Method and system for unattended child detection

Patent metadata

Field	Value
Publication number	US-11801774-B2
Application number	US-201916663691-A
Country	US
Kind code	B2
Filing date	Oct 25, 2019
Priority date	Mar 21, 2014
Publication date	Oct 31, 2023
Grant date	Oct 31, 2023

Abstract

A radar sensor system and method for ascertaining whether an unattended child is present within an automotive vehicle. The radar sensor system carries out the method and includes a transmitter, at least one sensor, and processing circuitry. The method includes the steps of: illuminating at least one occupiable position within the vehicle with radiation of multiple frequencies; generating radar sensor signals from reflections of the transmitted radiation, a plurality of the radar sensor signals corresponding to different frequencies; and operating the processing circuitry for generating and determining if a first indicator value indicative of motion in the occupiable position satisfies a first predetermined criteria and, if so, generating and determining a second indicator value indicating a degree of repetitive pattern within the radar sensor signals, and determining presence of an unattended child in the vehicle if the second indicator value satisfies a second predetermined criteria.

First claim

The invention claimed is:

1. A radar sensor system for a vehicle, the system comprising:
a transmitter, for illuminating at least one occupiable position within the vehicle with radiation, the radiation exhibiting multiple frequencies;
at least one sensor for generating radar sensor signals from radiation reflected as a result of the transmitted radiation, a plurality of the radar sensor signals corresponding to different frequencies;
processing circuitry, coupled to the at least one sensor, the processing circuitry being configured to carry out the steps of:
generating, based on the radar sensor signals, a first indicator value, the first indicator value indicating a degree of motion associated with the occupiable position;
determining whether the first indicator value satisfies a first predetermined criteria; and
when the first indicator value satisfies the first predetermined criteria, generating, based on radar sensor signals, a second indicator value indicating a degree of repetitive pattern within the radar sensor signals, wherein the second indicator value is, or is derived from, the product of multiple breathing indices, each breathing index being related to breathing rate.

2. The radar sensor system of claim 1 , wherein the first predetermined criteria is that the first indicator value lies between a first threshold value and a second threshold value.

3. The radar sensor system of claim 2 , wherein
(i) the first threshold value is such that the first indicator value being below the first threshold value is indicative of an empty seat or environment;
(ii) the second threshold value is such that the first indicator value being above the second threshold value is indicative of a moving person or child; and
(iii) the first threshold value and the second threshold value are such that the first indicator value being between the first threshold value and the second threshold value is indicative of a sleeping child being present in the occupiable position or of an influence from sources external to the vehicle.

4. The radar sensor system of claim 1 , wherein the first indicator value is based on an amplitude of the radar sensor signals.

5. The radar sensor system of claim 1 , including the step of determining that a child is present with respect to the at least one occupiable position within the vehicle when the second indicator value satisfies a second predetermined criteria.

6. The radar sensor system of claim 5 , wherein the first predetermined criteria is that the first indicator value lies between a first threshold value and a second threshold value, and wherein the second predetermined criteria is that the second indicator value lies above a third threshold value.

7. The radar sensor system of claim 5 , wherein the frequencies of the transmitted radiation are dynamically varied such that the steps of (i) determining whether the first indicator value satisfies a first predetermined criteria and (ii) determining that a child is present with respect to the at least one occupiable position within the vehicle when the second indicator value satisfies a second predetermined criteria are periodically carried out in parallel.

8. The radar sensor system of claim 1 , wherein at least one breathing rate index is derived from motion determined based on the radar sensor signals.

9. The radar sensor system of claim 1 , wherein the second indicator value is dependent upon a breathing rate variation index, the breathing rate variation index being derived from motion determined based on the radar sensor signals and indicating a degree of variation in breathing rate.

10. The radar sensor system of claim 9 , wherein the second indicator value is based on a combination of both the breathing rate and breathing rate variation index.

11. The radar sensor system of claim 1 , wherein the second indicator value comprises a breathing signature.

12. A radar sensor system for a vehicle, the system comprising:
a transmitter, for illuminating at least one occupiable position within the vehicle with radiation, the radiation exhibiting multiple frequencies;
at least one sensor for generating radar sensor signals from radiation reflected as a result of the transmitted radiation, a plurality of the radar sensor signals corresponding to one or more frequencies;
processing circuitry, coupled to the at least one sensor, the processing circuitry being configured to carry out the steps of:
generating, based on the radar sensor signals, a first indicator value, the first indicator value indicating a degree of motion associated with the occupiable position;
determining whether the first indicator value satisfies a first threshold;
when the first indicator value does not satisfy the first threshold, determining that a child is not present in the vehicle;
when the first indicator value satisfies the first threshold, determining whether the first indicator value satisfies a second threshold; and
when the first indicator value satisfies the second threshold, determining that a child is present in the vehicle.

13. The radar sensor system of claim 12 , wherein the steps of determining whether the first indicator value satisfies the first threshold and determining whether the first indicator value satisfies the second threshold are performed based on radar sensor signals occurring during a first predetermined period.

14. The radar sensor system of claim 13 , wherein the first predetermined period is 5-15 seconds.

15. The radar sensor system of claim 12 , wherein, when the first indicator value does not satisfy the second threshold, then generating, based on radar sensor signals, a second indicator value indicating a degree of repetitive pattern within the radar sensor signals, wherein the second indicator value is, or is derived from, the product of multiple breathing indices, each breathing index being related to breathing rate.

16. The radar sensor system of claim 15 , including the step of determining that a child is present with respect to the at least one occupiable position within the vehicle when the second indicator value satisfies a second predetermined criteria.

17. The radar sensor system of claim 16 , wherein the second predetermined criteria is that the second indicator value lies above a third threshold value.

18. The radar sensor system of claim 16 , wherein the one or more frequencies of the transmitted radiation are dynamically varied such that the steps of (i) determining whether the first indicator value satisfies the first threshold, (ii) determining whether the first indicator value satisfies the second threshold, and (iii) determining that a child is present with respect to the at least one occupiable position within the vehicle when the second indicator value satisfies a second predetermined criteria are periodically carried out in parallel.

19. The radar sensor system of claim 12 , wherein
(i) the first threshold is such that the first indicator value being below the first threshold is indicative of an empty seat or environment;
(ii) the second threshold is such that the first indicator value being above the second threshold is indicative of a moving person or child; and
(iii) the first threshold and the second threshold are such that the first indicator value being between the first threshold and the second threshold is indicative of a sleeping child being present in the occupiable position or of an influence from sources external to the vehicle.

20. A method of using a radar sensor system, the radar sensor system co

Assignees

• Iee Sa

Inventors

• Lu-Dac Mathieu
• Di Mario Cola Patrick
• Tatarinov Dimitri
• Diewald Andreas
• Watgen Claude
• Calmes Sam
• Larsen Peter

Classifications

• A61B5/0507 Primary

  using microwaves or terahertz waves · CPC title

• B60N2/0035

  characterised by the sensor data transmission, e.g. wired connections or wireless transmitters therefor; characterised by the sensor data processing, e.g. seat sensor signal amplification or electric circuits for providing seat sensor information · CPC title

• B60N2210/20

  Radar · CPC title

• B60N2/266

  with detection or alerting means responsive to presence or absence of children; with detection or alerting means responsive to improper locking or installation of the child seats or parts thereof · CPC title

• B60N2/0022

  for sensing anthropometric parameters, e.g. heart rate or body temperature · CPC title