Dragonfly-algorithm-optimization-based global robust sliding mode control method for water-surface trajectory tracking

Abstract

The invention, which belongs to the field of ships, discloses a dragonfly-algorithm-optimization-based global robust sliding mode control method for water-surface trajectory tracking. The method comprises: step one, establishing a three-degree-of-freedom motion model of a ship to obtain a position and an orientation of the ship; step two, filtering a first-order high-frequency interference force and measuring noises in a wave force by using a nonlinear estimation filter; step three, designing a global-robustness-based trajectory tracking sliding mode controller; step four, designing a Butterworth low-pass filter according to the actual situation; step five, optimizing important parameters in the trajectory tracking sliding mode controller by introducing a dragonfly optimization algorithm;and step six, forming a closed-loop system by the trajectory tracking sliding mode controller, the Butterworth low-pass filter, the nonlinear estimation filter, and a surface ship and inputting a desired trajectory. According to the invention, the asymptotic convergence of the trajectory tracking error is ensured; the non-robustness of the conventional sliding mode control approaching segment is eliminated; and the global rapid stability is realized.

Description

technical field [0001] The invention belongs to the field of ships, and in particular relates to a global robust sliding mode control method for track tracking of surface ships based on dragonfly algorithm optimization. Background technique [0002] Ship trajectory tracking belongs to ship dynamic positioning in a broad sense. Specifically, the ship reaches the originally set position through the control of the trajectory tracking system within the specified time. A controller with high performance trajectory tracking capability is required for surface vessels. Designing the controller of a surface ship is challenging. The uncertainty of the dynamic model, the strong ocean disturbance, the underactuation of the model, and the incomplete constraints of the kinematics are the most important factors for the designer to design the trajectory tracking control of the surface ship. problems that must be dealt with. At present, a lot of research has been done on this problem from ...

AI Technical Summary

Problems solved by technology

The global sliding mode control is realized by designing a nonlinear global sliding mode surface equation. On the basis of ensuring the stability of the sliding mode control, the approaching process in the sliding mode control is eliminated, but at the same time, it is faced with the complex setting of the sliding mode parameters and the There is a problem of high frequency chattering

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