Underwater Vehicle Position Deviation for Water Current Profiling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for determining water current velocity profiles in marine environments are inaccurate, costly, and environmentally disruptive, particularly due to side lobe interference and the need for expensive equipment, which hinders precise navigation and positioning of underwater vehicles and nodes.
Innovation Solution
A method involving a batch of underwater vehicles that record deviations from predefined estimated positions to actual positions, using hydrodynamic models and real-time inertia measurements, to calculate updated horizontal water current velocities, allowing for high-resolution profiles without new hardware, reducing the need for extensive acoustic ranging and enabling more accurate node deployment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If ADCP is used to measure water current velocity profile, then current velocity data can be obtained, but side lobe interference causes loss of data close to the boundary (6-12% of water column)
Solution Approach 1:
The patent replaces the acoustic Doppler current profiler (ADCP) system with a mechanical tracking system. Underwater vehicles are equipped with position recording devices that track their actual positions and compare them against planned positions. The deviation data is used to calculate water current velocity profiles, substituting the acoustic field-based ADCP method with a mechanical position-tracking approach that avoids side lobe interference issues.
2Measurement precision
If conventional current meter measurement equipment is used, then current profile data can be obtained, but the equipment is costly and physically heavier and volumously larger in deeper waters
Solution Approach 1:
The patent makes underwater vehicles serve multiple functions: they perform their primary mission tasks while simultaneously acting as mobile current measurement platforms. The vehicles use their own position tracking and navigation systems to collect deviation data for current profile calculation, eliminating the need for separate, specialized current meter equipment and reducing overall system weight and volume.
Solution Approach 2:
The underwater vehicles use their own built-in position recording devices, navigation systems, and propulsion mechanisms to measure water current velocities. The vehicles serve themselves by utilizing their operational data (position deviations from planned paths) to generate current profile information, without requiring external measurement equipment.
3Measurement precision
If ADCP is deployed to measure water current velocity, then velocity profile can be produced, but it contributes to noise pollution in the ocean
Solution Approach 1:
The patent replaces the acoustic-based ADCP system with a mechanical position-tracking system. Instead of emitting acoustic pulses that create noise pollution, the system uses underwater vehicles that record their positions and calculate current velocities from positional deviations. This mechanical approach eliminates the acoustic noise generation inherent in ADCP operations.
4Measurement precision
If batch of underwater vehicles are deployed to record position deviations, then updated water current velocity profile can be calculated, but requires processing of deviation data from multiple vehicles
Solution Approach 1:
The patent combines deviation data from multiple underwater vehicles into a consolidated data set for calculating the water current velocity profile. By merging position information from several vehicles operating in the same water column, the system achieves more accurate and representative current velocity measurements while sharing the processing load across the batch of vehicles.
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 method provides a precise, cost-effective, and environmentally friendly way to determine water current profiles, improving navigation and positioning of underwater units, reducing noise pollution, and enabling efficient deployment of seismic nodes with enhanced accuracy and reduced operational costs.
Implementation Method 1
The vehicle is by first means determining an actual position
Implementation Method 2
using hydrodynamic models and real-time inertia measurements, to calculate updated horizontal water current velocities
Data Source
AI summary
The invention relates to a method for determining a water current velocity profile in a water column by registration of a deviation between a first position and a second position of an underwater vehicle travelling in the water column. A batch of underwater vehicles is deployed from a surface vessel into the water. The vehicle(s) steers to the first position, which for the first batch is a predefined estimated position (PEP). The vehicle is by first means recording the second position, which is the actual position (AP). The difference ΔP between the predefined estimated position PEP and the actual position is registered and based on the difference a deviation data set is calculated. An updated current profile or stack of horizontal water current velocities UV is determined.