Fault-tolerant control method for fast terminal sliding mode of nonlinear system under actuator fault

Abstract

The invention discloses a novel fast terminal sliding mode fault-tolerant control method for a nonlinear system. For an actuator fault with an unknown fault limit of the system, an extended state observer is designed to estimate a total uncertain item of a fault item contained in the system and a derivative thereof, the fault limit does not need to be known in advance, and the practicability of a fault-tolerant algorithm is improved. Aiming at the requirement that a system is stable in finite time, a new fast terminal sliding mode surface is designed, the convergence speed is higher than that of a linear sliding mode surface in the whole process, and then convergence of the sliding mode surface in the finite time is achieved. For the buffeting problem of a traditional sliding mode control law, a switching item is put into a first-order derivative of the control law, so that buffeting of the control law is greatly reduced. The fast terminal sliding mode fault-tolerant control method is used for fast terminal sliding mode fault-tolerant control of a nonlinear system containing actuator faults.

Description

technical field [0001] The invention relates to a fast terminal sliding mode-based fault-tolerant control method designed for nonlinear systems with actuator faults, and belongs to the technical field of nonlinear system fault-tolerant control. Background technique [0002] Today, with the rapid development of science and technology, people have designed more and more complex high-precision systems, hoping that they can replace humans to perform more complex and dangerous tasks. However, due to the complexity of the working environment and the various devices of the instrument itself, the system is likely to fail during the execution of the task, so that it cannot complete the specified task, and even cause huge losses. In order to ensure that the system does not affect the execution of tasks after a fault occurs, fault-tolerant control emerges as the times require. The purpose of fault-tolerant control is to keep the closed-loop stability of the system and meet certain per...

AI Technical Summary

Problems solved by technology

[0003] Quadrotor UAV is a highly intelligent and integrated aerial vehicle, which is widely used in agricultural irrigation, aerial photography and military operations. UAVs are widely used in complex and dangerous environments, which will greatly threaten the safety and reliability of UAVs

Any failure of the quadrotor drone can easily damage the drone's own instruments, onboard instruments, and facilities in its surrounding environment

However, in traditional terminal sliding mode control, when the system state error is close to zero, the convergence speed of the terminal sliding mode will be slower than that of the linear sliding mode, resulting in the convergence time not being globally optimal

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