Vehicle Audio System Localization Using Inaudible Chirp Signals
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Solution Overview
Problem
Current methods for localizing mobile devices within vehicles are inefficient and do not accurately determine their position, especially in noisy environments, as they rely on complex audio signal processing and may disturb passengers with audible frequencies.
Innovation Solution
A method and system that utilize a vehicle-mounted audio system with multiple speakers to emit an acoustic signal, which the mobile device records, allowing for the calculation of arrival times and positions based on time-of-arrival or time-difference-of-arrival methods, using high-frequency, inaudible chirp signals to minimize noise interference and enhance signal differentiation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If complex audio signal processing is used to localize mobile devices, then localization capability is achieved, but noise interference increases and measurement precision decreases
Solution Approach 1:
The patent changes the frequency parameter of the acoustic signal to ultra-high frequencies (above 20kHz) that are inaudible to humans. This parameter change allows the system to achieve precise localization measurements without the harmful effect of noise interference, as the high-frequency chirp signals can be clearly distinguished from ambient noise and do not disturb passengers
Solution Approach 2:
The patent extracts only the necessary components for localization by using unidirectional signal transmission from vehicle speakers to mobile device microphones. This extraction approach isolates the localization function from other audio processing complexities, enabling precise measurement while filtering out unnecessary noise interference through selective signal processing
2Difficulty of detecting and measuring
If audible frequency signals are used for localization, then signal detection is easier, but passenger disturbance increases
Solution Approach 1:
The patent changes the frequency parameter from audible ranges to ultra-high frequencies (above 20kHz). This parameter change resolves the contradiction by making the signals undetectable to human ears (eliminating passenger disturbance) while remaining easily detectable by mobile device microphones, which can accurately capture and process these high-frequency chirp signals for localization purposes
3Device complexity
If simple localization methods are used, then system complexity is reduced, but localization accuracy decreases
Solution Approach 1:
The patent employs periodic chirp signal transmission from vehicle speakers at controlled intervals. This periodic action simplifies the system by using repetitive, predictable signal patterns that are easy to generate and process, while simultaneously improving localization accuracy through time-of-arrival measurements that leverage the known periodic structure of the transmitted signals
Solution Approach 2:
The patent introduces high-frequency chirp signals as an intermediary carrier for localization information. These chirp signals serve as a simple yet effective mediator that enables accurate time-of-arrival measurements without requiring complex processing systems, thus achieving high localization accuracy with minimal system complexity
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
This approach accurately localizes mobile devices within vehicles by filtering and processing high-frequency acoustic signals, reducing noise interference and passenger disturbance, thereby improving the precision and usability of in-vehicle device localization.
Implementation Method 1
triggering an audio system, which includes a plurality of speakers, mounted on a vehicle to play an acoustic signal
Implementation Method 2
obtaining a recording of playback of the acoustic signal from the mobile device
Data Source
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AI summary
Method and system for localizing a mobile device in a vehicle is provided. The method may include: triggering an audio system mounted on a vehicle, which audio system includes a plurality of speakers, to play an acoustic signal; and calculating a position of a mobile device in the vehicle based on a recording of the audio system's playback of the acoustic signal, which is recorded by the mobile device, and position information of the plurality of speakers. Localization may be more accurate.