WO2009001267A2

WO2009001267A2 - System for controlling a plurality of light sources

Info

Publication number: WO2009001267A2
Application number: PCT/IB2008/052451
Authority: WO
Inventors: Kumar Arulandu; Naveen K. Mehta
Original assignee: Koninklijke Philips Electronics N.V.
Priority date: 2007-06-28
Filing date: 2008-06-20
Publication date: 2008-12-31
Also published as: WO2009001267A3

Abstract

A lighting system (100) comprises: a plurality of controllable lighting devices (2) each having an associated address (n); a central controller (10) for providing a command signal (Sc) including address command signals (AC(n)); at least one decentralized control unit (150) comprising an input (151) for receiving the command signal (Sc1N) and an output (152) for outputting an output command signal (SCOUT) including address command signals (AC(n)OUT)- Each lighting device is responsive to the address command signal (AC(n)) corresponding to its device address (n). The lighting devices are arranged in series for passing on the command signal, such that the output command signal is always identical to the input command signal. The DCU calculates, for at least one address X, an adapted output address command signal (AC'(X)OUT) differing from the corresponding input address command signal (AC(X)IN) and based on a function input signal received at its function input (156).

Description

SYSTEM FOR CONTROLLING A PLURALITY OF LIGHT SOURCES

FIELD OF THE INVENTION

The present invention relates in general to a lighting system comprising a plurality of controllable lighting devices, and a central controller for individually controlling the lighting devices.

BACKGROUND OF THE INVENTION

Lighting systems have been developed, wherein a central controller is capable of individually controlling a plurality of lighting devices. One obvious way of implementation is a central controller having a plurality of outputs, wherein each individual lighting device is connected to a respective output, but this is complicated and would require a lot of electrical cables. Thus, lighting systems have been developed comprising a common communication line running from one lighting device to the next.

The central controller issues digital command signals and address signals. Each lighting device has a specific address, and is responsive only to the command signal associate with an address signal indicating its specific address. It is possible that two or more devices have the same address, which means that they will have the same response to the same command signal.

The lighting devices may receive power individually from a suitable power source, typically mains. However, it is also possible that the lighting devices receive power via the common communication line.

An example of such communication system is the DMX (Digital Multiplex) system, using the DMX protocol, also known as DMX512. It is noted that this system and protocol are known per se, so an elaborate description and explanation are not needed here. By way of example, reference is made to US patents 6175771 and 7065418. In the following explanation, it will be assumed that the DMX protocol is used, but it is noted that the invention is not restricted to this protocol since the invention can also be implemented using different existing or future protocols.

SUMMARY OF THE INVENTION Although the concept of centralized control is advantageous in the sense that a user can control the behaviour of all lighting devices from one central location, there are situations where decentralized control features are desirable. As an example of such decentralized control feature, "dimming" and "motion detection" will be mentioned, but there are several other types of control features conceivable. Now a disadvantage of the concept of centralized control is the fact that the command signals for the lighting devices which are to be controlled by the decentralized control feature must be transmitted by the central controller.

It may be that the central controller itself is capable of performing, for instance, dimming, but this would require the user to go to the central controller whereas it is much more convenient if the user could give the command for dimming at the location where the dimming is required, which may be remote from the central controller.

The desirability of a decentralized control feature implies a separate control device located at some distance from the central controller. Such control device must be connected to the central controller in order to enable the central controller to issue the appropriate command signals. This involves the disadvantage that the central controller must be provided with inputs for connecting the control devices, that control lines must be arranged for connecting the control devices to the central controller, and that the central controller must be "told" by the user which lighting devices are to be influenced by the control devices. This would make the design of the central controller quite complicated and hence expensive.

It is of course possible to disconnect the lighting devices which are to be controlled by the decentralized control feature, and to incorporate them in a second network governed by the decentralized control feature, but this is not in conformity with the desire of central control. For instance, it is possible that it is desirable that the colour of all lighting devices is controlled by the central controller, but that the light level of a subgroup of the lighting devices is controlled by a decentralized dimmer or that the lighting devices are only used if a decentralized detector detects the presence of people.

It is a general object of the present invention to overcome or at least reduce the above-mentioned problems.

To this end, the present invention provides a decentralized control unit having an input for receiving command signals from the central controller, having functionality for amending the received command signals, and having an output for outputting the amended command signals. Further advantageous elaborations are mentioned in the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects, features and advantages of the present invention will be further explained by the following description of one or more preferred embodiments with reference to the drawings, in which same reference numerals indicate same or similar parts, and in which:

Figure 1 is a block diagram schematically illustrating a lighting system according to the prior art; Figure 2 is a graph schematically illustrating a communication protocol;

Figure 3 is a block diagram schematically illustrating a lighting system according to the present invention;

Figure 4 is a block diagram illustrating a decentralized control unit.

DETAILED DESCRIPTION OF THE INVENTION

Figure 1 schematically shows a lighting system 1 according to the prior art, comprising a plurality of controllable lighting devices 2, individually distinguished by the addition of an index between brackets. Each lighting device 2 receives power from a suitable power source, for instance mains, but this is not shown in the figure for sake of simplicity. For controlling the controllable lighting devices 2, the lighting system 1 comprises a communication system 3, comprising a central controller 10, device interfaces 20, and a communication line 30 comprising a plurality of line portions 31. The central controller 10 has an output terminal 12 for providing command signals (by way of example: DMX command signals). Each lighting device 2 has a corresponding device interface 20, for receiving and processing the command signals and generating lamp drive signals in correspondence with the received command signals. Each device interface 20 has a device interface input 21 and a device interface output 22. Each device interface 20 is designed to provide at its device interface output 22 an output signal identical to the command input signal received at its device interface input 21. A first line portion 31(0) connects the output terminal 12 of the central controller 10 to the device interface input 21(1) of a first device interface 20(1). Further, the device interface output 22(i) of a device interfaces 20(i) is always connected to the device interface input 21(i+l) of a next device interfaces 20(i+l) via a next line portion 3 l(i). Figure 2 is a graph schematically illustrating the DMX communication protocol. It is noted that the present invention can be implemented in conjunction with different communication protocols.

In figure 2, the horizontal axis represents time, while the vertical axis represents the command signal Sc. The figure shows a sequence of data packets, each data packet containing a command for a lighting device. Data packets are distinguished by a start byte and a stop byte, as is known. Further, the sequence of data packets is distinguished by a start code as well, as is known.

Each device interface 20 has a device address, which can be set by a user. Typically, the address is set by means of DIL switches. If the interface comprises 8 such switches, which each can represent a value 0 or 1 , the address can be set at any value between 000000000 and 111111111, i.e. there are 512 addresses possible. However, the address can be set in a different manner, and the number of possible addresses may be more or less.

A command for a device having address n is included in the n-th data packet of the sequence of data packets, i.e. the sequence of data packets contains at least 512 successive data packets. Thus, an interface having address n will be responsive to the data of the n-th data packet and will ignore all other data. It is noted that the devices may all have mutually different addresses, but it is also possible that two or more devices have the same address, which means that they constitute a group of devices which all respond in the same way.

Each interface will relay the data packets from its input through to its output. This means that the command signals in the line portions 31(i) are all mutually identical to each other.

In the following, a command signal in general will be indicated as Sc; this includes the sequence of data packets. A specific command signal for address n will be indicated as address command signal AC(n); this includes the n-th data packet. For a device interface, input and output signals will be distinguished by addition of index IN and OUT, respectively. Thus, for each device interface, the relationship AC(n)ouτ = AC(Ii)_1N applies for all values of n. Figure 3 is a block diagram comparable to figure 1, illustrating a lighting system 100 according to the present invention. The difference between the prior art system and the inventive system is the presence of at least one decentralized control unit 150. In a possible embodiment, this decentralized control unit 150 is a dimmer. In another possible embodiment, this decentralized control unit 150 is an event detector, for instance a movement detector or a time clock.

Figure 4 is a block diagram illustrating the decentralized control unit 150, hereinafter indicated as DCU, in some more detail. The DCU 150 has an input 151 for receiving an input command signal Sc_1N, ^and has an output 152 for outputting an output command signal SCOUT- The DCU 150 further has a user-settable mode switch 153, a user- settable address selection device 154, and a processor 155.

In the case of for instance a dimmer, the DCU further has a user input for setting a desired dim level. In the case of for instance a movement detector, the DCU further has a sensor for sensing movement. For receiving the corresponding information, the processor 155 comprises a function input 156.

For mounting the DCU 150 in the system, the DCU 150 is treated as any lighting device. Assume that a prior art system 1 of figure 1 is to be adapted by introduction of a DCU 150 between lighting devices 2(i) and 2(i+l). First, line portion 31(i) is removed. DCU input 151 is connected to the device interface output 22(i) of the device 2(i), and DCU output 152 is connected to the device interface input 21(i+l) of the next device 2(i+l).

For configuring the DCU 150, the user sets the mode switch 153 to select between a mode "all addresses" and a mode "one single address". For the "one single address" mode, the user sets the address selection device 154 to define one single address X. In the following, it is assumed that the user has set the "one single address" mode.

In operation, the DCU behaves in the same way as a device interface of a lighting device, in that it receives at its input 151 an input command signal Sc_1N, ^and outputs at its output 152 an output command signal SCOUT- Further, the output address command signals AC(n)ouτ ^are equal to the input address command signals AC(Ii)_1N for all values of n, with the exception for n = X. For address X, the processor 155 calculates an adapted output address command signal AC'(X)ouτ on the basis of the input address command signal AC(X)_1N ^and on the basis of the function input signal received at its function input 156.

In the example of a dimmer, wherein the function input signal may define a dim level of α (α being a value in the range 0-1), the processor 155 calculates the adapted output address command signal AC'(X)ouτ such that, on processing by a device interface, it results in a light output that is a factor α lower than the light output which would result on processing the original input address command signal AC(X)_1N- This will be expressed in a formula as AC(X)_0UT = α- AC(X)_1N.

In the example of an event detector, the processor 155 calculates the adapted output address command signal AC'(X)ouτ such that an addressed device interface either follows the original input address command signal AC(X)_1N or does not respond at all, depending on the function input signal. It will be assumed that the event sensor can only make a distinction between "yes, event detected" and "no, no event detected", and that the function input signal accordingly can take two possible values which will be indicated as " 1 " and "0", respectively. Thus, the adapted output address command signal AC'(X)ouτ can be expressed in a formula as AC'(X)ouτ = P-AC(X)_1N, in which β represents the function input signal, either being equal to 1 or equal to 0.

It is noted that, if the user selects the "all addresses" mode instead of the "one single address" mode, the above applies to all addresses instead of applying only to one single address X. So, in that case AC'(n)ouτ ⁼ α-AC(n)iN or AC'(n)ouτ ⁼ P-AC(^_1N for all values of n.

It is noted that no adaptations are needed for the lighting devices 2. Each lighting device still receives a "normal" command signal Sc, containing "normal" address command signals AC(n). A lighting device receiving an adapted address command signal AC(X) has no means of determining whether the address command signal originates from the central controller 10 or from a DCU, and has no means of determining whether the address command signal has been adapted: the adapted address command signal AC(X) complies with the communication protocol in all aspects. However, the advantageous effect is achieved that lighting devices having a certain address X which are located downstream of the DCU have a different response as compared to lighting devices having the same address X which are located upstream of the DCU.

Summarizing, the present invention provides a lighting system (100) which comprises: a plurality of controllable lighting devices (2) each having an associated address (n); - a central controller (10) for providing a command signal (Sc) including address command signals (AC(n)); at least one decentralized control unit (150) comprising an input (151) for receiving the command signal (Sc_1N) and an output (152) for outputting an output command signal (SCOUT) including address command signals (AC(n)ouτ)-

Each lighting device is responsive to the address command signal (AC(n)) corresponding to its device address (n). The lighting devices are arranged in series for passing on the command signal, such that the output command signal is always identical to the input command signal.

The DCU calculates, for at least one address X, an adapted output address command signal (AC'(X)ouτ) based on the corresponding input address command signal (AC(X)_1N) and based on a function input signal received at its function input (156).

While the invention has been illustrated and described in detail in the drawings and foregoing description, it should be clear to a person skilled in the art that such illustration and description are to be considered illustrative or exemplary and not restrictive. The invention is not limited to the disclosed embodiments; rather, several variations and modifications are possible within the protective scope of the invention as defined in the appending claims.

For instance, instead of one data byte, the DCU can take two or more bytes as input if a lighting unit requires more than one input byte in a command signal. For instance, it may be that a lighting unit requires RGB-signals for setting a colour. In such case, three successive data bytes would all have the same address information, and the order of the bytes may determine which is for R, which is for G, and which is for B.

Also, other types of manipulation by the DCU are possible. For instance, it is possible that the DCU makes the address command signal AC(X) for a certain address X equal to the address command signal AC(Y) for a certain address Y. In that case, AC'(X)ouτ = AC(Y)_1N would apply. This allows for a COPY/PASTE functionality, where a user, satisfied with the setting of lighting unit Y, can give a command to the DCU in order to have the same setting for lighting unit X. It also allows for an INTERCHANGE functionality, where a user, satisfied with the setting of lighting units X and Y, wishes to make amendments to his interior decoration so that lighting unit X should in future have the current setting of lighting unit Y while lighting unit Y should in future have the current setting of lighting unit X. In that case, AC(X)_0UT = AC(Y)_1N and AC(Y)_0UT = AC(X)_1N would apply. Of course, this can be combined with dimming and/or presence detection. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. A computer program may be stored/distributed on a suitable medium, such as an optical storage medium or a solid-state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems. Any reference signs in the claims should not be construed as limiting the scope.

In the above, the present invention has been explained with reference to block diagrams, which illustrate functional blocks of the device according to the present invention. It is to be understood that one or more of these functional blocks may be implemented in hardware, where the function of such functional block is performed by individual hardware components, but it is also possible that one or more of these functional blocks are implemented in software, so that the function of such functional block is performed by one or more program lines of a computer program or a programmable device such as a microprocessor, microcontroller, digital signal processor, etc.

Claims

CLAIMS:

1. Decentralized control unit ( 150) for a lighting system ( 100), the DCU ( 150) comprising: an input (151) for receiving an input command signal (Sc_1N) including address command signals (AC(n)n^); - an output (152) for outputting an output command signal (SCOUT) including address command signals (AC(n)ouτ); a processor (155) having a function input (156) for receiving a function input signal; wherein the processor (155) is designed to generate the output address command signals (AC(n)ouτ) on the basis of the received input address command signals (AC(II)_1N); wherein the processor (155) is designed, for at least one address X, on the basis of the function input signal received at its function input (156), to calculate an adapted output address command signal (AC'(X)ouτ) differing from the corresponding input address command signal (AC(X)ΪN).

2. DCU (150) according to claim 1, capable of operating in an operative mode "one single address", wherein the processor (155) is designed, when operating in the operative mode "one single address", to calculate the adapted output address command signal (AC'(X)ouτ) for one single address (X) only and, for all other addresses, to calculate the output address command signal (AC(n)ouτ) to be equal to the received input address command signal (AQn)_1N).

3. DCU (150) according to claim 2, further comprising a user-settable address selection device (154) for defining one single address X.

4. DCU (150) according to claim 1, capable of operating in an operative mode "all addresses", wherein the processor (155) is designed, when operating in the operative mode "all addresses", to calculate the adapted output address command signal (AC'(X)ouτ) for all addresses.

5. DCU (150) according to claim 1, further comprising a user-settable mode switch (153), capable of selecting between an operative mode "all addresses" and an operative mode "one single address".

6. DCU (150) according to claim 1, wherein the processor (155) is designed to calculate the adapted output address command signal AC'(X)ouτ in accordance with the formula AC'(X)ouτ ⁼ OfAC(X)_1N, wherein AC(X)_1N represents the corresponding input address command signal and wherein α represents a dimming factor received at its function input (156).

7. DCU (150) according to claim 1, wherein the processor (155) is designed to calculate the adapted output address command signal AC'(X)ouτ in accordance with the formula AC'(X)ouτ ⁼ P-AC(X)_1N, wherein AC(X)_1N represents the corresponding input address command signal and wherein β represents a value 1 or 0 in accordance with an event detection signal received at its function input (156).

8. DCU (150) according to claim 1, wherein the processor (155) is designed to calculate the adapted output address command signal AC'(X)ouτ for a certain address X in accordance with the formula AC'(X)ouτ ⁼ AC(Y)_1N, wherein AC(Y)_1N represents the input address command signal for a different address Y.

9. DCU (150) according to claim 1, wherein the DCU (150) is implemented as a dimmer.

10. DCU (150) according to claim 1, wherein the DCU (150) is an event detector, for instance a movement detector or a time clock.

11. Lighting system (100), comprising a plurality of controllable lighting devices (2) and a communication system (3), the communication system comprising a central controller (10), a plurality of device interfaces (20), and a communication line (30) coupling the device interfaces in a series arrangement to an output terminal (12) of the central controller; wherein each device interface (20(i)) is associated with a corresponding lighting device (2(i)); wherein each device interface (20(i)) has allocated a user-selectable address

(n); wherein the central controller (10) is designed for providing a command signal (Sc) including address command signals (AC(n)); wherein each device interface (20(i)) has a device interface input (21(i)) and a device interface output (22(i)); wherein the device interface output (22(i)) of a device interface (20(i)) is connected to the device interface input (21(i+l)) of a next device interface (20(i+l)) via a line portion (31(i)) of a communication line (30); wherein each device interface (20(i)) is responsive to the address command signal (AC(n)) corresponding to its device address (n) for driving the corresponding lighting device (2) in correspondence with said address command signal (AC(n)); wherein each device interface (20(i)) is designed to provide at its device interface output (22(i)) an output command signal (SCOUT) identical to the command input signal (Sc_1N) received at its device interface input (21(i)), so that AC(n)ouτ ⁼ AQn)_1N applies for all values of n; the lighting system (100) further comprising at least one DCU (150) according to claim 1, having its DCU input (151) connected to the device interface output (22(i)) of a first lighting device (2(i)) and having its DCU output (152) connected to the device interface input (21(i+l)) of a second lighting device (2(i+l)).

12. lighting system (100), comprising: a plurality of controllable lighting devices (2) each having an associated address (n); a central controller (10) for providing a command signal (Sc) including address command signals (AC(n)); at least one decentralized control unit (150) comprising an input (151) for receiving the command signal (Sc_1N) and an output (152) for outputting an output command signal (SCQUT) including address command signals (AC(n)ouτ); wherein each lighting device is responsive to the address command signal (AC(n)) corresponding to its device address (n); wherein the lighting devices are arranged in series for passing on the command signal, such that the output command signal of a lighting device is always identical to its input command signal; wherein the DCU (150) calculates, for at least one address X, on the basis of a function input signal received at a function input (156), an adapted output address command signal (AC'(X)ouτ) differing from the corresponding input address command signal (AC(X)IN).