Attitude control method and system based on quad-rotor unmanned helicopter

Abstract

An embodiment of the invention discloses an attitude control method and system based on a quad-rotor unmanned helicopter. The method includes the steps: extracting differential signals for controlling reference state input values by a tracking differentiator; acquiring expanded state output quantity under current attitude adjustment based on an expanded state observer; acquiring initial control output quantity of a nonlinear feedback controller based on error design; performing disturbance compensation for the initial control output quantity by unknown disturbance observation values in the expanded state observer to obtain control output values of an inner ring attitude controller. The transient process is arranged, the differential signals of a controlled object are extracted by the tracking differentiator, change of reference input signals is softened by tracking the reference input signals, output overshooting of the system is decreased, and robustness is enhanced.

Description

technical field [0001] The invention relates to the technical field of unmanned aerial vehicles, in particular to a method and system for attitude control based on a quadrotor unmanned aerial vehicle. Background technique [0002] The quadrotor UAV aircraft has the characteristics of vertical take-off and landing, simple structure, and strong maneuverability. It has become a research hotspot in recent years and has achieved great development in the consumer field. Quadrotor UAV aircraft generally adopt a symmetrical structure layout, the mechanical structure is relatively simple, and the four rotors are evenly distributed, with underactuation, strong coupling and high-order nonlinearity, which puts forward high requirements for the design of the UAV flight control system. The flight control system is composed of two parts: controller hardware and software algorithm. Under the premise that the current consumer drone hardware platforms are basically consistent, the software al...

AI Technical Summary

Problems solved by technology

[0004] The control defects of the traditional PID algorithm are: (1) the original error is directly generated in the form of e=v-y

(2) There is no good way to generate the differential signal of e

(3) Linear combination is not necessarily the best combination

(4) The introduction of the integral feedback of the error signal e has many negative effects

[0006] 1) Based on the assumption that the UAV system is near the equilibrium point, its control performance will be greatly reduced when the state of the aircraft deviates from the equilibrium point in a large range

[0007] 2) The algorithm is less robust to system model uncertainty and external disturbances

[0008] 3) In PID control, the I parameter of the integral action item is difficult to adjust, and the D parameter of the differential action item is difficult to adjust

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