Patent Publication Number: US-2023138573-A1

Title: Non-coaxial systems, methods, and devices for detecting smoke

Description:
TECHNICAL FIELD 
     The present disclosure relates to non-coaxial methods, devices, and systems for detecting smoke. 
     BACKGROUND 
     Smoke detection methods, devices, and systems can be implemented in indoor environments (e.g, buildings) or outdoor environments to detect smoke. As an example, a Light Detection and Ranging (LiDAR) smoke detection system can utilize optical systems, such as laser beam emitters and light receivers, to detect smoke in an environment. Smoke detection can minimize risk by alerting users and/or other components of a fire control system of a fire event occurring in the environment. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    illustrates a system for detecting smoke in accordance with an embodiment of the present disclosure. 
         FIG.  2    illustrates a system for detecting smoke in accordance with an embodiment of the present disclosure. 
         FIG.  3    illustrates a system for detecting smoke in accordance with an embodiment of the present disclosure. 
         FIG.  4    illustrates a method for detecting smoke in accordance with an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Non-coaxial methods, devices, and systems for detecting smoke are described herein. One or more embodiments include a laser emitter configured to emit a laser beam, and a light receiver. The light receiver may comprise a first receiver lens, wherein a field of view of the first receiver lens includes at least a portion of the laser beam. The light receiver may also comprise a second receiver lens, wherein a field of view of the second receiver lens includes at least a portion of the laser beam and a region between an edge of the field of view of the first receiver lens and the laser emitter. 
     Certain smoke detection systems may use laser beam emitters in conjunction with light receivers to detect smoke. For example, a smoke detection system may use Light Detection and Ranging (LiDAR) technology to detect smoke. For instance, when a laser beam is emitted in an indoor environment, it may encounter an object, substance, or material and light may be reflected and/or scattered to the light receiver. If no object, substance, or material is present in the path of the laser, the light will instead reflect and/or scatter off a wall of the indoor environment and back to the light receiver. The smoke detection system can determine the difference between a received light signal that has been reflected and/or scattered off a wall or light reflected off another object, substance, or material, because the intensity of the received light signal will be considerably greater if it has been reflected and/or scattered off a wall as opposed to reflecting and/or scattering off a substance such as smoke. Additionally, a light signal that has passed through smoke will be slightly attenuated. 
     As such, by rotating a laser beam emitter and light receiver of a smoke detection system and emitting pulses of light from the laser beam emitter, an indoor environment can be scanned to detect smoke. For example, such a system may be positioned in a corner of a room and rotated from zero to ninety degrees to scan the entire room for smoke. By recording the alignment, position, and orientation of the smoke detection system at the time that the smoke is detected, the approximate location of the smoke can also be determined. 
     In previous approaches, the components of a LiDAR smoke detection system (e.g., the laser beam emitter and the light receiver) may be co-axial (e.g., colinear) Making the path of the outgoing light beam and the light receiver of such a system co-axial can eliminate blind spots in the detection system (e.g., areas in which the detection system may be unable to detect the presence of smoke) that may occur if the light beam and light receiver were not co-axial. However, such co-axial configurations can be optically complex, costly, and time-consuming to manufacture. 
     Embodiments of the present disclosure, however, can improve the field of view of such smoke detection systems and devices, and therefore reduce or eliminate any blind spots of the system, without the need for the emitter(s) and receiver(s) to be co-axial. Thus, embodiments of the present disclosure can ease the complexity, manufacturing constraints and costs of smoke detection systems and devices while maintaining a complete field of view (e.g., reducing or eliminating blind spots) for the smoke detection system or device. 
     In some examples, one or more embodiments include a smoke detection system comprising a laser emitter configured to emit a laser beam, and a light receiver. The light receiver may comprise a first receiver lens, wherein a field of view of the first receiver lens includes at least a portion of the laser beam. The light receiver may further comprise a second receiver lens, wherein a field of view of the second receiver lens includes at least a portion of the laser beam and includes a region between an edge of the field of view of the first receiver lens and the laser emitter. 
     In some examples, one or more embodiments may include a smoke detection system, comprising a laser emitter configured to emit a laser beam, a LiDAR receiver, and a processor. The LiDAR receiver may comprise a first receiver lens, wherein a field of view of the first receiver lens includes at least a portion of the laser beam. The LiDAR receiver may also include a second receiver lens, wherein a field of view of the second receiver lens includes at least a portion of the laser beam and includes a region between an edge of the field of view of the first receiver lens and the laser emitter. The processor may be configured to detect smoke based on light received by the LiDAR receiver. 
     In some examples, one or more embodiments may include a method of detecting smoke, comprising emitting a laser beam from a laser beam emitter while rotating the laser beam emitter and positioning a light receiver such that the light receiver is non-coaxial with the laser beam. The light receiver may comprise a first receiver lens, wherein a field of view of the first receiver lens includes at least a portion of the laser beam. The light receiver may also comprise a second receiver lens, wherein a field of view of the second receiver lens includes at least a portion of the laser beam and includes a region between an edge of the field of view of the first receiver lens and the laser emitter In the following detailed description, reference is made to the accompanying drawings that form a part hereof. The drawings show by way of illustration how one or more embodiments of the disclosure may be practiced. 
     These embodiments are described in sufficient detail to enable those of ordinary skill in the art to practice one or more embodiments of this disclosure. It is to be understood that other embodiments may be utilized and that process, electrical, and/or structural changes may be made without departing from the scope of the present disclosure. 
     As will be appreciated, elements shown in the various embodiments herein can be added, exchanged, combined, and/or eliminated so as to provide a number of additional embodiments of the present disclosure. The proportion and the relative scale of the elements provided in the figures are intended to illustrate the embodiments of the present disclosure and should not be taken in a limiting sense. 
     The figures herein follow a numbering convention in which the first digit or digits correspond to the drawing figure number and the remaining digits identify an element or component in the drawing. Similar elements or components between different figures may be identified by the use of similar digits. For example, 101 may reference element “01” in  FIG.  1   , and a similar element may be referenced as 201 in  FIG.  2   . 
     As used herein, “a”, “an”, or “a number of” something can refer to one or more such things, while “a plurality of” something can refer to more than one such things. For example, “a number of components” can refer to one or more components, while “a plurality of components” can refer to more than one component. Additionally, the designator “N”, as used herein particularly with respect to reference numerals in the drawings, indicates that a number of the particular feature so designated can be included with a number of embodiments of the present disclosure. This number may be the same or different between designations. 
     As described herein, a fire control system may be any system designed to detect and/or provide a notification of fire events. For example, a fire control system may include smoke detection systems and/or devices (e.g., systems  100  and  200 ) that can sense a fire occurring in the facility, alarms (e.g., speakers, strobes, etc.) that can provide a notification of the fire to the occupants of the facility, fans and/or dampers that can perform smoke control operations (e.g., pressurizing, purging, exhausting, etc.) during the fire, and/or sprinklers that can provide water to extinguish the fire, among other components. A fire control system may also include a control unit such as a physical fire control panel (e.g., box) installed in the facility that can be used by a user to directly control the operation of the components of the fire control system. In some embodiments, the fire control system can include a non-physical control unit or a control unit located remotely from the facility. 
     As used herein, the terms “light” or “beam” can include any type of light beam, such as a laser. These terms can also include pulses of light. 
     As used herein, the term “emitter” or “light emitter” can be any device, system, or apparatus configured to emit light. The light emitted can be pulses, such as pulses of lasers. A “light emitter” may be, for example, a LiDAR transmitter. 
     As used herein, the term “light receiver” can be used to describe any sensor, detector, lens, or combination thereof configured to receive light and/or to convert light into a form that is readable by an instrument. A “light receiver” may be, for example, a LiDAR receiver or an electro-optical sensor. In some embodiments, a light receiver may include a clock or processing resources. The light receiver may be configured to measure the time taken for a pulse of light to travel from an emitter, reflect and/or scatter off an object, substance, or material, and travel back to the receiver. 
     As used herein, the term “reflected” may be used to refer to light that is not only reflected but may be reflected and/or scattered. For example, the light may be reflected off a surface at an angle of incidence equaling the angle of reflection. Light that is incident on a surface or material can also be scattered in a multitude of directions in accordance with embodiments of the present disclosure. 
       FIG.  1    illustrates a system  100  for detecting smoke  117  in accordance with an embodiment of the present disclosure. As shown in  FIG.  1   , the system  100  may include a light emitter  101  configured to emit a beam  103 . For example, the light emitter  101  may be a laser emitter, and the beam  103  may be a laser beam. In some embodiments, the light emitter  101  may be a photodiode or a laser diode. Although the beam  103  is illustrated in  FIG.  1    as a single beam of light, in some embodiments, the light emitter  101  may emit pulses of light. For example, the light emitter  101  may emit a beam  103  at a particular time interval. 
     As illustrated in  FIG.  1   , the beam  103  may illuminate smoke  117 . The smoke  117  (e.g., the presence of the smoke) may be detected by the system  100  when the light forming the beam  103  is reflected from the smoke  117  to a light receiver  105  of system  100 . The light receiver  105  may be configured to receive reflected light as a result of the beam  103  encountering an object, substance, or material (e.g., smoke  117 ). In some embodiments, the light receiver  105  may be, for example, a LiDAR receiver (e.g., a LiDAR sensor). 
     Although not illustrated in  FIG.  1    for clarity and so as not to obscure embodiments of the present disclosure, the system  100  may also include a processor configured to detect smoke based on light received through the light receiver  105 . For instance, the processor may determine whether reflected light indicates the presence of smoke. The processor may do so, for example, by measuring and analyzing the intensity of reflected light received by the receiver  105 . If the intensity of the reflected light is below a certain level, the processor may determine that smoke  117  is present. For example, the processor may compare the intensity level of the reflected light to that which would be expected for light reflected against a wall or another hard object; if the comparison indicates the intensity level of the reflected light is less than the expected intensity, the processor can determine that smoke  117  is present. 
     The processor may also determine the location of the smoke  117 . For example, the processor may be able to determine the location (e.g., the exact location) of the smoke  117  with respect to the light receiver  105  by measuring the amount of time between when the laser beam  103  pulse was emitted and when the reflected light was received by the light receiver  105 . 
     The processor may also be configured to then take an action in response to detecting smoke. For example, although not illustrated in  FIG.  1    for clarity and so as not to obscure embodiments of the present disclosure, upon detecting smoke, the processor may be configured to transmit a signal to a cloud, control panel, central monitoring system, user, or other device of a fire control system indicating the smoke has been detected. The processor may also be configured to transmit data, such as motion of the emitter  101  and/or location of the smoke  117 , to any of the foregoing examples. Data may be transmitted from the processor with a unique identifier for the environment (e.g., a room) in which the system  100  is located. The processor may have embedded software for analyzing and transmitting data and/or for detecting smoke  117 . 
     The light receiver may include a first (e.g., primary) receiver lens  107  and a second (e.g., secondary) receiver lens  109 . The primary receiver lens  107  and the secondary receiver lens  109  may be, for example, Fresnel lenses. In some embodiments, the sizes of lenses  107  and  109  may be proportional to the size of the area to be monitored for smoke (e.g., the larger the area to be monitored for smoke, the greater the sizes of lenses  107  and  109 ). The secondary receiver lens  109  may be designed to collect light reflected from smoke  117  that is much closer to detector system  100  than light reflected from smoke that is further away from detector system  100  and within the field of view of the primary receiver lens  107 . Accordingly, the secondary receiver lens  109  may be significantly smaller in size than the primary receiver lens  107 . 
     In some embodiments, the primary receiver lens  107  may be a Fresnel lens of, for example, 90-110 mm in diameter. One or both receiver lenses  107  and  109  may be molded from clear plastic. The receiver lenses  107  and  109  may be disc-shaped with multiple concentric, grooved rings. This may allow the receiver lenses  107  and  109  to collect light and direct it to a photo-sensitive element within the light receiver  105 . In some embodiments, the secondary receiver lens  109  may be constructed by molding a small part of the primary receiver lens  107  at an angle to the remainder of the receiver lens  107 . This would effectively make the secondary lens  109  a smaller lens within the primary receiver lens  107 . 
     As shown in  FIG.  1   , the light emitter  101  and the light receiver  105  may be non-coaxial. For example, light emitter  101  may be positioned at an angle with respect to light receiver  105 , and the laser beam  103  emitted by light emitter  101  and the fields of view  111  and  113  of the primary and secondary receiver lenses  107  and  109 , respectively, may not be parallel, as illustrated in  FIG.  1   . As such, although the field of view  111  of the primary receiver lens  107  may include at least a portion of the beam  103  (e.g., field of view  111  partially overlaps the beam  103 ), a portion of beam  103  may be outside field of view  111  but not outside field of view  113 , such that the beam  103  may also illuminate smoke  117  that is positioned outside of the field of view  111  of the primary receiver lens  107 , but is not outside the field of view  113  of secondary receiver lens  109 . 
     In some embodiments, the secondary receiver lens  109  may be attached to the primary receiver lens  107 . For example, the secondary receiver lens  109  may be molded within the primary receiver lens  107 . Further, the secondary receiver lens  109  may be positioned at an angle with respect to the primary receiver lens  107 . As such, the field of view  111  of the primary receiver lens  107  may differ from the field of view  113  of the secondary receiver lens. Accordingly, the secondary receiver lens  109  may expand an overall field of view of the light receiver  105 . 
     The field of view  113  of the secondary receiver lens  109  may at least partially overlap with the field of view  111  of the primary receiver lens  107 . The field of view  113  of the secondary receiver lens  109  may include at least a portion of the beam  103 . For instance, field of view  112  may include portions of the beam  103  that may not be within the field of view  111  of the primary receiver lens  107 . Furthermore, the field of view  113  of the secondary receiver lens  109  may include (e.g., cover) a region  115  between an edge  111 - 1  of the field of view  111  of the primary receiver lens  107  and light emitter  101 . The edge  111 - 1  may be between the laser beam  103  and the second receiver lens  109 . Accordingly, the combined fields of view  111  and  113  of the primary and secondary receiver lenses, respectively, may capture the entire, or nearly the entire, beam  103 . 
     The angle at which the primary receiver lens  107  is positioned with respect to the secondary receiver lens  109  may correspond to how much of beam  103  can be captured. This angle may be determined based on, for example, a distance between the emitter  101  and the receiver  105 , an angle of the beam  103  with respect to the field of view  111  of the primary receiver lens  107 , and/or an angle of the field of view  113  (e.g., angle of view) of the secondary receiver lens  109 . 
     Although not shown in  FIG.  1   , the system  100  may include a rotation device configured to rotate the light emitter  101 . The rotation device may be mechanical or electrical. It may be configured to rotate the light emitter  101  at a given speed and/or over a given range. For example, if the system  100  is set up in the corner of a room, the rotation device may rotate the light emitter  101  from 0 degrees to 90 degrees. If the emitter  101  emits pulses such as beam  103  periodically as the rotation device moves, the system  100  may be able to scan an entire room or region for smoke such as smoke  117 . The rotation device may rotate the receiver  105  and the light emitter  101  together. 
       FIG.  2    illustrates a system  200  for detecting smoke in accordance with an embodiment of the present disclosure. Some portions and/or elements of smoke detection system  200  can be analogous to smoke detection system  100  as shown and described in connection with  FIG.  1   . For example, field of view  211 , and field of view edge  211 - 1 , of primary receiver lens  207  can be analogous to field of view  111 , and filed of view edge  111 - 1 , respectively, of primary receiver lens  107  previously described in connection with  FIG.  1   . However, rather than a single light emitter (e.g., as shown in  FIG.  1   ), smoke detection system  200  may include multiple light emitters  201 - 1  and  201 - 2 , wherein each light emitter  201 - 1  and  201 - 2  emits a different beam (laser beams  203 - 1  and  203 - 2 , respectively). Each light emitter  201 - 1  and  201 - 2  may be positioned on an opposite side of light receiver  205 , wherein the light receiver  205  is configured to receive light reflected by the beams  203 - 1  and  203 - 2  off of objects, substances, and materials, such as smoke  217 - 1  and  217 - 2 . 
     Further, the light receiver  205  of the smoke detection system  200 , rather than including a primary receiver lens and a single secondary receiver lens (e.g., as shown in  FIG.  1   ), can include a primary receiver lens  207  and a number of secondary receiver lenses  209 - 1  and  209 - 2 . Secondary receiver lens  209 - 2  can ensure that smoke, such as smoke  217 - 2 , can still be detected, even if it is outside of the fields of view  211  and  213 - 1  of the primary receiver lens  207  and other secondary receiver lens  203 - 1 , and the emitter  201 - 2  can be non-coaxial with the light receiver  205 . 
     In some embodiments, the emitter  201 - 2  can be positioned outside of the region  215  between the first edge  211 - 1  of the field of view  211  of the primary receiver lens and emitter  201 - 1 . The field of view  213 - 2  of the emitter  201 - 2  can include at least a portion of the beam  203 - 2  emitted by the emitter  201 - 2 . Additionally, the field of view  211  of receiver lens  207  may include at least a portion of the beam  203 - 2 . 
     Secondary receiver lens  209 - 2  can have a field of view  213 - 2  which includes a region  221  between an edge  211 - 2  of the field of view  211  of the primary receiver lens  207  and the emitter  201 - 2 . This can allow additional smoke, such as smoke  217 - 2 , that is located outside the field of view  211  of the primary receiver lens  207  and the field of view  213 - 1  of the other secondary receiver lens  209 - 1  to be detected. 
       FIG.  3    illustrates a system  300  for detecting smoke in accordance with an embodiment of the present disclosure. System  300  may include a light emitter  301  which is configured to emit a beam  303  and positioned vertically above or below a light receiver  305 . The beam  303  may illuminate smoke  317 . However, all of or a portion of the beam  303  may be outside of the field of view of the light receiver  305  (e.g., field of view  111  shown in  FIG.  1    and field of view  211  shown in  FIG.  2   ). As such, the light receiver may include a first receiver lens  307  and a second receiver lens  309 . The second receiver lens  309  may be positioned at an angle with respect to the primary receiver lens  307  such that the field of view  313  of the second receiver lens overlaps with portions of the beam  303  that do not overlap with the field of view of the first receiver lens  307 . 
       FIG.  4    illustrates a method  400  for detecting smoke (e.g., smoke  217 - 1  and  217 - 2  in  FIG.  2    and/or  117  in  FIG.  1   ) in accordance with an embodiment of the present disclosure. As illustrated in  FIG.  4   , method  400 , at block  402 , may include emitting a laser beam (e.g., beam  103  and/or  203  of  FIGS.  1  and  2   , respectively) from a laser beam emitter (e.g., emitters  101  and/or  201 - 1  and  201 - 2  of  FIGS.  1  and  2   , respectively). Further, the beam can be emitted while rotating the laser beam emitter. For example, the laser beam emitter may be rotated with a range of motion appropriate to scan an entire room for smoke, based on the positioning of the laser beam emitter within that room. This may include, for example, rotating the emitter between 0 and 90 degrees, between 90 and 180 degrees, or between 0 and 180 degrees. 
     At block  404 , method  400  may include positioning a light receiver (e.g., light receivers  105  and/or  205  of  FIGS.  1  and  2   , respectively) such that the light receiver is non-coaxial with the path of the laser beam. In some embodiments, the light receiver may comprise a primary receiver lens (e.g., lens  107  and  207 ) and a secondary receiver lens (e.g., lens  109 ,  209 - 1 , and  209 - 2 ), as previously described herein. The field of view (e.g., field of view  111  and  211 ) of the primary receiver lens may include at least a portion of the laser beam, as previously described herein. The field of view (e.g., field of view  113 ,  213 - 1 , and  213 - 2 ) of the secondary receiver lens may also include another portion of the laser beam, and a region (e.g., regions  115 ,  215  and  221 ) between an edge (e.g., edge  111 - 1 ,  211 - 1 , and  211 - 2 ) of the field of view of the primary receiver lens and the laser emitter, as previously described herein. 
     At block  406 , method  400  may include illuminating smoke via the laser beam. This illumination may occur when the path of the laser beam intersects with the smoke. 
     At block  408 , method  400  may include detecting the smoke via light reflected from the smoke to the light receiver. For example, the light may be received by the light receiver via the primary receiver lens and/or the secondary receiver lens. For instance, at least a portion of the smoke may be positioned within the field of view of the secondary receiver lens. The smoke may be detected by measuring the intensity of the light received by the light receiver and comparing that intensity to an expected intensity for smoke, as previously described herein. If smoke is detected, the method can also include transmitting a signal indicating the presence of the smoke to at least one of another device within a fire control system, a fire control panel, a central monitoring station, a cloud, or a user, as previously described herein. 
     Although specific embodiments have been illustrated and described herein, those of ordinary skill in the art will appreciate that any arrangement calculated to achieve the same techniques can be substituted for the specific embodiments shown. This disclosure is intended to cover any and all adaptations or variations of various embodiments of the disclosure. 
     It is to be understood that the above description has been made in an illustrative fashion, and not a restrictive one. Combination of the above embodiments, and other embodiments not specifically described herein will be apparent to those of skill in the art upon reviewing the above description. 
     The scope of the various embodiments of the disclosure includes any other applications in which the above structures and methods are used. Therefore, the scope of various embodiments of the disclosure should be determined with reference to the appended claims, along with the full range of equivalents to which such claims are entitled. 
     In the foregoing Detailed Description, various features are grouped together in example embodiments illustrated in the figures for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the embodiments of the disclosure require more features than are expressly recited in each claim. 
     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.