Portable Device Audio Path Detection via Test Signal
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Solution Overview
Problem
In automotive environments, existing technologies fail to reliably determine whether an audio path is operational between a portable device and a vehicle's head unit, leading to missed audio outputs due to volume settings or inactive speakers, even when a connection is established at the physical layer.
Innovation Solution
A portable device generates a test audio signal, either in audible or inaudible frequencies, and uses its embedded microphone or the head unit's microphone to determine if the audio signal is converted to sound, ensuring an operational audio path for navigation instructions and other audio outputs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a connection is established at the PHY layer between portable device and head unit, then connectivity is achieved, but audio path operational status cannot be reliably determined
Solution Approach 1:
The portable device generates a test audio signal, transmits it to the head unit, and then uses a microphone to detect whether the signal was successfully converted to sound and transmitted. This feedback loop provides reliable information about the actual audio path operational status, resolving the contradiction between connectivity and audio path reliability.
Solution Approach 2:
Before providing actual navigation instructions or audio output, the portable device performs a preliminary test by generating a test audio signal to verify the audio path is operational. This preliminary action prevents loss of important audio information by ensuring the audio path works before critical audio is transmitted.
2Ease of operation
If test audio signal is generated at audible frequency, then audio path detection is straightforward, but user may hear the test signal causing distraction
Solution Approach 1:
The portable device changes the frequency parameter of the test audio signal to an inaudible range (ultrasonic or infrasonic frequencies). This allows the test signal to be detected by the microphone for audio path verification without causing user distraction, resolving the contradiction between detection ease and harmful effects.
Solution Approach 2:
Instead of using the actual audio content that would be transmitted, the portable device creates a copy or substitute test signal with modified parameters (inaudible frequency). This copy serves the detection purpose without producing the harmful effect of user distraction.
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 method allows the portable device to accurately assess the operational status of the audio path, ensuring that navigation instructions and other audio outputs are effectively heard by the user, even in conditions where the head unit's volume is low or speakers are turned off, by iteratively modifying the test signal parameters to detect the audio path's availability.
Implementation Method 1
the portable device can generate a test audio signal, provide the test audio signal to the head unit, and determine whether the one or more speakers of the external device converted the audio signal to sound
Data Source
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AI summary
Providing navigation instructions in an automotive environment includes generating, at the portable device, a test audio signal. The test audio signal is provided to the head unit of the vehicle via a short-range communication link. The portable device then detects whether the test audio signal has been converted to sound by one or more speakers in the head unit of the vehicle. In response to detecting the audio signal at the portable device, a vocalized navigation instruction is directed to the head unit for announcement via the one or more speakers of the head unit. Otherwise, in response to not detecting the test audio signal at the portable device, the vocalized navigation instruction is provided via a speaker of the portable device.