Accurate track tracking control method based on finite time expansion state observer

Abstract

The present invention provides an accurate track tracking control method based on a finite time expansion state observer. The method comprises the following steps of: establishing a mathematical modeland a kinematic equation representing current unmanned ship motion features, designing a combined nonsingular rapid terminal sliding-mode control law according to the unmanned surface ship motion tracking errors and a nonsingular rapid terminal sliding-mode surface, designing a finite time expansion state observer according to the unmanned ship motion features, and designing an accurate track tracking control law according to the combined nonsingular rapid terminal sliding-mode control law and the finite time expansion state observer. Through design of the finite time expansion state observer, the lump interference comprising external interference and a complex nonlinear term can be observed by the finite time to a small enough range to avoid the limitation of the approximation observation. Through the designed combined nonsingular rapid terminal sliding-mode control law and the nonsingular rapid terminal sliding-mode unmanned ship track tracking controller, the accurate track tracking control method achieves the accurate track tracking control performance in a complex external interference.

Description

technical field [0001] The present invention relates to the technical field of ship control engineering and ship automatic navigation, in particular, to a precise track tracking control method based on a finite time expansion state observer. Background technique [0002] As countries pay more and more attention to maritime rights and interests, unmanned surface vehicles have attracted widespread attention in recent years due to their ability to reduce mission execution costs and manpower costs. Adopting a certain control algorithm can not only enable the unmanned ship to accurately track a given mission trajectory, but also enhance its robustness and anti-interference ability. Common unmanned ship control algorithms include backstepping, methods based on cascaded systems, and fuzzy neural networks. In the absence of interference, methods based on backstepping and cascaded systems can achieve good tracking results, and achieve global asymptotic or global exponential stabilit...

AI Technical Summary

Problems solved by technology

In the absence of interference, methods based on backstepping and cascaded systems can achieve good tracking results, and achieve global asymptotic or global exponential stability. Good results have been achieved in the field of trajectory tracking control, but the problem of trajectory tracking control of unmanned surface vehicles under complex disturbances is still open and challenging

In the case of considering disturbances, there have been some control methods based on fuzzy logic systems and neural networks in recent years. However, such control methods based on approximation techniques can only achieve asymptotic or exponential stability, and there are certain bounded approximation residuals. , resulting in greatly reduced tracking accuracy

[0003] The existing methods can only ensure that the tracking error can be stabilized to the zero point or the neighborhood near the zero point when the time tends to infinity, which only has asymptotic convergence characteristics, slow convergence speed, and low control accuracy

In addition, the existing disturbance observation technology is less able to achieve limited time observation, and it is difficult to observe the disturbance value quickly and accurately

In summary, the existing methods are difficult to achieve precise track tracking control of unmanned surface vehicles under the interference of complex external environments

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