Sensing system for fire event detection

Abstract

Systems, methods, and devices are described herein that provide a sensing system for fire event detection in a space within a facility. In one embodiment, a method includes activating a physical sensor of a physical alarm system detector device to monitor a space of a facility for an occurrence of a fire event, defining a virtual voxel structure mapped in at least three dimensions to a virtual monitoring space created to represent the space of the monitored facility, and localizing the virtual object within the virtual voxel structure by mapping the virtual object location within the space based on the location of the physical object sensed with the physical sensor.

Description

Technical Field

[0001] The present disclosure relates to systems, methods, and apparatus for providing a sensing system for fire event detection. Background Art

[0002] Facilities equipped with fire alarm systems allow early detection of fire events, such as fires within buildings. Typically, such facilities are large and can be complex (e.g., large buildings, multiple floors, facilities with multiple buildings) and such alarm systems allow firefighters to arrive faster.

[0003] The system utilizes specialized fire / smoke sensing devices (e.g., fire detectors that detect heat and / or smoke detectors that detect smoke particles to detect fire) dispersed throughout the facility that can detect when a fire may be occurring. These alarm system devices transmit sensor information to a building alarm system control panel that collects and analyzes the data to determine if a fire event is occurring and contacts emergency personnel to come to the facility to address the fire. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] Figure 1 is an example of a fire / smoke alarm system detector device according to one or more embodiments of the present disclosure.

[0005] Figure 2 is a three-dimensional voxel visualization according to one or more embodiments of the present disclosure.

[0006] Figure 3 is an example of a single detector of a fire alarm system in a space within a building with an object obscuring the sensing field in accordance with one or more embodiments of the present disclosure.

[0007] Figure 4 is an example of multiple detectors of a fire alarm system in a space within a building with an object obscuring the sensing field according to one or more embodiments of the present disclosure.

[0008] Figure 5 are examples of system input and output devices for a fire alarm system according to one or more embodiments of the present disclosure.

[0009] Figure 6 is an illustration of a smoke sensing device sensing a light-colored smoke plume against a dark background, according to one or more embodiments of the present disclosure.

[0010] Figure 7 is an illustration of a smoke sensing apparatus sensing a light-colored smoke plume against a patterned background, according to one or more embodiments of the present disclosure.

[0011] Figure 8is an illustration of a smoke sensing apparatus utilizing a time-gated video sensor and a pulsed illuminator to sense a light-colored smoke plume against a patterned background, according to one or more embodiments of the present disclosure. DETAILED DESCRIPTION

[0012] Embodiments of the present disclosure provide multi-dimensional information that can be used, for example, to provide location and distance to smoke and thermal events. Some embodiments combine aspects of three-dimensional (3D) range sensing, 3D smoke detection using LiDAR (Light Detection and Ranging technology), thermal imaging, and object detection.

[0013] Embodiments of the present disclosure provide rich situational awareness data to enable rapid, focused responses to threats such as smoke, fire, and intrusion. In addition, by combining data types (e.g., 3D voxel location, smoke intensity, temperature), the system can support optimal decision making to minimize the risk of loss of life or damage to assets.

[0014] Some embodiments include LiDAR-based system components for measuring and / or mapping a 3D environment.An enhanced LiDAR system may, for example, be capable of detecting backscatter from smoke.

[0015] The thermal imaging system components can be used to cover at least some of the same physical environment. The thermal imaging sensor can, for example, identify the temperature of an object or whether an object is hot but has not yet produced smoke. For example, a room may have a motor that drives a piece of equipment, and the motor becomes hot during operation. The thermal imaging sensor can determine the temperature of such an object and identify such an object.

[0016] Additionally or alternatively, a camera (video imaging sensor) may be used to cover at least some of the same environment, for example the camera may be part of an enhanced camera system capable of detecting smoke plumes, for example.

[0017] Additionally, in some embodiments, the LiDAR component may be replaced by a "structured light" triangulation system to provide the functionality provided by the LiDAR component (e.g., detecting backscatter from smoke). In some embodiments, the LiDAR may be a mechanically scanned beam, for example, or in other embodiments, may be replaced by a time-gated (time-of-flight) camera.

[0018] In the following Detailed Description, reference is made to the accompanying drawings which form part of the present Detailed Description. The drawings show, by way of illustration, the manner in which one or more embodiments of the present disclosure may be practiced.

[0019] These embodiments are described in sufficient detail to enable one of ordinary skill in the art to practice one or more embodiments of the present disclosure. It is to be understood that other embodiments may be utilized and process, electrical and / or structural changes may be made without departing from the scope of the present disclosure.

[0020] It should be understood that the elements shown in the various embodiments herein may be added, exchanged, combined and / or eliminated to provide multiple additional embodiments of the present disclosure. The proportions and relative sizes of the elements provided in the drawings are intended to illustrate embodiments of the present disclosure and should not be limiting.

[0021] The figures herein follow the following numbering convention: the first digit or digits correspond to the figure number, and the remaining digits identify the element or component in the figure. Similar elements or components between different figures may be identified by using similar numerals. For example, 334 may refer to Figure 3 element "34" in, and Figure 4 Similar elements in may be referenced as 434.

[0022] As used herein, "a" or "several" things may refer to one or more such things, and "multiple" things may refer to more than one such things. For example, "several sensors" may refer to one or more sensors, and "multiple sensors" may refer to more than one sensor.

[0023] Figure 1 is an example of a fire / smoke alarm system detector device according to one or more embodiments of the present disclosure. Figure 1 The fire / smoke alarm system detector device 100 comprises a processing unit 101 including a processor 102 and a memory 103. The processor processes executable instructions stored in the memory.

[0024] The memory includes executable instructions and data used by the executable instructions, received from other system devices and / or other non-system devices, and / or derived from the execution of the executable instructions. For example, voxel information (e.g., data and instructions for forming voxels and / or interpreting data), position information (e.g., data and instructions for deriving position and / or interpreting data), and / or distance information (e.g., data and instructions for deriving distance from a sensor and / or interpreting data) can be stored in the memory. The processing unit 101 can be, for example, a computing device such as a desktop or laptop computer or a computing device used as an alarm system control panel.

[0025] The alarm system of the present disclosure may include several sensor devices to achieve the functions described herein. For example, Figure 1The system 100 includes a LiDAR sensor 104 , a time-gated video sensor 105 , a communication interface 106 , a thermal imaging sensor 107 , a pulsed illuminator 108 , a video sensor 109 , and a communication unit 110 .

[0026] The LiDAR sensor 104 can be used, for example, to measure the distance to objects in a space (e.g., a room) within a building, and in some implementations can include measuring the distance to walls and / or corners of the space. The wall and / or corner measurements can be used, for example, to create a virtual space that corresponds to the physical space measured using the LiDAR sensor. The LiDAR sensor can also be used to identify the distance and location of smoke in a room.

[0027] Time-gated video sensor 105 may be used, for example, in conjunction with pulsed illuminator 108 such that coordination of the pulsed light round trip time with activation of an optical shutter in a receiving video sensor 109 (e.g., which detects smoke plumes and / or flames) enhances sensitivity to objects at a particular distance (such as smoke plumes) to help distinguish them from the background.

[0028] The communication interface 106 represents the components within the system 100 that provide any necessary communication links for accessing and / or storing data and / or executable instructions. These include, for example, devices that provide wireless, fiber optic, or Ethernet connections to and / or from system devices. The communication unit 110 manages communications between the plurality of sensor devices and an alarm system monitoring station at a control panel or external to the alarm system. For example, the communication unit 110 may transmit a complete voxel array data set to a separate monitoring system (e.g., an alarm system monitoring station), which will interpret the voxel array ( Figure 1 The meaning of the content of the virtual voxel structure shown in .

[0029] Figure 2 is a three-dimensional voxel visualization according to one or more embodiments of the present disclosure. The voxel visualization may be viewed by a user on a display, or may be a digital construct that is invisible to the user but usable by a computing device as if it had been viewed visually. The voxel visualization may be used to monitor a space within a building to determine whether an object of interest is present in the space, and the state (e.g., size, position, and / or movement) of the object may be determined and, in some embodiments, tracked over time. The object of interest may be any parameter that may be remotely sensed by any sensor of the system, such as color, reflectivity, temperature, gas concentration, velocity, acceleration, particle or smoke concentration, and the like.

[0030] Each voxel can be considered to be multi-dimensional. A voxel is a measurement of the volume in the structure to be imaged. Preferably, the voxels are cubes to easily determine the size of the voxel structure and the location of any objects therein. Each voxel represents a defined volume and can be located by coordinates on a three-dimensional grid. As used herein, a voxel is described by its location in space (e.g., three dimensions) and by having a time dimension; this is the time at which the detection system's sensor senses the voxel data, assuming that a fire / smoke detector device samples the environment periodically. In addition, each voxel can be linked to a list of objects of interest, as described above. A virtual voxel structure is a structure composed of multiple voxels.

[0031] exist Figure 2 , a portion of a space 211 is shown where data is collected by one or more sensors, showing three junctions between surfaces (e.g., walls, floor, ceiling (not shown or used in this example, but could be used)) 212, 214, 216 and a matrix 218 of adjacent defined areas 213 within the space 211. The creation of the virtual voxel structure is based on data associated with the actual physical space being monitored by the physical alarm system detector device providing the data (i.e., collected by the detector device or stored in memory by a technician or administrator).

[0032] A method for creating a virtual voxel structure includes: activating physical sensors of a physical alarm system detector device (located in or adjacent to a monitored space) to monitor the space of a facility for the occurrence of a fire event; defining a virtual voxel structure that maps in at least three dimensions (e.g., x, y, z) to a virtual monitoring space created to represent the space of the monitored facility; and positioning virtual objects within the virtual voxel structure by mapping the positions of the virtual objects within the space based on the positions of physical objects sensed using the physical sensors.

[0033] As used herein, mapping is the simulation of physical locations in actual physical space in a virtual environment, where the space and objects may have a different scale than the actual space and objects, but the scale relationship between the physical space and physical objects and the virtual space and virtual objects is the same. For example, the virtual space and virtual objects may both be scaled down by a factor of 30 relative to the physical space and physical objects so that the virtual environment can be related to the physical environment so that the information provided by the voxel structure provides accurate object positions and movements. This can be beneficial, for example, where a space is monitored over time and the position of a virtual object can be adjusted based on changes in the sensed position of a physical object.

[0034] When an object of interest 222 is detected, certain defined areas 220 containing the object of interest may be identified and selected. The object of interest may be, for example, smoke, flames, hot objects, people, and / or animals. The objects of interest may be identified by their color, reflectivity, temperature, gas concentration, and / or smoke concentration. Other information of interest may include, for example, the movement of the object of interest.

[0035] This information can help identify the location of the fire event, the size of the fire, and, in the case of monitoring over time, the growth of the fire, its direction of growth, recommended evacuation routes, and other useful information. As the object changes, more or different defined areas 213 affected by the object (e.g., object presence, heat, or some other object effect) can be identified. The object information can be acquired by one or more sensors. Figure 3 and Figure 4 Some examples of detector configurations that may be utilized are provided.

[0036] To create the voxel structure as shown, the computing device doing the creation may, for example, collect data from each detector whose data is being used and identify landmarks within the detector's field of view. If more than one detector is used, common landmarks may be identified and their locations determined by transforming the data from one detector into a coordinate system compatible with the first detector, or vice versa. The data sets may then be superimposed, and the position data are complementary.

[0037] Figure 3 334 is an example of a single detector of a fire alarm system in a space within a building with an object obscuring the sensing field in accordance with one or more embodiments of the present disclosure. Although the use of a single detector is cost-effective, when a single detector 334 is used to monitor an area (here bounded by walls 331 and 33 and floor 333), there is a possibility that a nearby object 330 will block the volume of space 338 behind it, making it impossible to sense the contents of the voxels in the blocked volume 338. Note that this is important because if there are thermal or other events, they will only be visible in area 336 and will not be visible to the detection system in area 338, and therefore will not be reported.

[0038] Such as Figure 3 and Figure 4One embodiment of the alarm system shown includes: several event detection devices having several sensors configured to detect events within a facility; and an alarm system control panel configured to receive information about the events or event detection devices and transmit the information to a computing device. The computing device is configured to activate physical sensors of the physical alarm system detector devices to monitor a space of the facility for fire events, define a virtual voxel structure that maps in at least three dimensions to a virtual surveillance space created to represent the space of the monitored facility, and locate virtual objects within the virtual voxel structure by mapping virtual object positions within the space based on positions of physical objects sensed using the physical sensors.

[0039] As described above, in some embodiments, the system includes a LiDAR sensor that measures the distance from the LiDAR sensor to the object. Alternatively or additionally, the system may include a pulsed illuminator and / or a gated video sensor. For example, when both are included, the pulsed illuminator can be used in conjunction with the gated video sensor, as described herein, so that the pulsed light round trip time can be coordinated with the activation of the optical shutter in the receiving video sensor.

[0040] A computing device embodiment of an alarm system may include a processor and a memory having instructions stored therein executable by the processor, wherein the instructions are executable to receive monitoring data from activated physical sensors of a physical alarm system detector device to monitor a space of a facility for the occurrence of a fire event. The instructions may also define a virtual voxel structure that maps in at least three dimensions to a virtual surveillance space created to represent the space of the monitored facility, and locate virtual objects within the virtual voxel structure by mapping virtual object positions within the space based on positions of physical objects sensed using the physical sensors.

[0041] Figure 4 4 is an example of multiple detectors of a fire alarm system in a space within a building with an object obscuring the sensing field according to one or more embodiments of the present disclosure. In this example, multiple detectors (434-1, 434-2) are utilized to sense an object 430 in an area (bounded by walls 431 and 432 and floor 433). Here, detector 434-1 senses in area 436-1, and detector 434-2 senses in area 436-2. The combination of their sensing data significantly reduces the obscured area to 438 compared to 338. Therefore, adding additional detectors or sensors at dispersed locations in an area and sensing directed objects can improve the effectiveness of a fire alarm system.

[0042] In some embodiments, the computing device may have executable instructions for reducing the size of the blocked area associated with a particular object in the space by utilizing sensor data from multiple sensors placed in at least two different locations relative to the object. For example, in some embodiments, the sensor data from the multiple sensors includes sensor data from another physical alarm system detector device positioned within the space, or in other embodiments, the sensor data from the multiple sensors includes sensor data from another sensor associated with the detector device 334 (e.g., wired or wirelessly connected).

[0043] One problem that this approach needs to overcome is the coordination of multiple detectors and combining their data into a correctly registered voxel array representation. In one approach, for this to happen, it can be assumed that there is a "master" detector that communicates bidirectionally with the other detectors. Figure 4 In an example of, two detectors (more detectors are possible) coordinate their measurements through identification of landmarks in the scene (sensing area sensed by that particular detector), which landmarks may be, for example, 3D structures such as corners or other objects.

[0044] Landmark information may be transmitted from any detector (e.g., detector 434-2) to a "master" detector (e.g., 434-1) so that the master detector can compare with the data it already has and perform a transformation into its local coordinate system (e.g., three physical dimensions plus time).

[0045] Once the coordinate transformation of the non-primary detectors into the primary detector's coordinate system is completed, the primary detector can then absorb the voxel information from all non-primary detectors and correctly combine it with the local (primary) voxel data to provide a more complete representation of the monitored volume with less obstruction.

[0046] Alternatively, if multiple detectors are used to monitor a zone, they may be implemented so that there is no single “master detector.” This allows for redundancy in the event of failure of any component.

[0047] Figure 5 is an example of a system input and output device for a fire alarm system according to one or more embodiments of the present disclosure. This aspect of the detector includes a pulsed light source that can project light over a wide area. In this example, the pulsed illuminator system 540 ( Figure 1 Component 108 ) includes a light source shown at two time periods 542 and 548 and a receiver (eg, video sensor) 544 and 549 at two time periods.

[0048] The light source 542 is pulsed, which means that upon command, it produces a very brief flash of light, which may have a duration of, for example, a few nanoseconds. The light pulses are reflected from objects 546 in its projection field, and these reflections can be received by a video sensor placed close to the light source.

[0049] The receiver may have a very fast shutter that can be operated on command. If the time between the command to generate a light pulse and the command to open the shutter corresponds to the round trip time for light to reflect from an object and return to the video sensor, then the object will be visible, while other objects in the scene will not be visible. This arrangement can be determined by the equation d = (ct) / 2, where d is the distance shown, c is a constant, and t is the travel time from 542 to 549.

[0050] In such embodiments, the timing combination of the pulses of light and the shutter allows the video sensor component to capture images at different distances from the video sensor, thereby allowing the position and distance of objects in the field of view of the image sensor to be determined. Such embodiments can also be adjusted to capture images before the background surface is illuminated, which may be beneficial if the background surface is not a color that forms a high contrast with the color of the smoke plume.

[0051] Figure 6 is an illustration of a smoke sensing device sensing a light colored smoke plume against a dark background in accordance with one or more embodiments of the present disclosure. One of the challenges of video smoke detection is that if there is little or no contrast between the color and reflectivity of the smoke plume compared to the background, it is difficult for a standard video system to identify it.

[0052] However, if there is a strong contrast, e.g. Figure 6 As shown, a good image of the plume can then be obtained and the plume can be identified without problems. Figure 6 6 is a view of a light-colored smoke plume against a high-contrast dark background using a standard camera as detector 634. In this example, detector 634 senses 636 in area 611 and detects object 650 (smoke plume) contrasted with background 652 (wall 632). Monitoring data may be received from activated physical sensors that include background surfaces that contrast with objects in the foreground of the background surfaces, such as Figure 6 As shown in the implementation scheme of .

[0053] Figure 7 is an illustration of a smoke sensing device sensing a light-colored smoke plume relative to a patterned background in accordance with one or more embodiments of the present disclosure. In this example, if the contrast is poor, or the background has some portions that match the plume color and reflectivity, the plume will become at least partially invisible or concealed. Figure 7 is a view of a light colored smoke plume against a patterned or non-contrasting background using a standard camera as detector 734.

[0054] exist Figure 7 , detector 734 senses 736 object 750 in area 711, but the background (wall 732) contains high contrast areas 754 and low contrast areas 755. The low contrast between object 750 and low contrast areas 755 can make it difficult for the detector to accurately determine the size and position of object 750.

[0055] Figure 8 834 ] is a view of a smoke sensing device utilizing a time-gated video sensor and a pulsed illuminator to sense a light-colored smoke plume relative to a patterned background in accordance with one or more embodiments of the present disclosure. In some embodiments, a view of a light-colored smoke plume relative to a patterned non-contrast background using a time-gated video sensor and a pulsed illuminator (also referred to as a time-of-flight sensor). The time between the activation of the pulsed light source and the time the sensor shutter is opened corresponds to the time it takes for the light pulse to arrive at the plume and the resulting light reflection to be detected by the sensor. By using time-gated video, as described herein, in this specific implementation, the smoke plume can be isolated from the background by controlling the delay between the start of an illumination pulse of light from the light source of the detector 834 and the time when the receiving shutter is also opened at the detector 834.

[0056] A novel aspect of the embodiments of the present disclosure includes that the data output is configured as a 3D+time coordinated voxel array. This is different from standard measurement systems that simply project depth or thermal information onto a 2-dimensional (x,y) representation. Another aspect is the use of a combination of multiple voxel data sources (from multiple detectors) to overcome the blockage problems created by using fewer detectors, and to provide a comprehensive (almost complete) representation of the monitored space, which is formed in at least one (e.g., primary) detector and transmitted as a complete voxel array to a separate monitoring system, which will interpret the meaning of the contents of the voxel array. In addition, the use of time-gated (time-of-flight) video and pulsed illumination in event detection is a novel concept. In addition, the use of more than one of the above-mentioned techniques ensures a much higher probability of detecting an event.

[0057] Although specific implementations have been illustrated and described herein, those of ordinary skill in the art will appreciate that any arrangement calculated to achieve the same technique may be substituted for the specific implementations shown. This disclosure is intended to cover any and all modifications or variations of various implementations of the present disclosure.

[0058] It should be understood that the above description is given in an illustrative rather than limiting manner.By reading the above description, combinations of the above embodiments, as well as other embodiments not specifically described herein, will be apparent to those skilled in the art.

[0059] The scope of the various embodiments of the present disclosure includes any other applications using the above-described structures and methods.The scope of the various embodiments of the present disclosure should therefore be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

[0060] In the above detailed description, various features are grouped together in the exemplary embodiments shown in the drawings for the purpose of simplifying the disclosure. This method of disclosure should not be interpreted as reflecting an intention that the embodiments of the present disclosure require more features than are expressly recited in each claim.

[0061] Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment.Thus the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment.

Claims

1. A method comprising: activating physical sensors (104, 105, 107, 109) of a physical alarm system detector device (101) to monitor a space of a facility for a fire event; defining a virtual voxel structure that maps in at least three dimensions to a virtual monitoring space (211) created to represent the space of the facility being monitored; and A virtual object (222) is positioned within the virtual voxel structure by mapping the virtual object's position within the space (211) based on sensing the position of the physical object using the physical sensors (104, 105, 107, 109).

2. The method of claim 1, wherein the method further comprises monitoring the space (211) over time and adjusting the position of the virtual object (222) based on sensed changes in the position of the physical object. The method according to claim 1 , wherein the virtual voxel structure is a structure composed of a plurality of voxels. The method of claim 3 , wherein each voxel is described by its position in three dimensions and having a time dimension.

5. The method of claim 4, wherein the time dimension is quantified by the time at which the sensor (104, 105, 107, 109) senses the voxel data of a particular voxel.

6. The method of claim 1, wherein the method further comprises coordinating a round trip time of pulsed light from a pulsed illuminator (542) with activation of an optical shutter in a receiving video sensor (549) of a gated video sensor assembly (105).

7. The method of claim 1, further comprising receiving data from a receiving video sensor (549) that detects a smoke plume or flame.

8. The method of claim 1 further comprising receiving data from a structured light triangulation system component that detects backscatter from smoke.

9. The method of claim 1, further comprising receiving data from a Light Detection and Ranging (LiDAR) system component (104) that detects backscatter from smoke.

10. The method of claim 1, further comprising receiving data from a thermal imaging component (107) that detects a temperature of the object.

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