Fire Locator Device, Fire Fighting System and Corresponding Operating Method

20210228927 · 2021-07-29

    Inventors

    Cpc classification

    International classification

    Abstract

    The present invention relates to a fire locator device (7) and a corresponding fire fighting system (1) comprising at least one housing (2) configured to be mounted at a certain height within or in proximity of an area of operation, in particular at a wall or a ceiling of a room (101) of a building (100), at least one sensor component (5a, 5b, 5c), wherein each sensor component (5a, 5b, 5c) of the at least one sensor component (5a, 5b, 5c) comprises a plurality of sensor elements (50) in a matrix arrangement sensitive at least to radiation, preferably to ultraviolet radiation or thermal radiation, in particular infrared radiation, a self-test component (52) for validating the operability of the at least one sensor component (5a, 5b, 5c), and a controller (9) configured to validate the operability of the at least one sensor component (5a, 5b, 5c) using the self-test component (52) and to receive sensor signals from the at least one sensor component (5a, 5b, 5c) for determining a location of a fire (F) within the area of operation.

    Claims

    1. A fire locator device comprising: at least one housing configured to be mounted at a certain height within or in proximity of an area of operation at a wall or a ceiling of a room of a building, at least one sensor component, wherein each sensor component of the at least one sensor component comprises a plurality of sensor elements in a matrix arrangement sensitive at least to ultraviolet radiation or thermal radiation, or infrared radiation, a self-test component for validating the operability of the at least one sensor component, and a controller configured to validate the operability of the at least one sensor component using the self-test component and to receive sensor signals from the at least one sensor component for determining a location of a fire within the area of operation.

    2. The fire locator device according to claim 1, wherein the self-test component comprises at least one thermal radiation source, the thermal radiation source being arranged in proximity to at least one of the sensor elements, wherein the controller is configured to validate the operability of at least one of the plurality of the sensor elements by evaluating a sensor signal response to a radiation from the at least one thermal radiation source.

    3. The fire locator device according to claim 2, wherein the at least one thermal radiation source is located outside a field of view of the at least one sensor component and configured to temporarily heat the at least one sensor component, such that, in case the at least one sensor component is operable, the sensor signal response of the at least one of the plurality of the sensor elements to a temporal heating of the at least one thermal radiation source is detectable.

    4. The fire locator device according to claim 1, wherein the controller is configured to effectuate a self-test of the at least one sensor component using the self-test component on a recurrent, periodic or daily basis.

    5. The fire locator device according to claim 1, wherein the controller is configured to sequentially compare sensor signals from the plurality of sensor elements with a threshold value for determining a location of a fire within the area of operation, wherein the threshold value includes an individual threshold value for each of the plurality of sensor elements, respectively.

    6. The fire locator device according to claim 1, wherein the controller is configured to adjust the sensor signal of at least one sensor element by providing a threshold value for the signal value of the corresponding sensor element which exceeds the signal value due to hot objects in the area of operation in case no-hazardous fire is present, and/or wherein the controller is configured to mask the sensor signal of at least one sensor element including blocking and/or ignoring the value for the signal value of the corresponding sensor element which exceeds the signal value due to hot objects in the area of operation in case no-hazardous fire is present, and/or wherein the controller is configured to determine malfunctions leading to a stop in operation including dead locks in the operability of the controller itself, using a watchdog timer.

    7. The fire locator device according to claim 1, further comprising at least one temperature sensor for determining a temperature of the area of operation or a temperature within or in proximity of the at least one housing.

    8. The fire locator device according to claim 1, wherein the controller is configured to receive an input signal from an external fire detection device.

    9. The fire locator device according to claim 1, wherein the at least one of the sensor components comprises an infrared sensing array forming the sensor elements.

    10. A fire fighting system for fighting a fire in an area of operation in a room of a building, comprising: the fire locator device according to claim 1, and a plurality of stationary fire fighting devices, each associated with and configured to distribute fire fighting agent within a respective zone of the area of operation, wherein the controller of the fire locator device is configured to: locate the zone of the area of operation having the fire by identifying those sensor elements of at least one of the sensor components which sense radiation exceeding a predetermined threshold level, and activate the at least one fire fighting device associated with the located zone.

    11. The fire fighting system according to claim 10, wherein the system further comprises an external fire detection device, wherein the controller of the fire locator device is configured to activate the at least one fire fighting device associated with the located zone only in case the fire detection device detects a fire.

    12. The fire fighting system according to claim 10, wherein the controller is configured to determine the operability of the sensor elements of the sensor components using the self-test component, and, in case at least one sensor element is determined to be inoperable, to activate the at least one fire fighting device associated with the zone corresponding to the inoperable sensor element in case a temperature signal indicative of a temperature from a temperature sensor exceeds a predefined threshold.

    13. A method of operating a fire locator device according to claim 1, the method comprising: validating an operability of the sensor elements of the sensor components by the self-testing component, determining a fire detection signal indicative of a fire from a fire detection device, determining a sensor signal for each sensor element of the sensor components, and determining an operation mode of at least one fire fighting device in response to the fire detection signal, the operability of the sensor elements and the sensor signals, the method optionally further comprising determining a temperature within the area of operation from at least one temperature sensor, wherein the operation mode of the fire fighting device is additionally determined in response to the determined temperature.

    14. The method according to claim 13, wherein the fire locator device is configured to selectively activate at least one of a plurality of stationary fire fighting devices in a normal activation mode, each of the stationary fire fighting devices associated with and configured to distribute fire fighting agent within a respective zone of the area of operation, wherein the controller locates the zone of the area of operation having the fire by identifying at least one hot spot formed by at least one sensor signal exceeding a predetermined threshold level, and wherein a normal activation mode is determined as the operating mode in which the at least one fire fighting device associated with the located zone is activated in case all sensor elements are determined to be operable, at least one sensor signal exceeds a predefined threshold, wherein the predefined threshold is predefined individually for each sensor element, respectively, and the fire detection signal indicates the presence of a fire.

    15. The method according to claim 13, wherein a normal operation mode is determined in case the sensor elements are determined to be operable and at least one of the following conditions are fulfilled: the fire detection signal indicates no fire and/or no sensor signal exceeds a predefined threshold, wherein the predefined threshold is predefined individually for each sensor element, respectively, and/or a maintenance warning mode is determined as the operation mode, and/or at least one of the sensor components or sensor elements is determined to be inoperable and/or a connection error is determined, and/or the fire detection device or the temperature sensor is determined to be inoperable and/or a connection error is determined, and/or a malfunction leading to a stop in operation is determined using a watchdog timer, and/or a first failure valve opening mode is determined as the operation mode in case at least one sensor element is determined to be inoperable, the fire detection signal indicates the presence of a fire and the temperature signal exceeds a predefined threshold, and/or a second failure valve opening mode is determined as the operation mode in case the fire detection signal indicates no presence of a fire, the temperature signal exceeds a predefined threshold, and at least one of the sensor signals exceeds a predefined threshold, respectively.

    Description

    [0092] Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings in greater detail.

    [0093] FIG. 1 shows a schematic block diagram of a fire locator device,

    [0094] FIG. 2 a schematic flowchart of an operation of the fire locator device shown in FIG. 1,

    [0095] FIG. 3 perspective views of a housing of an embodiment of the fire locator device,

    [0096] FIG. 4 a schematic view of hydraulics of the fire locator device,

    [0097] FIG. 5 a schematic view of a fire fighting system,

    [0098] FIG. 6 a schematic detail view of the system according to FIG. 5,

    [0099] FIG. 7 a, b a schematic detail view of an array sensor used in the system of FIGS. 5 and 6,

    [0100] FIG. 8 a schematic view of a first example of zones in a room,

    [0101] FIG. 9 a schematic view of a second example of zones in a room,

    [0102] FIG. 10 a schematic view of a third example of zones in a room,

    [0103] FIG. 11 a schematic view of a fourth example of zones in a room,

    [0104] FIG. 12 a perspective view of an embodiment of a fire locator device,

    [0105] FIG. 13 perspective views of a room,

    [0106] FIG. 14 a perspective view of zones in a room, and

    [0107] FIG. 15 a mapping between zones and the pixel grid.

    [0108] FIG. 1 schematically and exemplarily illustrates a layout of a fire locator device 7 of a fire fighting system 1 according to the present invention. The fire locator device 7 comprises a controller which is arranged to communicate with a plurality of further components of the fire locator device 7. Internally, fire locator device 7 comprises a watchdog timer 90 which validates the operability of controller 9, a memory 93, which is configured to store inter alia documentation and other computer instructions intended to be executed by controller 9 on a mainboard 92. Mainboard 92 further comprises at least one, in this example three, interfaces 94, which are configured to communicate with one of respective sensor components 5a, 5b and 5c.

    [0109] Mainboard 92 further comprises a power interface 95, which is configured to be connected to a power supply 78, such as a mains connection. Further, a serial interface 96, such as an USB interface, designed to communicate with, for instance, a computer, is provided. Finally, a maintenance button 98 is provided, with which a maintenance mode can be activated, for instance.

    [0110] Fire locator device 7 is further adapted to indicate its status using a status indicator 72, a maintenance indicator 74 and an acoustical indicator 76, for instance. The status indicator 72 and the maintenance indicator 74 can also be arranged in the same indicator, such as a single RGB-LED. Also other implementations are of course feasible. Acoustical indicator 76 can, for instance, indicate acoustically in case a fire is located by fire locator device 7.

    [0111] Fire locator device 7 is configured to communicate with a fire detection device 6, such as a smoke detector, which is provided external to fire locator device 7. Most importantly, fire locator device 7 in general is only configured to activate one or more out of fire fighting devices 3a, 3b, 3c, 3d and/or 3e in case fire detection device 6 confirms the presence of a fire, for instance detects smoke. In one example, each of fire fighting devices 3a, 3b, 3c, 3d and/or 3e comprises a relais or different interface, which is configured to communicate with controller 9. Fire detection device 6 is communicating with controller 9 by means of a connection 62, which can be provided as a wire or wirelessly.

    [0112] Each of the sensor components 5a, 5b and 5c comprises an array sensor 50 having a plurality of thermopile elements as sensor elements, a heating element 52 and an interface 54. Heating element 52 is part of self-test component and is configured to heat array sensor 50 in order to evaluate the sensor signal in response to the heating. In case at least one of the sensor elements of array sensor 50 is inoperable, a deviation of the expected signal response can be detected. Thus, it can reliably be detected that each of sensor component 5a, 5b, 5c is operating normally. The triggering of the self-testing of sensor component 5a, 5b and 5c is preferentially conducted or initiated by controller 9, while it can also automatically be initiated by a dedicated circuitry provided with each of sensor components 5a, 5b and 5c.

    [0113] Preferentially, heating element 52 is provided at a suitable position touching the sensors case to optimally heat up the sensor component. In other examples, the heating element 52 is provided at a suitable position in front of array sensor 50 or a transition component is provided, which is capable of moving heating element 52 to its operating position in front of or in proximity of array sensor 50 in case the self-testing is performed. In either case it is advantages that heating element 52 does not obstruct portions of the feel of view of array sensor 50, which could lead to less accurate localization results. Interface 54 is configured to provide the sensor signals originating from array sensor 50 to controller 9 and can further be configured to communicate or initiate signals relating to operation of heating element 52, i.e. to the self-testing functionality.

    [0114] In case at least one of the sensor elements of array sensor 50 indicates the presence of a fire, i.e. provides a signal value exceeding a predefined threshold, and, at the same time, fire detection device 6 indicates the presence of a fire, controller 9 is configured to open at least one of valve 32 connected to at least one of fire fighting devices 3a, 3b, 3c, 3d and/or 3e. Fire fighting devices 3a to 3e are not part of fire locator device 7 but are comprised in a system 1 for fire fighting, which will also be described with respect to the further figures. Expressed differently, the fire fighting devices 3a, 3b, 3c, 3d and 3e can be provided separate and distant from fire locator device 7, while it is of sole importance that controller 9 is capable of activating the respective fire fighting device 3a to 3e, if required.

    [0115] FIG. 1 further illustrates a thermistor 8, which is configured to determine a temperature within the area of operation. Thermistor 8 can be integrally formed with fire locator device 7 and provide an internal temperature thereof. Additionally, or alternatively, it can be arranged outside a housing of fire locator device 7 and provide an external temperature thereof. Further additionally or alternatively, thermistor 8 can be located remote from the further components of fire locator device 7, for instance at another location within the area of operation. In summary, thermistor 8 is configured to determine a temperature within the area of operation, which can be employed to further increase the reliability of the system. As further described below, the provision of thermistor 8 can ensure a double interlock system even in case one of the further components of system 1 fails.

    [0116] In order to determine which of fire fighting devices 3a to 3e is to be activated by controller 9, a mapping between sensor elements of array sensors 50 and zones of the area of operation, which is monitored by fire locator device 7 is determined or provided. Further, each of fire fighting devices 3a to 3e is associated with one of these zones, respectively. An example of the determination of zones and the association with respective sensor elements will be described below with reference to, for instance, FIGS. 7 to 11 and 13 to 15.

    [0117] FIG. 2 schematically and exemplarily illustrates a flow chart of an operation of the fire locator device 7 shown in FIG. 1. In this exemplary flow chart, it is expected that all sensor components 5a, 5b and 5c operate normally and without error. In a step S200, signals of sensor components 5a, 5b and 5c are subjected to a step called pixel masking. Pixel masking compares each individual signal value of each sensor element of the array sensors 50 of the respective sensor components 5a, 5b, 5c with an individual signal value threshold. The threshold may be the same for all sensor elements, but can also be individually assigned or adapted to the respective location, which is observed by the respective sensor element. For instance, at the location the respective sensor element monitors a higher than usual temperature is expected, the threshold value will be set to a higher value, such that the standard temperature expected at the respective location does not trigger the fire alarm signal. For reasons it is also possible not only to increase or decrease the thresholds, but also to completely ignore the sensor element, which is referred to as masking. One of these examples can be, for instance, a kitchen having a cooking hob, an oven or even a candle. After having subjected the signal values to step S200, i.e. to pixel masking, in a step S205 is evaluated whether the pixel values exceed the corresponding threshold. In the negative, i.e. in case sensor elements have signals lower than their respective threshold, the operating status is set to normal, i.e. a step S210. To the contrary, in case at least one of the sensor elements exceeds the respective threshold, a status is set to alarm in step S220 and a mapping is conducted between the pixel, i.e. the sensor element, to the spatial position within the area of operation observed in a step S230. The mapping is performed in order to determine which of fire fighting devices 3a to 3e is to be activated in response.

    [0118] Then, in a step S235, the double interlock is performed, in other words, it is determined whether the signal is a true fire. To this end, an output of fire detection device 6 is additionally considered. Only in case fire detection device 6 additionally indicates the present of a fire, step S240 is executed, leading to an activation of at least one of the fire fighting devices 3a to 3e. Thus, the fire fighting is initiated.

    [0119] FIG. 3 schematically and exemplarily illustrates perspective views of a housing 2 of fire locator device 7 as described above. Housing 2 comprises side surfaces 2a, 2b, 2c, at top surface 2d, a bottom surface 2e and a mounting extension 2f and rear surface 2g. At the front end side surfaces 2a, 2b, 2c openings for respective sensor components 5a, 5b, 5c and fire fighting devices 3a to 3e can be seen. While in this example one housing 2 comprises openings for also the fire fighting devices, it is contemplated that the fire fighting devices can be provided at a different housing separate from housing 2. The arrangement of in particular the side surfaces 2a, 2b, 2c allows for the sensor components 5a, 5b, 5c to observe or monitor a large area of operation when housing 2 is mounted at a wall or sealing of a monitoring space, such as a room of a building.

    [0120] FIG. 4 schematically and exemplarily illustrates a control structure and hydraulics, such as pipes and valves, of a fire locator device 7 of fire fighting system 1. It can be seen that a fire fighting agent valve 4 is provided, which connects fire fighting agent, for instance coming from a piping installation, with valves 32 of each of the respective fire fighting devices 3a to 3f. The three sensor components 5a, 5b, 5c are arranged substantially among the fire fighting devices 3a to 3e such that a broad angle of view can be monitored. In particular, the distribution of fire fighting devices 3a to 3e and sensor components 5a to 5c is such that coverage of the space or room to be monitored is optimized. It can be seen that both fire fighting agent valve 4 and valves 32 of each of the respective fire fighting devices 3a to 3e are in communicating connection with processor or controller 9, which activate each of the respective valves in case both the fire detection device 6 and at least one of sensor components 5a to 5c indicates presence of a fire. As further described in detail below, the double interlock activation can additionally or alternatively be employed using a temperature detected by thermistor 8.

    [0121] FIG. 5 shows a fire fighting system 1. The fire fighting system 1 is installed in a room 101 of a building 100. The room comprises a number of side walls 103, a ceiling 105 and a floor 106. Inside the room 101, a heat source 107 is installed. The room 101 is an example for an area of operation protected by the fire fighting device.

    [0122] It should be noted that, while an entire room 101 is illustrated in FIG. 5 and some of the consecutive figures, the system according to the invention can also be provided to protect only a part of the room. In this case, also a plurality of systems 1 according to the invention can be provided to protect the entire room. Thus, a room according to this invention is used as a defined area of operation under protection by fire fighting system 1, which can also be a part of a physical room, i.e. a construction being enclosed by walls and ceiling.

    [0123] The system 1 comprises a number of fire fighting devices 3a, b which are installed for example under the ceiling 105 of the room 101, but could alternatively also be wall-mounted. The fire fighting devices 3a, b may for example be open fire fighting nozzles of a deluge system.

    [0124] The system 1 further comprises a plurality of fire detection devices 6 installed in the room 101, for example under the ceiling 105 and/or on one of the side walls 103. While a plurality of fire detection devices 6 is illustrated in FIG. 5, it should be noted that also a single fire detection device is sufficient in other examples.

    [0125] The system 1 further comprises a fire locator device 7 that is configured to locate a fire F in the room 101. The fire detector devices 6 are configured to detect the presence of a fire in the room 101. The fire fighting devices 3a, b are each positioned such that they distribute fire fighting agent within a respective coverage zone 11 a, b (hereinafter also “zone”) of the room 101. The zones 11a, b may overlap.

    [0126] System 1 further comprises a controller 9 which is in signal communication with the fire fighting devices 3a, b with the fire detection devices 6 and with the fire locator device 7. The controller 9 is configured to activate the fire fighting devices 3a, b in reaction to a detection of the fire F as is detailed further herein below.

    [0127] Each of the sensor components 5a, 5b, 5c of the fire locator device 7, which was described in detail with reference to FIG. 4, comprises an array sensor 50 (FIGS. 7a, b) which has a defined field of view having a first view angle α1 and a second view angle α2 (FIG. 6). Within its field of view, the array sensor 50 is adapted to monitor a predetermined area, or zone, of the area of operation, e.g. of room 101. The array sensor 50 comprises a sensor array 15 having a plurality of n×m pixels arranged in a grid 17. Since the fire locator device 7 is stationary, i.e. fixedly installed in the room 101, once oriented, each of the pixels of the grid 17 is specifically assigned to a specific portion of the room 101. Depending on the distance of the fire locator device 7 from e.g. the floor 106 of the room 101 and depending on the specific view angles α1, α2, the grid 17 of pixels defines a projection 13 of the pixel grid 17 in the room 101. A fire F which lies within this projection 13 will be determined by the grid 17 of the sensor array 15.

    [0128] Preferably, the sensor array 15 is an infrared sensor array, in particular a thermopile array. The array sensor 50 is configured to generate for each pixel a signal representative for a temperature within the portion of the projection 13 in the room 101. The fire F will cause representative temperature signals to be generated by the array sensor 50. The controller 9 is configured to receive the representative temperature signals from the array sensor 50. Also, the controller 9 is configured to allocate specific threshold values T.sub.1, T.sub.2 to each pixel of the sensor array 15. There may be two or more different threshold values used across the array. According to the invention, it is possible to designate a threshold value that will be reached only in case of a fire, or not be reached at all, the latter being especially useful to permanently “blind” the array sensor from certain stationary hotspots that are indicative of non-hazardous fire related heat sources. More specifically, it is even possible to “blind” individual pixels of the sensor array 15 and thus keep the area, which is “excluded” to a minimum area around the stationary hot spots.

    [0129] However, each threshold value may also be indicative of a temperature limit, the breach of which happens only in case of a fire in that specific portion of the room. As soon as the temperature in the pixels of the sensor array 15 exceeds the predetermined threshold levels T.sub.1, T.sub.2 indicative of a fire, the controller not only has identified the presence of a fire F in the room 101, but additionally has located the portion within the projection 13 (FIG. 5) where the fire F resides by identifying the respective hot spot among the grid 17 (FIG. 7b) of pixels. This allows for very efficient allocation of the fire fighting device 3a or 3b that is ideally positioned to distribute fire fighting agent in the zone where the fire F has been located.

    [0130] Depending on whether the fire has been located in a zone that is overlapped by the zones 11a, b covered by a plurality of fire fighting devices 3a, b, the controller 9 may also activate more than one fire fighting device 3a, b, but ideally no more than two fire fighting devices 3a, b.

    [0131] In many rooms, in particular residential rooms, it is to be expected that stationary heat sources such as heat source 107 are present in a portion monitored by the fire locator device 7. In order to prevent false fire alarms, and in order to prevent inaccurate location of actual fires due to the influence of stationary heat sources, the controller 9 is configured to assign specific threshold values T.sub.2 to all pixels which are within range of the stationary hot spot 109 formed by the stationary heat source 107. As is depicted in FIG. 6 and FIG. 7b, the controller 9 could for example be programmed to assign a higher threshold value T.sub.2 to pixels 49 through 54 and 57 through 62, while assigning a lower threshold value T.sub.1 to the remaining pixels of the grid 17. By doing so, increased temperatures emanating from heat source 107 would not be flagged as hotspots indicative of a fire F, unless the predetermined higher threshold value T.sub.2 is exceeded.

    [0132] This allows the controller 9 to distinguish between a fire F and a fire-unrelated or non-hazardous-fire heat source NF. Basically, any number of stationary heat sources may be accounted for in this way.

    [0133] While the embodiments of FIG. 5 through 7b show a simple set-up of a room 101 having only one fire locator device, the invention also covers embodiments wherein the room 101, either due to its size or due to its complexity of its layout, requires the use of more than one fire locator device. Preferably, the entire floor 106 of the room is covered by grids 17 of pixels emanating from specifically mounted and oriented fire locator devices 7. Depending on economic factors and ease of installation, the number of fire locator devices for the size of the grid 17 of pixels for each fire locator device 7 may be modified according to need. At any rate, the invention allows for the use of array sensors 50 having sensor arrays 15 with comparatively low resolution (in particular when compared to prior art systems using high-resolution infrared camera systems).

    [0134] FIGS. 8 to 11 schematically and exemplarily illustrate different configurations or distributions of zones 210a-210e or 310a-310h in different rooms, respectively.

    [0135] FIG. 8 illustrates a layout of four zones 210a-210d, which are equal in size and apportion the surface area of the room among them. In other words, the four zones 210a-210d cover the entire surface area, i.e. the floor and—if necessary—at least part of the wall surface area of the room. A further, fifth zone 210e is located in the center of the room and overlays all of the other four zones in the center of the room. Fifth zone 210e is thus redundant and provided to limit the spacial extension and also the amount of the fire fighting agent dispersion.

    [0136] In FIG. 8, four examples of a fire F at different locations within the illustrated room, i.e. within different zones 210a-210e, are illustrated. Each of the examples of the fire F leads to the determination of a fire fighting area 220 by the controller 9, which is as follows. In the first example, since the fire F is located within zone 210a, the fire fighting area is determined to be comprised of zone 210a. In the second example, the fire F is located at the edge between zone 210a and zone 210b, such that both zone 210a and zone 210b are determined as the fire fighting area 220. The third example shows the fire F in the center of the room. In this example, only zone 210e is determined as fire fighting area 220. In the last example, the fire F is located close to the center within zone 210b. Thus, both the central zone 210e and zone 210b are determined as fire fighting area 220. In these examples, for the reasons discussed above, it is preferred that not more than two zones 210a-210e be determined as fire fighting area 220.

    [0137] In this example, both the room and each of the respective zones 210a-210e are of quadratic shape for the ease of illustration, while of course also different examples of shapes are contemplated. The quadratic shape is particularly beneficial in combination with specific controllable nozzles as fire fighting devices, e.g. fire fighting device 3a-3e, such as a Viking Model A full cone nozzle or a similarly operating, publically available nozzle.

    [0138] FIG. 9 substantially corresponds to the example of FIG. 8, wherein the room as an example of an area of operation—or likewise a part of the room—is rectangular and its surface is distributed among six zones 310a-310f, which are also in this example quadratic and of equal size. Two central zones 310g and 310h are respectively provided to overlap four adjacent of the zones 310a-310f, respectively. The determination of a fire fighting area 220 is performed analogous to the example of FIG. 9. In other word, not more than two zones 310a-310h are determined to be part of the fire fighting area (not shown in FIG. 5) at the time.

    [0139] FIG. 10 schematically illustrates a further example, wherein the room is split into two substantially independent regions of five zones 210a-210e, 310a-310d and 310g, respectively. For examples, each of the two groups of five zones can be coordinated and controlled by a particular, individual controller 9 and/or fire locator device 7. In other examples, the two groups can also be controlled commonly by a single controller 9 and/or fire locator device 7.

    [0140] In the example of FIG. 10, the two fully overlapping regions 210e, 310g are not adjacent to each other, different from the example of FIG. 9, in which two completely overlapping zones 310g, 310h are adjacent to each other. In the example of FIG. 10 a fire F is illustrated in the center of the room. In this example, the fire fighting area 220 is extended to include two zones 210b, 210d, and 310a, 310c of each of the first and second group of zones 210, 310, respectively.

    [0141] Accordingly, in this example also the situation, in which more than two zones are comprised in the fire fighting area 220 is illustrated. The example of FIG. 10 is particularly useful in case two substantially independent systems for fire fighting are arranged in the same room. In this case, two zones per independent system are comprised in the fire fighting area 220, respectively. Then, again, not more than two zones will be activated concurrently, i.e. designated as the fire fighting area 220

    [0142] It is of course contemplated that also in the example of FIG. 10 a further fully overlapping zone can be defined in between the zones 210e and 310g. In this particular case, it would be beneficial to protect the entire room as illustrated in FIG. 10 with a single system for fire fighting according to the invention.

    [0143] FIG. 11 schematically and exemplarily illustrates the effect of overlapping zones in the example of five zones 210a-210e. In this example, overlapping regions 212a-212k are formed in the overlapping area between two adjacent zones 210a-210e, respectively.

    [0144] Overlapping regions 212a and 212b correspond to the region in which zone 210a overlaps zone 210b and vice versa. Accordingly, the fire fighting area 220 in case a fire F is detected in either region 212a or region 212b will be comprised of both zone 210a and 210b. Likewise, in overlapping regions 212c and 212d zones 210a and 210c will form the fire fighting area 220. A fire F in overlapping region 212e or 212f will yield a fire fighting area 220 with zones 210c and 210d, while a fire F in overlapping region 212g or 212h will result in fire fighting area 220 being formed of zones 210b and 210d.

    [0145] Finally, in case a fire is present in the outer region of zone 210e, i.e. the region near the edge of zone 210e, which are indicated with 212i, 212j, 212k or 212l, the fire fighting area 220 is formed of zone 210e and one of zones 210a-210d, respectively. Thus, also in this example with overlapping regions, it can be ensured that not more than two zones will be comprised in the fire fighting area 220 at the same time.

    [0146] FIG. 12 illustrates a perspective view of an embodiment of a fire locator device 7 with a different shape of housing 2. The three sensor components 5a, 5b, 5c are provided in circular indentations of housing 2 and protrude therefrom with a substantially hemispherical form. Each of the respective casing or housing of the sensor components 5a, 5b, 5c comprises a conical well, wherein at the bottom of each well the array sensor 50 is located. The opening angle of the corresponding conical well corresponds to the field of view of the array sensor 50. In this embodiment, the fire fighting devices 3a-3e are external from the fire locator device 7 and not illustrated.

    [0147] FIG. 13 illustrates perspective views 1400, 1410 of room 101 as an example of the area of operation. In view 1400, the exemplary quadratic layout of room 101 including floor 106 and side walls 103 can be seen. In view 1410, the field of view of a fire locator device 7 having three sensor components, for instance fire locator device 7 of FIG. 12, is illustrated. A field of view 1420, a field of view 1430 and a field of view 1440 corresponds to one respective of sensor components 5a, 5b, and 5c.

    [0148] It can be seen that the entire surface of the room 101 is imaged by at least one of the sensor components 5a, 5b, 5c, i.e. the fields of view 1420, 1430, 1440 completely fill the area of the room 101. In central areas 1450, the fields of view of different sensor components partially overlap.

    [0149] FIG. 14 schematically illustrates room 101, in which the five zones 210a-210e and overlapping regions 212a-212k as illustrated in FIG. 11 are illustrated in a perspective view 1500.

    [0150] FIG. 15 illustrates an overlay of FIG. 14 with the imaging areas of the sensor components, wherein a projection of the pixel grid 17 of the sensor elements of sensor component 5b is provided as an overlay over zones 210-210e. Only the pixel grid 17 of sensor component 5b is illustrated, wherein the mapping between zones 210a-210e and sensor elements of the respective sensor component is likewise determined for sensor component 5a and 5c.

    [0151] Sensor elements corresponding to a region 1601 will not be mapped to any of zones 210a-210e, since they image an area outside the area of observation. Sensor elements corresponding to a region 1602 will be mapped to zone 210a, region 1603 will be mapped to zone 210c and the further sensor elements corresponding to a region 1604 will be mapped to one or more of zones 210b, 210d and 210e.

    LIST OF REFERENCE SIGNS

    [0152] 1 system [0153] 2 housing [0154] 2a,b,c side surface [0155] 2d top surface [0156] 2e bottom surface [0157] 2f mounting extension [0158] 2g rear surface [0159] 3a,b,c,d,e fire fighting device [0160] 32 valve [0161] 4 fire fighting agent valve [0162] 5a,b,c sensor component [0163] 50 array sensor [0164] 52 heating element [0165] 54 interface [0166] 6 fire detection device [0167] 7 fire locator device [0168] 72 status indicator [0169] 74 maintenance indicator [0170] 76 acoustical indicator [0171] 78 power supply [0172] 8 thermistor [0173] 9 controller [0174] 90 watchdog timer [0175] 92 mainboard [0176] 93 memory [0177] 94 interface [0178] 95 power interface [0179] 96 serial interface (USB) [0180] 98 maintenance button [0181] 11a,b zone [0182] 13 projection of pixel grid [0183] 15 array [0184] 17 pixel grid [0185] 100 building [0186] 101 room [0187] 103 side wall [0188] 105 ceiling [0189] 106 floor [0190] 107 heat source [0191] 109 stationary hot spot [0192] 210a-e zone [0193] 212a-1 overlapping region [0194] 220 fire fighting area [0195] 310a-h zone [0196] 1400, 1410 perspective views of the room [0197] 1420, 1430, 1440 field of view of sensor component [0198] 1450 central area [0199] 1500 perspective view [0200] 1601, 1602, 1603, [0201] 1604 region of pixel grid [0202] m, n grid parameters [0203] F fire [0204] NF fire-unrelated heat source or non-hazardous fire [0205] T.sub.1, T.sub.2 threshold [0206] α.sub.1, α.sub.2, α.sub.3 angle, field of view