Variable Acoustical Damping for Vehicle Engine Sound Control
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Solution Overview
Problem
Existing acoustical damping systems for vehicle engine intake and exhaust sounds fail to dynamically adjust sound levels in response to varying vehicle use conditions, such as sporty driving or quiet environments, leading to inadequate sound levels for driver and passenger experience.
Innovation Solution
A variable acoustical damping device controlled by a system comprising a controller and selection device, which adjusts the resonance frequency of a Helmholz resonator to either coincide with or shift away from the engine's rotational sound frequency, using control patterns selected based on vehicle conditions like transmission mode, audio device usage, and passenger presence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a fixed Helmholz resonator is used to minimize intake air sound or exhaust air sound, then the noise level at specific frequency is reduced, but the system cannot adapt to different driving conditions requiring different sound levels
Solution Approach 1:
The patent applies the dynamics principle by making the resonator characteristics variable rather than fixed. The controller dynamically adjusts the resonance frequency and damping characteristics of the Helmholz resonator based on detected engine operating conditions (rotational speed, load, temperature). This allows the system to adapt its sound damping performance to different driving conditions, switching between noise reduction mode and sporty driving mode with vigorous sound feedback.
Solution Approach 2:
The patent implements parameter changes by modifying the physical parameters of the resonator system in real-time. The controller changes the resonance frequency parameter and damping coefficient parameter according to sensor inputs. By varying these parameters, the system can optimize sound damping at different frequencies corresponding to different engine speeds, and adjust the overall damping level to provide either quiet operation or vigorous sound feedback as needed.
2Object-affected harmful factors
If the resonance frequency of the resonator is controlled to coincide with the peak frequency of intake air sound, then the overall sound level is reduced, but the sound becomes too low for enjoyable sporty driving
Solution Approach 1:
The system uses dynamics to switch between different operational states. In normal driving conditions, the resonator is configured to coincide its resonance frequency with the peak intake air sound frequency, maximizing noise reduction. In sporty driving conditions, the controller detects the change in operating parameters and dynamically reconfigures the resonator to shift its resonance frequency away from the peak sound frequency, thereby preserving vigorous sound feedback for driver enjoyment.
Solution Approach 2:
The system applies preliminary anti-action by proactively adjusting the resonator characteristics before the driver experiences inadequate sound feedback. The controller continuously monitors engine parameters and preemptively modifies the resonator's damping characteristics to maintain appropriate sound levels for the anticipated driving condition, preventing the problem of insufficient sound feedback before it occurs.
3Object-affected harmful factors
If the resonator is designed to minimize noise during audio playback or quiet conversation, then the sound environment becomes quiet, but the system cannot provide vigorous sound feedback when needed
Solution Approach 1:
The patent employs dynamics to create a multi-state resonator system that can adapt to different acoustic requirements. The controller detects various operational contexts (audio playback mode, quiet conversation mode, sporty driving mode) through sensor inputs and相应地 adjusts the resonator's damping characteristics. This enables the system to provide quiet noise reduction during audio playback or conversation, while maintaining the capability to deliver vigorous sound feedback when sporty driving conditions are detected.
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
Enables dynamic adjustment of intake and exhaust sound levels to provide a more vigorous sound during sporty driving or minimize noise during audio playback or quiet conversations, enhancing the driving experience.
Implementation Method 1
A Helmholz resonator is known as an acoustical damping device. Damping frequency or resonance frequency f of the resonator 90 is determined by cross-sectional area S of the branch tube 94, length L of the branch tube 94 and volume V of the chamber 96
Implementation Method 2
The present invention relates to systems and methods for controlling acoustical damping of intake air sound or exhaust air sound of vehicle engines
Data Source
AI summary
A control system (10) controls a variable acoustical damping device (20) disposed in a sound producing channel (5) of a vehicle engine (1). The control system includes a controller (12) and a selection device (14). The controller is coupled to the variable acoustical damping device and stores a plurality of control patterns (A. B) for different levels of acoustical damping of the acoustical damping device. The selection device outputs a selection signal to the controller so that the controller controls the variable acoustical damping device based on one of the control patterns corresponding to the selection signal.