Vehicle Engine Sound Enhancement Using Real Harmonic Capture
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Solution Overview
Problem
Existing engine sound enhancement methods often produce artificial sounds, especially in sporty engines with rapidly-changing RPM, and require delicate tuning for authenticity, while traditional methods struggle to maintain realism.
Innovation Solution
Using an accelerometer mounted directly on the engine to capture original harmonic content and enhance engine sound in real-time by filtering spurious content with bandpass filters guided by RPM, rather than relying on synthesized signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If digitally synthesized engine sound is used, then sound enhancement can be achieved, but the sound becomes artificial and unresponsive especially in sporty engines with rapidly-changing RPM
Solution Approach 1:
The patent captures the actual engine sound through a sensor (microphone or accelerometer) mounted on the engine, creating a real-time copy of the authentic engine acoustic signature. This captured signal is then processed and enhanced rather than synthesized from scratch, preserving the original engine's unique sound characteristics while allowing for real-time enhancement that responds naturally to RPM changes.
Solution Approach 2:
The patent replaces traditional mechanical sound synthesis methods with electronic signal processing. Instead of using physical acoustic chambers or resonance chambers to generate engine sound, the system uses electronic filtering, amplification, and processing of the captured engine sound signal to achieve enhancement, allowing for more precise and responsive control.
2Reliability
If traditional acoustic sound synthesis is used, then authentic engine sound can be achieved, but delicate tuning of narrowband and broadband sound layers is required
Solution Approach 1:
The system captures the engine's own sound signature directly from the engine using a sensor, allowing the engine to essentially tune itself. The captured signal already contains the authentic harmonic structure and characteristics of that specific engine, eliminating the need for manual tuning of multiple sound layers. The processing system simply enhances what is already there rather than constructing it from separate components.
Solution Approach 2:
The patent changes the approach from adjusting multiple acoustic parameters (narrowband and broadband sound layers) to a single parameter change: amplifying and filtering the captured engine sound signal. This single parameter approach (signal enhancement gain and frequency filtering) replaces the complex multi-parameter tuning process while maintaining authenticity.
3Reliability
If a sensor is mounted inside the engine to capture original sound, then authentic harmonic content can be captured, but the sensor may be exposed to high temperature and mechanical stress
Solution Approach 1:
The patent uses the engine block or engine housing as an intermediary medium. The sensor is mounted on the external surface of the engine rather than inside, and it captures the vibrations and sound that travel through the engine structure. The engine block itself acts as a transmission medium, carrying the authentic harmonic content from the internal combustion processes to the externally mounted sensor, protecting the sensor from direct exposure to extreme conditions while still capturing the original sound.
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 provides a more realistic and authentic engine sound enhancement within the vehicle cabin by utilizing the original engine sound, maintaining sound quality and responsiveness to operating conditions.
Implementation Method 1
an accelerometer mounted on the engine to capture original harmonic content
Implementation Method 2
an accelerometer mounted on the engine to capture original harmonic content
Implementation Method 3
enhance engine sound in real-time by filtering spurious content with bandpass filters guided by RPM
Implementation Method 4
output the enhanced engine sound for playback in the vehicle cabin
Data Source
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AI summary
Embodiments are disclosed for enhancing engine sound. An example method for a vehicle comprises acquiring a signal including harmonic content generated by an engine of the vehicle, upmixing the signal into a plurality of channels for a given number of engine orders, adjusting an order filter for each engine order of the given number of engine orders based on operating conditions of the engine, filtering each channel of the plurality of channels with the corresponding order filter, mixing the filtered channels into a mono output, and outputting the mono output to at least one speaker in the vehicle. The mono output is delayed based on a position of the at least one speaker such that an occupant of the vehicle perceives the mono output as originating from the engine.