Underwater Echo Imaging With Frequency-Segmented Angle Processing

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Solution Overview

Problem

Underwater detection devices using the multi-ping method experience positional errors in target object display on echo images due to rapid rotation of the transmitter and receiver, which causes the reception signal direction to change, incorporating signals from unintended directions.

Innovation Solution

The device generates echo signals by utilizing reception signals at specific frequencies within defined unit rotation angles, extracting dominant signal components, and arranging them to create a signal for each unit angle, thereby suppressing errors in the position of the target object on the echo image.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the transmitter and receiver rotate at high speed to shorten the echo image updating period, then productivity is improved, but measurement precision deteriorates due to positional errors in target object display

Engineering Contradiction:
Improveecho image updating periodVSAvoidposition of target object
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent divides the reception signals into multiple frequency bands and processes each frequency band separately. By segmenting the signal processing based on frequency, the system can associate each reception signal with the correct transmission direction even during high-speed rotation, thereby maintaining measurement precision while achieving high productivity through multi-frequency parallel processing

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the parameter of frequency separation in signal processing. By processing reception signals at different frequencies separately and associating them with corresponding transmission directions, the system resolves the positional error problem caused by high-speed rotation while maintaining the benefits of rapid updating

Inventive Principle:
Principle #35Parameter changes

2Productivity

If multiple transmission waves at different frequencies are transmitted simultaneously to increase rotational speed, then productivity is improved, but loss of information increases due to mixing of reception signals from different directions

Engineering Contradiction:
Improverotational speedVSAvoidreception signal direction
Core Design Contradiction:
ProductivityVSLoss of information

Solution Approach 1:

The patent segments the reception signals by frequency, processing each frequency component separately. This segmentation prevents mixing of direction information from different frequencies, allowing the system to maintain accurate directional information while transmitting multiple frequencies simultaneously for high-speed rotation

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses frequency as an intermediary to distinguish between different transmission directions. By assigning different frequencies to different transmission waves and processing them separately, the system can identify and separate reception signals from different directions, preventing information loss while enabling high-speed multi-frequency operation

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 approach ensures accurate representation of the underwater environment by using the dominant signal components within each section, effectively suppressing errors in a position of a target object displayed on an echo image, allowing for precise detection of underwater features.

Implementation Method 1

a transmitter having one or more ultrasonic transducers, and a receiver having a plurality of ultrasonic transducers

Methodology Applied
Scientific EffectUltrasonic wave transmission: Ultrasound

Implementation Method 2

transmits a transmission wave underwater and detects a target object based on a reflection wave thereof

Methodology Applied
Scientific EffectAcoustic reflection: Reflection

Implementation Method 3

a receiver having a plurality of ultrasonic transducers... converts reflection waves of the first and second pulses into echo signals

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentEP4286889B1Underwater detection device and underwater detection method
Publication Date: 2025.12.10 FURUNO ELECTRIC CO LTD
  • EP4286889B1 patent drawingFigure 1
  • EP4286889B1 patent drawingFigure 2
  • EP4286889B1 patent drawingFigure 3

AI summary

An underwater detection device (1) includes a transmitter (2), a receiver (3), an actuator (4), a controller (11), and a signal processor (20). The transmitter (2) transmits a transmission wave. The receiver (3) receives a reflection wave of the transmission wave. The actuator (4) rotates the transmitter (2) and the receiver (3) in a mutually synchronized fashion. The controller (11) makes the transmitter (2) transmit a plurality of transmission waves at mutually different frequencies (f1, f2, f3, f4) in order, for every given unit rotation angle (Δα01, Δα04). The signal processor (20) generates an echo signal for indication in a direction (D01, D04) of the unit rotation angle (Δα01 Δα04) based on a reception signal at each of the frequencies (f1, f2, f3, f4) acquired from a range of the unit rotation angle (Δα01, Δα04).