Adaptive Sliding Mode Control Method Of Quad Aerial Rotor

Quad rotor robot, with many significant advantages, such as vertical take-off and landing, hover freely, all sorts of attitude flying, strong adaptability and high flexibility, has broad application prospects in the military, civil, commercial and other fields. Quad rotor has simple structure and can control the speed of four propellers by adjusting the rotational speed of motor, then can control the fight attitude of unmanned aerial vehicle. Meanwhile, influenced by itself complex dynamic characteristics, the control system of the quad rotor have highly nonlinear, strong coupling and sensitive interference and it is also very complex to control the attitude. Therefore, how to both control the flight attitude accurately and to improve its anti-interference is the difficult problem which the control system of the quad rotor will face.Because the attitude control is the key to the whole control system, this paper proposes an adaptive sliding mode control method to the attitude control problem. This method contacts the adaptive control method with sliding variable structure control method. It can increases the robustness of the system and also compensates the error caused by model error and external disturbance. So it comes to desired requirements. Based on the quad rotor provided by lab as the research object, the paper studies and discusses its model and attitude control algorithm and main work content is as follows:First of all, the paper analyzes the research background and development situation about home and abroad to quad rotor at present, then propose the research content aiming at some of major problems currently; Secondly, the quad rotor set up by laboratory is used for flight experiments, then introduces its hardware and software platforms which should be configured before testing to ensure the progress smoothly of flight experiments; Thirdly, according to the force of the flight system, the dynamic model is established by using the Newton-Euler equation and should be simplified. Then a sliding mode variable structure control method is proposed to combine with adaptive control method which will be applied to two closed loop circuit respectively, and then proved to guarantee that the system is asymptotically stable by Lyapunov theorem. Finally, the algorithm is verified by Matlab simulation experiment and the result will be analyzed. It can be seen that the adaptive sliding mode control method has invariance to parameter perturbation and external disturbances and is feasible.