Movable Ballast Control of Towed Trawl Catenary During Turns
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Solution Overview
Problem
Existing trawling systems face challenges in controlling the vertical position of towed objects, leading to issues such as dynamic loads, wire tangling, reduced controllability, and seabed damage, particularly during changes in depth or turns.
Innovation Solution
A control system with movably connected ballast members on towing members, equipped with sensing and detecting means, allows for precise control of the towed object's position by manipulating the ballast members based on seabed distance measurements, using a control unit to adjust the catenary and geometry of the towing system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the towing vessel maintains higher speed to keep the trawl functional, then the trawl maintains its integrity and spreading, but the turn radius increases and maneuverability decreases
Solution Approach 1:
The patent applies dynamics by making the ballast members movable along the towing members, allowing the system to adapt its configuration dynamically. The ballast members can be repositioned to adjust the catenary curve and towing geometry in real-time, enabling the trawl to maintain functionality at lower speeds and during turns without compromising stability or integrity.
2Speed
If the towing vessel reduces speed to improve maneuverability, then turn radius decreases, but the trawl may stall and collapse
Solution Approach 1:
The patent applies preliminary action by proactively adjusting the ballast member positions before and during turns or speed changes. The control system anticipates the need to maintain trawl stability by repositioning ballast members to optimize the catenary curve and towing geometry in advance, preventing stall or collapse before they occur.
Solution Approach 2:
The patent implements feedback through the control system that continuously monitors towing conditions and automatically adjusts ballast member positions. This closed-loop control ensures the trawl maintains optimal configuration during speed variations and turns, preventing instability while enabling improved maneuverability at lower speeds.
3Device complexity
If fixed ballast elements are used to maintain depth, then depth control is simple, but the system lacks adaptability to changing conditions
Solution Approach 1:
The patent transforms the static ballast system into a dynamic one by enabling movable ballast members along the towing members. This allows the system to adapt to changing towing conditions, depths, and maneuvers while maintaining relatively simple control through automated or manual repositioning of the movable ballast elements.
4Force
If the towing wire forms a deep catenary to reduce dynamic loads, then the towing member can absorb more shock, but the controllability of the towed object decreases
Solution Approach 1:
The patent applies segmentation by dividing the traditional single-function towing wire into a segmented system with movable ballast members positioned at specific locations. This segmentation allows different portions of the towing system to perform different functions - the catenary portion absorbs dynamic loads while the ballast members provide controllability, resolving the contradiction between shock absorption and control.
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
Enables reduced trawling speed without compromising integrity, minimizes seabed contact, and enhances control during turns, reducing damage to marine flora and fauna while maintaining optimal catching efficiency.
Implementation Method 1
one or more ballast members movably connected to a respective one of said one or more towing members and controllably movable at least a distance along its respective towing member
Implementation Method 2
the towing member catenary
Data Source
Figure 1~2
Figure 3~5
Figure 6~8
AI summary
A control system for a towed object (1, 6; 20; 30; 50) in or on a body of water comprise one or more towing members (3) extending between the object (1) and a towing vessel (2). One or more ballast members (4) are movably connected to a respective one of said one or more towing members (3) and controllably movable at least a distance along its respective towing member. The towed object (1) may be controlled by moving one or more ballast members (4) on a towing member (3) in order to control the catenary (c) of a towing member (3). Individual ballast members (4) may be manipulated individually in order to correct, preserve or otherwise change the geometry of a trawl.