Adaptive Vehicle Sound Synthesis for Consistent Driver Feedback

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Solution Overview

Problem

New vehicle architectures, such as electric vehicles, lack engine noise, leading to an unexpected silence for drivers, and existing sound synthesis systems struggle to provide optimal audible feedback under varying background noise conditions.

Innovation Solution

A vehicle sound synthesis system that includes a controller communicating with vehicle components to generate a synthesized engine noise (SEN) signal, adjusting its level based on background noise, using a combination of microprocessors, ASICs, and signal processing modules to create a realistic engine sound experience, incorporating Engine Order Cancellation and Real Time Sound Synthesis to mask or enhance engine noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If engine noise is reduced or eliminated in new vehicle architectures, then vehicle noise levels decrease, but driver feedback and expected auditory cues are lost

Engineering Contradiction:
Improvevehicle noiseVSAvoiddriver feedback
Core Design Contradiction:
Object-affected harmful factorsVSLoss of information

Solution Approach 1:

The system creates a synthetic copy of engine noise using audio processing. A microphone captures actual engine noise, and a processor generates a synthetic audio signal that replicates the engine sound characteristics. This synthetic copy is then played through the audio system to provide driver feedback while allowing the actual engine noise to be reduced or eliminated.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The audio system acts as an intermediary between the engine and the driver. Instead of the driver directly hearing engine noise through the vehicle structure, the system uses microphones, processors, and speakers to mediate the sound transmission. This intermediary approach allows selective reproduction of engine sounds while blocking unwanted noise.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of information

If synthetic engine noise is generated to provide driver feedback, then auditory cues are restored, but background noise may mask the synthetic sound

Engineering Contradiction:
Improvedriver feedbackVSAvoidbackground noise masking
Core Design Contradiction:
Loss of informationVSObject-affected harmful factors

Solution Approach 1:

The system dynamically adjusts parameters of the synthetic engine noise based on detected background noise conditions. When background noise levels are high, the system increases the volume and adjusts the frequency characteristics of the synthetic engine sound to ensure it remains audible and provides effective driver feedback.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system uses microphones to continuously monitor background noise levels and adjusts the synthetic engine noise generation accordingly. This feedback loop ensures that the synthetic sound remains audible and effective across varying driving conditions, automatically compensating for changes in ambient noise.

Inventive Principle:
Principle #23Feedback

3Object-affected harmful factors

If the level of synthetic engine noise is increased to overcome background noise, then audibility is improved, but sound quality and realism may deteriorate

Engineering Contradiction:
ImproveaudibilityVSAvoidsound quality
Core Design Contradiction:
Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The system dynamically adjusts multiple parameters of the synthetic engine noise including volume, frequency distribution, and spectral characteristics. Rather than simply increasing overall level, the processor modifies the frequency spectrum to maintain realism - emphasizing frequencies where engine sounds are most characteristic while suppressing frequencies where background noise dominates.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system applies different processing to different frequency bands of the synthetic engine noise. Certain frequency ranges are enhanced to maintain realism and recognizability, while other ranges are adjusted to match background noise conditions. This localized quality adjustment preserves sound quality across varying volume levels.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3807870B1System for adaptive magnitude vehicle sound synthesis
Publication Date: 2023.10.25 HARMAN INT IND INC
  • EP3807870B1 patent drawingFigure 1
  • EP3807870B1 patent drawingFigure 2
  • EP3807870B1 patent drawingFigure 3~4

AI summary

A vehicle sound synthesis system is provided with a loudspeaker, a microphone and a controller. The loudspeaker is adapted to project sound indicative of synthesized engine noise (SEN) within a cabin of a vehicle in response to receiving an adjusted SEN signal. The microphone is disposed in the cabin and adapted to provide a microphone signal having a SEN component and a noise component. The controller is programmed to receive the microphone signal, adjust a SEN signal based on the microphone signal, and provide the adjusted SEN signal to the loudspeaker.