Vehicle Seat Speaker Phase Control for Adjustable Tactile Feedback
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Solution Overview
Problem
Existing in-vehicle audio systems provide inconsistent and subjective tactile feedback through vehicle seat vibrations, which may be annoying to some listeners and cannot be easily adjusted.
Innovation Solution
An in-vehicle speaker system with multiple low-frequency speakers mechanically coupled to a vehicle structure, facing in different directions, allows for adjustable tactile feedback control by varying input signals and phases to match listener preferences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a woofer is used to improve audio quality and provide tactile feedback, then the audio experience is enhanced for some listeners, but the tactile feedback becomes annoying for other listeners
Solution Approach 1:
The system dynamically adjusts the tactile feedback level by controlling the relative phases of multiple speakers. The controller can switch between different phase configurations (e.g., 0° phase difference for maximum tactile feedback, 180° phase difference for minimal tactile feedback), allowing the tactile feedback characteristic to change adaptively based on listener preferences while maintaining audio quality.
Solution Approach 2:
The invention changes the phase parameter of the audio signals sent to different speakers to control tactile feedback. By adjusting the phase difference between speakers (e.g., using first and second phases that are 0°, 90°, or 180° apart), the system can modulate the vibration amplitude and thus the tactile feedback intensity independently of the audio volume.
2Force
If the volume of audio playback is increased to enhance tactile feedback, then the tactile effect is stronger, but the tactile feedback becomes more annoying to listeners
Solution Approach 1:
The system independently controls tactile feedback strength through phase manipulation rather than relying solely on volume increase. The controller can maintain moderate audio volume while achieving strong tactile feedback by using constructive interference (0° phase difference), or conversely, reduce tactile feedback to acceptable levels even at high volume by using destructive interference (180° phase difference).
Solution Approach 2:
Instead of using mechanical volume control to adjust tactile feedback, the system replaces this with a signal processing approach using phase modulation. This allows tactile feedback control to be achieved through electrical signal manipulation rather than mechanical amplitude adjustment, providing finer control and independence from volume settings.
3Device complexity
If a single woofer is used to provide tactile feedback, then the system is simple, but the tactile feedback cannot be adjusted to different levels
Solution Approach 1:
The system segments the tactile feedback control by using multiple speakers (at least two) with independent phase control. Each speaker can be controlled with a different phase angle, allowing the tactile feedback to be adjusted by changing the relative phases. This segmentation enables adjustability while keeping each individual speaker simple in design.
Solution Approach 2:
The multiple speakers serve dual functions: they produce audio output and they generate tactile feedback through their relative phase relationships. The same speakers that deliver the music also create the vibration effects, eliminating the need for separate tactile feedback devices while providing adjustable control over the feedback level.
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 personalized tactile feedback adjustment, enhancing the audio experience by allowing listeners to choose between no tactile feedback and maximum tactile feedback, independent of audio volume settings.
Implementation Method 1
Vibrations caused by the speaker are transmitted into the vehicle structure. A listener may obtain tactile feedback by being in touch with the vehicle structure.
Data Source
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AI summary
The disclosure relates to an in-vehicle speaker system comprising at least one first low frequency speaker arranged to face in a first direction; and at least one second low frequency speaker arranged to face in a second direction, wherein the first and second speakers are mechanically coupled to a vehicle seat to generate tactile feedback to a user in the seat, and wherein the first and second directions are different from one another, in particular opposite to one another, the in-vehicle speaker system further comprising a controller to control input voltages of the first and second speakers relative to one another, thereby to adjust the amount of said tactile feedback. The disclosure further relates to method of providing tactile feedback in a vehicle seat.