Embracing Distributed Acoustic Sensing in Car Cabin for Children Presence Detection

Contactless acoustic sensing has been actively exploited in the past few years to enable a large range of applications, ranging from fine-grained vital sign monitoring to coarse-grained human tracking. However, existing acoustic sensing systems mainly work on smartphone or smart speaker platforms. In this paper, we envision an exciting new acoustic sensing platform, i.e., car cabin which is inherently embedded with a large number of speakers and microphones. We propose the new concept of distributed acoustic sensing and develop novel designs leveraging the unique characteristics of rich multi-path in car cabin to enable fine-grained sensing even when the primary reflection is totally blocked. By using child presence detection as the application example, we show that child presence can be detected through body motions or even subtle breath (when the child is sleeping or in coma) at all locations in the cabin without any blind spots. We further show that the proposed system can robustly work in different car cabins, achieving an average detection accuracy of 97% and a false alarm rate always below 2% under different scenarios including those challenging ones such as rear-facing seat blockage. We believe the proposed distributed sensing modality in car cabin pushes acoustic sensing one big step towards real-life adoption.