Control of Unstable Systems

Aircraft with four or more horizontal rotors have undergone an accelerated evolution in recent years. Research groups in the area of systems engineering, control engineering students, and amateurs in general are working on the implementation of more robust models and controllers, so that they can work with more detailed, accurate, and therefore more realistic simulations of the behavior of quadrotors. Many authors, thinking in the future in a practical implementation and limited in computing power by the imposed lightness in weight, choose to keep relatively simple the modeling of the vehicle dynamics which makes possible to control the quadrotor using classical control techniques of linear systems such as PID, through the linearization of the dynamics of behavior of the device around an operating point that is usually chosen according to where the device should hover. However, wide range flight or more complex maneuvers require a better performance of the control system.