Seat-Occupancy Detection System and Breathing Rate Monitoring Based on a Low-Cost mm-Wave Radar at 60 GHz

Antonio Lazaro,Marc Lazaro,David Girbau,Ramon Villarino

doi:10.1109/access.2021.3105390

Antonio Lazaro, Marc Lazaro + Show 2 more

Open Access

https://doi.org/10.1109/access.2021.3105390

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Abstract

This work presents a seat-occupancy detection system based on a PCR (Pulsed Coherent Radar) at the unlicensed 60 GHz ISM band. The radar can measure distances with sub-millimeter resolution. Therefore, the system can detect the presence of people occupying the seats by measuring small movements of the body, such as those produced by breathing. In consequence, the system not only measures seat-occupancy but also breathing rate, which is estimated from the amplitude peaks after filtering the amplitude measured by the radar to remove the noise. The effect of the car vibrations and random body movement is experimentally studied. Measurements performed with adults, as well as with a baby emulator sitting in a child seat, are presented. Comparison of the system with another that measures the breath based on airflow shows good agreement and permits its validation.

Highlights

V EHICLE Seat-occupancy detection systems have taken on importance with the introduction of the airbag system
WORK A seat occupancy detection system based on an integrated PCR (Pulse Coherent Radar) technology at the unlicensed 60 GHz ISM frequency band, has been investigated
The radar can measure distance with sub-millimeter resolution, allowing to distinguish small body movements, which are used to detect the presence of persons

Summary

INTRODUCTION

V EHICLE Seat-occupancy detection systems have taken on importance with the introduction of the airbag system. Conventional seat belt reminder systems work with weight sensors They produce undesired alarms when the seats are occupied by luggage or purchases. In addition to meeting regulatory requirements, seat occupancy detection systems can be used to improve passenger comfort, for example, controlling the air conditioning system according to the occupancy rate. Another application is to warn of the presence of children or pets. It is able to detect occupation avoiding both the contact with the passenger as well as the installation of any auxiliary equipment in the seat and, second, thanks to the measurement of vital signs (such as breathing rate), it is possible to distinguish objects from living beings and to track the conditions of drivers.

RELATED WORKS

EXPERIMENTAL VALIDATION

SEAT OCCUPANCY

BREATHING RATE RESULTS

CONCLUSION AND FUTURE WORK