In this paper, an inversion controller is designed for the attitude of aircraft.
The simulation results show that the designed inversion controller is effective for controlling the stable flight of a Four-rotor aircraft. In order to improve the dynamic performance and stability of the aircraft better, the angle measurement deviation is taken into account in the design of the attitude controller to make the attitude designed.
The angle measurement deviation of the state controller is small, so the Four-rotor aircraft can be better controlled. The integral inversion controller is designed.
The two controllers are verified by simulation experiments.
In recent years, Four-rotor aircraft has gradually become a research hotspot at home and abroad due to its wide use. The control research of aircraft includes many fields, such as digital filtering, position estimation based on GPS, data fusion of sensors, etc.
Whether the control algorithm is correct or not directly affects the quality of the control system, and even determines the success or failure of the whole system. Therefore, scholars from all over the world devote themselves to the research of control algorithm. The inversion method has its own advantages for the processing of control systems. Especially in the control of non-linear systems, some characteristics of the system, such as transition quality, can be effectively improved.
Four-rotor aircraft is a typical non-linear control system. Although its non-linear mathematical model is simplified, there is still a coupling between attitude control and position control. The controller designed by this method has the characteristics of systematization and structuralization. The matching constraints and non-linear growth conditions of the system are not very strict. The inversion method is widely used in aerospace because of its good transient performance. For attitude control of aircraft, the adaptive inversion control method is proposed in reference [1]. The design method of inversion stabilization control law based on Lyapunov function is proposed in reference [2]. The inversion sliding mode control method is proposed in reference [3].
The adaptive neural network control algorithm based on inversion control method is proposed in reference [4]. The inversion capacity is proposed in reference [5]. Error control method, the control methods in these literatures are improved on the basis of inversion control method. Aiming at the attitude angle control of aircraft, based on the inversion controller, thermostatic element the angle measurement deviation is taken into account in the design of the controller, which makes the designed attitude controller less affected by the angle measurement deviation. The dynamic performance and stability of the aircraft in flight are better. Four-rotor aircraft controls the aircraft through the thrust generated by four propellers. There are usually two common coordinate systems to describe Four-rotor aircraft: inertial coordinate system and body coordinate system.
The two coordinate systems can be converted to each other. The rotation matrix from the body coordinate system to the inertial coordinate system is represented by R and T. In actual flight, the control effect of the inverted attitude controller needs to be improved due to the influence of wind and angle measurement deviation during flight. In this section, the controller based on integral inversion control algorithm is designed.
The deviation of angle measurement is taken into account in the design of controller, so that the attitude controller is less affected by the deviation of angle measurement, thus achieving better flight control effect for aircraft. Taking roll angle as an example, the design of attitude controller is explained.
From Fig. 1 and Fig. 2, it can be clearly seen that the pitch angle controlled by the controller based on integral inversion control algorithm is smaller than that controlled by the controller based on inversion control algorithm, and the overshoot of the roll angle is smaller, thus the attitude of the system will be more stable.
For the attitude control of aircraft, the integral inversion controller makes the aircraft more stable and less overshoot than the inversion controller, so the integral inversion controller makes the dynamics and stability of the aircraft better.