Finite time control method for quadrotor aircraft based on hyperbolic tangent enhanced constant-speed approach law and fast terminal sliding mode surface

Abstract

The invention discloses a finite time control method for a quadrotor aircraft based on a hyperbolic tangent enhanced constant-speed approach law and a fast terminal sliding mode surface. The method comprises the following steps: 1, determining a transfer matrix from a body coordinate system based on the quadrotor aircraft to an inertial coordinate system based on the earth; 2, analyzing a quadrotor aircraft kinetic model according to the Newton-Euler equation; 3, calculating a tracking error, and designing a controller according to the fast terminal sliding mode surface and a first-order derivative thereof. Aiming at a quadrotor aircraft system, the method combines the hyperbolic tangent enhanced constant-speed approach law control and the fast terminal sliding mode control, so the methodcan increase the approach speed during departing from the sliding mode surface, also can reduce the jitter, improves the quickness and robustness of the system, achieves the quick and stable control,also can achieve the finite time control of the tracking error, and solves a problem that only when time approaches to infinity in the conventional sliding mode surface, can the tracking error approach to zero.

Description

technical field [0001] The invention relates to a finite-time control method of a four-rotor aircraft based on a hyperbolic tangent-enhanced constant-velocity approach law and a fast terminal sliding mode surface. Background technique [0002] Due to the characteristics of simple structure, strong maneuverability and unique flight mode, quadrotor aircraft has attracted extensive attention from scholars and scientific research institutions at home and abroad, and has quickly become one of the hot spots in international research. Compared with fixed-wing aircraft, rotorcraft can lift vertically, has low environmental requirements, does not need a runway, reduces costs, and has huge commercial value. The development of aircraft has made many dangerous high-altitude operations easy and safe, deterring other countries in military aspects, and greatly increasing work efficiency in civilian aspects. Quadrotors are highly flexible, can achieve rapid transitions of motion and hoveri...

AI Technical Summary

Problems solved by technology

[0004] In order to overcome the problem that the traditional sliding mode surface cannot realize finite time control and further accelerate the approaching speed of the reaching law and reduce chattering, the present invention adopts the fast terminal sliding mode control and the constant velocity approaching law based on hyperbolic tangent enhancement , through the idea of ​​switching control, the singularity problem is avoided, the approach speed of the system to the sliding surface is accelerated, the chattering is reduced, and the limited time control is realized

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