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EP-4226743-B1 - LUMINAIRE SYSTEM AND METHOD FOR DETERMINING WATER INGRESS INTO A LUMINAIRE

EP4226743B1EP 4226743 B1EP4226743 B1EP 4226743B1EP-4226743-B1

Inventors

  • DEIXLER, PETER
  • BROERS, HARRY
  • KRAJNC, Hugo, José
  • VAN DRIEL, WILLEM, DIRK

Dates

Publication Date
20260513
Application Date
20210929

Claims (12)

  1. A luminaire system (100) comprising: a lighting unit (101) being adapted to provide light (107) in the visible spectrum, a housing (102) containing at least a part of the lighting unit (101), wherein the lighting unit (101) and the housing (102) are parts of a luminaire, a sensing means (103) positioned at or within the housing (102) adapted to sense a functional parameter indicative of a functional characteristic of the luminaire that is influenced by water ingress into at least a part of an inner structure of the luminaire, wherein the functional characteristic refers to a characteristic of the luminaire that is functionally related to a function of the luminaire; wherein the sensed functional parameter is indicative of a pressure profile of a pressure difference between an inside and an outside part of the luminaire over a time period and/or of a temperature profile of the luminaire measured during a change of the lighting unit from one operational state to another; and a water ingress determination unit (104) being adapted to determine water ingress into at least a part of the inner structure of the luminaire based on the sensed functional parameter by utilizing a functional relation between an amount of water and/or water vapor present in the inner structure of the luminaire and the sensed functional parameter.
  2. The luminaire system according to claim 1, wherein the water ingress determination unit (104) is adapted to determine the water ingress into at least a part of the inner structure of the luminaire by comparing the sensed functional parameter with a predetermined baseline of the sensed functional parameter.
  3. The luminaire system according to claim 2, wherein the baseline of the functional parameter is predetermined based on a parameter model that is adapted to model the functional parameter of the lighting unit (101) with respect to an ambient environmental condition and/or an operational and/or a water ingress state of the lighting unit (101).
  4. The luminaire system according to claim 1, wherein the sensing means (103) is adapted to sense the functional parameter of the luminaire at different operational states of the lighting unit (101) and wherein the water ingress determination unit (104) is adapted to determine water ingress into at least a part of the inner structure of the luminaire based on a comparison of the sensed functional parameters determined at different operational states of the lighting unit (101).
  5. The luminaire system according to claim 1, wherein the sensing means (103) is positioned at the housing (102) of the luminaire and is adapted to sense as functional parameter being indicative of a pressure within at least a part of the housing (102) of the luminaire a deformation of at least a part of the housing (102).
  6. The luminaire system according to claim 5, wherein the housing (102) comprises at least a flexible part and a rigid part, wherein the flexible part is more flexible than the rigid part, and wherein the sensing means (103) is adapted to sense a deformation of the housing (102) by sensing the deformation of the flexible part of the housing (102).
  7. The luminaire system according to claim 1, wherein the sensing means (103) is adapted to sense as functional parameter being indicative of a pressure within at least a part of the housing (102) of the luminaire a mechanical force applied to at least a part of the housing (102).
  8. The luminaire system according to any one of the preceding claims, wherein a further sensing means is provided that is adapted to sense a humidity parameter indicative of a humidity within at least a part of the housing (102) of the luminaire, wherein the water ingress determination unit (104) is adapted to determine water ingress into at least a part of the inner structure of the luminaire further based on the humidity parameter.
  9. The luminaire system according to claim 1, wherein the housing (102) comprises a sinkhole provided such that water present in the housing (102) will accumulate in the sinkhole, wherein a further sensing means is adapted to sense the presence of water in the sinkhole.
  10. A luminaire system according to any one of the preceding claims further comprising a functional parameter providing unit adapted to provide a functional parameter with respect to another luminaire being part of the luminaire system or being external to the luminaire system, wherein the water ingress determination unit (104) is adapted to receive the provided functional parameter and to determine water ingress into at least a part of the inner structure of the luminaire further based on the provided functional parameter.
  11. A method for determining water ingress into at least a part of an inner structure of a luminaire, wherein the method (200) comprises: providing (210), by a sensing means, measurements of a sensed functional parameter of the luminaire comprising a lighting unit and a housing containing at least a part of the lighting unit, wherein the functional parameter is indicative of a functional characteristic of the luminaire that is influenced by water ingress into at least a part of the inner structure of the luminaire, wherein the functional characteristic refers to a characteristic of the luminaire that is functionally related to a function of the luminaire; wherein the functional parameter is indicative of a pressure profile of a pressure difference between an inside and an outside part of the luminaire over a period of time and/or of a temperature profile of the luminaire measured during a change of the lighting unit from one operational state to another; and determining (220), by a water ingress determination unit, water ingress into at least a part of the inner structure of the luminaire based on the sensed functional parameter utilizing a functional relation between an amount of water and/or water vapor present in the inner structure of the luminaire and the functional parameter.
  12. A computer program product for determining water ingress into a luminaire, wherein the computer program product comprises program code means causing a computer to execute the method according to claim 11.

Description

FIELD OF THE INVENTION The invention relates to a luminaire system, a method and a computer program product for determining water ingress into a lighting unit. BACKGROUND OF THE INVENTION Water ingress in luminaires is an epidemic failure that continues to appear near the top of the yearly incidents. Water ingress often leads to either corrosion, condensation on transparent parts such as windows of the luminaires, or even catastrophic product field failures, both for outdoor and indoor luminaires. In connected luminaire systems comprising a plurality of luminaires, there is an unmet need to monitor each individual luminaire for possible water condensation and/or water ingress. Therefore, there is a need for low-cost sensor hardware to achieve this water ingress sensing function. There is further a need for a sensing function capable of predicting whether the water ingress only leads to condensation or has even resulted in accumulated water puddles. Water puddles may lead to product failure that might even be safety critical. On the other extreme of severity, condensation usually occurs first on lenses and reflectors and only decreases the luminaire's ability to properly illuminate an environment and/or impacts the aesthetic appearance of the luminaire. Hence, there is a desire to measure the water ingress precisely and easily for each individual luminaire to overcome these problems. US 2017/184659A1 discloses a light fixture including at least one light fixture component. The light fixture can also include at least one sensor that measures at least one parameter associated with the at least one light fixture component. The light fixture can further include a prognostic and health monitoring (PHM) system coupled to the at least one sensor, where the PHM system analyzes at least one measurement, made by the at least one sensor, to identify at least one factor that affects longevity of the at least one light fixture component. US 2011/304268 A1 discloses a lighting device which may include at least one semiconductor light source, at least one sensor and evaluation electronics functionally connected to the at least one sensor, wherein the evaluation electronics are arranged to trigger at least one action of the lighting device upon at least one predetermined sensor signal of the at least one sensor. JP2003139897 A relates to a UV irradiation device, whereby detecting water leakage inside a lamp house is achieved by comparing the inside pressure of the lamp house with the outside pressure. SUMMARY OF THE INVENTION It is an object of the present invention to provide a luminaire system according to claim 1, a method according to claim 11 and a computer program product according to claim 12 allowing for an improved persistence and safety of a luminaire. In a first aspect, a luminaire system is presented, wherein the system comprises a) a lighting unit being adapted to provide light, b) a housing containing at least a part of the lighting unit, wherein the lighting unit and the housing are parts of a luminaire, c) a sensing means positioned at or within the housing adapted to sense a functional parameter indicative of a functional characteristic of the luminaire that is influenced by water ingress into at least a part of an inner structure of the luminaire, and d) a water ingress determination unit being adapted to determine water ingress into at least a part of the inner structure of the luminaire based on the sensed functional parameter. Since the water ingress determination unit is adapted to determine water ingress into at least a part of the inner structure of the luminaire based on a sensed functional parameter indicative of a functional characteristic of the luminaire that is influenced by water ingress, the water ingress can be detected indirectly based on the influence of the water within the luminaire. Thus, direct measurements of the water within the luminaire that are constructional challenging can be avoided. Moreover, generally already small amounts of water that are difficult to measure with common water or moisture sensors can have an impact on a functional characteristic of the luminaire, for instance, a pressure within the housing of the luminaire and can hence allow to detect the presence of the water before a "real" damage of the luminaire, for instance, corrosion is expected. This allows to improve the persistence and safety of a luminaire. The luminaire comprises at least one lighting unit. The lighting unit is adapted to provide light. In particular, the lighting unit is adapted to provide light, wherein the light comprises electromagnetic radiation with a wavelength from a predetermined range of the electromagnetic spectrum. In particular, the light can comprise electromagnetic radiation with different discrete wavelengths or a continuous wavelength range from a predetermined range of the electromagnetic spectrum. Preferably, the lighting unit is adapted to provide at least visible light. The