Engine Harmonic Sound Stage Tuning Across RPM and Load
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Solution Overview
Problem
Current engine harmonic enhancement (EHE) technologies fail to dynamically adjust the sound stage in response to varying engine RPMs and load, limiting the ability to control the width and location of the sound stage effectively.
Innovation Solution
The method involves determining a fundamental frequency corresponding to the engine RPM, calculating harmonics, gain values, and phase values as functions of RPM, and combining these to generate dynamic harmonic enhancement signals for left and right channels or front and rear channels, with adjustable phase and gain differences to control the sound stage width and location.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional EHE technologies are used, then engine harmonic enhancement is provided, but the sound stage cannot be dynamically adjusted in response to varying engine RPMs and load
Solution Approach 1:
The patent applies dynamics by making the sound stage parameters (width, location, depth) variable and adjustable in real-time based on engine operating conditions. The system dynamically modifies harmonic enhancement signals using time-varying gain values and phase values that respond to changing RPM and load, transforming a static EHE system into an adaptive one that continuously optimizes sound stage characteristics throughout the engine operating range.
Solution Approach 2:
The patent implements parameter changes by systematically varying multiple signal processing parameters including gain values, phase values, and their differences across left/right and front/rear channels. These parameter modifications are functions of engine RPM and load, allowing the sound stage properties to be independently controlled and adjusted without fundamentally changing the system architecture.
2Ease of operation
If per harmonic phase differences are introduced to control sound stage width, then sound stage width control is achieved, but signal processing complexity increases
Solution Approach 1:
The patent applies segmentation by processing each harmonic component independently with its own gain and phase values. Rather than treating the entire signal as a single entity, the system segments the harmonic enhancement signal into individual frequency components (fundamental and harmonics), allowing precise control of sound stage width through per-harmonic phase differences while maintaining systematic organization of the processing operations.
Solution Approach 2:
The patent implements partial action by applying phase differences selectively to specific harmonics rather than uniformly to all frequency components. The system can choose to apply different phase relationships to different harmonic orders, enabling fine-grained control of sound stage width where only certain harmonics contribute to width perception, thus reducing unnecessary processing complexity.
3Ease of operation
If magnitude differences are introduced between front and rear channel signals, then front-rear sound stage control is achieved, but channel separation complexity increases
Solution Approach 1:
The patent applies local quality by applying different gain values to different spatial channels (left/right, front/rear) based on their specific roles in creating the sound stage. Each channel receives tailored magnitude adjustments that reflect its spatial position and function, allowing independent control of sound stage location in the front-rear dimension while maintaining appropriate characteristics for each speaker channel.
4Adaptability or versatility
If dynamic adjustment of sound stage parameters is implemented, then immersive acoustic experience is enhanced, but computational requirements increase
Solution Approach 1:
The patent implements periodic action by updating the gain and phase parameters at regular intervals corresponding to engine operating cycles or RPM changes. Rather than continuously recalculating all parameters at every instant, the system updates sound stage control parameters periodically based on engine state transitions, reducing computational load while maintaining the dynamic responsiveness needed for an immersive acoustic experience throughout the engine operating range.
Data Source
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.