Engine Harmonic Enhancement Controller for Realistic Cabin Audio
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Solution Overview
Problem
Modern automobiles, designed to reduce cabin noise, often attenuate engine noise along with road noise using sound dampening materials, resulting in a diminished and unnatural engine sound experience for drivers, particularly in vehicles where engine noise is desired for driving enrichment.
Innovation Solution
An engine harmonic enhancement system that uses a controller to generate a control parameter based on engine load and throttle position signals, applying specific scaling factors to engine harmonic signals to produce a more realistic and dynamic engine noise experience, distinguishing between positive and negative engine loads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If sound dampening materials are used to reduce cabin noise, then overall noise level is reduced, but engine noise becomes unnatural
Solution Approach 1:
The system dynamically changes the parameters of the synthesized engine noise based on actual engine operating conditions. By monitoring engine parameters such as RPM, load, and throttle position, the system adjusts the frequency content, amplitude, and harmonic structure of the synthesized noise to match the actual engine sound characteristics at different operating points, thereby maintaining natural realism despite the presence of sound dampening materials.
Solution Approach 2:
The system makes the synthesized engine noise dynamic rather than static. The audio output continuously adapts to changing engine conditions, with the harmonic content and amplitude modulated in real-time to reflect the actual engine state. This dynamic approach ensures that the synthesized noise remains faithful to the natural engine sound across the full range of operating conditions, even when attenuated by sound dampening materials.
2Object-affected harmful factors
If synthesized engine noise is played through audio system, then engine noise is enhanced, but distinction between positive and negative load is lost
Solution Approach 1:
The system uses feedback from multiple engine sensors (torque, throttle position, RPM) to accurately determine the current operating state and distinguish between positive and negative load conditions. This feedback information is used to dynamically adjust the synthesized noise characteristics, ensuring that the directional information about engine load is preserved and accurately represented in the enhanced audio output.
Solution Approach 2:
The system changes specific parameters of the synthesized noise based on load direction. During positive load (acceleration), the system emphasizes certain harmonic content and amplitude characteristics, while during negative load (deceleration/engine braking), it adjusts the parameters to reflect the different acoustic signature, thereby preserving the distinction between opposing load directions in the enhanced noise output.
Data Source
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AI summary
A controller is configured to receive a first signal representative of a load on an engine and to generate a control parameter based on the first signal, one or more harmonic scaling elements, each configured to receive the control parameter and a different engine harmonic signal of a plurality of engine harmonic signals and to generate a scaled version of the received engine harmonic signal. Each, harmonic scaling element includes a harmonic specific mapping element for mapping the control parameter to a harmonic specific scaling factor, wherein at least some of the harmonic specific scaling factor values of the harmonic specific mapping element are mapped to control parameter values which are associated with a negative load on the engine, and an adjustable gain element for forming a scaled version of the received engine harmonic signal including applying the harmonic specific scaling factor to the received engine harmonic signal.