Mobile Device Locator Using Orthogonal Acoustic Patterns
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Solution Overview
Problem
Existing technologies fail to accurately determine the location of a mobile device within a vehicle cabin, leading to unsafe usage of smartphone apps during driving, as they cannot distinguish between the driver and passengers, resulting in unnecessary restriction of functionality for passengers.
Innovation Solution
An audio system in the vehicle transmits orthogonal acoustic detection patterns via stereo speakers, which are correlated by a mobile device's microphone to calculate the time difference of arrival, determining the device's location and adjusting its operation mode accordingly, such as locking the screen if near the driver.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If acoustic detection patterns are transmitted via stereo speakers to locate mobile devices, then the ability to distinguish driver from passenger location is improved, but the device complexity and energy consumption increase
Solution Approach 1:
The system divides the acoustic detection into separate orthogonal patterns transmitted through different stereo speakers. Each speaker transmits a distinct detection pattern (first pattern via first speaker, second pattern via second speaker), allowing the mobile device to determine its location by comparing arrival times of these segmented acoustic signals at different microphones.
Solution Approach 2:
The existing stereo speaker system and mobile device microphone are made multi-functional. The speakers not only play audio but also transmit orthogonal detection patterns for location determination. The microphone not only captures audio but also detects the arrival times of acoustic patterns from different speakers, enabling location tracking using existing hardware.
2Measurement precision
If orthogonal acoustic detection patterns are transmitted sequentially with time offset, then location determination accuracy is improved, but the time required for detection increases
Solution Approach 1:
The system transmits orthogonal acoustic detection patterns in a periodic sequential manner with a predetermined time offset between them. The first detection pattern is transmitted at a first time, and the second detection pattern is transmitted at a second time with a known time offset. This periodic transmission allows the mobile device to calculate arrival time differences while maintaining a balanced detection interval.
3Reliability
If the system restricts mobile device functionality when near the driver, then driving safety is improved, but passenger usability deteriorates
Solution Approach 1:
The system applies different operational restrictions based on the local location of the mobile device within the vehicle cabin. When the device is detected near the driver's position (determined through acoustic pattern analysis), restrictive measures such as blocking app usage or displaying warnings are applied. When the device is detected near passenger positions, full functionality is maintained, allowing passengers to use apps freely.
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
Accurately locates the mobile device within the vehicle cabin, enabling safe operation by distinguishing between driver and passenger locations, thereby preventing unsafe usage of apps while driving without restricting passengers.
Implementation Method 1
a time difference of arrival module to determine a time difference of arrival of the first acoustic signal and the second acoustic signal
Implementation Method 2
determine a first time value from a cross-correlation of the first acoustic signal and the first detection pattern; and determine a second time value from a cross-correlation of the second acoustic signal and the second detection pattern
Implementation Method 3
an audio system for a vehicle, the audio system being configured to transmit an acoustic signal for determining the location of a mobile device in a vehicle cabin
Data Source
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AI summary
A method and apparatus of determining the position of a mobile device in a region of a vehicle cabin are described. The mobile device has a speaker and at least one microphone. The vehicle has an audio system comprising at least two speakers. The mobile device detects first and second acoustic signals respectively transmitted via the first and second vehicle speaker. The acoustic signals comprise a respective detection pattern. The detection patterns are mutually orthogonal. The detected acoustic signals may be compared or correlated with the detection patterns and a respective matched acoustic signal generated. The location of the mobile device within a region of the vehicle cabin may be determined based on the time difference of arrival of the first matched acoustic signal and the second matched acoustic signal. The mode of operation of the mobile device may be set or changed dependent on the location of the mobile device.