Adaptive Acoustic Control Device for Vehicle Sound Field Management
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Solution Overview
Problem
The existing sound reproduction systems in vehicles lack adaptive control mechanisms to maintain effective sound field management when the sound field characteristics in the vehicle compartment change, leading to inadequate sound control.
Innovation Solution
An acoustic control device that utilizes adaptive finite impulse response filters to control speaker sound pressures, incorporating sound detectors, a control signal generating unit, a sound field characteristic learning unit, and a control filter updating unit to ensure sound pressure differences between viewing and quiet areas are maintained at a predetermined level.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a fixed control filter is used in the sound reproduction system, then the system structure is simple, but the system cannot adapt when sound field characteristics change
Solution Approach 1:
The control filter is changed from a fixed structure to a dynamic adaptive structure. The control filter updating unit continuously updates the control filter coefficients based on feedback from sound detectors and reference signals, enabling the system to adapt to changing sound field characteristics in the vehicle compartment.
Solution Approach 2:
A feedback mechanism is introduced where sound detectors detect actual sound pressures in different regions, and the control filter updating unit uses this feedback along with reference signals to sequentially update the control filter. This closed-loop feedback enables the system to maintain appropriate sound control despite sound field changes.
2Measurement precision
If sound pressure is increased in the viewing area, then sound clarity is improved, but sound pressure in quiet areas also increases
Solution Approach 1:
The control filter is designed to create different sound pressure characteristics in different spatial regions. By updating the control filter based on sound field characteristics between speakers and sound detectors in specific regions, the system achieves high sound pressure in the viewing area while maintaining low sound pressure in quiet areas, providing region-specific sound quality.
Solution Approach 2:
The vehicle compartment is divided into distinct regions (viewing area and quiet areas) with different sound pressure requirements. The control system segments the sound field control by using multiple sound detectors in different regions and updating the control filter to satisfy different sound pressure conditions in each segmented region.
Data Source
AI summary
An acoustic control device includes a control signal generating unit configured to perform signal processing on a sound source signal by a control filter, which is an adaptive FIR filter, to generate a control signal that controls speakers, and a control filter updating unit configured to update sequentially and adaptively the control filter in a manner that a difference between a sound pressure in a viewing area and a sound pressure in a quiet area becomes a predetermined level.