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EP-4740047-A1 - LUMINAIRE WITH PRECIPITATION ESTIMATION

EP4740047A1EP 4740047 A1EP4740047 A1EP 4740047A1EP-4740047-A1

Abstract

A luminaire has a precipitation sensor for detecting precipitation at the location of the luminaire based on detected sounds. The precipitation sensor receives information from other luminaires in the vicinity of the luminaire, wherein the luminaire and the other luminaires in the vicinity form a set of luminaires. The detected sounds at the luminaire and the received information are combined to derive a precipitation estimate. In particular, a subset of the set of luminaires is selected and the information associated with that subset is used to derive the precipitation estimate.

Inventors

  • DEIXLER, PETER
  • YU, JIN

Assignees

  • Signify Holding B.V.

Dates

Publication Date
20260513
Application Date
20240702

Claims (14)

  1. 1. A luminaire (10), comprising: a light source (12); and a precipitation sensor (14,16,18,20) for detecting precipitation at the location of the luminaire, wherein the precipitation sensor comprises: a microphone (14) for detecting sounds at the luminaire; an input (16) for receiving information derived from detected sounds at other luminaires in the vicinity of the luminaire, wherein the luminaire and the other luminaires in the vicinity form a set of luminaires; an output (18) for delivering information derived from detected sounds at the luminaire to said other luminaires in the vicinity of the luminaire; and a processor (20) for processing the detected sounds at the luminaire and the received information and adapted to derive a precipitation estimate therefrom, wherein the processor is adapted to: select a subset of the luminaires based on at least one predefined selection criterion; use the information associated with the subset of the luminaires to derive the precipitation estimate.
  2. 2. The luminaire of claim 1, wherein the at least one predefined selection criterion comprises one or more of: obstruction above by vegetation; obstruction above by man-made structures; ambient non-precipitation noise levels.
  3. 3. The luminaire of any one of claims 1 to 2, wherein the precipitation estimate comprises an estimate of one or more of: the occurrence of precipitation; an intensity of precipitation; a precipitation droplet size.
  4. 4. The luminaire of claim 3, wherein the processor (20) is adapted to select a time-varying subset.
  5. 5. The luminaire of claim 4, wherein the time-varying subset has a different number of members at different times.
  6. 6. The luminaire of any one of claims 1 to 5, wherein the precipitation sensor further comprises one or more of: a vibration sensor; a wind speed sensor; a temperature sensor; a humidity sensor; a pressure sensor; a daylight sensor; a RF sensor.
  7. 7. The luminaire of any one of claims 1 to 6, wherein the precipitation sensor further comprises a radar sensor.
  8. 8. The luminaire of claim 7, wherein at least one predefined selection criterion comprises a proximity of trees or branches as determined by the radar sensor.
  9. 9. The luminaire of any one of claims 1 to 8, comprising a radio system (16,18) for delivering and receiving information to and from the other luminaires.
  10. 10. The luminaire of any one of claims 1 to 9, wherein the information received and delivered comprises a precipitation level probability distribution.
  11. 11. The luminaire of any one of claims 1 to 10, wherein the processor is adapted to derive a shared precipitation level for the area of the set of luminaires.
  12. 12. The luminaire of any one of claims 1 to 11, wherein the at least one predefined selection criterion comprises a type and/or mounting orientation of the other luminaires.
  13. 13. The luminaire of any one of claims 1 to 12 wherein the precipitation estimate is an estimated rainfall and/or rain drop size.
  14. 14. A streetlight comprising: a pole; and the luminaire according to any of claims 1 to 13, wherein the luminaire is mounted to said pole.

Description

LUMINAIRE WITH PRECIPITATION ESTIMATION FIELD OF THE INVENTION This invention relates to luminaires, such as road lighting luminaires, and it relates in particular to the detection of rain or other precipitation using a luminaire. BACKGROUND OF THE INVENTION Heavy rain intensity is known to reduce visibility and cause many road accidents. It would be desirable to be able to detect rain with high granularity (i.e., hyperlocal detection) so that action can be taken in response to local rain conditions. It would be of particular interest to be able to use an existing infrastructure, such as the streetlighting infrastructure, for this purpose. Various precipitation sensing techniques are known, including a tippingbucket rain gauge, an optical (infra-red) rain gauge (commonly used in automotive windshields), and a capacitive sensor. It is also known to use a microphone that measures rainfall intensity based on the sounds made when the rain strikes a sensor. For example, WO 2016/156563 discloses the detection of precipitation in the outdoor environment of a luminaire. The luminaire has a precipitation detection module that is configured to convert an accelerometer output signal and/or microphone output signal into frequency domain waveforms by execution of a Fast Fourier Transform algorithm. Once the frequency domain representations of the accelerometer output signal and/or microphone output signal are obtained, the frequency domain waveforms are compared to reference precipitation information to detect the occurrence of precipitation in the outdoor environment of the luminaire. The reference precipitation information stored includes a priori information on one or more frequency ranges and associated amplitude levels which is indicative of precipitation. In the case of streetlighting, the most obvious architecture is to use a microphone-equipped outdoor sensor bundle that is mounted below the luminaire and use the audio data to detect the sound made by the rain drops on the top of the luminaire. However, tree branches above a streetlight will strongly influence the amount of rain falling onto the top of the luminaire housing. Leaves will result in a delay between the onset of rain and the rain drops falling on the luminaire. Similarly, after the rain has stopped, leaves will continue to drip water droplets onto the luminaire. Compared to the unobstructed rain, the presence of leaves will also modify how many raindrops fall on the luminaire housing, as well as the size of individual raindrops. This problem may be addressed by calibrating the audio-based rain detection algorithm of the individual luminaires to take into account different luminaire housings as well as the rain-shielding by tree branches and objects. However, the calibration of an audioresponse curve of rainfall is cumbersome, and the calibration parameters will be very sensitive to changes in the environment of the streetlight (e.g., as the tree canopy above the streetlights changes over the seasons; or when overhanging branches of trees are regularly pruned for example to protect electricity lines). There is a need for an improved rain (or other precipitation) sensing approach. SUMMARY OF THE INVENTION The invention is defined by the claims. According to examples in accordance with an aspect of the invention, there is provided a luminaire, comprising: a light source; and a precipitation sensor for detecting precipitation at the location of the luminaire, wherein the precipitation sensor comprises: a microphone for detecting sounds at the luminaire; an input for receiving information derived from detected sounds at other luminaires in the vicinity of the luminaire, wherein the luminaire and the other luminaires in the vicinity form a set of luminaires; an output for delivering information derived from detected sounds at the luminaire to said other luminaires in the vicinity of the luminaire; and a processor for processing the detected sounds at the luminaire and the received information and adapted to derive a precipitation estimate therefrom, wherein the processor is adapted to use the information associated with a subset of the luminaires to derive the precipitation estimate. This luminaire measures a precipitation level, such as rainfall. The precipitation level can be used to control the lighting as a function of the weather conditions, for example to provide different lighting for different road conditions when the luminaire is part of a streetlight. The system of the invention estimates the precipitation level using a subset of luminaires rather than simply at an individual luminaire or simply by combining data from a set of luminaires. Instead, an intelligent selection is made of luminaires that should be used to contribute to an overall precipitation level estimate. The luminaires of the set from which the subset is chosen are in the same general vicinity, i.e., expected to experience the same precipitation level. The set is for example