Anti-tampering daylight harvesting system

• US 9,596,734 B2
• Filed: 04/03/2014
• Issued: 03/14/2017
• Est. Priority Date: 04/04/2013
• Status: Active Grant

• Current Assignee: Signify Holding B.V. (Signify N.V.)
• Original Assignee: Philips Lighting Holding BV (Signify N.V.)
• Inventors: Delnoij, Roger Peter Anna, Vangeel, Jurgen Mario, Klein Swormink, Michel Albertus Theodorus, Verbeek, Petrus Antonius, Hensing, Johannes Martinus Maria, Kalfs, Johannes Jozef Wilhelmus, Klompenhouwer, Michiel Adriaanszoon
• Primary Examiner(s): Hammond, Crystal L
• Application Number:
  US14/782,065
• Publication Number:
  US 20160066391A1
• Time in Patent Office: 1,076 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: H05B 47/11 by determining the brightness or colour temperature of ambient light
• CPC Class Codes: Y02B 20/40 Control techniques providing energy savings, e.g. smart controller or presence detection

Abstract

The present invention relates to a method for controlling a lighting device in a daylight harvesting system. When a user tampers with a sensor, in order to decrease the light level light level measured and therefore increase the light intensity of the lighting device, the tampering is detected. Based on this tamper detection the light intensity of the lighting device is controlled based on a set value (e.g. 70% dimming).

Claims

1. A control device for controlling the light intensity of at least one lighting device operationally coupled to the control device comprising:

an input arranged for receiving, from a light sensor operationally coupled to the input, light level measurements; and

a controller arranged for determining, based on at least one light level measurement received via the input, whether the light sensor has been tampered with; and

further arranged for controlling the at least one lighting device according to a fallback mode if it has been determined that the light sensor has been tampered with and controlling the at least one lighting device according to a daylight harvesting mode if it has been determined that the light sensor has not been tampered with;

wherein the fallback mode comprises controlling the light intensity of the at least one lighting device based on a stored program accessible to the controller; and

wherein the daylight harvesting mode comprises controlling the light intensity of the at least one lighting device based on the at least one light level measurement,

wherein the controller is arranged for determining whether the light sensor has been tampered with based on comparing the at least one light level measurement to any of;

a light sensor dark current value,

a second light level measurement, wherein the second light level measurement is received via the input after the at least one lighting device has been controlled to either increase or decrease the light intensity,

a third light level measurement, wherein the third light level measurement is received via the input in a second time period, and wherein the at least one light level measurement is received via the input in a first time period, and wherein the end of the first time period and the start of the second time period are at least one minute apart.

2. The control device of claim 1, wherein the controller is further arranged to control an audio or visual indicator based on determining whether the light sensor has been tampered with.

3. The control device of claim 1, wherein the controller is further arranged to transmit to an external monitoring system a signal indicating whether the light sensor has been tampered with.

4. The control device of claim 1, further comprising the light sensor operationally coupled to the input of the control device.

5. A daylight harvesting system (S) comprising the control device of claim 4, further comprising the at least one lighting device operationally coupled to the control device.

6. A method of controlling the light intensity of at least one lighting device in a daylight harvesting system comprising the steps of:

receiving a light level measurement from a light sensor;

determining whether the light sensor has been tampered with; and

controlling the at least one lighting device in a daylight harvesting mode if the sensor has not been tampered with and controlling the at least one lighting device in a fallback mode if the light sensor has been tampered with;

wherein the fallback mode comprises controlling the light intensity of the at least one lighting device based on a stored program; and

wherein the daylight harvesting mode comprises controlling the light intensity of the at least one lighting device based on at least one light level measurement,

wherein the step of determining whether the light sensor has been tampered with comprises any of;

comparing at least one light level measurement to a light sensor dark current value,

receiving a first light level measurement;

controlling the at least one lighting device to either increase or decrease the light intensity;

receiving a second light level measurement; and

comparing the first light level measurement to the second light level measurement,

comparing a first light level measurement received in a first time period to a third light level measurement received in a second time period, wherein the end of the first time period and the start of the second time period are at least one minute apart.

7. The method of claim 6, further comprising the step of controlling an audio or visual indicator based on determining whether the light sensor has been tampered with.

8. The method of claim 6, further comprising the step of transmitting to an external monitoring system a signal indicating whether the light sensor has been tampered with.

9. A computer program product for controlling the light intensity of at least one lighting device in a daylight harvesting system comprising software code portions for performing the steps of claim 6 when said product is run on a computer.