life. We also have developed a small battery-powered coaxial helicopter [4][5][6] with a total weight of about 200 g and a rotor diameter of about 35 cm. The final development goal for the helicopter is to monitor disaster zones after an earthquake and to make environmental measurements.…”

Underwater Robot Swarms: Challenges and Opportunities

“…This means that they require minimal sensors for stabilisation. The most common example of this is the contra-rotating helicopter with passive stabiliser bar (Holland et al, 2005;Matsue et al, 2005;Ohkura et al, 2005;De Nardi et al, 2006), which can be found in almost every hobby/toy shop around the globe. The top rotor is coupled to a weighted fly-bar and hinged in a way that controls the angle of attack of the rotor blades, the gyroscopic forces of this bar and the gravitational forces acting on it allow it to act as both a 2-axis gyroscope, for pitch and roll, and 3D accelerometer.…”