Sonar Stereo Audio Signal Generation via Directional Segmentation

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Solution Overview

Problem

Conventional sonar systems struggle to effectively separate and locate individual sound sources in a noisy environment, as louder background noise masks weaker sound signals, making it difficult to distinguish between spatially separable sound sources.

Innovation Solution

A device and method that processes only selected directional signals from a sonar system to create a stereo audio signal, simulating human hearing and ear alignment, allowing for better separation of sound sources by weighting and delaying signals based on their amplitude and position relative to the main listening direction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If all directional signals from a sonar system are processed and reproduced simultaneously, then complete spatial coverage is achieved, but weaker sound sources are masked by louder background noise

Engineering Contradiction:
Improvedetection reliabilityVSAvoidnoise masking
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent segments the complete set of directional signals into multiple selectable groups or subsets. Instead of processing all directional signals simultaneously, the system divides them into manageable segments that can be selectively processed and reproduced, allowing weaker signals to be heard without being masked by louder ones.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies partial action by processing only a selected portion of the available directional signals rather than all of them. This selective processing reduces the overall noise level and allows weaker sound sources to be detected without being overwhelmed by the complete signal set.

Inventive Principle:
Principle #16Partial or excessive action

2Quantity of substance

If multiple directional signals are reproduced simultaneously through a mono audio signal, then all sound sources are captured, but target separation becomes impossible due to signal mixing

Engineering Contradiction:
Improvesignal quantityVSAvoidtarget separation information
Core Design Contradiction:
Quantity of substanceVSLoss of information

Solution Approach 1:

The patent transitions from mono audio reproduction to stereo audio reproduction, adding a spatial dimension to the signal output. By assigning directional signals to left and right audio channels with appropriate weighting and delay, the system creates a stereo sound field that preserves directional information and enables target separation through spatial cues.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Measurement precision

If directional signals are weighted and delayed to simulate human hearing, then directional resolution is improved, but the system complexity increases

Engineering Contradiction:
Improvedirectional resolutionVSAvoidsignal processing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by systematically adjusting weighting factors and time delay parameters for different directional signals based on their azimuth angles. These parameter modifications simulate human ear response and improve directional resolution, while the systematic approach keeps the complexity manageable through consistent mathematical relationships.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2212709B1Device and method for generating a stereo audio signal
Publication Date: 2011.03.23 ATLAS ELEKTRONIK GMBH
  • EP2212709B1 patent drawingFigure 1
  • EP2212709B1 patent drawingFigure 2
  • EP2212709B1 patent drawingFigure 3

AI summary

The invention relates to a device and a method for generating a stereo audio signal (11, 14) from underwater sound signals received by means of a sonar system. The sonar system comprises a receiver antenna (1) having a reference direction (BR) fixed to the antenna and a plurality of underwater sound receivers (2), a direction generator (6), and a stereo mixer (7). The underwater sound receivers (2) acquire received signals (3, 5) from the underwater sound signals and provide said signals to a direction generator (6). The direction generator (6) generates direction signals (8) by directionally dependent time delay and cophasally combining the received signals and providing said signals to the stereo mixer (7). Each direction signal (8) is associated with a primary receiving direction (HR) as a function of the respective time delay, said primary receiving direction being disposed in an acoustic monitoring plane (UE) and being pivoted relative to the reference direction (BR). A main listening direction (63) and at least one monitoring sector (61) are located in the monitoring plane (UE), one or more adjacent primary receiving directions (HR) being located in said monitoring sector and an imaging sector (62) in an imaging plane (AE) spanned by the stereo audio signal (14) being associated with said monitoring sector. A left and right audio signal (43, 44) of the stereo audio signal (14) may be generated by means of the stereo mixer (7) for playback by means of an acoustic stereo playback unit (13), wherein both audio signals comprise cumulative signals of weighted and time-delayed direction signals (8). One or more monitoring sectors (61) may be selected, wherein the stereo mixer (7) processes only the direction signals (8) for forming the left and right audio signal (43, 44) having primary receiving directions (HR) in the selected monitoring sector(s) (61).