Autonomous Flight Control for RC Helicopter Using a Wireless Camera

Abstract

In recent years, there are a lot of researches on the subject of autonomous flight control of a micro radio control helicopter. Some of them are about flight control of unmanned helicopter (Sugeno et al., 1996) (Nakamura et al., 2001). The approach using the fuzzy control system which consists of IF-Then control rules is satisfying the requirements for the flight control performance of an unmanned helicopter like hovering, takeoff, rotating, and landing. It is necessary to presume three dimensional position and posture of micro RC helicopter for the autonomous flight control. A position and posture presumption method for the autonomous flight control of the RC helicopter using GPS (Global Positioning System), IMU (Inertial Measurement Unit), Laser Range Finder (Amida et al., 1998), and the image processing, etc. had been proposed. However, the method using GPS cannot be used at the place which cannot receive the electric waves from satellites. Therefore, it is a problem that it cannot be used for the flight control in a room. Although the method which uses various sensors, such as IMU and Laser Range Finder, can be used indoors, you have to arrange many expensive sensors or receivers in the room beforehand. So, these methods are not efficient. On the other hand, the method using an image inputted by a camera can be used in not only outdoors but also indoors, and is low price. However, this method needs to install many artificial markers in the surroundings, and it is a problem that the speed of the image inputting and image processing cannot catch up the speed of movement or vibration of a RC helicopter. A method presuming the three dimensional position and posture of a RC helicopter by the stereo measurement with two or more cameras installed in the ground was also proposed. In this case, the moving range of the RC helicopter is limited in the place where two or more cameras are installed. Moreover, there is a problem for which a high resolution camera must be used to cover a whole moving range. (Ohtake et al., 2009) Authors are studying an autonomous flight of a RC helicopter with a small-wireless camera and a simple artificial marker which is set on the ground. This method doesn’t need to set the expensive sensors, receivers, and cameras in the flight environment. And, we thought that a more wide-ranging flight is possible if the natural feature points are detected from the image obtained by the camera on the RC helicopter. This chapter contains the following contents.