Essay On Quadrotor

Abstract— A quadrotor, or quadrotor helicopter, is an aircraft that becomes airborne due to the lift force provided by four rotors usually mounted in cross configuration, hence its name. They are of particular interest due to their small size, great maneuverability and hovering capability. However quadrotors have a limited payload capacity because they require four motors for operation, which consumes more power than conventional Unmanned Aerial Vehicles. This reduces the number of sensors and mission critical equipment they are able to carry. Due to this limitation researchers have turned to vision-based techniques for navigation of UAVs. Vision-based navigation provides a large number of useful features that extend quadrotors capabilities. They include the basic control functions of keeping the quadrotor roll and pitch angles stable (attitude control), controlling the vehicle trajectories when flying in free spaces (course stabilization), and keeping the altitude at proper height over ground. A color camera tracks the image features under the quadrotor and above ground. These blobs are located on a known geometric shape.
Keywords— stabilization, tracking algorithm, blob estimation visual-servo control.
INTRODUCTION
A quadrotor also known as quadrotor unmanned aerial vehicle (UAV) consists of two pairs of counter-rotating rotors and

The proposed system’s block diagram is presented in Figure 2. The block diagram consists of a vehicle block which incorporates the vehicle dynamics, camera model, sensors and filtering stage. The control Module and estimation Module, use the Kalman filtering theory for state observation, and the reference trajectory model as a complement for setting accuracy attitude references. The control design proceeds by developing PID control equations in order to control: target position tracking and