Engine Harmonic Sound Stage Control with RPM-Based Phase Tuning
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Solution Overview
Problem
Existing engine harmonic enhancement methods fail to dynamically control the sound stage in response to varying engine RPMs and loads, limiting the ability to create a tailored sonic experience for vehicle occupants.
Innovation Solution
The method involves determining fundamental frequencies and harmonics corresponding to engine RPM, calculating gain and phase values as functions of RPM and load, and generating harmonic enhancement signals with adjustable phase and gain differences between channels to control the sound stage width and location, allowing for dynamic positioning of the sound stage based on engine conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If per harmonic phase difference between left and right channel EHE signals is introduced, then sound stage width is controlled, but system complexity increases
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the phase difference parameter between left and right channel EHE signals based on engine RPM. The phase difference is calculated as a function of RPM, allowing the sound stage width to be controlled through parameter modification rather than complex structural changes. This resolves the contradiction by achieving adaptability through parameter control while maintaining relatively simple system architecture.
2Adaptability or versatility
If magnitude difference between front and rear channel EHE signals is introduced, then front-rear controllable sound stage is achieved, but device complexity increases
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the magnitude difference parameter between front and rear channel EHE signals based on engine RPM and load conditions. The magnitude of rear channel signals is controlled relative to front channel signals through RPM-dependent gain adjustments, enabling front-rear sound stage positioning without requiring complex additional hardware. This resolves the contradiction by achieving versatility through parameter control.
3Adaptability or versatility
If dynamic EHE sound stage control is implemented, then acoustic experience is enhanced, but computational requirements increase
Solution Approach 1:
The patent applies periodic action by updating the EHE sound stage parameters at regular intervals based on engine RPM changes rather than continuously. The system calculates phase and magnitude differences at discrete RPM thresholds and maintains these settings until the next threshold is reached. This periodic update approach reduces computational energy consumption while still providing dynamic adaptation to engine conditions, resolving the contradiction between adaptability and energy use.
Data Source
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AI summary
A method to produce a dynamic sound stage for engine harmonic enhancement (EHE). Dynamic refers to the ability to position the sound stage at different positions as the engine operates at various RPMs and load. In order to control the sound stage width, a phase difference can be introduced between a first audio channel (e.g., a left audio channel) and second audio channel (e.g., a right audio channel). In the most general case, the phase difference can be introduced per harmonic per RPM. In this approach, the phase difference can be adjusted such that a vehicle occupant will perceive each harmonic signal to have a particular width. This width can be adjusted independently per RPM regions by tuning the per harmonic phase difference.