Improved UKF algorithm for unmanned ship alignment under severe sea conditions

Abstract

The invention discloses an improved UKF algorithm for unmanned ship alignment under severe sea conditions. The improved UKF algorithm re-empowers an innovation vector in a sliding window by using a projection statistical algorithm, realizes real-time estimation of a measurement noise variance matrix, aims at the situation that each observed quantity is inevitably not only affected by single external interference during unmanned ship alignment under severe sea conditions, solves a self-adaptive factor matrix by utilizing a genetic algorithm, and adjusts the measurement noise variance matrix optimally. Compared with the prior art, the improved UKF algorithm has the advantages that compared with a conventional self-adaptive robust UKF algorithm, the improved UKF algorithm achieves optimization of the self-adaptive adjusting capacity, and can improve the precision and stability of unmanned ship alignment under severe sea conditions.

Description

[0001] Field [0002] The invention belongs to the technical field of surveying and mapping, and in particular relates to an improved UKF algorithm for aligning unmanned ships under harsh sea conditions. Background technique [0003] For unmanned ships operating at sea, strong winds and waves are common adverse sea conditions that affect their navigation and normal work, which will cause the ship to sway in six degrees of freedom, among which yaw, roll and pitch have adverse effects on the ship maximum. Before work, the unmanned ship is towed to the sea by the mother ship and released randomly. The uncertainty of this release makes the unmanned ship have a large misalignment angle in the initial alignment. The initial alignment problem under large misalignment angles has important practical significance. Considering the actual impact of harsh sea conditions on the work of unmanned ships, it will not only swing sharply, but also be affected by external interference such as im...

AI Technical Summary

Problems solved by technology

Using the open-circuit method to construct a mathematically stable platform to isolate the carrier from swinging and achieve rapid alignment, since there is no feedback correction, it is only suitable for purely ideal swinging environments; by finding the zero-speed shaking center, the swing base self-alignment problem is transformed into The static base alignment problem, but the application of the closed-loop compensation method makes the selection of the initial value of the closed-loop and the determination of the switching time a problem

The classic compass alignment is also applied to the initial alignment of marine SINS under harsh conditions, but rough alignment must be performed before the fine alignment of the horizontal azimuth, which has limitations

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