Audio Control System Mitigating Tire Noise via Active Anti-Noise
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Solution Overview
Problem
Vehicle tires can produce unexpected noise within the passenger cabin due to differences in shape and construction, detracting from the driving experience by not matching consumer expectations of normal sounds associated with vehicle operation.
Innovation Solution
An audio control system that uses a Fourier Transform module to determine the frequencies corresponding to wheel rotational speeds and applies sound through speakers to mitigate tire noise, ensuring a more pleasurable aural experience by canceling or attenuating tire noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If tire shape and construction are varied to improve vehicle performance, then vehicle handling and grip are enhanced, but unexpected noise is generated within the passenger cabin
Solution Approach 1:
The system captures the harmful tire noise signal and transforms it into a beneficial anti-noise signal through active noise control. The microphone array records the noise, the processor analyzes it to determine frequency and amplitude, then generates an inverted signal that when played through speakers cancels the original noise, converting the harmful acoustic wave into a beneficial noise-reduction mechanism
Solution Approach 2:
The patent introduces several intermediary elements between the noise source and the passenger cabin. These include microphone arrays that capture noise, processors that analyze and transform the noise signal, and speakers that generate anti-noise. These intermediaries mediate the noise transmission path, allowing the system to control and reduce tire noise while maintaining the performance benefits of varied tire construction
2Use of energy by moving object
If conventional powertrain sounds are altered to improve fuel efficiency, then energy consumption is reduced, but consumer expectations of normal vehicle sounds are not met
Solution Approach 1:
The system applies preliminary anti-action by generating anti-noise signals before the harmful sounds fully propagate into the passenger cabin. The microphone array continuously monitors tire noise, the processor preemptively calculates the required anti-noise parameters, and the speakers output compensating sounds that cancel the unwanted frequencies before they can significantly affect passenger comfort
Solution Approach 2:
The system dynamically changes acoustic parameters including frequency, amplitude, and phase of sound waves. The processor analyzes the tire noise parameters in real-time and adjusts the anti-noise signal parameters accordingly, creating a dynamic sound profile that adapts to varying driving conditions while maintaining fuel efficiency benefits
Data Source
AI summary
A Fourier Transform (FT) module configured to determine amplitudes of acceleration at predetermined orders, respectively, by performing a FT on a plurality of values of acceleration associated with a wheel. An order module is configured to identify one of the predetermined orders where one of the amplitudes is greater than a predetermined value and to, based on the one of the amplitudes and a rotational speed of the wheel, determine an order of a frequency corresponding to the rotational speed of the wheel. A sound control module is configured to set characteristics for outputting sound at the order of the frequency corresponding to the rotational speed of the wheel. An audio driver module is configured to, based on the characteristics, apply power to a speaker within a passenger cabin of the vehicle at the order of the frequency corresponding to the rotational speed of the wheel.