Steering Wheel Speaker Control for Stable In-Car Stereo Imaging

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Solution Overview

Problem

Existing acoustic devices struggle to provide a reliable stereophonic effect in vehicles due to obstacles between speakers and drivers, and the movable steering wheel alters speaker positions, disrupting the intended sound localization.

Innovation Solution

An acoustic device with speakers mounted on the steering wheel, a steering angle detection unit, and a signal processing unit that adjusts filter coefficients based on the steering angle to generate output signals, ensuring a stereophonic effect even when the steering angle is not 0 degrees, and stopping the effect when it becomes impractical to maintain.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If speakers are mounted on the steering wheel to eliminate obstacles between speakers and drivers, then the reliability of sound delivery is improved, but the speaker positions change with steering angle, disrupting the intended sound localization

Engineering Contradiction:
Improvesound delivery reliabilityVSAvoidsound localization precision
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The system dynamically adjusts filter coefficients based on the steering angle to compensate for changes in speaker positions. The control unit receives steering angle information and modifies the acoustic processing parameters in real-time, allowing the system to maintain accurate sound localization despite the speakers moving with the steering wheel rotation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system uses feedback from the steering angle detection unit to continuously monitor and adjust the acoustic output. By incorporating the steering angle as a feedback parameter, the control unit can adapt the filter coefficients to maintain the intended stereophonic effect regardless of the steering wheel's position.

Inventive Principle:
Principle #23Feedback

2Manufacturing precision

If filter coefficients are adjusted based on steering angle to maintain sound localization, then the stereophonic effect is maintained, but the processing complexity increases

Engineering Contradiction:
Improvesound localization precisionVSAvoidsignal processing complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The system pre-calculates and stores filter coefficients for various steering angles in advance. Instead of performing complex real-time calculations, the control unit simply retrieves the appropriate pre-computed coefficients based on the current steering angle, significantly reducing the processing complexity while maintaining sound localization precision.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If the stereophonic effect is maintained at all steering angles, then the sound quality is consistent, but the processing load increases unnecessarily when the effect becomes impractical

Engineering Contradiction:
Improvesound quality consistencyVSAvoidprocessing energy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system changes the operational parameters based on the steering angle, maintaining the stereophonic effect only within a practical range. When the steering angle exceeds certain thresholds making the effect impractical, the system adjusts the filter coefficients to disable or simplify the stereophonic processing, reducing energy consumption while maintaining quality when needed.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3547717B1Acoustic device and mobile object
Publication Date: 2023.12.13 SOCIONEXT INC
  • EP3547717B1 patent drawingFigure 1~2
  • EP3547717B1 patent drawingFigure 3
  • EP3547717B1 patent drawingFigure 4

AI summary

An acoustic device (1) that provides a stereophonic effect to a driver of a mobile object includes: a plurality of speakers (an L channel speaker (11) and an R channel speaker (12)) mounted on a steering wheel (10) that controls a traveling direction of the mobile object; a steering angle detection unit (13) configured to detect a steering angle (α) of the steering wheel (10); and a signal output unit (2) configured to output a plurality of output signals obtained by performing, on a sound signal, a process relating to the stereophonic effect and depending on the steering angle (α), respectively to the plurality of speakers.