Underwater Vehicle Cable Management via Buoyant Intermediary

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Solution Overview

Problem

Existing underwater vehicle systems with surface-based bases face challenges such as excessive drag and maneuverability issues due to long cables, and inefficiencies in working at great depths and between distant zones, with current systems either experiencing high tensile forces or laborious operations when switching between locations.

Innovation Solution

A system featuring an underwater vehicle with an onboard energy reserve, remotely controlled via a thin optical fiber connected to a float and a plunger, allowing for deployment and retraction of the fiber and flexible link, enabling decoupling of forces and facilitating efficient maneuverability and reuse of the fiber, suitable for working at great depths and between distant zones without the need to bring the vehicle to the surface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of stationary object

If a long cable is used to connect the ROV to the surface boat, then the ROV can operate at greater depths and distances, but the drag and tensile forces increase to the point where maneuverability is lost

Engineering Contradiction:
Improvecable lengthVSAvoidmaneuverability
Core Design Contradiction:
Length of stationary objectVSEase of operation

Solution Approach 1:

The system divides the connection into two separate segments: a first cable connecting the streamlined body to the ROV, and a second cable connecting the streamlined body to the surface boat. This segmentation allows each cable to be optimized independently, with the first cable being shorter and lighter while the second cable handles the majority of the drag and tensile forces.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The streamlined body acts as an intermediary element between the surface boat and the ROV. It serves as a floating anchor point that reduces the effective cable length and minimizes drag on the ROV, while also providing a stable platform for cable connection and signal transmission.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Length of stationary object

If a long cable is used to connect the ROV to the surface boat, then the ROV can operate at greater depths, but the tensile forces become too great for small vessels without dynamic positioning

Engineering Contradiction:
Improvecable lengthVSAvoidtensile force
Core Design Contradiction:
Length of stationary objectVSForce

Solution Approach 1:

The connection is segmented into two cables with different functions: the first cable (ROV to streamlined body) is optimized for minimal drag and short length, while the second cable (streamlined body to boat) is designed to handle the majority of tensile forces and drag loads, protecting the vessel and ROV from excessive forces.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The streamlined body provides buoyant counterweight that offsets the weight of the ROV and cable system, reducing the tensile force that must be borne by the surface vessel. This allows small vessels without dynamic positioning to operate effectively.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

3Length of stationary object

If an optical fiber is used to connect the HROV to the surface, then the fiber can be very long without excessive drag, but the fiber must be cut and discarded after use causing pollution

Engineering Contradiction:
Improveoptical fiber lengthVSAvoidoptical fiber waste
Core Design Contradiction:
Length of stationary objectVSLoss of substance

Solution Approach 1:

The system enables recovery and reuse of the optical fiber by incorporating a retrieval mechanism on the streamlined body. The fiber can be wound back onto the streamlined body or retrieved along with it, allowing the same fiber to be reused for multiple operations at different locations, eliminating the need to discard it after a single use.

Inventive Principle:
Principle #34Discarding and recovering

4Productivity

If the HROV is moved between distant work areas by towing, then the optical fiber can be reused, but the fiber and vehicle must be recovered to the surface which is time-consuming

Engineering Contradiction:
Improveoperational efficiencyVSAvoidtime to recover and redeploy
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The streamlined body serves as a floating base that remains at the surface or near-surface position while the ROV operates at depth. When moving between work areas, only the ROV needs to be towed to the new location and reconnected to the streamlined body via the first cable, while the streamlined body and optical fiber infrastructure remain in place, significantly reducing deployment time compared to recovering everything to the surface.

Inventive Principle:
Principle #24Intermediary (Mediator)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This system ensures good maneuverability of the underwater vehicle, reduces waste by allowing fiber reuse, and simplifies operations by maintaining autonomy and eliminating the need to switch optical fibers when moving between work areas, thus enhancing operational efficiency and reducing environmental pollution.

Implementation Method 1

remotely controlled from the base via at least a first optical fiber

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 2

a positive buoyancy element, called a float, linked by wire to the underwater vehicle, solely via the first optical fiber(s)

Methodology Applied
Scientific EffectBuoyancy: Archimedes' Principle (Buoyancy)

Implementation Method 3

a negative buoyancy element, called a diver, linked to the base

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP2621796B1System comprising an underwater vehicle and a base situated at the surface
Publication Date: 2015.02.25 INSTITUT FR DE RES & DEV POUR LEXPL DE LA MER IFREMER
  • EP2621796B1 patent drawingFigure 1
  • EP2621796B1 patent drawingFigure 2~3
  • EP2621796B1 patent drawingFigure 4~5

AI summary

System comprising an underwater vehicle (10) and a base (40) situated at the surface. The underwater vehicle (10) has an on-board reserve of energy and is controlled remotely from the base via at least one first optical fibre (15). The system comprises: a positive-buoyancy element known as a float (20), connected by wire to the underwater vehicle (10), only via the first optical fibre (15); and a negative-buoyancy element known as a sinker (30) connected to the base (40). The float (20) and the sinker (30) are connected by wire by means of a first flexible link (25). This system also comprises: a first device (12), provided on the float (20) and/or on the underwater vehicle (10), for winding in and paying out the first optical fibre (15); and a second device (32), provided on the float (20) and/or on the sinker (30), for winding in and paying out the first flexible link (25).