Automotive Audio Playback Verification Using Embedded ID Signals

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Solution Overview

Problem

Current methods for monitoring safety-related audio signals in automotive applications are complex and prone to errors due to ambient noise and changing signal path conditions, failing to reliably verify the correct playback of audio signals beyond the digital domain.

Innovation Solution

A system and method that combines an audio signal with an identification signal, using frequency-shift keying to overlay a modulated carrier frequency, allowing for simple verification of the identification signal's presence in the played-back sound, reducing processing complexity and increasing reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If full frequency domain analysis is used to monitor audio signals, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improvedetection accuracyVSAvoidprocessing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts only the essential verification information from the audio signal by using digital signal processing to identify specific acoustic features (frequency, duration, energy levels) rather than analyzing the entire signal. This extraction approach maintains detection accuracy while significantly reducing processing complexity compared to full frequency domain analysis.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The monitoring process is segmented into distinct stages: signal acquisition, feature extraction, verification against expected parameters, and failure detection. This segmentation allows each stage to be optimized independently, reducing overall system complexity while maintaining measurement precision through focused analysis at each step.

Inventive Principle:
Principle #1Segmentation

2Reliability

If ambient noise and changing signal path conditions are accounted for, then reliability is improved, but device complexity increases

Engineering Contradiction:
Improveverification reliabilityVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system uses feedback by comparing the verified audio signal characteristics against pre-stored expected values and adjusting the verification process accordingly. This feedback mechanism allows the system to adapt to changing conditions (ambient noise, signal path variations) without requiring complex real-time environmental modeling, thereby improving reliability while controlling system complexity.

Inventive Principle:
Principle #23Feedback

3Device complexity

If digital domain checksum verification is used, then device complexity is reduced, but measurement precision deteriorates

Engineering Contradiction:
Improveprocessing complexityVSAvoidanalog signal monitoring capability
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent transitions from purely digital domain verification to incorporating acoustic domain verification by analyzing actual audio signal characteristics (frequency, duration, energy). This dimensional change from digital data checking to physical acoustic measurement enables monitoring of analog signal integrity while maintaining manageable complexity through focused feature extraction rather than full signal analysis.

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

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 minimizes the impact of ambient noise and changing signal conditions, providing reliable verification of audio signal playback with reduced complexity, ensuring accurate detection of errors in the audio chain.

Implementation Method 1

using frequency-shift keying to overlay a modulated carrier frequency

Methodology Applied
Scientific EffectFrequency-shift keying: Phase Modulation

Data Source

PatentEP4325893A1Monitoring of audio playback for automotive applications
Publication Date: 2024.02.21 APTIV TECHNOLOGIES AG
  • EP4325893A1 patent drawingFigure 1
  • EP4325893A1 patent drawingFigure 2~3A
  • EP4325893A1 patent drawingFigure 3B~4

AI summary

The present invention relates to a system (1) for playback and monitoring of playback of audio signals (8), comprising: an audio signal generating module (2) configured to generate an audio signal (8); an identification signal generating module (3) configured to generate an identification signal (9) associated with the audio signal (8); a combining module (4) configured to combine the audio signal (8) and the identification signal (9) into a combined audio signal (10); a playback module (5) configured to play back a sound based on the combined audio signal (10); and a verifying module (6) configured to process the played back sound in order to verify that the played back sound contains the identification signal (9). The invention also relates to a corresponding method.