US 12,245,346 B2
Lighting fixture time determination system and method
Guy Saadi, Or Yehuda (IL); Micha Ben-Ezra, Or Yehuda (IL); Eliav Gnessin, Or Yehuda (IL); and Philip Desautels, Or Yehuda (IL)
Assigned to TONDO SMART LTD., Or Yehuda (IL)
Appl. No. 17/760,306
Filed by Tondo Smart LTD., Or Yehuda (IL)
PCT Filed Feb. 9, 2021, PCT No. PCT/IL2021/050154
§ 371(c)(1), (2) Date Aug. 8, 2022,
PCT Pub. No. WO2021/161306, PCT Pub. Date Aug. 19, 2021.
Claims priority of provisional application 62/975,222, filed on Feb. 12, 2020.
Prior Publication US 2023/0069889 A1, Mar. 9, 2023
Int. Cl. H05B 47/10 (2020.01); H05B 47/16 (2020.01)
CPC H05B 47/16 (2020.01) 18 Claims
OG exemplary drawing
 
1. A lighting fixture comprising a processing circuitry configured to:
determine a current time using a fallback time determination method upon one or more preceding time determination methods failings, the fallback time determination method being different than the preceding time determination methods; and
perform a time-based operation on one or more light sources of the lighting fixture upon one or more rules that designate times for performing the time-based operation being met by the determined current time, wherein the current time is determined using a current date;
wherein the processing circuitry determines the current date by:
obtaining (a) a day lengths table indicative of lengths of days at known dates at the geographical location of the lighting fixture, and (b) a sequence of measurements acquired by the ambient light sensor, each indicating a respective amount of ambient light determined by the ambient light sensor at a corresponding timestamp;
identifying, within the sequence of measurements:
a. a first change of a trend in the measurements indicative of occurrence of a first sunrise, the first change starting at a first timestamp being the timestamp of the earliest measurement associated with the first change;
b. a second change of a trend in the measurements indicative of occurrence of first sunset, adjacent to the first change, the second change starting at a second timestamp being the timestamp of the earliest measurement associated with the second change;
c. a third change of a trend in the measurements indicative of occurrence of a second sunrise, the third change starting at a third timestamp being the timestamp of the earliest measurement associated with the third change;
d. a fourth change of a trend in the measurements indicative of occurrence of second sunset, adjacent the third change, the fourth change starting at a fourth timestamp being the timestamp of the earliest measurement associated with the fourth change;
determining (a) a first length of day, being the difference between the second timestamp and the first timestamp, and (b) a second length of day, being the difference between the fourth timestamp and the third timestamp; and
determining the current date by comparing the first length of day and the second length of day with the day lengths table.