Patent approved info24 Oct 2025 15:05
Claims
1. In a driver or occupant monitoring system, the system including at least one electromagnetic emission source and an imaging camera, a method of detection of occlusion of the electromagnetic emission source, comprising the steps of:
(a) modulating the electromagnetic emission source intensity in a predetermined manner according to an encoded modulation pattern;
(b) detecting if the modulation pattern is present in at least a region of an image captured by the imaging camera by applying a matched filter that matches the encoded modulation pattern to the captured imagery;
(c) on the basis of the degree of encoded modulation pattern present as detected by the matched filter, determining if the emission source is occluded;
(d) upon detection of the emission source being occluded, transitioning the electromagnetic emission source to a lower power state.
2. The method as claimed in claim 1, wherein said modulation pattern includes a temporal modulation of the electromagnetic emission source.
3. The method as claimed in claim 1, wherein said modulation pattern includes a spatial modulation of the electromagnetic emission source.
4. The method as claimed in claim 1 wherein said modulating includes at least one of pseudo random modulation, sine or square wave modulation.
5. The method as claimed in claim 1 wherein said image is divided into a number of tiled regions, and the detection step is applied to each tiled region.
6. The method as claimed in claim 1 wherein the electromagnetic emission source is determined to be occluded upon detection of no modulation pattern in at least one region of an image.
7. The method as claimed in claim 1 wherein the electromagnetic emission source is determined to be occluded upon detection of no modulation pattern in a predetermined number of regions of an image.
8. The method as claimed in claim 1 wherein the low power state is entered for a predetermined period of time.
9. The method as claimed in claim 1 wherein the electromagnetic emission source is an infrared light source.
10. The method as claimed in claim 9 wherein the infrared light source is a light emitting diode.
11. The method as claimed in claim 9 wherein the infrared light source is a vertical-cavity surface-emitting laser (VCSEL).
12. The method as claimed in claim 1 wherein the method complies with IEC-62471.
13. The method according to claim 1 wherein the electromagnetic emission source emits light in a structured light pattern.
14. The method according to claim 13 wherein the electromagnetic emission source is determined to be occluded upon detection of no structured light pattern in one or more images.
15. The method according to claim 1 including the step of applying intensity changes to a plurality of images captured by the imaging camera.
16. The method according to claim 15 wherein the detecting step (b) includes the sub-steps of:
passing knowns values of output intensity of the electr
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