System and method for lighting control in buildings

Abstract

System (1) for lighting control in buildings, comprising a central control unit (10) and at least one luminaire (20) controlled by the central control unit (10), wherein the central control device (10) is designed to take into account the influence of the outside light in an area to be illuminated by the luminaire (20) when controlling the luminaire (20), wherein the system has a sensor for determining the outside light (15) and the central control unit (10) is configured to calculate the influence of the outside light taking into account the information obtained from the sensor, and wherein, in order to calculate the influence of the external light, the central control unit (10) takes into account information which • the spatial design of a room (100) or an area in which the light fixture (20) is located, • the position of the light (20) in the room (100) or area as well as • the arrangement and design of facilities (105) through which outside light can enter the room (100) or area, concerning, whereby the information consists of positional data which essentially completely describe the spatial design of the building, the arrangement of the light fixture(s) and of facilities through which outside light can enter the building.

Description

[0001] The present invention relates to a system for controlling lighting in buildings, wherein several, preferably distributed, luminaires are controlled via a central control unit. The present invention further relates to a corresponding method for controlling lighting.

[0002] To achieve uniformly coordinated lighting control in larger buildings or building complexes, centrally controlled lighting systems are often used. The luminaires located in the various areas or rooms are centrally controlled by a corresponding control unit, and their brightness is adjusted accordingly. This ensures a consistent appearance for the building in terms of its illumination, and also guarantees, for example, that certain areas are always sufficiently bright to allow people to work comfortably or move around safely.

[0003] Since lighting larger buildings involves considerable energy consumption, there is a growing search for solutions that utilize available daylight. This means that the luminaires should ideally have adjustable brightness and be controlled in such a way that, together with the incoming light from outside, a desired overall brightness is achieved in a specific area. Increases or decreases in outside brightness are thus compensated for as much as possible by adjusting the luminaires accordingly. In this way, the available daylight can be used efficiently, and only as much energy is consumed as is actually necessary to ensure adequate illumination of workplaces or other areas of the building.

[0004] However, adjusting the brightness settings for the various luminaires requires knowledge of the influence of daylight or the light entering the areas to be illuminated from outside. Two main solutions for this are known in the prior art.

[0005] Firstly, brightness sensors are often used to detect the ambient light level in a specific area to be illuminated. For example, a brightness sensor can be positioned on the work surface of a workbench. The brightness detected by the sensor corresponds to the total brightness resulting from the ambient light and the additional artificial light illuminating the workspace. Within a control loop, the lights intended for illuminating the workspace are then controlled so that the total brightness at the workspace detected by the sensor meets a desired setpoint.

[0006] While the influence of the outside light can be taken into account very precisely in the manner described above, and it can be conveniently ensured that certain areas are actually illuminated evenly, the use of appropriate sensors and additional means for controlling the lights is associated with a relatively high level of effort.

[0007] An alternative, and particularly more cost-effective, solution is therefore to manually assess the fundamental influence of the outside light in a first step and to take this into account when setting up the lighting system or in the algorithms for controlling the luminaires. In this case, brightness measurements are taken in various areas of the building before the system is put into operation, in order to determine the influence of the outside light entering the building. The findings are then incorporated into the subsequent control algorithms for the luminaires, whereby the central control unit determines the corresponding setpoints and transmits them to the luminaires. For this purpose, the central control unit first receives information regarding the general ambient brightness, or...of daylight and, based on this and taking into account the previously determined measured values, creates corresponding control signals for controlling the lights.

[0008] While this design requires fewer components, as it eliminates the need for sensors, the initial measurements provide only relatively imprecise information regarding the actual influence of the ambient light. Therefore, this solution primarily represents a cost-effective compromise to at least partially account for the influence of daylight.

[0009] DE 103 38 535 A1 and DE 198 42 465 A1 also describe systems in which the daylight level within a room is determined using experimental measurement methods and the luminaires within the room are controlled accordingly based on this measurement information.

[0010] Based on this, the present invention is therefore based on the objective of providing a novel solution in which the influence of daylight can be taken into account better or more accurately in the control of lighting systems, without the need for the use of additional measuring instruments such as local sensors or the like.

[0011] The problem is solved by a system for controlling lighting in buildings, which has the features of claim 1, and by a method according to claim 4. Advantageous embodiments of the invention are the subject of the dependent claims.

[0012] The solution according to the invention is based on the idea of ​​determining the influence of outside light based on detailed information regarding the spatial design of a room or area to be illuminated, the arrangement of the luminaires located therein, and the arrangement and design of devices through which outside light can enter the room or area. For this purpose, it is necessary to obtain detailed information regarding the geometric design of the building to be illuminated. This information relates not only to the dimensions and arrangement of the rooms themselves, but also to the positions of the luminaires and the windows or other translucent surfaces through which daylight can enter the building.Precise knowledge of this data makes it possible to determine the influence of ambient light much more accurately within specific areas of a room to be illuminated, without requiring the use of local sensors or similar devices. The information calculated in this way regarding the influence of ambient light is significantly more accurate than that achievable with the prior art example mentioned above, where brightness values ​​are measured in specific areas of a room to be illuminated before the system is put into operation. Therefore, the present invention enables significantly better, more accurate, and more efficient lighting control, while keeping the technical effort required to implement the entire lighting system to a minimum.

[0013] According to the present invention, a lighting control system for buildings is proposed, comprising a central control unit and at least one luminaire controlled by the central control unit. The central control unit is configured to take into account the influence of the ambient light in the area to be illuminated by the luminaire when controlling it. The system includes a sensor for determining the ambient light, and the central control unit is configured to calculate the influence of the ambient light based on the information received from the sensor. According to the invention, the central control unit considers information relating to the spatial layout of a room or area in which the luminaire is located, the position of the luminaire in the room, and the ambient light level when determining the influence of the ambient light.The information pertains to the area as well as the arrangement and design of devices through which outside light can enter the room or area, wherein the information consists of positional data that essentially completely describe the spatial design of the building, the arrangement of the luminaire(s), and the devices through which outside light can enter the building. Preferably, the system comprises several luminaires, and the central control unit is designed to determine the influence of the outside light on the area to be illuminated by each luminaire.

[0014] As with the prior art lighting control system described above, it is provided that the central control unit is supplied with basic information regarding the ambient light. For this purpose, a so-called daylight sensor can be provided, which is located on the exterior of the building and determines the basic ambient brightness and its directional dependence. The way in which this ambient light then affects the individual areas is then calculated, as described above, based on the precise geometric information. According to an advantageous embodiment of the invention, the central control unit can also be configured to take into account objects located in the vicinity of the building, particularly with regard to their shading and / or reflection properties, when calculating the influence of the ambient light.The calculation of the influence of external light also takes into account reflective surfaces in the building's vicinity, such as the glass facades of neighboring buildings. Furthermore, it considers the extent to which such objects lead to a reduction in the perceived amount of external light at certain times of day.

[0015] According to the invention, the information used to calculate the influence of external light consists of positional data that essentially completely describe the spatial design of the building, the arrangement of the luminaire(s), and the arrangement and dimensions of any devices through which external light can enter the building. This information can be collected and made available to the system in various ways, some of which will be described in more detail later.

[0016] According to the present invention, a method for controlling lighting in buildings is also proposed, wherein, when controlling luminaires, the influence of the outside light in an area to be illuminated by the respective luminaire is taken into account, wherein the influence of the outside light is calculated taking into account the information obtained from a sensor for determining the outside light, and according to the invention, information relating to the design of a room or area in which the luminaire is located, the position of the luminaire in the room or area, and the arrangement and design of devices through which outside light can enter the room or area is taken into account to determine this influence of the outside light, wherein the information is position data through which the spatial design of the building, the arrangement of the luminaire, etc., can be determined.The lighting fixtures and devices through which outside light can enter the building are described in essentially complete detail.

[0017] Knowing this precise positional information also offers the additional advantage of having exact information regarding the location of the various light fixtures within the building. In the event of a malfunction caused by a light fixture, its position within the building can now be easily determined, significantly simplifying maintenance work. Furthermore, this information can be used to create a three-dimensional visualization of the building. The positioning of the various light sources within the building can then be displayed very clearly. Until now, only general lighting design programs were used for this purpose, which, however, were not based on such precise positional information. Consequently, such lighting design programs are also unsuitable for calculating control information for operating the light fixtures during subsequent operation.Instead, in these systems, preferred arrangements for the luminaires are determined once according to the state of the art, and then a suitable control of the luminaires is determined without further consideration of the influence of the outside light.

[0018] The invention will now be explained in more detail with reference to the accompanying drawing. The drawing shows: Fig. 1 schematically a room to be illuminated, into which daylight also enters in addition to the artificial light generated by lamps; Fig. 2 schematically the basic idea of ​​the present invention, namely to describe the design of a room to be illuminated by means of exact position information; Fig. 3a and Fig. 3b Representations for taking into account objects located in the vicinity of the building to be illuminated when controlling the lighting.

[0019] Based on Fig. First, the problem underlying the invention will be clarified. A room in a building, generally designated by reference numeral 100, is shown, containing several workstations 110, 111, and 112. These workstations are to be illuminated by the luminaires 20 of a lighting system 1, the control of which is carried out by a central control unit 10. This control unit is connected to the luminaires 20 via a common bus line 11 and is configured to transmit control signals – preferably digital – to the luminaires 20, which are used, in particular, to adjust the brightness of the luminaires 20. It is particularly desirable that, at least within a predetermined working time period, the workstations 110 to 112 are continuously illuminated with a constant brightness.

[0020] In this case, it must be taken into account that workstations 110 to 112 are not only illuminated by the artificial light from the luminaires 20, but also by daylight from outside through the windows 105 located on one side of room 100. This daylight provides additional illumination for the workstations, and preferably the luminaires 20 are controlled in such a way that the overall brightness resulting from daylight and artificial light remains essentially unchanged. For this purpose, it is necessary to obtain the most precise possible information about the influence of the outside light.

[0021] Accordingly, the lighting system 1 additionally features a so-called daylight measuring head 15, which is typically located on the exterior facade of the building. Such daylight measuring heads are already known from the prior art. They serve to determine not only the overall brightness of the outside light but also its directional dependence. The daylight measuring head 15 thus provides information about the direction from which daylight falls on the building facade and its intensity. Alternatively, it would also be conceivable to determine the directional dependence and / or the intensity of the daylight using theoretical models. However, more precise information can be obtained in this regard with the help of the measuring head 15.

[0022] This general knowledge about the intensity and directional dependence of the outside light is, however, not yet sufficient to determine the influence of daylight at the various workplaces or the area to be illuminated by the respective luminaires 20 with sufficient accuracy. Depending on where in the room 100 to be illuminated the workplace is located, the outside light entering through the windows 105 can have a different effect. For example, with a light incidence corresponding to arrow I in Fig. 1. Workstations 111 and 112 are primarily illuminated, while workstation 110 is in the shaded area. If, however, the outside light comes from the direction of the second arrow II – for example, later in the day – then workstation 112 is more likely to be in the shaded area.

[0023] To account for such effects, it has been proposed to experimentally determine the influence of outdoor light before commissioning the lighting system using numerous measurements. For example, the incident outdoor light was measured at various locations within room 100, possibly at different times of day, and based on this, an optimal arrangement for the luminaires 20 and a corresponding control of these by the central control unit 10 were determined. However, such a procedure is very complex and does not always yield satisfactory results, as the measurements inherently provide only limited information regarding the time-of-day-dependent influence of outdoor light.

[0024] According to the present invention, this problem is now solved by calculating the influence of the outside light based on detailed information regarding the geometric design of the room, the arrangement of the luminaires within it, the areas to be illuminated, and the means by which the outside light can enter the room, starting from knowledge of the general properties of the outside light. The concept according to the invention thus provides that the lighting system or the control device calculates the influence of daylight or outside light for each area to be illuminated and then controls the luminaires responsible for the corresponding area accordingly.

[0025] This requires precise information regarding the geometric design of the room or the building as a whole. One way to provide this information is in Fig. Figure 2 shows, but this is purely an example of a section of a single floor of a building. This concept can, however, be extended to all floors of the building in a similar manner.

[0026] In this case, the spatial conditions are described by using vectors to describe key points relating to the geometric design of the space to be illuminated, as well as other information relevant to the lighting. Fig. Figure 2 shows only a few example vectors which, in this case, describe the corner points of a room 100 to be illuminated. The origin point for these vectors is preferably a corner of the room or the building, whereby the choice of this origin is irrelevant for the realization of the concept according to the invention. It is only important that all location information provided to the system originates from the same reference point. With the help of these vectors, the arrangement, extent, and design of the room 100, as well as its orientation, can be described. The spatial designs and dimensions of other rooms in the building are then defined in the same way.

[0027] In addition, the system is provided with information regarding the possibilities for outside light to enter room 100. This means that the arrangement and dimensions of windows 105 are also described, again using corresponding vectors not shown here. The description of the arrangement and design of windows 105—as well as of room 100—is not only in the depicted horizontal XY plane but also, of course, in a perpendicular or vertical direction to describe the position and height of the window front and of room 100 as a whole. Finally, the system is also provided with information about the position of light fixtures in the room or building, with the corresponding location data preferably provided by 3-dimensional vectors.

[0028] Based on this detailed spatial description, it is now possible to calculate how the outside light striking the window front 105 from a specific direction illuminates certain areas within the room 100. For example, based on the information provided by the daylight sensor 15, the control unit 10 calculates how the areas of the room 100 are illuminated by the daylight. Based on this information, the corresponding luminaires 20 are then controlled to achieve the desired overall brightness in the respective area.

[0029] It is therefore essential that the available information regarding the spatial conditions enables the control unit 10 to perform an accurate calculation of the daylight entering room 100. In this way, the influence of the outside light present at a given time can be determined much more precisely, and thus the luminaires can be controlled more effectively without the need for local brightness sensors.

[0030] However, a prerequisite for carrying out the method according to the invention is that the most accurate and complete possible positional data regarding the spatial layout of the building is available. This information can be obtained in various ways, preferably using corresponding building plans where possible, provided these describe the building's design with sufficient accuracy. In addition, corresponding points can also be measured and made available to the system, for example, using appropriately calibrated laser distance measurements or a portable GPS device.

[0031] Having this precise positional information is also advantageous because it allows for a simple visualization of the lighting arrangement within the building. For example, in the event of a malfunction caused by a light, its position can be easily determined and graphically displayed, significantly simplifying maintenance work since the light can now be located immediately. Another benefit of knowing the positional data is that this information can be used to create a 3D visualization of the building and its lighting fixtures. This allows for a very clear representation of the entire lighting system's design, which offers significant advantages when planning the lighting control system.

[0032] Further development of this previously described concept is available in the Fig. 3a and Fig. Figure 3b illustrates this. In addition to information regarding the design of the building to be illuminated, information about objects in the building's vicinity is also taken into account. As the figures schematically depict, such objects can influence the external light by reflecting it ( Fig. 3a) or shade ( Fig. 3b) If the position and geometric shape of such an object are again described and taken into account by corresponding vectors, then – with additional knowledge of any reflection properties of the object – it is possible to calculate exactly how this influences the directional dependence and intensity of the external light. The resulting control of the luminaires is thus further refined by this extension.

[0033] In summary, the concept according to the invention, which involves precisely describing the building to be illuminated using corresponding positional data, leads to a very effective and convenient control of the light sources located in the building. A particular advantage is that this precise control can be achieved without the use of additional sensors that monitor individually illuminated areas. Furthermore, knowledge of the positional data also leads to further advantages with regard to the visualization of the lighting system and the building as a whole.

Claims

[1] System (1) for controlling lighting in buildings, comprising a central control unit (10) and at least one luminaire (20) controlled by the central control unit (10), wherein the central control device (10) is designed to take into account the influence of the outside light in an area to be illuminated by the luminaire (20) when controlling the luminaire (20), wherein the system has a sensor for determining the outside light (15) and the central control unit (10) is configured to calculate the influence of the outside light taking into account the information obtained from the sensor, and wherein, in order to calculate the influence of the external light, the central control unit (10) takes into account information which • the spatial design of a room (100) or an area in which the light fixture (20) is located, • the position of the light (20) in the room (100) or area as well as • the arrangement and design of facilities (105) through which outside light can enter the room (100) or area, concerning, whereby the information consists of positional data which essentially completely describe the spatial design of the building, the arrangement of the light fixture(s) and of facilities through which outside light can enter the building. [2] System according to claim 1, characterized by that this has several lights (20), wherein the central control device (10) is designed to determine the influence of the outside light in the area to be illuminated by the light (20) for each light (20). [3] System according to any one of the preceding claims, characterized by, that the central control device (10) is designed to take into account objects located in the vicinity of the building, in particular with regard to their shading and / or reflection properties, when calculating the influence of the external light. [4] Method for controlling lighting in buildings, wherein the influence of the outside light in an area to be illuminated by the respective luminaire (20) is taken into account when controlling luminaires (20), wherein the influence of the outside light is calculated taking into account the information obtained from a sensor for determining the outside light (15), and wherein information is taken into account in the calculation of the influence of the outside light which • the spatial design of a room (100) or an area in which the light fixture (20) is located, • the position of the light (20) in the room (100) or area as well as • the arrangement and design of facilities (105) through which outside light can enter the room (100) or area, concerning, whereby the information consists of positional data which essentially completely describe the spatial design of the building, the arrangement of the light fixture(s) and of facilities through which outside light can enter the building. [5] Method according to claim 4, characterized by , that when calculating the influence of external light in the vicinity of the building, objects located therein must be taken into account, in particular with regard to their shading and / or reflection properties.

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