Research on the Control Algorithm of Coaxial Rotor Aircraft based on Sliding Mode and PID

Abstract

In this paper, a sliding mode PID control algorithm of coaxial rotor aircraft has been proposed. After that, Adams/MATLAB simulation and experiments were used for verification. The results show that this control method can achieve satisfactory results. Firstly, when considering of the aerodynamic interaction between upper and lower rotor, it is difficult to establish an accurate mathematical model, and the aerodynamic interference between the upper and lower rotors and the brandishing motion of the blades are calculated by using the blade element theory and the dynamic inflow model, and the other parts which are not accurately modeled are compensated for by the control algorithm. Secondly, the sliding mode control algorithm and the PID control algorithm are combined to control the attitude of the aircraft. Among them, the PID control algorithm is used to establish the relationship between attitude and position, so that the aircraft can fly and hover more steadily. Thirdly, the three-dimensional model of the aircraft was imported into Adams to establish the dynamic simulation model. Then, the controller was established in Simulink, after that, and then the controller and the dynamic simulation model were combined for joint simulation. And the sliding mode PID control algorithm has been compared with traditional PID control algorithm through the simulation. Finally, the sliding mode PID control algorithm is verified by the experiment compared with the traditional PID algorithm. The results verify the superiority and practicability of the control method designed in this paper.