Buoyancy control method of unpowered rapid submerging and floating AUV

Abstract

The invention provides a buoyancy control method of an unpowered rapid submerging and floating AUV. By recording the change time t of the AUV from the horizontal posture to the vertical posture and performing weighted fusion calculation on the approximate uniform motion speed of the AUV in the vertical posture, an accurate and sufficient motion distance is provided for the change process of the AUV from the vertical posture to the horizontal posture before the AUV reaches the target depth; in the diving or floating process that the vertical posture of the AUV is changed into the horizontal posture and in the diving or floating process that the AUV is in the horizontal posture, the AUV is in the horizontal posture; a depth and speed double-closed-loop control method is adopted for continuously adjusting the buoyancy adjusting mechanism, and on the basis, a nonlinear expansion state observer is utilized for estimating and compensating marine environment interference borne in the diving or floating process. Under the condition that power propulsion devices such as a main propeller, an auxiliary propeller and a rudder are not used, the underwater robot dives or floats upwards to the target depth more accurately and rapidly.

Description

technical field [0001] The invention relates to a method for accurately controlling the buoyancy of a fast submersible AUV that does not use power propulsion devices such as propellers and rudders, and belongs to the technical field of unpowered navigation. Background technique [0002] With the acceleration of marine development, unmanned unmanned autonomous underwater vehicle (AUV) technology has been greatly developed, and has been widely used in marine scientific research, marine resource investigation, salvage and lifesaving and other fields. For AUVs with an aspect ratio greater than 2, when they perform deep-sea investigation tasks, they basically rely on propellers and rudders for diving or surfacing, which consumes a lot of energy, which in turn reduces the time it takes to perform tasks at predetermined depths. , resulting in the execution of the task may not be completed at one time, which requires multiple dive missions to a certain fixed sea area. If the AUV us...

AI Technical Summary

Problems solved by technology

For example, in the article "Research on AUV Depth Control Based on Buoyancy Adjustment System", it is mentioned that the depth gauge is used as the feedback element for measuring depth, and the controller continuously adjusts the buoyancy adjustment mechanism to reach the target depth according to the input information and feedback information; In the article "Application Research on Operational AUV", it is mentioned that the depth gauge is used as the feedback element, and the vertical velocity of the carrier is calculated by differential calculation, so as to control the depth of the AUV carrier. Both articles use the depth feedback control loop. However, this method is aimed at the problem of control overshoot due to the large inertia and slow response of the AUV attitude change; in the patent application number 201710667016.1, a precise buoyancy control method for an oil bladder underwater glider is proposed. The ocean density model uses the control of the hydraulic pump to adjust the drainage of the oil bladder, and controls the buoyancy and gravity of the AUV to achieve a balance at any depth, but this method will cause frequent adjustments of the AUV at the target depth

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