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CN-121995078-A - DVL-based ocean current flow speed and direction measuring method and device suitable for AUV

CN121995078ACN 121995078 ACN121995078 ACN 121995078ACN-121995078-A

Abstract

The invention discloses a method and a device for measuring the flow speed and the flow direction of ocean current based on DVL, which are applicable to AUV, wherein the method comprises the steps of simultaneously obtaining the speed of the ocean floor and the speed of a water layer to be measured by using a Doppler velocimeter DVL, and differencing the two speeds to obtain the three-dimensional ocean current speed under a DVL carrier coordinate system; converting the ocean current speed into a geographic coordinate system based on the attitude information of the AUV, dead reckoning the converted ocean current speed, accumulating the displacement of ocean current in the east direction and the north direction in a preset time period in real time, and calculating and outputting the flow speed and the flow direction of the ocean current under the geographic coordinate system according to the accumulated displacement and the reckoning time period. The invention carries out time integration on the ocean current movement through dead reckoning, effectively smoothes DVL instantaneous velocity measurement noise, obviously improves measurement precision and stability under a low flow velocity environment, does not need to add new hardware, can directly reuse the existing integrated navigation system of the AUV, and has the advantages of low cost, easy integration, strong engineering practicability and the like.

Inventors

  • BAI LONG
  • Zeng ang
  • Wen Zhuofan
  • WEI XIAOPAN
  • DONG ZHENGQI
  • LIU YAPENG

Assignees

  • 宜昌测试技术研究所

Dates

Publication Date
20260508
Application Date
20251230

Claims (7)

  1. 1. A DVL-based current flow rate and direction measurement method for an AUV, comprising the steps of: S1, simultaneously acquiring the submarine speed and the speed of a water layer to be detected by using a Doppler velocimeter DVL, and differencing the submarine speed and the speed to the water layer to be detected to obtain the ocean current three-dimensional speed under a DVL carrier coordinate system; s2, converting the ocean current three-dimensional speed from a DVL carrier coordinate system to a geographic coordinate system based on the attitude information of the AUV; S3, dead reckoning is carried out based on the converted ocean current speed so as to accumulate the displacement of ocean current in the preset time length under the geographic coordinate system in real time; And S4, calculating and outputting the flow speed and the flow direction of the ocean current under a geographic coordinate system according to the accumulated displacement and the preset duration.
  2. 2. The method according to claim 1, wherein in step S1, the difference between the two is specifically the subtraction of the pair of seafloor velocities from the velocity of the water layer to be measured.
  3. 3. The method according to claim 1, wherein in step S2, the converting comprises: Firstly, according to installation error parameters and scale coefficients between a DVL and an inertial navigation system, converting the three-dimensional speed of ocean current under a DVL carrier coordinate system into the inertial navigation system carrier coordinate system; And then, converting the ocean current speed under the carrier coordinate system of the inertial navigation system into the geographic coordinate system by utilizing the real-time attitude matrix of the AUV.
  4. 4. The method according to claim 1, wherein in step S3, the position of the start point of the dead reckoning is a real-time position of the AUV at a start time, and the displacement includes at least an east displacement component and a north displacement component.
  5. 5. The method according to claim 4, wherein in step S4, the calculating the flow rate and the flow direction specifically includes: Calculating the sea current plane synthetic displacement within the preset duration according to the east displacement component and the north displacement component; Calculating the average flow velocity of the ocean current according to the plane synthetic displacement and the preset duration; and calculating the flow direction angle of the ocean current according to the proportional relation between the east displacement component and the north displacement component.
  6. 6. The method according to any one of claims 1 to 5, characterized in that it is performed by an integrated navigation system carried by the AUV, which integrated navigation system integrates a satellite navigation device, an inertial navigation device and the doppler velocimeter DVL.
  7. 7. A DVL-based ocean current flow rate and direction measurement device for an AUV, comprising: At least one processor, and A memory communicatively coupled to the at least one processor; Wherein the memory stores instructions executable by the at least one processor to enable the at least one processor to perform the method of any one of claims 1 to 6.

Description

DVL-based ocean current flow speed and direction measuring method and device suitable for AUV Technical Field The invention belongs to the technical field of underwater ocean current measurement, and particularly relates to a DVL-based ocean current flow velocity and direction measurement method and device suitable for an AUV. Background Autonomous underwater unmanned underwater vehicle (autonomous underwater vehicle, AUV) plays an increasingly important role in the fields of ocean development and national defense due to the advantages of small volume, low use cost, intelligent autonomous operation, convenient maintenance, good concealment and the like. Along with the gradual expansion of the AUV application field, the requirement on a control system is higher and higher, and the autonomous control capability of attitude, track, positioning hover and the like in a complex ocean current environment is particularly suitable for the operation capability in the complex ocean current environment. The AUV is required to accurately measure the current speed and direction of the underwater operation environment in real time, provide the current information for the control system, and increase the adaptability of the underwater operation environment. Currently, the AUV is used for measuring the sea current, and the bottom speed measurement and the water layer speed measurement are realized by means of DVL. However, certain measurement noise exists in the three axial speed outputs of the DVL, so that the fluctuation range of flow direction measurement is large in an environment with small ocean currents, and ocean current information cannot be obtained effectively. Disclosure of Invention Aiming at the defects, in order to realize effective measurement of ocean currents with smaller flow rates, the invention provides a DVL-based ocean current flow rate and direction measuring method and device suitable for an AUV, which can solve the requirement of the AUV on effective measurement of the ocean current flow rate and direction in an environment with smaller flow rate, and the method is simple and efficient and has high engineering application value. The technical scheme for realizing the invention is as follows: A DVL-based current flow rate and direction measurement method for an AUV, comprising the steps of: S1, simultaneously acquiring the submarine speed and the speed of a water layer to be detected by using a Doppler velocimeter DVL, and differencing the submarine speed and the speed to the water layer to be detected to obtain the ocean current three-dimensional speed under a DVL carrier coordinate system; s2, converting the ocean current three-dimensional speed from a DVL carrier coordinate system to a geographic coordinate system based on the attitude information of the AUV; S3, dead reckoning is carried out based on the converted ocean current speed so as to accumulate the displacement of ocean current in the preset time length under the geographic coordinate system in real time; And S4, calculating and outputting the flow speed and the flow direction of the ocean current under a geographic coordinate system according to the accumulated displacement and the preset duration. Further, in the step S1, the difference between the two is specifically that the speed of the sea bottom pair is subtracted from the speed of the water layer to be detected. Further, in step S2, the converting includes: Firstly, according to installation error parameters and scale coefficients between a DVL and an inertial navigation system, converting the three-dimensional speed of ocean current under a DVL carrier coordinate system into the inertial navigation system carrier coordinate system; And then, converting the ocean current speed under the carrier coordinate system of the inertial navigation system into the geographic coordinate system by utilizing the real-time attitude matrix of the AUV. Further, in step S3, the position of the start point of the dead reckoning is a real-time position of the AUV at the start time, and the displacement at least includes an east displacement component and a north displacement component. Further, in step S4, the calculating the flow rate and the flow direction specifically includes: Calculating the sea current plane synthetic displacement within the preset duration according to the east displacement component and the north displacement component; Calculating the average flow velocity of the ocean current according to the plane synthetic displacement and the preset duration; and calculating the flow direction angle of the ocean current according to the proportional relation between the east displacement component and the north displacement component. Further, the method is performed by an integrated navigation system carried by the AUV, which is integrated with a satellite navigation device, an inertial navigation device and the doppler velocimeter DVL. A DVL-based ocean current flow rate and directi