Sliding mode control method and controller for four-rotor aircraft

Abstract

The application provides an adaptive sliding mode control method for a four-rotor aircraft. The aircraft is controlled by a controller, the controller is in the form of a sub-loop control structure, and the outer ring of the sub-loop control structure is a position controller. The method comprises: determining a height control law U1 and a horizontal position control law Ux, Uy of the aircraft from the tracking error between the actual position x, y, z of the aircraft and a desired trajectory xd, yd, zd by the position controller with the use of an RBF network adaptive sliding mode control algorithm; determining a roll angle phi d and a given pitch angle theta d of the aircraft according to the horizontal position control law Ux, Uy; and determining a roll angle control law U2, a pitch angle control law U3 and a yaw angle control law U4 of the aircraft from the tracking error between the actual attitude angles phi, theta and psi and the given attitude angles phi d, theta d and psi d with the use of the RBF network adaptive sliding mode control algorithm.

Description

technical field [0001] The present application relates to the field of aircraft, and more specifically, to a sliding mode control method of a quadrotor aircraft and the aircraft thereof. Background technique [0002] Quadrotor aircraft is a butterfly-shaped aircraft with vertical take-off and landing and hovering functions. It has the advantages of simple structure, small size and flexible maneuverability. For the control of quadrotor aircraft, there are mainly the following difficulties: 1) It is very difficult to establish an accurate dynamic model, and the system will be affected by gravity, gyro effect and external disturbance during flight; 2) quadrotor aircraft has 6 degrees of freedom , The underactuated system with 4 input quantities has control difficulties such as high nonlinearity and strong coupling. [0003] For the design of the quadrotor aircraft control system, the commonly used control algorithms are: adaptive control, backstepping, sliding mode control, ro...

AI Technical Summary

Problems solved by technology

For the control of quadrotor aircraft, there are mainly the following difficulties: 1) It is very difficult to establish an accurate dynamic model, and the system will be affected by gravity, gyro effect and external disturbance during flight; 2) quadrotor aircraft has 6 degrees of freedom , an underactuated system with 4 inputs, which has control difficulties such as high nonlinearity and strong coupling

[0003] For the design of the quadrotor aircraft control system, the commonly used control algorithms are: adaptive control, backstepping, sliding mode control, robust control, etc., the above methods have achieved certain research results, but considering that the actual system usually There are uncertainties such as inaccurate modeling and unknown parameters. How to solve the strong dependence of the controller on the model and improve the robustness of the closed-loop system is the key to realize the control of quadrotor aircraft with uncertainties.

For the four-rotor aircraft system with uncertainty, some scholars proposed a radial basis function (Radial Basis Function, RBF) neural network adaptive proportional integration differentiation (Proportion Integration Differentiation, PID) control algorithm, the basic idea is based on the PID algorithm On the basis of using the neural network to select and adjust the PID parameters, although the self-learning and self-adaptive ability of the neural network has a certain nonlinear control effect, the PID algorithm in the controller is a traditional linear control method, which is not suitable for quadrotor aircraft. nonlinear system

Images