Doppler Log Speed Meter Variable Correction Coefficient
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Solution Overview
Problem
Existing Doppler-type log speed meters face inaccuracies due to varying navigational conditions such as draft state and ship speed, as they use a constant correction coefficient regardless of these changes, leading to measurement errors.
Innovation Solution
A Doppler-type log speed meter with a processor module that determines and applies a variable correction coefficient based on navigational conditions, including draft, ship speed, and water depth, using a multilayer-type log speed meter for accurate flow velocity measurements across different water depths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a constant correction coefficient is used for log speed measurement, then the device complexity is reduced and ease of operation is improved, but measurement precision deteriorates under varying navigational conditions
Solution Approach 1:
The patent implements dynamic correction by switching between multiple correction coefficients based on navigational conditions. The system determines whether the ship is in shallow water or deep water and applies the appropriate correction coefficient accordingly, transforming the static correction approach into a dynamic adaptive system that maintains measurement precision across varying conditions.
Solution Approach 2:
The patent changes the parameter of correction coefficient from a single constant value to multiple variable values based on water depth conditions. By defining different correction coefficients for shallow water and deep water scenarios, the system adapts its correction parameters to match the actual navigational environment, thereby improving measurement accuracy without excessive complexity.
2Ease of operation
If a single correction coefficient is applied regardless of navigational conditions, then ease of operation is improved, but measurement precision deteriorates due to varying draft state and ship speed
Solution Approach 1:
The system performs self-service by automatically determining the appropriate correction coefficient based on measured navigational parameters. The log speed measurement device itself gathers the necessary information (water depth, ship speed) and selects the correct correction coefficient without requiring external intervention or complex manual configuration, thus maintaining ease of operation while improving precision.
Solution Approach 2:
The system uses feedback from measured navigational conditions (draft state, ship speed, water depth) to automatically select the appropriate correction coefficient. This closed-loop approach ensures that the correction coefficient always matches the current operational state, improving measurement accuracy while keeping the operation simple through automated decision-making.
3Measurement precision
If correction coefficient varies with navigational conditions, then measurement precision is improved, but device complexity increases due to multiple correction coefficients
Solution Approach 1:
The patent segments the correction coefficient into distinct categories based on navigational conditions (shallow water vs. deep water). By dividing the correction coefficient management into discrete segments rather than using a continuous complex model, the system achieves improved measurement precision while keeping the device complexity manageable through clear segmentation of operational modes.
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 approach significantly enhances measurement accuracy by dynamically adjusting the correction coefficient according to navigational conditions, providing a more precise log speed calculation.
Implementation Method 1
detects a plurality of reflective waves which are reflected by reflective objects at different water depths corresponding to an acoustic wave emitted toward the seabed
Implementation Method 2
Sound-type (Doppler-type) speed meters of ships have been known as speed meters which measure a log speed of the ship
Data Source
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AI summary
A log speed meter is provided, which may be capable of obtaining a suitable correction coefficient for calculating a log speed based on measured flow velocity according to navigational condition of a ship. The log speed meter may hold information on different correction coefficients according to navigational condition of the ship, measure a first flow velocity at a given water depth in fluid where the ship is floating, acquire the correction coefficient corresponding to the navigational condition of the ship at a timing of measuring the first flow velocity, and correct the first flow velocity based on the acquired correction coefficient to calculate the log speed.