WO2009115091A1 - A method of adjusting a light detector and a light detector for exercising the method - Google Patents

A method of adjusting a light detector and a light detector for exercising the method Download PDF

Info

Publication number
WO2009115091A1
WO2009115091A1 PCT/DK2009/000069 DK2009000069W WO2009115091A1 WO 2009115091 A1 WO2009115091 A1 WO 2009115091A1 DK 2009000069 W DK2009000069 W DK 2009000069W WO 2009115091 A1 WO2009115091 A1 WO 2009115091A1
Authority
WO
WIPO (PCT)
Prior art keywords
light detector
light
potentiometer
threshold value
calibration
Prior art date
Application number
PCT/DK2009/000069
Other languages
French (fr)
Inventor
Poul Erik Normann Nielsen
Original Assignee
Schneider Electric Industries Sas
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Schneider Electric Industries Sas filed Critical Schneider Electric Industries Sas
Publication of WO2009115091A1 publication Critical patent/WO2009115091A1/en

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J1/00—Photometry, e.g. photographic exposure meter
    • G01J1/10—Photometry, e.g. photographic exposure meter by comparison with reference light or electric value provisionally void
    • G01J1/16—Photometry, e.g. photographic exposure meter by comparison with reference light or electric value provisionally void using electric radiation detectors
    • G01J1/18—Photometry, e.g. photographic exposure meter by comparison with reference light or electric value provisionally void using electric radiation detectors using comparison with a reference electric value
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B47/00—Circuit arrangements for operating light sources in general, i.e. where the type of light source is not relevant
    • H05B47/10—Controlling the light source
    • H05B47/105—Controlling the light source in response to determined parameters
    • H05B47/11—Controlling the light source in response to determined parameters by determining the brightness or colour temperature of ambient light
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B20/00—Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
    • Y02B20/40—Control techniques providing energy savings, e.g. smart controller or presence detection

Definitions

  • the present invention relates to a method of setting the threshold value for a turn-on/turn-off functionality of a light detector.
  • the light detector In order to be able to meet the conditions that are encountered in practical use, the light detector is to be adjustable to the effect that its threshold value is caused to be somewhere between 0 and 1000 lux.
  • a potentiometer is used for setting the threshold value of the light detector. If, for instance, the light detector is located in a comparatively dark passage, it may be very difficult to adjust the threshold value to a setting of about eg 50 lux, as the potentiometer will be experienced as being extremely sensitive and difficult to set.
  • a known solution for improving the options of setting the threshold value is a logarithmic scale, whereby the left half of the travelling of the potentiometer is used for setting from 0 to 100 lux, while the right half is used for setting from 100 to 1000 lux.
  • Another solution is a switch that switches the setting range of the potentiometer between a low range, eg 0 to 100 lux, and a high range, eg 100 to 1000 lux. It is the object of the invention to provide a method by which, compared to the prior art, a more accurate setting of the threshold value is accomplished, irrespective of how high or low the corresponding light level is.
  • the light detector is caused to be in a calibration state; that the light intensity is measured a predetermined period of time after the light detector has been caused to be in the calibration state; that the dynamic range of the setting of the threshold value is redefined electronically in dependence of the measured light intensity; and that the light detector is caused to leave its calibration state.
  • the light detector is caused to assume the calibration state by a potentiometer being set in an extreme position.
  • the dynamic range can be redefined purely electronically by means of eg a microprocessor as will be explained at a later stage.
  • the scale is redefined such that two-thirds deflection of the potentiometer corresponds to the light intensity that is measured in the calibration state.
  • the invention also relates to a light detector for exercising the method, which light detector comprises a light sensor and a calibration unit for setting of a threshold value for the turn-on/turn-off functionality of the light detector.
  • the light detector is characterised in that an activation means is provided for bringing the calibration unit to a calibration state, where the light intensity is measured; and that the dynamic range for setting the calibration unit depends on the measured light intensity in the calibration state.
  • Figure 1 shows a flow chart of the adjustment process according to the invention
  • Figure 2 shows an example of a flow chart of an embodiment for redefining an adjustment range
  • Figure 3 schematically shows a number of components of the light detector that are important to the invention.
  • Figure 1 shows a number of operations for redefining the dynamic range for setting the threshold value of the light detector. Neither setting of threshold value nor redefining in accordance with the invention is performed until after the light detector has been mounted in the use position. Then an adjustment of the threshold value is performed by 1 , and if it is easy to adjust the threshold value, no further action is taken. If, however, it turns out that it is difficult to set the threshold value, it is due to the fact that the current background light has an intensity that entails that a potentiometer (see figure 3) is to be adjusted only very little to set a desired threshold value. According to the invention, the scale of the potentiometer is redefined as will be explained below.
  • the meter must first be caused to be in a calibration state, which is, in the preferred embodiment, accomplished by turning the potentiometer being turned completely to the left (see figure 3). That is detected by a microprocessor in the light detector, and thereby a signal light is lit to the effect that the operator has the time to move before the current background light is measured.
  • the redefinition process 7 from figure 1 will be explained in further detail.
  • Tmax Ki ⁇ L, wherein Tmax corresponds to the light value desired to be represented by the one extreme position of the potentiometer.
  • Tmin Tmax - K 2 is determined, wherein Tmin corresponds to the light value desired to be represented by the other extreme position of the potentiometer.
  • FIG. 3 schematically shows a number of components that are necessary for the invention to work.
  • 10 is designated a complete apparatus, eg a PIR movement sensor or other electrical equipment that depends on a light detector with a well defined threshold value, wherein what is set forth underneath the line L relates to the components that are necessary for the light detector, whereas what is set forth above the line L constitutes the remainder of the apparatus.
  • the entire apparatus has a common power supply 11 , while the particular application has its own application hardware 12.
  • the light detector according to the invention can also be a stand-alone unit and merely comprise the components that will be described below.
  • a microprocessor is shown which is connected to a light detector 14 and an adjustment unit 15. Moreover, eg a light diode 16 is provided for signalling the state of the light detector.
  • a potentiometer is outlined, and if, eg in step 1 in figure 1 , it turns out that the scale of the potentiometer is inconvenient for the adjustment of the threshold value, a redefinition of the adjustment range of the potentiometer is performed in accordance with the invention.
  • the potentiometer is turned completely to the left in accordance with a preferred embodiment and as shown in the box 18. This is detected by the microprocessor which turns on the diode 16 to indicate that the operator has to move, see step 4 in figure 1.
  • the micro-controller 13 along with the application hardware 12 can be configured such that predetermined lamps are turned off such that the room is brought to a reference state. Then the current background light is measured, following which the adjustment range for the potentiometer is redefined, see the explanation to figure 2. Following the redefinition, the potentiometer in the box 17 can be used to accomplish a precise adjustment of the threshold value, due to the measurement range of the potentiometer now being brought in accordance with the background illumination with a sufficient sensitivity. By a preferred embodiment, the potentiometer is redefined such that a two-thirds deflection of the potentiometer corresponds to the light intensity that is measured in the calibration state.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Photometry And Measurement Of Optical Pulse Characteristics (AREA)

Abstract

The invention concerns a method of setting the threshold value of a turn- on/turn-off functionality for a light detector. According to the invention, the threshold value is redefined electronically in response to a light intensity which is measured in a calibration state. A detector for exercising the method comprises a microprocessor (13) for controlling the calibration process in dependence of user-friendly activation means (18) in the detector.

Description

A method of adjusting a light detector and a light detector for exercising the method
The present invention relates to a method of setting the threshold value for a turn-on/turn-off functionality of a light detector.
It is very widely used to employ light detectors for turn-on/turn-off functionality. Both the turning on/the turning off of light in the context of dusk and in connection with work illumination in a building may be concerned. Often, the measurement of light is combined with movement sensors (PIR), the light level determining whether the movement sensor is to activate or deactivate eg lamps.
In order to be able to meet the conditions that are encountered in practical use, the light detector is to be adjustable to the effect that its threshold value is caused to be somewhere between 0 and 1000 lux. However, this has given rise to difficulties in the prior art where, typically, a potentiometer is used for setting the threshold value of the light detector. If, for instance, the light detector is located in a comparatively dark passage, it may be very difficult to adjust the threshold value to a setting of about eg 50 lux, as the potentiometer will be experienced as being extremely sensitive and difficult to set.
A known solution for improving the options of setting the threshold value is a logarithmic scale, whereby the left half of the travelling of the potentiometer is used for setting from 0 to 100 lux, while the right half is used for setting from 100 to 1000 lux. Another solution is a switch that switches the setting range of the potentiometer between a low range, eg 0 to 100 lux, and a high range, eg 100 to 1000 lux. It is the object of the invention to provide a method by which, compared to the prior art, a more accurate setting of the threshold value is accomplished, irrespective of how high or low the corresponding light level is.
This object is accomplished in that the light detector is caused to be in a calibration state; that the light intensity is measured a predetermined period of time after the light detector has been caused to be in the calibration state; that the dynamic range of the setting of the threshold value is redefined electronically in dependence of the measured light intensity; and that the light detector is caused to leave its calibration state.
In this way, one is always able to move the potentiometer comparatively much around the desired threshold value, irrespective of where, within the range of from 0 to 1000 lux, it is situated. Redefinition of the dynamic range is carried out with a predetermined time delay to the effect that the fitter/the user has the time to move before the intensity of the background light is measured.
According to a preferred embodiment, the light detector is caused to assume the calibration state by a potentiometer being set in an extreme position.
The dynamic range can be redefined purely electronically by means of eg a microprocessor as will be explained at a later stage. By a preferred embodiment, the scale is redefined such that two-thirds deflection of the potentiometer corresponds to the light intensity that is measured in the calibration state.
Following the redefinition, an adjustment of the threshold value is made, which is very easy to do accurately due to the scale of the potentiometer now being redefined to operate within precisely the current range of the light intensity. The invention also relates to a light detector for exercising the method, which light detector comprises a light sensor and a calibration unit for setting of a threshold value for the turn-on/turn-off functionality of the light detector.
The light detector is characterised in that an activation means is provided for bringing the calibration unit to a calibration state, where the light intensity is measured; and that the dynamic range for setting the calibration unit depends on the measured light intensity in the calibration state.
The invention will now be explained in further detail by the following description of an embodiment, reference being made to the drawing, wherein
Figure 1 shows a flow chart of the adjustment process according to the invention;
Figure 2 shows an example of a flow chart of an embodiment for redefining an adjustment range, while
Figure 3 schematically shows a number of components of the light detector that are important to the invention.
Figure 1 shows a number of operations for redefining the dynamic range for setting the threshold value of the light detector. Neither setting of threshold value nor redefining in accordance with the invention is performed until after the light detector has been mounted in the use position. Then an adjustment of the threshold value is performed by 1 , and if it is easy to adjust the threshold value, no further action is taken. If, however, it turns out that it is difficult to set the threshold value, it is due to the fact that the current background light has an intensity that entails that a potentiometer (see figure 3) is to be adjusted only very little to set a desired threshold value. According to the invention, the scale of the potentiometer is redefined as will be explained below.
As shown by 2, the meter must first be caused to be in a calibration state, which is, in the preferred embodiment, accomplished by turning the potentiometer being turned completely to the left (see figure 3). That is detected by a microprocessor in the light detector, and thereby a signal light is lit to the effect that the operator has the time to move before the current background light is measured.
By 5 and 6 the room is brought to a reference state in which the light intensity is measured, and by 7 the adjustment area is redefined as will be explained in further detail in the context of figure 2. By 8 it is indicated that the calibration has ended, and by 9 the light detector is brought to normal operation.
With reference to figure 2, the redefinition process 7 from figure 1 will be explained in further detail. Once the operator is outside the field of vision of the sensor, the light level (=L) is measured, see 7A. First, an upper limit for the threshold value is calculated in 7B, Tmax = Ki ■ L, wherein Tmax corresponds to the light value desired to be represented by the one extreme position of the potentiometer. In 7C, a lower threshold Tmin = Tmax - K2 is determined, wherein Tmin corresponds to the light value desired to be represented by the other extreme position of the potentiometer. By a preferred embodiment, the scale is redefined such that Ki = 3/2 and K2 = Tmax. In this way, Tmin = 0, but it will be understood that other constants could be selected corresponding to the extreme positions of the potentiometer representing other light values. Thereby a random sensitivity area can be obtained about the measured background illumination. Figure 3 schematically shows a number of components that are necessary for the invention to work. By 10 is designated a complete apparatus, eg a PIR movement sensor or other electrical equipment that depends on a light detector with a well defined threshold value, wherein what is set forth underneath the line L relates to the components that are necessary for the light detector, whereas what is set forth above the line L constitutes the remainder of the apparatus. The entire apparatus has a common power supply 11 , while the particular application has its own application hardware 12. The light detector according to the invention can also be a stand-alone unit and merely comprise the components that will be described below.
By 13 a microprocessor is shown which is connected to a light detector 14 and an adjustment unit 15. Moreover, eg a light diode 16 is provided for signalling the state of the light detector.
In boxes 17 and 18, a potentiometer is outlined, and if, eg in step 1 in figure 1 , it turns out that the scale of the potentiometer is inconvenient for the adjustment of the threshold value, a redefinition of the adjustment range of the potentiometer is performed in accordance with the invention. To bring the meter to the calibration state, the potentiometer is turned completely to the left in accordance with a preferred embodiment and as shown in the box 18. This is detected by the microprocessor which turns on the diode 16 to indicate that the operator has to move, see step 4 in figure 1. By an embodiment where the light detector is combined with a PIR sensor, the micro-controller 13 along with the application hardware 12 can be configured such that predetermined lamps are turned off such that the room is brought to a reference state. Then the current background light is measured, following which the adjustment range for the potentiometer is redefined, see the explanation to figure 2. Following the redefinition, the potentiometer in the box 17 can be used to accomplish a precise adjustment of the threshold value, due to the measurement range of the potentiometer now being brought in accordance with the background illumination with a sufficient sensitivity. By a preferred embodiment, the potentiometer is redefined such that a two-thirds deflection of the potentiometer corresponds to the light intensity that is measured in the calibration state.

Claims

C l a i m s
1. A method of setting the threshold value of a turn-off/turn-on functionality for a light detector, characterised in • that the light detector is caused to be in a calibration state;
• that the light intensity is measured a predetermined period of time after the light detector has been brought to the calibration state;
• that the dynamic range of the setting of the threshold value is redefined electronically in response to the measured light intensity, and
• that the light detector is caused to leave the calibration state.
2. A method according to claim 1 , characterised in that the light detector is brought to the calibration state by a potentiometer being set in an extreme position.
3. A method according to clam 2, characterised in that said predetermined period of time is indicated by light or sound.
4. A method according to claims 2 or 3, characterised in that the dynamic range is redefined such that the light intensity which is measured during the calibration state corresponds to the two-thirds point of the adjustment range of the potentiometer.
5. A method according to claims 1-4, characterised in that an adjustment of the threshold value is performed after the dynamic range has been redefined.
6. A light detector for exercising the method according to claim 1 and comprising a light sensor and a calibration unit for setting a threshold value for the turn-on/turn-off functionality of the light detector, characterised in that an activation means is provided for bringing the calibration unit to a calibration state, wherein the light intensity is measured; and that the dynamic area for setting the calibration unit depends on the measured light intensity in the calibration state.
7. A light detector according to claim 6, characterised in that the calibration unit comprises a potentiometer; and that the calibration state is activated by bringing the potentiometer to an extreme position.
8. A light detector according to claim 7, characterised in that the potentiometer also serves for adjustment of the threshold value, the dynamic range of the potentiometer comprising a position corresponding to the light intensity in the calibration state.
9. A light detector according to claim 8, characterised in that the calibration unit is configured for redefining the dynamic range of the potentiometer to the effect that two-thirds deflection corresponds to the light intensity as measured in the calibration state.
PCT/DK2009/000069 2008-03-19 2009-03-19 A method of adjusting a light detector and a light detector for exercising the method WO2009115091A1 (en)

Applications Claiming Priority (2)

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DKPA200800419 2008-03-19
DKPA200800419 2008-03-19

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102018106143B3 (en) * 2018-03-16 2019-08-01 Steinel Gmbh Programmable sensor device and operating method

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1339266A2 (en) * 2001-12-28 2003-08-27 Kotka Terminal Equipment OY Twilight switch
EP1353538A1 (en) * 2002-04-08 2003-10-15 Theben AG Programmable ambient-light circuit
EP1725081A2 (en) * 2005-05-11 2006-11-22 Dietmar F. Brück Method for setting light intensity thresholds in motion detectors
US20060278808A1 (en) * 2005-05-05 2006-12-14 Hick Robert L Closed Loop Daylight Harvesting Light Control System Having Auto-Calibration
US20070185675A1 (en) * 2006-02-08 2007-08-09 Konstantinos Papamichael Method for calibrating a lighting control system that facilitates daylight harvesting

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1339266A2 (en) * 2001-12-28 2003-08-27 Kotka Terminal Equipment OY Twilight switch
EP1353538A1 (en) * 2002-04-08 2003-10-15 Theben AG Programmable ambient-light circuit
US20060278808A1 (en) * 2005-05-05 2006-12-14 Hick Robert L Closed Loop Daylight Harvesting Light Control System Having Auto-Calibration
EP1725081A2 (en) * 2005-05-11 2006-11-22 Dietmar F. Brück Method for setting light intensity thresholds in motion detectors
US20070185675A1 (en) * 2006-02-08 2007-08-09 Konstantinos Papamichael Method for calibrating a lighting control system that facilitates daylight harvesting

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102018106143B3 (en) * 2018-03-16 2019-08-01 Steinel Gmbh Programmable sensor device and operating method

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