Patent Publication Number: US-7710271-B2

Title: Method and system for lighting control

Description:
FIELD OF THE INVENTION 
   The invention relates to a method for controlling a lighting system. 
   BACKGROUND OF THE INVENTION 
   WO 2004/057927 discloses a method for configuration a wireless controlled lighting system. The prior art system comprises a central master control device, several local control master devices, which are linked to the central master device, and, associated with each local control master device, one or more lighting units and a portable remote control. Each lighting unit and the portable control are linked to their associated local control master device by a wireless connection. Light emitted by a lighting unit is modulated by an identification code, which was stored in the lighting unit before controlling the lighting unit. The portable control is suitable to receive the modulated light and to derive therefrom the identification code of the source lighting device. The portable control has a user interface by which a user can enter additional data, which is sent to its associated local control master device together with the identification code received from a lighting unit. Said additional data may contain an indication of a switch or key which the user assigns to the lighting unit to operate the lighting unit from then on, such as for turning on or off. Then, the data is communicated to the central master device for general lighting management. 
   With the prior art method and system the control of lighting units is carried out by forward control only, that is, without any kind of feedback about actual lighting conditions and locations of the lighting units. For example, an object can be illuminated by any number of lighting units directly, but also indirectly as a result of reflections. With the prior art system it is not possible to measure lighting effects caused by different lighting units on an object and to change controlling of the lighting units dependent on the measured lighting effects. 
   OBJECT OF THE INVENTION 
   It is an object of the invention to solve the drawbacks of the prior art and to provide an improvement thereof. 
   In particular, it is an object of the invention to measure lighting effects caused by the operation of different lighting units on their environment and to control said operation dependent on the measured effects. 
   SUMMARY OF THE INVENTION 
   The above object of the invention is achieved by a method where the property of the light is measured and can be any of several properties of the light, for example intensity of composite of light, intensities of light of different colors and emission directions. With said method a user can easily design, apply, redesign, and so on, a lighting scheme dependent on data of light sources and locations where specific effects are wanted. 
   Preferably, at the lighting arrangement, lighting arrangement data is comprised with data of at least one property, apart from the identification code, of the lighting arrangement. Accordingly, the main control device is informed about the properties or specifications of a lighting arrangement, such as about its power and its time and temperature dependent light emission, so that the central control device can take this in account when controlling the lighting arrangement, in particular concurrent with the controlling of other lighting arrangements. 
   Preferably, at the main control device, the lighting arrangement is controlled in concordance with a control program, a scheme of light effects to be generated by the light arrangement and the data received from the user control device and associated with the lighting arrangement. Accordingly, upon being provided with a control program and a scheme of wanted light effects and data received from the user controlled device, the main control device can control the lighting arrangements without additional support or input from a user. 
   In particular, said at least one light property of a lighting arrangement is determined at the lighting arrangement itself and data representing said property is transmitted by modulating light emitted by it, which data is then relayed by the user control device to the main control device. The light property data can be fixed, that is, stored in advance in the lighting arrangement, or the property may be measured by the lighting arrangement at suitable times to provide such data. 
   Preferably, said at least one light property of a lighting arrangement is measured at the user control device. As a consequence, properties of light emitted by different lighting arrangements are measured according to identical standards and measures and means for determining light properties at the lighting arrangements can be reduced. 
   Preferably, dependent on said data received by it, the main control device controls the at least one lighting arrangement to maintain a lighting effect, which said at least one lighting arrangement has on the user controllable device. As a result, a user may drag a lighting effect, such as a light spot, just by moving the user control device through the area covered by the lighting arrangement or the lighting arrangements. 
   Preferably, before controlling said at least one lighting arrangement, the main control device is provided with a priori data about a lighting effect said at least one lighting arrangement has at several locations, and during said controlling the main control device takes said a priori data in account. By doing so, at the time of controlling a lighting arrangement, the burden to determine light properties thereof can be reduced to just one time, that is, before the lighting arrangement is put in actual use. 
   Preferably, before controlling said at least one lighting arrangement, the main control device is provided with a priori data about an environment which can be lighted by said at least one lighting arrangement, and during said controlling the main control device takes said a priori data in account. Any lighting arrangement will have limited lighting coverage of objects. The arrangement will effect different intensities of light and shadows at different locations. By providing the main control device with data about such entities the main control device can take this in account when controlling different lighting arrangements, in particular for concurrently obtaining and/or maintaining specific lighting effects at different locations. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will become more gradually apparent from the following exemplary description in connection with the accompanying drawings, in which: 
       FIG. 1  shows a block diagram of a control system according to the invention in which the method according to the invention is applied; 
       FIG. 2  shows diagrammatically an example of practicing the method and system according to the invention; and 
       FIG. 3  shows diagrammatically another example of practicing the method and system according to the invention. 
   

   DETAILED DESCRIPTION OF EMBODIMENTS 
   The system shown in  FIG. 1  comprises one or more lighting arrangements  2 , which may each comprise one or more lighting units, each lighting unit being schematically indicated by reference numeral  4 . Lighting units  4  associated with a lighting arrangement  2  may be arranged at different locations in a room or in some other area to be lighted. Light emitted by a lighting unit  4  is indicated by a group of dashed arrows  6 . 
   A lighting arrangement  2  comprises means, for storing an identification code, which is unique for the lighting arrangement  2 , control means for supplying the lighting unit  4 , and means for modulating the supply of a lighting unit  4  and therewith modulating the light output of the lighting unit  4 , dependent on data, which at least comprises said identification code. 
   The system shown in  FIG. 1  further comprises a main control device  10  and a user control device  12 . In particular, the user control device  12  is a hand held device, which is portable by a user. The user control device  12  is provided with light sensing means, of which a light entrance dome  14  is shown only, which is suitable to receive light from its environment, that is, from one or more lighting units  4 , either directly or indirectly after reflection on objects such as walls. Arrows  16  and  18  indicate light which the user control device  12  receives from different lighting units  4 . Arrows  20 - 26  indicate light which is received by the user control device  12  from other lighting units  4  and/or other sources, possibly by reflection. 
   The user control device  12  can communicate with the main control device  10  via a wireless connection, which is indicated by reference numeral  28 . 
   Each lighting arrangement  2  is connected to the main control device  10  via a link  30 , which can be of any type. 
   The main control device  10  contains a processor, which runs a control program in concordance with a scheme for lighting locations covered by the lighting units  4  of the lighting arrangements  2 , such as for light intensity, light color range and light direction. The program uses data, which is obtained about such locations a priori while using the user control device  12  by a user. 
   At the time of feeding the main control device  10  with data about lighting conditions at locations covered by the lighting arrangements  2  the user uses the user control device  12  to receive light at each of said locations from any lighting arrangement  2  covering the location, deriving an identification code, of a single lighting arrangement  2  or, in case of receiving composite direct or indirect light from several lighting arrangements  2 , several identification codes originating from respective lighting arrangements  2 . The user control device measures some property of the received light of interest, apart from representing data, such as average light intensity during some interval. Then, the user control device  12  transmits data, which represents a value of a measured light property together with one or more derived identification codes, to the main control device  10 . Then, the program of the main control device  10  can determine the influence or effect a specific control of the main control device  10  has on the lighting at the current location of the user control device  12 . Having gained data on several locations, the main control device  10  can control the lighting arrangements  2  in several ways to obtain wanted light effects in some or all of said locations. 
   According to the invention a location of the user control device  12  is determined to provide location data, which the main control device  10  takes in account when controlling a lighting arrangement  2  or lighting arrangements  2 . The location of the user control device  12  can be determined in different ways. For example, the user control device  12  can determine its location itself, such as by using GSM or by monitoring its position with respect to reference objects, which are located in the room or other area covered by the lighting system and which may be transmitter for transmitting modulated light or ultrasound. As an alternative, the main control device  10  can determine the location of the user control device  12 . For example, the user control device  12  may be provided with a transmitter for transmitting light or ultrasound and the main control device may comprise, or may be connected to, several receivers at different reference locations for receiving such light or sound to therefrom calculate the position of the user control device  12 . Such means are well known to persons skilled in this art and are not part of the invention per se. Therefore a detailed description thereof is omitted here. For the same reason a detailed description of means for modulating light by data, in particular an identification code, means for receiving such modulated light and deriving data therefrom is omitted here. 
   In  FIG. 2  reference numeral  34  indicates a wall, such as a wall of an exhibition room. A painting  36  is attached to the wall  34 . The painting  36  and other exhibition objects (not shown) can be lighted by several lighting units  4  of one or more lighting arrangements  2 . Preferably, each lighting unit  4  is equipped with means for dimming, directing and focusing light emitted by the lighting unit  4 . 
   In the example of  FIG. 2  the lighting units  4  are in such states, as controlled by the main control device  10 , that they generate a specific light effect, such as a light spot  38 , at some location at the wall  34 . A user  40  carries the user control device  12 , such that the user control device may receive light from lighting units  4 . The user  40  may control a user interface (not shown in detail), such as a button, of the user control device  12  to instruct the main control device  10  to determine current data about the light received by the user control device  12 , identification codes of lighting arrangements the light originates from, and data about the location of the user control device  12 . Further, by operating said user interface the user  40  may instruct the main control device  10  also to track the user control device  12  when it moves and to keep determining said data when the user control device  12  moves. This way the main control device may learn about lighting effects in three dimensions resulting from light which is emitted by one or more lighting units  4  associated with specific states of control of the lighting units  4  by the main control device  10 . Thus, the main control device  10  may learn about which light effects it may create by which ways of control it may do so. 
   In addition, the user  40  may instruct the main control device  10  to not only track the user control device  12  when it moves, but also to control the lighting arrangements  2  or their lighting units  4  such as to maintain a light effect at the changing location of the user control device  12 . As a result, the light effect is dragged by the user control device  12  to any other location. That is, provided that the main control device  10  has been provided a priori, such as by the learning process described above, with data about the way or ways it may change control of the lighting arrangements  2  to maintain said light effect at a changing location of the user control device  12 . This way the user  40 , when moving in a direction as indicated by arrow  42 , may drag the light spot  38  along a track indicated by arrow  44  from the wall  34  outside the painting  36  towards a specific detail of the painting  36 . The user  40  needs not to know how the main control device  10  controls the lighting arrangements  2  to achieve such dragging. The user may fully concentrate on the light scheme of the exhibition he wants to create. 
   In  FIG. 3  reference numeral  46  indicates a stage and reference numeral  48  indicates a back wall. In the situation as indicated lighting units  4  are in states in which they produce a specific light effect, such as a light spot  50 , on the stage  46 . Similar to the example of  FIG. 2  the user  40  may instruct the main control device  10  to track the user control device  12  when it moves, to gain data about a light effect as determined by the user control device as it moves, and to maintain said light effect at a changing location of the user control device  12  as it moves by properly controlling the lighting arrangements  2 . This way a director may easily create an attractive lighting scheme for a performance which is to be made on said stage  46 . 
   With the method and system according to the invention means are obtained by which lighting effects, which are a result of controlling lighting arrangements in specific locations, can be determined via an user control device  12  and communicated to the main control device  10  to therewith control the lighting arrangements  2 , in any of several possible ways to obtain wanted light effects in said locations and dependent on a location of the user control device  12 . The method and system according to invention allow to provide the main control device easily with data about possible lighting effects in several locations and about several alternative ways to produce the light effects. In addition, the method and system according to the invention allow to drag a specific light effect at a specific location to be dragged to another location, just by moving the user control device  12 . 
   It is noted that several modifications can be carried out without departing from the scope of the invention as determined by the amended claims. For example, the data which a lighting arrangement  2  uses to modulate light may comprise data about properties or specifications of the lighting arrangement  2 . This additional data can be relayed through the user control device  12  together with the identification code of the lighting arrangement  2  to the main control device  10 . Then, the main control device  10  can take said additional data in account when controlling the operation of said lighting arrangement  2  or lighting arrangements  2 . Said additional data may refer to capacities about color dependent light intensities, and light directional information. 
   It is also observed that, within the scope of the appended claims, monitoring, tracking and dragging a light effect does not require, for example, to hold a button of the user control device  12  pushed down. It is also possible to “copy”, “memorize”, “paste” and “scroll” a light effect which is detected at some location. Pasting and scrolling include transmitting an alternative location from the user control device  12  to the main control device  10 . Operating one or more buttons and/or a scroll wheel of the user control device  12  by the user may initiate such transmission of an alternative location. Handling commands like this by the main control device  10  is not much different from handling similar commands supplied by operating a computer mouse. Therefore, method steps or software for handling such commands are omitted in this description.