WO2010124902A2 - Method and device for setting a target brightness value of a luminaire - Google Patents

Abstract

A method and a device for setting a target brightness value of a luminaire are provided, wherein a first brightness value is measured before switching off the luminaire and a second brightness value is measured after switching off the luminaire, and wherein the target brightness value is set on the basis of the first brightness value and the second brightness value. Furthermore, a corresponding luminaire is provided.

Description

description

Method and device for setting a brightness setpoint of a luminaire

The invention relates to a method and a device for setting a brightness setpoint of a lamp and a corresponding lamp.

There are lights known that automatically adjust their brightness to an ambient brightness. For example, with the onset of dusk, the brightness of such a luminaire is increased, so that a user is provided with a preferably constant brightness on the working surface independently of any other ambient brightness.

The constant brightness impression is achieved by keeping a brightness setpoint as constant as possible.

In conventional luminaires or lighting systems for daylight-dependent control of a proportion of artificial light, the user must manually set or specify the brightness setpoint. This is done either by means of a potentiometer, a control button or a remote control.

If the luminaire itself is dimmable, the proportion of artificial light can be changed manually until the resulting brightness value is set

Total brightness of artificial light and daylight corresponds to the desired brightness. This value is then stored manually as the brightness setpoint.

If the luminaire is not dimmable, then a switch-on threshold or a switch-off threshold are set manually via corresponding control elements. In this case, it is disadvantageous that both the dimmable and the non-dimmable luminaire must each be laboriously set to the desired brightness setpoint. This causes a considerable adjustment effort in the event that a variety of adjustable lights are mounted, for example in the form of individual ceiling lights. Also, the brightness setpoint, for example, due to different office equipment (eg dark instead of bright carpets) change, so that a renewed adjustment of the brightness setpoint is necessary. If the adjustment is not made, improper illumination may result in an unsuitable working environment.

The object of the invention is to avoid the above-mentioned disadvantages and in particular to provide an efficient way to set a brightness setpoint of a luminaire.

This object is achieved according to the features of the independent claims. Further developments of the invention will become apparent from the dependent claims.

To achieve the object, a method for setting a brightness setpoint of a luminaire is proposed,

- in which before switching off the lamp, a first brightness value is measured;

- in which after switching off the lamp, a second brightness value is measured; - In which the brightness setpoint based on the first brightness value and on the basis of the second brightness value is set.

This approach allows for efficient calibration of the luminaire to the brightness setpoint. The luminaire thus determines its own contribution to the ambient light and can thus determine the brightness setpoint or switch-on and switch-off thresholds determine without the need for manual intervention by a user.

The brightness setpoint generally corresponds to a default value regarding a total brightness of light and ambient light emitted from the lamp.

In particular, compliance with the setpoint can be achieved by means of the turn-on and turn-off thresholds using the ambient light, e.g. of daylight.

The lamp mentioned here may also include a lighting system with a plurality of bulbs. In particular, a control system for setting a plurality of lighting means may be provided.

A refinement is that a multiplicity of first brightness values and a multiplicity of second brightness values are measured and an adjustment of the brightness desired value is carried out as a function of the multiplicity of first and second brightness values.

Thus, for example, a controller, e.g. in the form of a processor unit, which stores a plurality of measured values, and depending on several of the measured values (for example, they may become increasingly significant over time, i.e., old measured values may be weighted correspondingly lower) determine the brightness setpoint.

Another development is that the first brightness values and / or the second brightness values are measured at least partially iteratively or at specific times. Thus, it is possible, for example, that each time the lamp is switched off again, first and second brightness values are determined.

In particular, it is a development that a weighting or averaging over a plurality of first brightness values and / or weighting or averaging over a plurality of second brightness values is performed.

Thus, it is possible for individual first and / or second brightness values to have little or no influence on the adaptation of the brightness setpoint, if these are not within a predetermined range. Thus, measurements that are most likely based on an atypical situation or a measurement error can be sorted out.

It is also a further development that a predetermined number of first brightness values and / or second brightness values are temporarily stored and in which the brightness setpoint is determined on the basis of the plurality of temporarily stored values.

Furthermore, it is a development that a switch-on threshold of the luminaire is determined on the basis of a difference between the first brightness value and the second brightness value.

In the context of an additional development, a switch-off threshold of the luminaire is determined on the basis of the switch-on threshold plus a predetermined tolerance.

A next development is that a hysteresis is provided between the switch-off threshold and the switch-on threshold of the luminaire. One embodiment is that the first brightness value is measured immediately before the luminaire is switched off.

Thus, the lamp can be turned off manually or automatically (for example, via the brightness control). In this case, first the first brightness value can be measured, then the light is switched off and then the second brightness value is measured. In this case, the "Turn off the light" process will provide the trigger for the measurements and for turning off the light.

An alternative embodiment is that the first brightness value and / or the second brightness value is / are measured using at least one sensor.

A next embodiment is that the at least one sensor comprises a brightness sensor, in particular a photodiode, a photoresistor or a phototransistor.

It is also an embodiment that the lamp is a dimmable lamp.

Also, the above object is achieved by means of a controller for carrying out the method as described herein.

Furthermore, the above object is achieved by means of a luminaire comprising - at least one sensor,

a control for setting a

A brightness setpoint of the luminaire based on a first brightness value measurable by the at least one sensor and based on a second brightness value measurable by the at least one sensor, wherein - Before switching off the lamp, the first brightness value can be measured;

- before switching off the lamp, the second brightness value is measurable; - The brightness setpoint based on the first brightness value and on the basis of the second brightness value is adjustable.

A further development is that the lamp has at least one lamp, wherein the

Illuminant may preferably comprise an optical system. The light-emitting means may be a semiconductor light-emitting element, in particular a light-emitting diode.

Embodiments of the invention are illustrated and explained schematically below with reference to the drawings.

Show it:

Fig.l schematically shows a curve that is a linear

Dependence of a measured value of the sensor on one

Brightness illustrated;

2 shows a hysteresis curve A-c-B-d for illustrating an on-off behavior of the luminaire depending on the brightness;

3 by way of example a luminaire comprising a luminous means, in particular two sensors, one

Control and a control.

The approach proposed here allows automatic determination of a brightness setpoint of a luminaire. Furthermore, on and off thresholds for the luminaire can be determined automatically. The luminaire mentioned here is, for example, a lighting system comprising at least one light source. Each bulb can have its own optics. As light sources are semiconductor elements, such as light emitting diodes used.

Example: non-dimmable luminaire:

The luminaire has at least one sensor for measuring brightness. The sensor may comprise a photodiode and / or a phototransistor and / or a photoresistor. Preferably, the sensor has a linear or essentially linear relationship between the detected measured value and a brightness.

FIG. 1 schematically shows a curve 101 which illustrates a linear dependence of a measured value of the sensor on a brightness.

Before switching off the luminaire, a brightness value I is measured and after switching off the luminaire, a brightness value II is measured.

In particular, between the two times to

Measurement of the brightness values I and II are chosen a relatively short period of time, so that the risk of falsification of the result by changing ambient light influences is low.

From the difference of the brightness value I and the brightness value II, a brightness change d 1 caused by the artificial light of the luminaire can be determined.

This change in brightness d 1 corresponds to the linear relationship between the curve shown in the curve 101 Measured value and the brightness of that brightness, which is achieved, for example without daylight content (and / or without proportion of ambient light) by the artificial light of the lamp.

This change in brightness d 1 is again a value that is used in the lighting design of the luminaire or a

Lighting system comprising this lamp has been determined such that a minimum illuminance, e.g. a job is safely achieved. In other words, the change in brightness d 1 corresponds to a brightness that ensures adequate illumination of the workstation in the absence of any ambient light.

A measured value A in FIG. 1 indicates a brightness below which the luminaire is to be switched on (switch-on threshold).

2 shows a hysteresis curve A-c-B-d for illustrating an on-off behavior of the luminaire depending on the brightness.

The illumination by the lamp as well as an influence of the ambient light (e.g., daylight) give a total brightness according to a point c in Fig.2. The luminaire is switched off with increasing ambient light at a point B. Point B is the brightness change d1 and an additional brightness difference Δ (e.g., 10%) above the brightness of point A.

After switching off the lamp is due to the remaining ambient light, a brightness corresponding to a point d. If this brightness decreases further to a value corresponding to the measured value to point A, the lamp is switched on again. With the hysteresis shown in Figure 2 is a constant switching on and off and thus a disturbing vibration of the brightness of the lamp effectively prevented.

Example: Dimmable luminaire:

In the case of a dimmable luminaire, the measurement of the brightness change d 1 caused by the luminaire takes place correspondingly. Thus, the point A can be determined, from which (or when it falls below), the lamp is turned on.

The point B for switching off the dimmable luminaire may be slightly above the switch-on threshold A, e. G., Irrespective of the brightness change dl. on A + 10%.

Since the dimmable lamp on reaching the switch-on threshold A initially turns on with a minimum luminous flux and is dimmed to this minimum luminous flux even when reaching the switch-off, the hysteresis curve shown schematically in Figure 2 is correspondingly narrower and shallower.

Further embodiments:

In order to enable an efficient determination of the brightness setpoint, it is possible to check before the storage of the corresponding threshold values (switch-on threshold A, switch-off threshold B) whether the brightness change d 1 lies in a predefined (meaningful) range and / or if the measured values provided by the at least one sensor lie in a (largely) linear region of the respective sensor element.

Thus, it is effectively prevented that the storage takes place, for example, in previously unused lights or at too high daylight rate. It is also possible for the brightness setpoint determination to be carried out automatically iteratively, for example at certain predefined times, for example during a day or during different days. The determined measured values can be individually weighted and the brightness setpoint can be tracked on the basis of the weighted measured values. It is thus possible for the luminaire to independently adjust the brightness setpoint for changing conditions, eg changes in the furnishing of an office. It is also possible that excessive changes are treated as measurement errors, discarded or weighted correspondingly weak. This has the advantage that the adapting lamp responds mainly to continuous changes and less to short-term changes.

Furthermore, it is possible that the luminaire or the control unit of the luminaire has a provisional desired value as the brightness setpoint and adapts itself in the mounted environment. Such an adaptation can e.g. initially fast, because not many measurements are available and the first measurements have a higher weighting accordingly. With prolonged use, the luminaire may self-illuminate within the given measurements with a larger time constant, e.g. as part of an averaging of the last x measurements, adapt.

The solution proposed here makes it possible to completely dispense with manual startup and determination of the brightness setpoint values. Likewise, components such as potentiometers or an interface for input devices (buttons, switches, etc.) could be dispensed with. The light or the light control system can already be calibrated after the first switch-off. 3 shows by way of example a luminaire 306 comprising a luminous means 301, two sensors 302, 303, a controller 304 and an operating element 305.

3 shows, by way of example, the two sensors 302, 303. It is also possible for only one sensor or a multiplicity (including different sensors) to be provided.

The controller 304 may be implemented as a microcontroller, a processor, or the like. with a corresponding usual

Circuit (memory, input-output interface, etc.) to be executed.

The control element 305 is optional and may have switches, buttons, potentiometers and display elements.

The light source 301 is driven by the controller 304. In the light source 301 or in the controller 304, a driver circuit (not shown) may be provided for this purpose.

The sensors 302, 303 provide measured values, which are preferably proportional to a recorded brightness. The control element 305 is connected to the controller 304.

List of reference numbers:

101 Curve of a sensor (brightness as a function of

Measured value, e.g. Current) A switch-on threshold

B Switch-off threshold c Brightness immediately after switching on d Brightness immediately after switching off

I measured value before switching off the luminaire (to determine the brightness setpoint)

II Measured value after switching off the luminaire (to determine the brightness setpoint) dl Brightness change (caused by the luminaire)

301 bulbs

302 sensor

303 sensor

304 control

305 control element

306 light

Claims

claims 1. Method for setting a brightness setpoint of a luminaire, - in which before switching off the lamp, a first brightness value (I) is measured; - in which after switching off the lamp, a second brightness value (II) is measured; - In which the brightness setpoint based on the first brightness value (I) and based on the second brightness value (II) is set. 2. The method of claim 1, wherein a plurality of first brightness values and a plurality of second brightness values are measured and an adjustment of the brightness setpoint in dependence on the plurality of first and second brightness values is performed. 3. The method of claim 2, wherein the first brightness values and / or the second brightness values are measured at least partially iteratively or at certain times. 4. The method according to any one of the preceding claims, wherein a weighting or averaging over a plurality of first brightness values and / or weighting or averaging over a plurality of second brightness values is performed. 5. The method according to any one of the preceding claims, wherein a predetermined number of first Brightness values and / or second brightness values are cached and in which the brightness setpoint is determined based on the plurality of cached values. 6. The method according to any one of the preceding claims, wherein a switch-on threshold (A) of the luminaire based a difference between the first brightness value and the second brightness value is determined. 7. The method of claim 6, wherein a switch-off threshold (B) of the lamp is determined based on the switch-on threshold plus a predetermined tolerance. 8. The method of claim 7, wherein a hysteresis is provided between the turn-off and the turn-on of the lamp. 9. The method according to any one of the preceding claims, wherein the first brightness value is measured immediately before turning off the lamp. 10. The method according to any one of the preceding claims, wherein the first brightness value and / or the second brightness value is measured by at least one sensor / are. 11. The method of claim 10, wherein the at least one sensor comprises a brightness sensor, in particular a photodiode, a photoresistor or a phototransistor. 12. The method according to any one of the preceding claims, wherein the lamp is a dimmable lamp. 13. Control for carrying out the method according to any one of the preceding claims. 14. Lamp (306) comprising at least one sensor (302, 303), a controller (304) for setting a brightness setpoint of the luminaire (306) based on a first brightness value (I) measurable by the at least one sensor (302, 303) and based on a second brightness value (II), which is measurable by the at least one sensor (302, 303), wherein - Before switching off the lamp, the first brightness value (I) is measurable; - before switching off the lamp, the second brightness value (II) is measurable; - The brightness setpoint based on the first brightness value (I) and based on the second brightness value (II) is adjustable.