Method and autonomous underwater vehicle able to maintain a planned arrangement

Patent metadata

Field	Value
Publication number	US-2016355247-A1
Application number	US-201515117858-A
Country	US
Kind code	A1
Filing date	Feb 5, 2015
Priority date	Feb 19, 2014
Publication date	Dec 8, 2016
Grant date	—

Abstract

Methods and devices are configured to maintain a planned arrangement of autonomous underwater vehicles (AUVs). An AUV performs a corrective motion to adjust its current position relative to other AUVs emitting signals, so that the AUV's corrected position matches a planned position of the AUV in the planned arrangement better than its current position. The corrective motion is determined based on the location of the AUVs whose emitted signals are detected by the AUV.

First claim

What is claimed is:

1 . A method for maintaining a planned arrangement of autonomous underwater vehicles, AUVs, deployed in water, the method comprising:
detecting, by an autonomous underwater vehicle, AUV, among the AUVs, one or more signals emitted at a predetermined moment by one or more among the AUVs, respectively; automatically estimating a current position of the AUV relative to the one or more AUVs, based on the detected one or more signals; and performing a corrective motion to adjust the current position to better match a planned position of the AUV in the planned arrangement, wherein any of the one or more AUVs emitting has potentially drifted to be away from a respective planned position in the planned arrangement, at the predetermined moment.

2 . The method of claim 1 , wherein the corrective motion is defined by a heading and a thrust necessary to move the AUV toward the planned position.

3 . The method of claim 1 , wherein the one or more signals have individual signatures enabling the AUV to determine identity of each of the one or more AUVs emitting one of the one or more signals, a time of arrival corresponding to each of the one or more signals and an angle relative to a reference direction from which each of the one or more signals has arrived.

4 . The method of claim 3 , wherein the estimating of the current position includes:
calculating each of one or more distances between the AUV and the one or more AUVs emitting the one or more signals, based on the time of arrival, respectively; determining positions of each of the one or more AUVs relative to the AUV, using corresponding one of the distances and the angle, respectively; calculating possible corrective motions based on the positions, respectively; generating a box in a thrust versus heading space, the box covering representations of the possible corrective motions; and selecting the corrective motion inside the box according to a predetermined rule.

5 . The method of claim 1 , further comprising:
preserving an orientation of the AUV relative to the reference direction.

6 . The method of claim 1 , wherein the planned formation arrangement is substantially horizontal, and the method further comprises:
maintaining a predetermined depth by the deployed AUVs.

7 . The method of claim 1 , wherein
multiple among the AUVs are configured to detect the one or more signals, each of the multiple among the AUVs then automatically estimating a current position thereof and performing a respective corrective motion to adjust the current position thereof to better match a planned position thereof in the planned arrangement.

8 . The method of claim 7 , wherein the one or more among the deployed AUVs emit signals simultaneously at plural predetermined moments, the detecting of the one or more signals triggering the multiple among the AUVs to estimate the current position thereof relative to the one or more among the AUVs, and to perform the corrective motion.

9 . The method of claim 8 , wherein the plural predetermined moments occur at a predetermined time interval.

10 . An autonomous underwater vehicle, AUV, usable in a planned arrangement of autonomous underwater vehicles, AUVs, deployed in water, the AUV comprising:
a body hosting a motor able to move the body horizontally; a vector receiver attached to the body and configured to detect one or more signals emitted at a predetermined time by one or more among the deployed AUVs; and a controller configured
to automatically estimate a current position of the body relative to the planned arrangement, based on the detected one or more signals, and
to control the motor to perform a corrective motion to adjust the current position to better match a planned position of the AUV in the planned arrangement,
wherein any of the one or more among the deployed AUVs emitting the signals has potentially drifted being away from a respective planned position in the planned arrangement, at the predetermined time.

11 . The AUV of claim 10 , wherein the controller determines and sends to the motor, a heading and a thrust characterizing the corrective motion.

12 . The AUV of claim 10 , wherein the one or more signals have individual signatures enabling the controller to determine identity of each of the one or more AUVs emitting one of the one or more signals, a time of arrival corresponding to each of the one or more signals and an angle relative to a reference direction from which each of the one or more signals has arrived.

13 . The AUV of claim 12 , wherein, to estimate the current position, the controller is configured:
to calculate distances between the AUV and each of the one or more AUVs emitting the one or more signals, using the time of arrival; to determine positions of each of the one or more AUVs relative to the AUV, using corresponding one of the distances and the angle; to calculate possible corrective motions based on the positions, respectively; to generate a box in a thrust versus heading space, the box covering representations of the possible corrective motions; and to select the corrective motion inside the box according to a predetermined rule.

14 . The AUV of claim 12 , further comprising at least one of:
a compass which allow tracking the reference direction; and a timer synchronized with timers on the one or more AUVs emitting signals to measure traveling times of the one or more signals from the one or more AUVs to the AUV.

15 . The AUV of claim 10 , the AUV further comprising:
a depth maintaining mechanism configured to maintain a predetermined depth of the AUV.

16 . The AUV of claim 10 , the AUV further comprising:
a pinger configured to emit a signal at the predetermined time.

17 . A controller configured to control a motor of an autonomous underwater vehicle, AUV, usable in a planned arrangement of autonomous underwater vehicles, AUVs, the controller comprising:
an interface configured
to receive data related to one or more signals emitted at a predetermined time by one or more among the deployed AUVs, the one or more signals being detected by a vector receiver attached to the AUV, and
to transmit commands to a motor able to move the AUV horizontally; and
a data processing unit configured
to automatically estimate a current position of the AUV relative to the one or more AUVs, based on the data, and
to generate the commands directing the motor to perform a corrective motion to adjust the current position to better match a planned position of the AUV in the planned arrangement,
wherein any of the one or more among the deployed AUVs emitting the one or more signals, has potentially drifted being away from a respective planned position in the planned arrangement, at the predetermined time.

18 . The controller of claim 17 , wherein to automatically estimate the current position of the AUV relative to the one or more AUVs, the data processing unit is configured:
to calculate distances between the AUV and each of the one or more AUVs emitting the one or more signals, using the time of arrival; to determine positions of each of the one or more AUVs relative to the AUV, using corresponding one of the distances and the angle; to calculate possible corrective motions based on the positions, respectively; to generate a box in a thrust versus heading space, the box covering representations of the possible corrective motions; and to select the corrective motion inside the box according to a predetermined rule.

19 . The controller of c

Assignees

• Cgg Services Sa

Inventors

• Ibn Seddik Mohamed Saad

Classifications

• G05D1/10 Primary

  Simultaneous control of position or course in three dimensions (G05D1/12 takes precedence) · CPC title

• G01V1/3817

  Positioning of seismic devices · CPC title

• B63G8/16 Primary

  by direct use of propellers or jets · CPC title

• B63G2008/004

  autonomously operating · CPC title

• B63G8/14

  Control of attitude or depth (of torpedoes F42B19/00) · CPC title