Vehicle Engine Sound Enhancement Using Real-Time Harmonic Filtering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for enhancing vehicle engine sound often result in artificial or unresponsive sounds, particularly for sporty engines with rapidly-changing RPM, and require delicate tuning processes for authentic acoustic synthesis.
Innovation Solution
The original engine sound is measured using an accelerometer mounted directly on the engine block, and its harmonics are enhanced in real-time by filtering out spurious content, creating a more realistic sound enhancement within the vehicle cabin by using the original sound as a source rather than synthesized signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If digitally synthesized engine sound is used based on current operating conditions, then the sound enhancement can be adjusted to match desired engine sound, but the sound becomes artificial and unresponsive for sporty engines with rapidly-changing RPM
Solution Approach 1:
The patent uses a microphone to capture the actual engine sound and creates a digital copy of the original engine acoustic signal. This copied signal is then processed through filtering and synthesis to enhance specific frequency ranges while preserving the authentic characteristics of the original engine sound, rather than generating entirely artificial synthesized sound waves.
Solution Approach 2:
The patent introduces an intermediary processing system that captures the original engine sound, filters it to remove spurious content, and synthesizes enhanced harmonics. This intermediary process allows the system to maintain authenticity by basing the enhancement on real engine sound rather than pure synthesis, while still achieving the desired sound modification.
2Reliability
If traditional acoustic sound synthesis is used with layers of narrowband and broadband sound, then authentic engine sound can be achieved, but a delicate tuning process is required
Solution Approach 1:
The patent changes the approach from traditional multi-layer acoustic synthesis to a parameter-based filtering system. Instead of manually tuning multiple narrowband and broadband sound layers, the system uses digital filters to selectively enhance specific frequency ranges and harmonics of the captured engine sound, simplifying the tuning process while maintaining authenticity.
Solution Approach 2:
The patent replaces the traditional mechanical/acoustic synthesis approach with a digital signal processing system. The original engine sound captured by the microphone is processed through digital filtering and harmonic enhancement algorithms, substituting the complex mechanical tuning of acoustic layers with computationally efficient digital signal manipulation.
3Measurement precision
If a sound pressure sensor such as a microphone is used to capture engine sound, then the original engine sound can be captured, but all other sound artifacts occurring close to the engine are also captured
Solution Approach 1:
The patent extracts the desired engine sound signal from the captured audio by using digital filtering to isolate and enhance specific frequency ranges corresponding to engine harmonics. The filtering process separates the authentic engine sound from unwanted sound artifacts, removing only the harmful frequency components while preserving the original engine acoustic characteristics.
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 authentic and responsive engine sound enhancement, maintaining the engine's natural sound characteristics while adjusting to operating conditions, ensuring a realistic and enhanced auditory experience for drivers.
Implementation Method 1
a sensor such as an accelerometer is installed directly onto the engine block, which captures the harmonic content originally generated by the engine
Implementation Method 2
the engine harmonics may be enhanced in real-time by filtering the spurious content
Data Source
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.