Dependable takeoff and landing control of a small-scale helicopter with a wireless camera

This paper presents a takeoff and landing controller for a small-scale helicopter with a wireless camera. The camera is a single sensor for control of the helicopter, and it is a wireless device. The camera looks downward, and it takes an image of a specified mark on the ground every frame. Feedback controllers do not work well at a low altitude, since the camera does not take a correct image of the mark. To avoid this, the presented controller for takeoffs and landings consists of a combination of feedback controllers and feedforward controllers. Feedforward controllers are used, when the helicopter is near to the ground. When the helicopter is at a high altitude, the helicopter is controlled by a dependable feedback controller proposed by the authors. The dependable feedback controller decides whether each captured image is noisy or noise-free in real-time, since the wireless camera sometimes captures noisy images. If the current image is determined as noise-free, then the helicopter is controlled by a PD controller. If the current image is decided as noisy, then a feedforward controller is used. Noisy images are not used to make the control signal.