Engine Harmonic Sound Management for Hybrid Power Transitions

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Solution Overview

Problem

Existing engine harmonic enhancement systems fail to accurately replicate the natural sound of vehicle engines, especially in quiet vehicles like electric ones, and struggle to provide a consistent sonic experience during transitions between internal combustion and electric power in hybrid vehicles.

Innovation Solution

An active sound management system that includes a harmonic extractor device capable of determining the fundamental frequency of engine harmonics from RPM signals and a harmonic modifier that adjusts these harmonics based on target values using lookup tables and vehicle state parameters to produce a natural and consistent engine sound experience.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If existing engine harmonic enhancement systems are used, then engine sound can be enhanced in the vehicle cabin, but the system fails to accurately replicate the natural sound of vehicle engines

Engineering Contradiction:
Improveaccuracy of engine sound replicationVSAvoidconsistency of sonic experience during power transitions
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The system dynamically adjusts harmonic parameters based on real-time engine operating conditions including RPM, load, and power source status. The harmonic enhancement levels and frequency characteristics are continuously modified to match the actual engine sound profile across different operating states, ensuring accurate replication and consistent experience during transitions between internal combustion and electric power modes.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes multiple acoustic parameters simultaneously including harmonic frequency, amplitude, and spectral distribution based on engine operating conditions. By adjusting these parameters dynamically according to RPM and load data, the system accurately replicates the natural variation in engine sound characteristics across different operating ranges while maintaining consistency during power transitions.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If harmonic enhancement is applied to improve engine sound in the cabin, then the sonic experience is improved, but excessive noise levels may occur outside the vehicle

Engineering Contradiction:
Improvequality of engine sound experienceVSAvoidnoise levels outside vehicle
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The system applies harmonic enhancement selectively to specific frequency ranges and harmonics that are perceptible and desirable within the vehicle cabin environment. By targeting specific acoustic bands that matter for driver feedback while limiting overall sound pressure level increases, the system improves in-cabin sonic experience without generating excessive external noise that would be harmful to surrounding environments.

Inventive Principle:
Principle #3Local quality

3Measurement precision

If the system accurately extracts and modifies harmonics to provide natural engine sound, then the sound experience is enhanced, but the system complexity increases

Engineering Contradiction:
Improveaccuracy of harmonic extractionVSAvoidcomplexity of sound processing system
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The sound processing system is divided into distinct functional modules including harmonic extraction, parameter analysis, enhancement calculation, and output synthesis. Each module handles a specific aspect of the sound processing task, allowing for independent optimization and simplification of individual components while maintaining overall system accuracy in harmonic extraction and modification.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3424043B1Vehicle engine sound management
Publication Date: 2024.01.24 BOSE CORP
  • EP3424043B1 patent drawingFigure 1
  • EP3424043B1 patent drawingFigure 2
  • EP3424043B1 patent drawingFigure 3

AI summary

An active sound management system (10) comprises a transducer (103) that senses an actual sound or vibration from a sound generating source (102) and generates a transducer signal (132) in response to sensing the actual sound or vibration; a harmonic extractor device (104) that extracts a plurality of harmonics from the transducer signal; and a harmonic modifier device (106) that adjusts a feature of the extracted harmonic to be within a predetermined threshold with respect to a target harmonic corresponding to a desired sound.