Lighting system

Abstract

Lighting system (1) for illuminating an object (2) located in an object space (8), with - a lighting unit (3) designed to emit illuminating light (4b) into the object space (8), - a distance measuring unit (5) for recording a distance image (41) of the object space (8) with the object (2) located therein, which is arranged in a fixed position relative to at least a part of the lighting unit (3), - a marker system (6) comprising a marker emitter unit (6ba) for emitting a marker signal (7) and a marker receiver unit (6ab) for detecting at least one signal component (7a) of the marker signal (7), wherein the lighting system (1) is designed to - to locate the object (2) in an area of ​​the object space (8) using the distance image (41) and to individualize it using the signal part received with the marker receiver unit (6ab) and - depending on this, to illuminate the object (2) with the lighting unit (3), and wherein the lighting system (1) is designed to - to determine the distance of the marker emitter unit (6ba) from the marker receiver unit (6ab) from the signal component (7a) of the marker signal (7) detected by the marker receiver unit (6ab).

Description

Technical field

[0001] The present invention relates to a lighting system for illuminating an object located in an object space. State of the art

[0002] The lighting system in question can be used, for example, to illuminate a stage, such as a concert stage in the entertainment industry. One goal is at least partially or even fully automated lighting that adapts, for instance, to the position or movement of a performer on stage. A spotlight, for example, can automatically follow a performer on stage. Such a performer could be a presenter or actor, but of course any other object can also be subject to automated lighting, such as vehicles or animals, etc. (see below for details). This is intended to illustrate one advantageous application area, but does not initially limit the system's general scope.

[0003] From DE 10 214 227 A1 a system for irradiation is known in which an object or a person is captured from several sides.

[0004] From EP 0 814 344 A2 a combination of lighting unit and camera for automatic tracking is known. Description of the invention

[0005] The present invention is based on the technical problem of specifying a particularly advantageous lighting system.

[0006] This is achieved according to the invention with a lighting system according to claim 1. In addition to a lighting unit for emitting the illumination light, this system comprises a distance measuring unit for capturing a distance image and a marker system. The distance measuring unit can capture a distance image within a specific detection field (field of view, FoV), referred to here as object space. Unlike a conventional two-dimensional image, this distance image additionally contains distance information, a kind of depth (for details regarding possible technical implementation, reference is made to the disclosure below). The distance image can, for example, be structured such that each pixel is assigned a distance value, which is also referred to as a spatial pixel or voxel. In principle, this corresponds to three-dimensional points in object space.In the area where the object is located, many pixels typically have a similar distance value (depending on the size, orientation, etc. of the object), resulting in a point cloud.

[0007] The inventor has now determined that an object located in object space can be accurately located within that space, at least in a specific area, using a distance image. This can be achieved, for example, by evaluating or using a point cloud as described above. This point cloud can then be identified, for instance, through image processing, such as using a gradient or grayscale method. Therefore, apart from special cases (see details below), an object located within the object field can generally be located reliably and with sufficient accuracy.

[0008] On the other hand, object detection or classification based on the distance image can be computationally intensive and therefore time-consuming, which can be problematic given dynamic lighting conditions. The distance image itself may also have resolution limitations, meaning that while the object's location can be determined with sufficient accuracy, further differentiation is not possible. To illustrate, it can be difficult to distinguish, for example, whether the detected object is actually the presenter or actor being illuminated, or perhaps a stagehand. Similar examples can be found for other objects or object classes.

[0009] Therefore, a marker system is also included. The object to be illuminated, e.g., the actor, is equipped with the marker emitter unit, and the marker receiver unit then detects the marker signal or a portion thereof. The lighting system is then configured to individualize the object using the signal component received by the marker receiver unit. Thus, by evaluating this signal component, additional information is obtained beyond the distance image, which can be used, for example, to decide whether the object should be illuminated or not. The "individualization" of the object can also occur, for example, if the area determined based on the distance image is not sufficiently precise for deciding on the lighting, such as when multiple actors or...Objects shadow each other, and the marker signal is then used for localization and thus individualization within the area (see below for details).

[0010] In summary, the combination of distance measurement unit and marker system enables both precise localization within the object space and object individualization. The latter means that, in abstract terms, a marker or label is assigned to the object, which can, for example, simplify decision diagrams for automation, generally increase reliability, and / or shorten decision-making processes. Furthermore, the distance measurement unit is located on or near the lighting unit, resulting in a good correlation between the distance image and the illuminated space, thus reducing computational effort and enabling faster response times.

[0011] Preferred embodiments are found in the dependent claims and the entire disclosure, whereby the description of the features does not always differentiate in detail between apparatus and process or use aspects; in any case, the disclosure is implicitly to be read with regard to all claim categories. The description thus always refers both to the lighting system, which is set up for a specific operation, and to a corresponding operating method or corresponding uses.

[0012] A particular advantage of the lighting system according to the invention arises from the arrangement of the distance measuring unit on the lighting unit, fixed to at least a part of it (usually a base, also referred to as a luminaire foot or luminaire holder, see below). This spatial proximity or even integration (the distance measuring unit could, for example, also be embedded in the base) can simplify the subsequent correlation of the distance image with the control of the lighting unit. Figuratively speaking, the detected object space corresponds to what the lighting unit "sees" or where it shines. More abstractly, the distance measuring unit and the lighting unit are located within the same coordinate system due to their proximity. This avoids computationally intensive and therefore time-consuming coordinate transformations, which is particularly important given the sometimes rapid movements in the applications discussed (e.g., dance or sports, etc.).) can be of particular advantage.

[0013] In a simple example, it may even suffice if the marker system itself is not configured for further spatial differentiation within the object space. This could apply, for instance, to a use case where different objects need to be illuminated differently over time—for example, different actors each with a different colored light—but these objects or actors only appear sequentially (not simultaneously) in the object space for dramatic reasons. In this case, it is sufficient if the corresponding label is stored, figuratively speaking, for the entire object field (which only contains that one actor) using the respective marker emitter unit assigned to the respective object. Conversely, this example also illustrates that further differentiation may be of interest in more complex use cases; see below for details.The device also works without a marker unit as long as there is only one performer on stage. If this is the case, and it applies to many performance situations, the performer doesn't need a marker unit. The blob detection will locate the target person and control the spotlight anyway. A decision problem arises primarily when there are multiple blobs, especially when they overlap.

[0014] The distance measurement unit measures distance based on signal time-of-flight. For this purpose, an electromagnetic pulse is emitted into the object space; typically, a large number of pulses are emitted sequentially. When a pulse encounters the object, it is partially reflected back from its surface to the distance measurement unit and can be recorded as an echo pulse with a suitable sensor. If the pulse is emitted at time t0 and the echo pulse is detected at a later time t1, the distance d to the reflecting surface of the object can be determined via the time-of-flight Δt. A = t1 - t0 after d=ΔtA c / 2 to be determined. Here, c is the speed of light.

[0015] In general, for example, a distance measuring unit is conceivable that is only capable of solid angle resolution on one axis; preferably, solid angle resolution is given on two axes. The object space can therefore be divided into rows and columns, and thus solid angle segments, with a distance value being determined for each segment.

[0016] Depending on its specific design, the distance measuring unit can emit a pulse for distance measurement either into the entire object space, even in the case of solid angle resolution, or the pulses can be emitted sequentially (one after the other) into different segments of the object space (also referred to as "scanning mode"). The first option, in conjunction with a solid angle-sensitive detector, can still achieve solid angle resolution; see below for details. In the latter option, solid angle-selective emission, i.e., the sequential pulsing of individual segments, can be achieved, for example, via a movable mirror (e.g., a MEMS mirror). Before each subsequent pulse is emitted, a pause is observed (figuratively speaking, "listening") for a specific duration corresponding to the desired range to see if an echo pulse returns from the segment in question.

[0017] When it is generally stated that a lighting system is "configured" for a specific operation, this means, for example, that a corresponding program sequence is stored in a control unit. The possibilities for software implementation are just as diverse (standardized protocols such as DMX or ART-Net, or any other / custom-made programs and languages) as those of the hardware architecture. The control unit can be integrated into the lighting unit, partially or completely, but a decentralized setup is also possible. For controlling the lighting unit, there can be an interface for the commands to control the lighting, but an integrated design is also possible. The control unit, or parts of it, can be implemented in a conventional computer, but a custom design with microcontrollers is also possible.

[0018] Preferably, there is a user interface for input and / or output, preferably a display unit for graphical representation, also known as a Graphical User Interface (GUI), which may be implemented as a touchscreen. In the application, the lighting unit can operate fully automatically (without user intervention), but semi-automatic operation or switching between automatic operation and user control is also possible; for the latter, a console is preferably provided. The programs referred to above need not be static; they can, for example, be adapted by a user via an interface. Alternatively, an AI program for independently learning or optimizing processes and options is also possible.

[0019] In a preferred embodiment, the marker emitter unit is part of a marker device that also includes a receiver unit. Likewise, the marker receiver unit is part of a marker device that also includes an emitter unit. The marker devices are each designed symmetrically for transmitting and receiving (two-way system), and preferably they are identical in construction. Aside from the reduction in the number of different parts and the resulting increased user-friendliness, the symmetrical design can also offer advantages, for example, with regard to the calibration process, such as when several marker receiver units are used to determine their relative positions. Preferably, the two-way or symmetrical design is implemented with the same signal type, in particular a radio signal (e.g., UWB, see below, also regarding possible alternatives).

[0020] In a preferred embodiment, the marker system is radio-based, meaning the marker signal is a radio signal. While, in general, an ultrasound signal or, in the electromagnetic spectral range, a radar or infrared signal would also be conceivable, a radio signal can provide a technically robust and adequate implementation. Generally, the marker-emitter unit could also be an RFID tag; a two-way system is preferred (see below). The radio frequencies are below 3000 GHz (with a possible lower limit in the MHz range). Ultra-wideband (UWB) technology, which is particularly suitable for short-range communication, is preferably used for the marker signal.

[0021] In a preferred embodiment, not only the distance measuring unit but also the marker receiver unit is arranged on or near the lighting unit. Although integration into a movable part of the lighting unit is generally conceivable, an arrangement on or in the base is again preferred. The distance measuring unit and the marker receiver unit can, in particular, be fixed in position relative to each other.

[0022] In a preferred embodiment, the distance between the emitter and receiver units is determined from the signal component detected by the marker receiver unit. For example, the signal intensity can be measured, and the distance can be calculated from the power drop-off if the output power is known. If multiple marker receiver units are used, the distance measurement can also enable object localization via the marker signal (see below for details). However, it can also be advantageous in its own right, for example, by helping to improve localization in conjunction with the distance pattern. If several objects are located in the object space, a final determination of the object's position based on the distance pattern can be problematic, for example, if another object is in front of it from the perspective of the distance measuring unit, effectively obscuring it.The distance value obtained from the marker signal can then be used to locate the shadowed object.

[0023] In a preferred embodiment, the marker system includes a further marker receiver unit, which captures a signal component of the marker signal during operation. Advantageously, the lighting system can then be configured such that the position of the marker emitter unit, and thus of the object, is determined from the signal components captured by the different marker receiver units by means of triangulation.

[0024] For example, a first marker-receiver unit can receive a first signal component, and a second marker-receiver unit can receive a second signal component. Advantageously, the receiver units are positioned at a certain distance from each other, either in or near the object space, such as at the edge of a stage or even on the stage itself. The marker-emitter unit and the receiver units then form a triangle, and the object can be located based on the signal components. To illustrate, a first distance value can be determined from the first signal component, which, abstractly speaking, corresponds to a circle around the first marker-receiver unit in the two-dimensional plane of the stage. The second signal component forms a circle around the second marker-receiver unit, and the object can be located at the intersection of the circles. More marker-receiver units can also be used, thereby increasing the accuracy.

[0025] In a preferred embodiment, the lighting unit is designed to emit a cone of light along different beams. While these beams point in different directions, they nevertheless originate from a common source in a polar coordinate system. One possible implementation is a so-called scanner, in which the cone of light emitted by a light source falls onto a rotatable or tiltable mirror and is reflected in a specific direction depending on the mirror's rotational or tilting position. It is also conceivable to use multiple spotlight heads, which, while fixed in position relative to one another or movable, each emit their own cone of light in a distinct direction. Generally, a setup is preferred in which the same cone of light sweeps across different directions over time, which advantageously allows for tracking the object.

[0026] This is possible, for example, with the aforementioned scanner or a moving head spotlight discussed in detail below.

[0027] One or more light-emitting diodes (LEDs), which can also be in the form of micro-LEDs, can be used as the light source. These can be in the form of at least one individually packaged LED or at least one LED chip containing one or more light-emitting diodes. Several LED chips can be mounted on a common substrate ("submount") to form a single LED, or they can be mounted individually or together, for example, on a circuit board (e.g., FR4, metal core board, etc.) ("CoB" = Chip on Board). The at least one LED can be equipped with at least one dedicated and / or shared optical system for beam guidance, e.g., at least one Fresnel lens or a collimator. Instead of or in addition to inorganic LEDs, e.g., based on AlInGaN, InGaN, or AlInGaP, organic LEDs (OLEDs, e.g., polymer OLEDs) can also be used.

[0028] Quantum dot LEDs can also be used. The LED chips can be direct emitters or have a phosphor layer. Alternatively, the light-emitting component can be a laser diode or a laser diode array, such as a LARP (Laser-Activated Remote Phosphor) array. It is also possible to use one or more OLED light-emitting layers or an OLED light-emitting area. The emission wavelengths of the light-emitting components can be in the ultraviolet, visible, or infrared spectral range. The light-emitting components can also be equipped with their own converter. Furthermore, halogen lamps and discharge lamps can be used.

[0029] In a preferred embodiment, the lighting unit comprises a base and an arm, as well as a lamp head (preferably exactly one lamp head) for emitting the illumination. The arm is rotatably mounted on the base, and the lamp head is rotatably mounted on the arm. In application, the lighting unit is preferably oriented such that a plane of rotation resulting from the mounting of the arm on the base is horizontal, also referred to as pan (the axis of rotation about which it rotates is perpendicular to said plane of rotation). A plane of rotation resulting from the rotatable mounting of the lamp head on the arm is then preferably vertical; the corresponding degree of freedom is also referred to as tilt (the axis of rotation is again perpendicular to said plane of rotation).

[0030] In a preferred embodiment, the distance measuring unit is generally attached to a base of the lighting unit. Abstractly speaking, the distance measuring unit is stationary relative to the aforementioned origin of the polar coordinate system of the lighting unit; reference is made to the advantages stated above (no coordinate transformation required, etc.). It can be advantageous to position the distance measuring unit close to the lighting unit, for example, at a distance of no more than 1.5 m, 1 m, or 0.8 m (with possible lower limits of 0.1 m or 0.2 m). The distance is measured between the entrance pupil of the distance measuring unit and the light-emitting surface of the lighting unit (if this distance varies over time due to a movable mounting of the luminaire head, an average value is considered).

[0031] In a preferred embodiment, the distance measuring unit is attached to the base via a bracket and can be tilted into different positions relative to the base using this bracket. Generally, stepless tilting combined with a locking mechanism is also conceivable; preferably, a plurality of predefined tilt positions are provided. In each tilt position, the distance measuring unit can, for example, lock into place or be fixed with a locking screw. Despite this adjustability, the distance measuring unit is then fixed in position and orientation relative to the base.

[0032] In a preferred embodiment, a plane defined by the continuously or predefined adjustable tilt positions is parallel to a plane of rotation resulting from the mounting of the luminaire head on the base. Preferably, the luminaire head is not mounted directly on the base, but rather via an arm (see front), and the aforementioned plane of rotation results from the mounting of the arm on the base, see front (Pan). The plane defined by the different tilt positions lies perpendicular to an axis of rotation about which the different tilt positions can be transitioned into one another.

[0033] In a preferred embodiment, the distance measuring unit is designed to emit pulses in the infrared spectral range for distance measurement. The wavelengths can therefore be, for example, at least 700 nm, 750 nm, 800 nm, or 850 nm, with possible (independent) upper limits of, for example, at most 2000 nm, 1800 nm, or 1600 nm (each being increasingly preferred in the order of its mention). A particularly advantageous value can be, for example, around 905 nm; further advantageous upper limits result at 1500 nm, 1400 nm, 1300 nm, 1200 nm, 1100 nm, 1000 nm, or 950 nm.

[0034] Even independent of the specific spectral range, the distance image can be obtained in different ways; thus, there are various possibilities for achieving solid angle resolution. Reference is also made to the introductory remarks. Solid angle resolution can, on the one hand, result from the solid angle-selective emission of electromagnetic pulses, i.e., the solid angle segments are scanned. For this purpose, a movable or oscillating mirror, such as a MEMS mirror, is typically used, over which a laser beam is guided into the object space. Depending on the mirror position, the laser beam or laser pulse enters a respective segment of the object space, and the segments are pulsed sequentially (with a specific waiting period between pulses to see if an echo pulse returns).

[0035] An alternative approach involves emitting a light or radiation pulse into the entire object space, i.e., into all segments simultaneously. Differentiation between the various segments is then achieved using a solid-angle-resolving sensor, such as a photomixing detector, also known as a PMD sensor. This sensor can assign incoming echo pulses from different spatial directions, and thus from different segments, resulting in pixel- or segment-wise resolution.

[0036] In a preferred embodiment, a time-of-flight (TOF) camera is used as the distance measurement unit, operating according to the principle described above with a solid-angle-resolving sensor. The light pulse is emitted into the entire object space, and the time elapsed until the arrival of an echo pulse is measured for each pixel. To illustrate, such solid-angle resolution can be achieved, for example, by combining a conventional image sensor, e.g., CCD or CMOS, with an upstream optical system that maps the sensor area to infinity, with each pixel in its own distinct spatial direction. Conversely, an echo pulse arriving from a particular spatial direction is thus directed to its own pixel (or group of pixels). Regardless of the specific configuration, a typical TOF camera can capture approximately 20 images (frames) per second, which may be adequate for the present application.

[0037] In a preferred embodiment, the lighting system is configured to classify the object using the marker signal or signal component. Such object classes can be, for example, "human" and "vehicle" or "animal," although further differentiation is of course possible. For example, with humans, a distinction can be made between actors and extras, stagehands, or even the audience. Vehicles can be, for example, land vehicles, such as motor vehicles, even in miniaturized form, or aircraft, such as drones.

[0038] In general, robots, for example, can also be subsumed under this category or assigned to their own class. Furthermore, a distinction can be made between stage equipment and the actual performers, i.e., between the stage equipment, including loudspeakers, etc., on the one hand, and the actors, the musical group, or other individuals involved (presenter, etc.) on the other. The inventive approach of additional marking can be advantageous, for example, insofar as the stage equipment itself may be at least partially movable (e.g., on rails or freely movable, such as flying on a drone), which can make distinguishing it from the performers challenging.

[0039] In general, the marker signal can preferably carry information about the object, and classification can then preferably be performed solely on the basis of this information. Even independently of a subsequent classification, the object information can be modulated onto the preferred radio signal, for example via the carrier frequency or, in preferred UWB operation where individual pulses are generated, via pulse phase modulation or a change in the polarity or amplitude of the pulses.

[0040] A data set derived from the distance image and the marker signal can, of course, be supplemented with further input data. For example, acoustic data can be captured, such as rhythms and / or song or text content. It is also conceivable that an additional camera or scanner could be used to capture faces or geometric data. Independently of these specific components, the resulting data set can then be compared with various databases. For instance, a list or parameter set can be stored for each object class. The control unit can be connected to appropriate data storage systems directly or via a network or cloud connection. This also applies, of course, to databases containing details about the lighting unit (lighting control database, luminaire database, light source database, etc.).

[0041] Further input variables can originate, for example, from control systems of winches, flying mechanisms, stage machinery (both upper and lower), rotary encoders, linear encoders, light barriers, and / or limit switches. It is also conceivable that additional influencing variables could be captured via a smartphone, such as step count, direction of movement, position, and / or orientation (gyroscope information). User-related data, such as pulse rate, can also be included.

[0042] For evaluating the distance image, well-known methods can be used. For example, a geometric structure can be analyzed using morphological filtering (which can form the basis of image recognition), and threshold analysis, image segmentation, edge detection, and / or color analysis can also be applied to the distance image. Connected object or data points can be found and grouped using so-called connected-component labeling, which is sometimes also referred to as blob detection. In principle, it is also conceivable that the distance image is combined with another distance image (a process called stitching), which is captured with another distance measuring unit, also arranged on the illumination unit, to increase the detection angle. Preferably, however, exactly one distance measuring unit is provided on the illumination unit.

[0043] The invention also relates to a method for operating a lighting system as described above, wherein the object is equipped with the marker emitter unit, preferably with a two-way system (marker device) as described above. During operation, this emits the marker signal, which is detected by the marker receiver unit, which is preferably also part of a marker device. The marker receiver unit can, for example, be arranged at the edge of the stage, preferably together with one or more further marker receiver units. Simultaneously, the distance measurement unit captures the distance image of the object space, and the object is located within this space, or at least within a region thereof. The marker signal, or the detected signal components, are used for individualizing the object. Preferably, the object can also be located using the marker signal, which can increase accuracy.

[0044] Ideally, during operation, not just a single distance image is captured, but a large number of distance images are taken sequentially over time, e.g., at least 5 or 10 distance images per second (technical limitations may impose upper limits, e.g., 50, 40, or 30 distance images per second). If a time-of-flight (TOF) camera is used, it typically emits not just a single pulse to capture each distance image, but a pulse packet, i.e., several individual pulses in succession. This results in a corresponding number of echo pulses, and the signal-to-noise ratio can be improved, for example, by averaging.

[0045] In a preferred embodiment, a reference distance image of the object space is captured beforehand using the distance measuring unit. The distance measuring unit is already in its position relative to, for example, the stage, and the reference distance image is then captured during setup or calibration. At this stage, the object to be illuminated is not yet in the object space, but other objects, such as stage equipment, are ideally already in their positions. Later, when the distance image of the object space is captured with the object in it, the reference distance image can be used for a difference analysis. This allows those pixels or voxels that form a static background to be removed and therefore do not need to be considered further in the image evaluation. This can reduce computational effort and shorten response times.

[0046] In a preferred embodiment, multiple distance images are successively acquired during operation, i.e., during illumination when the object is located within the object space (see above). These distance images are then compared to one another using a differential analysis, allowing, for example, the generation of motion trajectories. If the object moves through the object space and is tracked with a light beam, a prediction can be made based on these motion trajectories. A future vector is thus created from the previous distance images, a process also known as prediction modeling. This allows for the prediction of the object's future position within a timeframe of, for example, up to 200 ms, enabling the lighting unit's control to be adjusted or prepared accordingly.

[0047] Difference analyses can also be used, for example, to weight pixels or voxels that are currently in motion differently than pixels / voxels that have been stationary for a longer period. This means that not only can a static background be subtracted (reference distance image, see above), but a dynamic adjustment of importance / less importance can also be made. Pixels / voxels that have been stationary for a longer period are then no longer evaluated with the same precision as moving pixels / voxels. They can also be excluded from subsequent distance images.

[0048] The invention also relates to the use of a lighting system described herein for illuminating a performance area. This could be, in particular, a stage, such as a concert or show stage, especially an arena, but of course also a theater stage or the like. The performance could, for example, also take place at a trade fair; thus, the illumination of exhibition areas and the like is particularly possible. Applications are also conceivable in the film and television sector, as well as for illuminating dance floors, including in discotheques.

[0049] In this application, multiple lighting units, each equipped with a stationary distance measuring unit, can be combined. They can illuminate the presentation area from different sides or from the same side. Depending on the specific arrangement, the number of lighting units with distance measuring units (especially time-of-flight cameras) can be increased as needed, particularly if the object areas do not overlap or only partially overlap. Conversely, an upper limit may also be desirable, for example, to prevent unwanted interactions between individual time-of-flight measurements. Thus, for instance, no more than 10, 8, or 6 lighting units or systems equipped according to the invention can be combined on the same presentation area.

[0050] In a network of lighting units, the object information or object coordinates determined by a lighting system according to the invention or the associated control unit can then be used to control further lighting units, e.g. to illuminate a common object.

[0051] If there are multiple objects that are to be illuminated differently, each is preferably equipped with its own marker-emitter unit (in particular, a separate marker device), with each marker signal preferably modulated with its own object information. Despite the additional marking via a marker-emitter unit, limiting the number of different or distinguishable objects can also be advantageous. In practice, for example, a maximum of 10, 8, or 6 objects can be distinguished and illuminated differently.

[0052] The lighting unit, including the distance measuring unit, can be fixed in position relative to the presentation area, for example, mounted on a stationary stand or support. However, a lighting unit that is movable, particularly sliding, relative to the presentation area is also conceivable. Since the distance measuring unit is fixed in position relative to the lighting unit or its base, the correlation between the reference or coordinate systems discussed above is not broken if the entire unit is moved. The lighting unit, including the distance measuring unit, can, for example, be moved on a rail, but an arrangement on a robot arm is also conceivable. Brief description of the drawings

[0053] The invention will now be explained in more detail using an exemplary embodiment, whereby the individual features within the scope of the dependent claims may also be essential to the invention in other combinations, and no distinction will be made in detail between the different claim categories.

[0054] In detail, it shows Fig. 1 an application of a lighting system according to the invention in a top view, looking down at a stage; Fig. 2 a lighting unit of the lighting system according to Fig. 1 in a detailed view; Fig. 3 again, looking schematically at a stage from above, a marker system as part of the lighting system according to Fig. 1; Fig. 4. A flowchart to illustrate the processes involved in detecting and illuminating an object with the lighting system according to Fig. 1. Preferred embodiment of the invention

[0055] Fig. Figure 1 shows a schematic representation of a lighting system 1 according to the invention, illustrating an application. This relates to the illumination of an object 2, for example, an actor or presenter on a stage (see below for details). For this purpose, the lighting system initially comprises a lighting unit 3. This unit consists of a base 3a and a lamp head 3b movably mounted on it; for further details see Figure 1. Fig. 2. A light source, e.g., LED-based, is arranged in the luminaire head 3b, usually in conjunction with optics. During operation, the luminaire head 3b can emit a cone of light 4 containing the illuminating light 4b along a beam 4a. Due to the movable mounting of the luminaire head 3b, the cone of light 4 can be moved across the display surface.

[0056] The lighting system 1 also includes a distance measuring unit 5, in this case a time-of-flight (TOF) camera. This camera can capture a distance image of an object space 8, allowing the object 2 to be located based on this distance image. The light cone 4 can then be automatically directed towards the object 2, or follow it if it is moving, by means of a corresponding control of the lighting unit 3. For this purpose, the distance image is evaluated; see also [reference to relevant section]. Fig. 4 and the detailed information in the introductory description.

[0057] The distance measuring unit 5 is attached to the base 3a of the lighting unit 3. This is advantageous because the TOF camera looks at the performance area or stage from the same point from which the lighting is provided. In simplified terms, the distance measuring unit 5 and the lighting unit 3 are arranged in the same reference system, meaning that the detection of object 2 in the distance image can be directly translated into control of the lighting unit 3 (in particular, pan / tilt coordinates).

[0058] Lighting system 1 further comprises a marker system 6, wherein a first marker device 6a and a second marker device 6b are shown. The former is arranged on the base 3a of the lighting unit 3, the latter is worn by the actor. Each of the marker devices 6a,b has an emitter unit 6aa,ba and a receiver unit 6ab,bb. During operation, the marker emitter unit 6ba, assigned to the actor, i.e., object 2, emits a marker signal 7 (a UWB signal). This signal, or a portion thereof, is detected by the marker receiver unit 6ab, which is assigned to the base 3a of the lighting unit 3. The marker signal 7 can, for example, carry information about object 2, which can be used to individualize it or to adjust the lighting (e.g., "object to be illuminated: yes / no" or "type of lighting: color, etc."). Further possibilities are also discussed in [reference to be added]. Fig. 3 referred.

[0059] The symmetrical design of the marker devices 6a,b can be advantageous, for example, during the calibration phase, i.e., when lighting system 1 is being installed on the stage. Please refer to the introductory description.

[0060] Fig. Figure 2 now shows the lighting unit 3 in more detail, specifically in a side view. The lighting unit 3 is designed as a moving-head spotlight; the light head 3b is mounted on the base 3a via an arm 3c. Relative to the base 3a, the arm 3c is rotatable in a plane 30a, which in this illustration and also in application is horizontal (pan). The light head 3b is rotatably mounted on the arm 3c in a plane 30b. In this illustration and in application, the plane 30b is vertical (tilt). With the light head 3b mounted accordingly, the light cone 4 can be moved across the performance area or stage, and in particular, the object 2 can be tracked.

[0061] Fig. Figure 3 shows a schematic representation of a stage 35, looking down at the performance area 35a. This view corresponds to that shown in Figure 3. Fig. 1. In contrast, the lighting unit 3 is no longer shown in detail here. Instead, the figure illustrates the marker system 6 in more detail. At the edge of the stage 35, not only is the marker device 6a arranged, but also two further marker devices 6c,d. Thus, there are two further marker receiver units 6cb,db.

[0062] Each of the marker receiver units 6ab,cb,db receives a respective signal component 7a,c,d of the marker signal 7. Knowing the output power, a respective distance value is calculated from the power drop based on the respective signal intensity. Each marker receiver unit 6ab,cb,db thus individually defines a circle 36a,c,d on which object 2 can be located. Since several measured values ​​are available from different locations, object 2 can be located at the intersection of the circles 36a,c,d. The marker receiver units 6ab,cb,db are each part of a bidirectional marker device 6a,c,d. During setup or calibration, for example, the relative distances between the markers can be determined. Object 2 can then be located using triangulation.

[0063] Fig. Figure 4 illustrates the processes in a control unit 40 of the lighting system 1 in a flowchart. The control unit 40 has one or more inputs 40a for the distance images and the measurement results of the marker receiver units 6ab, cb, db, as well as one or more outputs 40b for sending commands to the lighting unit 30 (either directly to it or to a control unit thereof). One input variable is the distance image 41, whereby a large number of distance images of the object space 3 are recorded over time, e.g., at a repetition rate of 20 Hz.

[0064] Specifically, the TOF camera can emit into the object space with a pulse duration of 41 ns and pulse pauses of the same duration. To capture each distance image, a pulse packet with, for example, 40,000 pulses can be used. Its duration is then 3.5 ms, which defines a measurement time window for phase images. A pulse frame can then consist of four pulse packets spaced 1.6 ms apart, resulting in a duration of 20.4 ms for the pulse frame. This is the measurement time window for the 3D images.

[0065] Generally, the pulse and / or pause durations, as well as the number of pulses per packet, can be preset internally by the camera. However, it is also possible to configure parameters based on demand and application, for example, during or before the lighting system is powered on. Adjustments during operation may even be possible. A certain degree of variability can be beneficial, for instance, in applications with multiple TOF cameras to prevent artifacts caused by mutual interference.

[0066] How Fig. As shown in Figure 4, the distance image is then subjected to image processing 42. In the case of the TOF camera, this can be done in combination with the 2D camera image; target points, also called blobs, are identified in object space 6 from the 3D distance image. The result is information, relative to a coordinate space 43, indicating where objects of interest from an illumination perspective are located. It should be noted that the representations according to the Fig. 1 and Fig. 3 are schematic in nature, and in practice a larger number of actors will often be on stage 35. In particular, situations may arise in which some of the actors are standing one behind the other from the perspective of the TOF camera, so that the actors can no longer be clearly located in the resulting coordinate system 43 based on the distance image 41. On the other hand, there may also be situations in which the decision regarding the lighting profile to be applied can be challenging even if there is only a single actor on stage (e.g., alternating with other actors who cannot be differentiated based on the distance image 41).

[0067] Therefore, the signal components 7a,c,d acquired by the marker receiver units 6ab,cb,db are used as further input variables, whereby object information 46 is obtained during an evaluation 45. This can include a position of the object on the display surface 35a determined by triangulation and / or information about the object class. Thus, it is also possible to obtain information independently of the localization according to Fig. Three different objects, for example, each with its own object information, can be encoded and thus made recognizable for the control unit 40.

[0068] Following a correlation 47 between the result of the image evaluation on the one hand and the evaluation of the object information on the other, the actual lighting scheme 48 can then be created. From the localization in the coordinate system 43, pan / tilt values ​​for controlling the lighting unit 3 can then be generated, for example, which can still take place within the control unit 40 or already in the control unit of the lighting unit 3.

[0069] Specifically, so-called light codes can be programmed and / or stored for the lighting. These can be fixed, e.g., "Follow the object" / "Change color after 10 seconds," etc., but adaptation during operation is also conceivable (e.g., triggered by certain movements of the object, such as jumping). Possible control functions of lighting unit 3 include, for example, pan, tilt, dimmer, focus, zoom, frost, color, relative iris, relative focus, and / or relative dimmer. Correlation with other effect devices and / or stage equipment (including clothing, etc., and even audience attire) or with effects on video projection and LED walls is also conceivable. REFERENCE MARK LIST 1 Lighting system 2 objects 3 lighting units 3a socket 3b Lamp head 3c Arm 4 light cones 4a beam 4b Lighting light 5 Distance measuring unit 6a-d Marker Devices 6aa,ba,ca,da emitter units 6ab,bb,cb,db receiver units 7 Marker signal 7a, c, d Signal components 8 object space 30a Rotation plane (pan) 30b Plane of rotation (tilt) 35 Stage 35a Presentation area 36a,c,d circles 40 Control unit 40a Entrances 40b Exits 41 Distance image 42 Image processing 43 Coordinate space 45 Evaluation (Marker signal) 46 Object information 47 Correlation 48 Lighting scheme

Claims

Lighting system (1) for illuminating an object (2) located in an object space (8), comprising: - a lighting unit (3) designed to emit illuminating light (4b) into the object space (8); - a distance measuring unit (5) for recording a distance image (41) of the object space (8) with the object (2) located therein, which is fixedly arranged relative to at least a part of the lighting unit (3); - a marker system (6) comprising a marker emitter unit (6ba) for emitting a marker signal (7) and a marker receiver unit (6ab) for detecting at least a signal component (7a) of the marker signal (7), wherein the lighting system (1) is configured to: - locate the object (2) in an area of ​​the object space (8) based on the distance image (41) and to individualize it using the signal component received by the marker receiver unit (6ab); and - depending on this, to (2) to illuminate with the lighting unit (3),and wherein the lighting system (1) is configured to determine the distance of the marker emitter unit (6ba) from the marker receiver unit (6ab) from the signal component (7a) of the marker signal (7) detected by the marker receiver unit (6ab). Lighting system (1) according to claim 1, wherein the marker emitter unit (6ba) is part of a first marker device (6b) which additionally has a receiver unit (6bb), and the marker receiver unit (6ab) is part of a second marker device (6a) which additionally has an emitter unit (6aa). Lighting system (1) according to claim 1 or 2, wherein the marker system (6) is radio-based, i.e. the marker signal (7) is a radio signal, in particular a UWB signal. Lighting system (1) according to one of the preceding claims, in which the marker receiver unit (6ab) is arranged in a fixed position relative to at least a part of the lighting unit (3). Lighting system (1) according to one of the preceding claims, wherein the marker system (6) has a further marker receiver unit (6cb,db) for detecting at least one signal component (7c,d) of the marker signal (7), wherein the lighting system (1) is configured to determine a position of the marker emitter unit (66a) relative to the marker receiver units (6ab,cb,db) from the signal components (7a,c,d) by means of triangulation. Lighting system (1) according to one of the preceding claims, in which the lighting unit (3) is designed to emit a cone of light (4) along different rays (4a) pointing in different directions, wherein the different rays (4a) have a common origin in a polar coordinate system. Lighting system (1) according to claim 6, wherein the lighting unit (3) has a base (3a) and an arm (3c), and a lamp head (3b) for emitting the lighting light (4b), wherein the arm (3c) is rotatably mounted on the base (3a) and the lamp head (3b) is rotatably mounted on the arm (3c). Lighting system (1) according to one of the preceding claims, in which the distance measuring unit (5) is fixedly attached to a base (3a) of the lighting unit (3). Lighting system (1) according to claim 8, in which a holder by means of which the distance measuring unit (5) is fixedly attached to the base (3a) is provided such that the distance measuring unit (5) can be brought into different tilting positions relative to the base (3a) with the holder. Lighting system (1) according to claim 9, in which a luminaire head (3b) of the lighting unit (3) provided for the emission of the lighting light (4b) is rotatable relative to the base (3a) in a plane of rotation (30a), wherein a plane spanned with the different tilt positions of the holder lies parallel to the plane of rotation (30a). Lighting system (1) according to one of the preceding claims, wherein the distance measuring unit (5) is designed to emit pulses in the infrared spectral range for distance measurement. Lighting system (1) according to one of the preceding claims, wherein the distance measuring unit (5) is a TOF camera. Lighting system (1) according to one of the preceding claims, which is configured to classify the object (2) using the signal component (7a) detected by the marker receiver unit (6ab). Method for operating a lighting system (1) according to one of the preceding claims, in which method - the object (2) is provided with the marker emitter unit (66a), - the marker signal (7) is detected with the marker receiver unit (6ab), - the distance image (41) of the object space (8) with the object (2) located therein is recorded with the distance measuring unit (5), - the object (2) is located in at least one area of ​​the object space (8) on the basis of the distance image (41), and - the object (2) is individualized on the basis of the marker signal (7) and illuminated accordingly. Method according to claim 14, in which a reference distance image of the object space (8) is taken in advance, before the object (2) is located in the object space (8), which is then used for a difference analysis in the course of an evaluation of the distance image (41). Method according to claim 14 or 15, wherein, when the object (2) is located in the object space (8), a plurality of distance images (41) are successively recorded, which are used in the course of an evaluation for a difference analysis, in particular for determining motion trajectories. Use of a lighting system (1) according to one of claims 1 to 13 for illuminating a performance area, in particular a stage, preferably in a method according to one of claims 14 to 16 .

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