Patent Description:
Detectors, such as sensors and imagers, are commonly used to monitor protected spaces for the presence of flame or gas. Sensors, such as mid-wave infrared non-imaging sensors, generally employ two or more sensor components with a common field of view which have filters tuned to admit electromagnetic radiation within different portions of the mid-wave infrared waveband, i.e., wavelengths between about <NUM> microns and about <NUM> microns. In flame detection applications, data from the sensors is analyzed to determine whether a flame is emitting electromagnetic radiation within one or more of the portions of the mid-wave infrared waveband admitted to the sensors by the spectral filters. In gas detection applications, data from the sensors is analyzed to determine whether gas within the common field of view of the sensor is absorbing electromagnetic radiation within one or more of the portions of mid-wave infrared waveband admitted to the sensors by the spectral filters. Such sensors are generally unable to spatially locate the flame or gas within the field of view of the sensor.

Imagers, such as visible, ultraviolet, or infrared imagers, generally employ a focal plane array sensitized to generate image data using electromagnetic radiation within their respective wavebands, (i.e. the visible waveband, with wavelengths from about <NUM> to <NUM> microns, the ultraviolet waveband, from between about <NUM> nanometers and about <NUM> nanometers, or the near-infrared, short-wave-infrared, mid-infrared, or long-infrared wavebands, with wavelengths between about <NUM> to <NUM> microns, about <NUM> to <NUM> microns, about <NUM> to <NUM> microns, and about <NUM> to <NUM> microns, respectively. ) In flame detection applications the image data is analyzed to determine whether a flame within the field of view of the imaging sensor is emitting electromagnetic radiation in the waveband to which the focal plane array is sensitized. In gas detection applications the image data is analyzed to determine whether gas within the field of view of the sensor is absorbing electromagnetic radiation in the waveband to which the focal plane array is sensitized. Imagers can be prone to false alarms and/or can have difficulty discerning certain flames or gases within the field of view of the imager. However, imagers of different types have different strengths for discerning various flame or gas types under various conditions. For example, a visible imager may have difficulty discerning translucent flames, whereas an infrared imager may discern such flames more easily.

Such systems and methods have generally been acceptable for their intended purpose. However, there remains a need for improved flame and gas detectors, methods of flame and gas detection, and algorithms for detecting and validating the presence of flame or gas in a scene of interest, in order to reduce the risk of false alarm events as well as provide greater reliability than current flame or gas detectors. <CIT> discloses an optical detector capable of converting the output from a video camera to a format compatible for combination with the output from a number of detectors. <CIT> discloses an array-based sensor for a flame detection apparatus capable of both imaging and measuring the intensity of radiation. <CIT> discloses a video camera configured to adjust its rate of data capture and evaluation based on signals from a number of detectors. <CIT> discloses a video recognition system for detecting the presence of fire, wherein an alarm is suppressed or triggered based on the application of rules associated with acceptable regions within the field of view of the video detector.

A flame or gas detection method is provided and defined by claim <NUM>. A flame or gas detection method includes determining non-imaging sensor system detection state for a scene of interest, determining an imaging sensor system detection state for the scene of interest, and validating one of the non-imaging sensor system detection state and the imaging sensor system detection state with the other of the non-imaging sensor system detection state and the imaging sensor system detection state. A flame or gas detecting system detection state is then indicated at a user interface including the validated one of the non-imaging sensor system detection state and the imaging system detection state. Determining the imaging sensor system detection state includes receiving image data from an imaging sensor for the scene of interest; receiving imaging sensor system reference data for the scene of interest; receiving an imaging sensor system keep-out definition for the scene of interest, the keep-out definition demarcating image data frames of the image data into a frame region where flame indication is eligible for determining the flame or gas detection state and frame regions where flame indication is ineligible for determining the flame or gas detection state, the frame regions where flame indication is ineligible for determining the flame or gas detection state being unmonitored; and determining the imaging sensor system detection state based on the image data from the imaging sensor, the imaging sensor system reference data, and the imaging sensor system keep-out definition for the scene of interest.

Optionally, further embodiments of the flame or gas detection method may include that determining the non-imaging sensor system detection state includes receiving non-imaging sensor data for the scene of interest; receiving non-imaging sensor system reference data for the scene of interest; and determining the non-imaging sensor system detection state based on the non-imaging sensor data and the non-imaging sensor system reference data for the scene of interest.

Optionally, further embodiments of the flame or gas detection method may include that generating the non-imaging sensor data from electromagnetic radiation incident on a non-imaging sensor in a mid-wave infrared waveband or an ultraviolet waveband.

Optionally, further embodiments of the flame or gas detection method may include that receiving a non-imaging sensor system health state, wherein the validating one of the non-imaging sensor system detection state and the imaging sensor system detection state with the other of the non-imaging sensor system detection state and the imaging sensor system detection state is based on the non-imaging sensor system health state.

Optionally, further embodiments of the flame or gas detection method may include that generating the image data from electromagnetic radiation incident on an imaging sensor in an infrared waveband or a visible light waveband.

Optionally, further embodiments of the flame or gas detection method may include that validating one of the non-imaging sensor system detection state and the imaging sensor system detection state with the other of the non-imaging sensor system detection state and the imaging sensor system detection state is based on the imaging sensor system keep-out definition for the scene of interest.

Optionally, further embodiments of the flame or gas detection method may include that validating one of the non-imaging sensor system detection state and the imaging sensor system detection state with the other of the non-imaging sensor system detection state and the imaging sensor system detection state is based on the imaging sensor system health state.

Optionally, further embodiments of the flame or gas detection method may include that the non-imaging sensor system detection state and the imaging sensor detection state are a non-imaging sensor system flame detection state and an imaging sensor system flame detection state.

Optionally, further embodiments of the flame or gas detection method may include that the non-imaging sensor system detection state and the imaging sensor system detection state are a non-imaging sensor system gas detection state and an imaging sensor system gas detection state.

A flame or gas detection system is also provided and defined by claim <NUM>. A flame or gas detection system includes a non-imaging sensor system with a non-imaging sensor field of view including a scene of interest; an imaging sensor system with an imaging sensor field of view including the scene of interest; and a processor. The processor is disposed in communication with the non-imaging sensor system, the imaging sensor system, and a memory having instructions recorded on the memory that, when executed by the processor, cause the processor to determine a non-imaging sensor system detection state for the scene of interest; determine an imaging sensor system detection state for the scene of interest; validate one of the non-imaging sensor system detection state and the imaging sensor system detection state with the other of the non-imaging sensor system detection state and the imaging sensor system detection state; and indicate, at a user interface operatively associated with the processor, a flame or gas detection system detection state comprising the validated one of the non-imaging sensor system detection state and the imaging sensor system detection state. Determining the imaging sensor system detection state includes receiving image data from an imaging sensor for the scene of interest; receiving imaging sensor system reference data for the scene of interest; receiving an imaging sensor system keep-out definition for the scene of interest, the keep-out definition demarcating image data frames of the image data into a frame region where flame indication is eligible for determining the flame or gas detection state and frame regions where flame indication is ineligible for determining the flame or gas detection state, the frame regions where flame indication is ineligible for determining the flame or gas detection state being unmonitored; and determining the imaging sensor system detection state based on the image data from the imaging sensor, the imaging sensor system reference data, and the imaging sensor system keep-out definition for the scene of interest.

Optionally, further embodiments of the flame or gas detection system may include that the instructions further cause the processor to determine the non-imaging sensor system detection state by receiving non-imaging sensor data from a non-imaging sensor for the scene of interest; receiving non-imaging sensor reference data for the scene of interest; and determining the non-imaging sensor system detection state based on the non-imaging sensor data and the non-imaging sensor reference data for the scene of interest.

Optionally, further embodiments of the flame or gas detection system may include that the non-imaging sensor is a mid-wave infrared waveband sensor or an ultraviolet waveband sensor.

Optionally, further embodiments of the flame or gas detection system may include that the instructions further cause the processor to receive a non-imaging sensor system health state, wherein the processor validates the one of the non-imaging sensor system detection state and the imaging sensor system detection state with the other of the non-imaging sensor system detection state and the imaging sensor system detection state based on the non-imaging sensor system health state.

According to the independent claim, the flame or gas detection system includes that the instructions further cause the processor to determine an imaging sensor system detection state by receiving image data from an imaging sensor for the scene of interest; receiving an imaging sensor system keep-out definition for the scene of interest; and receiving imaging sensor system reference data for the scene of interest, the imaging sensor system detection state based on the image data from the imaging sensor, the imaging sensor system keep-out definition, and the imaging sensor system reference data for the scene of interest.

Optionally, further embodiments of the flame or gas detection system may include that the imaging sensor system includes one of an infrared waveband imaging sensor and a visible light waveband imaging sensor.

Optionally, further embodiments of the flame or gas detection system may include that the processor to validate the imaging system detection state based on an imaging sensor system keep-out definition of the scene of interest.

Optionally, further embodiments of the flame or gas detection system may include that the instructions further cause the processor to receive an imaging sensor system health state and validate the imaging sensor system detection state with the imaging sensor system health state.

Optionally, further embodiments of the flame or gas detection system may include that the non-imaging sensor system is a mid-wave infrared non-imaging sensor system, and further comprising an ultraviolet non-imaging sensor system operatively associated with the processor.

Optionally, further embodiments of the flame or gas detection system may include that the imaging sensor system is an infrared imaging sensor system, and further comprising a visible waveband imaging sensor system operatively associated with the processor.

A computer program product is also provided and defined by claim <NUM>. The computer program product is tangibly embodied on a computer readable medium, the computer program product including instructions that cause the processor to perform operations including performing algorithms to determine a non-imaging sensor detection state for a scene of interest; performing algorithms to determine an imaging sensor detection state for the scene of interest; validating the one of the non-imaging sensor detection state and the imaging sensor detection state with the other of the non-imaging sensor detection state and the imaging sensor detection state; and indicating, at a user interface, a system detection state comprising the one of the non-imaging sensor detection state and the imaging sensor detection state. Performing algorithms to determine the imaging sensor system detection state includes receiving image data from an imaging sensor for the scene of interest; receiving imaging sensor system reference data for the scene of interest; receiving an imaging sensor system keep-out definition for the scene of interest, the keep-out definition demarcating image data frames of the image data into a frame region where flame indication is eligible for determining the flame or gas detection state and frame regions where flame indication is ineligible for determining the flame or gas detection state, the frame regions where flame indication is ineligible for determining the flame or gas detection state being unmonitored; and determining the imaging sensor system detection state based on the image data from the imaging sensor, the imaging sensor system reference data, and the imaging sensor system keep-out definition for the scene of interest.

Technical effects of the present disclosure include the capability to detect and validate the presence of flame or gas within a scene of interest using both non-imaging and imaging sensor data. In certain examples the present disclosure provides the capability to detect flame or gas to be detected within the scene of interest using sensor data with spatial specificity. In accordance with certain examples the present disclosure provides the capability to detect flame or gas within the scene of interest using sensor data with spatial specificity and validation. Technical effects additionally include the capability to detect flame or gas within the scene of interest using non-imaging and/or imaging sensor data according to location, e.g., within a keep-in region or a keep-out region of the scene of interest, of the flame or gas within the scene of interest.

The following descriptions of the drawings are by way of example only and should not be considered limiting in any way.

Reference will now be made to the drawings wherein like reference numerals identify similar structural features or aspects of the subject disclosure. For purposes of explanation and illustration, and not limitation, a partial view of an example implementation of a flame or gas detector constructed in accordance with the disclosure is shown in <FIG> and is designated generally by reference character <NUM>. Other embodiments of flame or gas detectors, flame or gas detection methods, and flame or gas detection algorithms, in accordance with the present disclosure, or aspects thereof, are provided in <FIG>, as will be described. The systems and methods described herein can be used for detecting and validating the presence of flame or gas in a scene of interest using both non-imaging sensor data and imaging data, such as from non-imaging sensor data and imaging data acquired from within a structure like a hanger, though the present disclosure is not limited to hangers or to stationary structures in general.

Flame or gas detection is typically accomplished using either non-imaging sensors or imaging sensors. Non-imaging sensors generally employ two or more non-imaging sensor components spectrally filtered to different sub-bands, e.g., within a mid-wave infrared waveband between about <NUM> microns and about <NUM> microns, and which output signals indicative of electromagnetic radiation within the different sub-bands. The signals output by such non-imaging sensors generally of indicate a detection state of the non-imaging sensor, i.e., whether the imaging sensor detects flame or gas and/or whether the imaging sensor does not detect flame or gas By spectrally tuning one or more of the sub-bands to include wavelengths where flame emits electromagnetic radiation (or gas absorbs electromagnetic radiation) such non-imaging sensors can generate signals containing information indicative of whether flame or gas is present within a scene. In the case of non-imaging sensors like thermopiles or pyroelectrics, strength of the signal generated by the sensors can be compared to a threshold known in the art to indicate the likely presences of flame or gas, and presence of flame or gas reported when the signal strength crosses the threshold.

Additionally, flame and gas typically do not present as constant, static phenomena, but rather fluctuate in intensity, and thus the detectable radiation (through emission or absorption) associated with the flame or gas also fluctuates over time within known frequency ranges over time, i.e. "flickers". Thus, the signal strength generated by the sensors can over time can be analyzed in the time/frequency domain, e.g., using flicker analysis, and presence of flame or gas reported when the time/frequency analysis indicates that flame or gas is present in the scene. While such non-imaging sensors are generally reliable, such non-imaging sensors are generally unable to provide sufficient spatial specificity to distinguish radiation absorption/emission sources generated in an area of interest from those adjacent to an area of interest, and therefore detection systems employing non-imaging sensors can generate false alarms - such as when a heat source like an engine moves in front of (or through) the scene of interest being monitored by the non-imaging sensor.

Imaging sensors, such as infrared imaging sensors and visible light (VL) imaging sensors, generally employ a camera-type device to discriminate between flame and non-flame sources in a scene of interest for purposes of providing a detection state, i.e., whether the imaging sensor detects flame or gas and/or whether the imaging sensor does not detect flame or gas. For example, infrared cameras can generate image data using electromagnetic radiation received within the infrared portion of the electromagnetic spectrum, and visible light cameras can generate image data using electromagnetic radiation received within the visible portion of the electromagnetic spectrum. Infrared images can be constructed from the infrared image data, visible images can be constructed from the visible light image data, and the infrared images and visible light images analyzed, e.g., using thresholding and/or with time/frequency analysis, to determine both whether flame or gas is present in the scene and, when flame or gas is present in the infrared image and/or visible light image, location of the flame or gas within the scene of interest. Such infrared and visible light imaging sensors are generally able to indicate flame or gas within a scene with some degree of confidence. However, some flame types and conditions can present challenges to such cameras, for example, due to flame translucency within the spectral bandpass of the imaging sensor and/or non-flame sources of electromagnetic energy within wavelengths of the spectral bandpass of the imaging sensor that may resemble flames.

As shown schematically in the exemplary flame/gas detector shown in <FIG>, the flame or gas detector <NUM> is configured to detect a flame <NUM> or a gas <NUM> within a scene of interest <NUM>, such as a hangar, using non-imaging sensor detection state(s) <NUM> and imaging sensor detection state(s) <NUM>. The flame or gas detector <NUM> generally includes a controller <NUM> which in turn includes a computer program product <NUM> having instructions that, when read by a processor, e.g., the processor <NUM>, cause the processor to perform operations including (a) determining the non-imaging sensor detection state(s) <NUM>, (b) determining the imaging sensor detection state(s) <NUM>, (c) deconflicting and validating one or more of the non-imaging sensor detection state(s) <NUM> and the imaging sensor detection state(s) <NUM> against the other of the detection states <NUM> and <NUM>, and (d) indicating a system flame or gas detection state <NUM> that includes a validated detection state at a user interface <NUM>, which may include a display and an input, examples may include a screen, a keyboard, touchscreen, joystick or mouse, and may also include audio output such as a speaker or sounder. Although the system flame or gas detection state <NUM> is shown as indicated at the user interface <NUM> it is to be understood and appreciated that the system flame or gas detection state <NUM> can be indicated other ways, like a signal communicated through a device interface, and remain within the scope of the present disclosure. Further, although shown and described herein in the context of a flame or gas detector <NUM> employed monitoring a scene of interest including a hanger, it is to be understood and appreciated that flame or gas detectors employed in other fixed structures, in defined outdoor spaces, and in vehicles can also benefit from the present disclosure.

In the example shown in <FIG> the flame or gas detector <NUM> includes a non-imaging sensor system <NUM>, an imaging system <NUM>, a controller <NUM>, and a link <NUM>. The link <NUM> may consist of one or more communication device(s) which may communicate using similar or different methods and/or protocols of communication, but for purposes of simplicity is referred to here as a singular communicative arrangement. It is contemplated that the link <NUM> can be a wired link or a wireless link, as suitable for an intended application. The link <NUM> communicatively connects the non-imaging sensor system <NUM> with the controller <NUM>. The link <NUM> also communicatively connects the imaging system <NUM> with the controller <NUM>. In certain examples the link <NUM> also communicatively connects the non-imaging sensor system <NUM> with the imaging system <NUM>.

The non-imaging sensor system <NUM> includes one or more non-imaging sensor(s) <NUM>. The non-imaging sensor(s) <NUM> have a non-imaging sensor field of view <NUM> and are configured to generate non-imaging sensor data <NUM> of a scene of interest within the sensor field of view <NUM>, e.g., the scene of interest <NUM>, the non-imaging sensor data <NUM> lacking positional information. The non-imaging sensor system <NUM> is operatively connected to the non-imaging sensor(s) <NUM> and is in turn configured to determine the sensor detection state(s) <NUM> using the non-imaging sensor data <NUM>. In certain examples the non-imaging sensor(s) <NUM> include an ultraviolet sensor. In accordance with certain examples the non-imaging sensor(s) <NUM> include a mid-wave infrared spectral (MWIR) sensor.

The imaging system <NUM> includes one or more imaging sensor(s) <NUM>. The imaging sensor(s) <NUM> have an imaging sensor field of view <NUM> and are configured to generate imaging sensor data <NUM> including position information of a scene of interest within the imaging sensor field of view <NUM>, e.g., the scene of interest <NUM>. The imaging system <NUM> is operatively connected to the imaging sensor(s) <NUM> and is in turn configured to determine the imaging sensor detection state(s) <NUM> using the imaging sensor data <NUM>. In certain examples the imaging sensor(s) <NUM> includes an infrared focal plane array. In other examples the imaging sensor(s) <NUM> include a visible light focal plane array.

It is contemplated that some or all of the imaging systems(s) <NUM> and non-imaging system(s) <NUM> overlap such that even though the fields of view, <NUM>, <NUM> may not be exactly the same, each overlaps all or a portion of another system's field of view <NUM>, <NUM> and the scene of interest <NUM>, such that they can be combined to fully overlap the scene of interest. It also is contemplated that the imaging system(s) <NUM> have known spatial registrations to one another such that even though the fields of view might not be aligned, the information from the imaging system(s) <NUM> can still be combined with one another with spatial specificity. Likewise, it is contemplated that the non-imaging system(s) <NUM> have known spatial alignment to one another such that even though the fields of view might not be aligned, the information from the non-imaging system(s) <NUM> can still be combined with one another with spatial specificity. Likewise, it is contemplated that the imaging system(s) <NUM> and the non-imaging system(s) <NUM> have known spatial registrations to one another such that even though the fields of view might not be aligned, the information from the imaging system(s) <NUM> and the non-imaging system(s) <NUM> can still be combined with one another with spatial specificity.

The controller <NUM> includes a processor <NUM>, a device interface <NUM>, a user interface <NUM>, and a memory <NUM>. The device interface <NUM> connects the controller <NUM> to the non-imaging sensor system <NUM> and the imaging system <NUM> through the link <NUM>. The processor <NUM> is connected to the device interface <NUM> for communication therethrough with the non-imaging sensor system <NUM> and the imaging system <NUM>. The processor <NUM> is also operably connected to the user interface <NUM> and is disposed in communication with the memory <NUM>. As shown in <FIG> the computer program product <NUM> is tangibly embodied on the memory <NUM>, which includes a non-transitory machine-readable medium having a plurality of program modules <NUM> recorded thereon that, when read by the processor, cause the process to execute certain operations. Among those operations are operations of a flame or gas detection method <NUM>, as will be described. It is contemplated that the controller <NUM> can be implemented using software, circuitry, or a combination of software and circuitry, as suitable for an intended application.

With reference to <FIG>, the flame or gas detection method <NUM> is shown. As shown with box <NUM>, the flame or gas detection method <NUM> includes determining non-imaging sensor detection state(s), e.g., the sensor detection state(s) <NUM> (shown in <FIG>). In certain examples the non-imaging sensor detection state(s) are determined using electromagnetic radiation received at a non-imaging sensor, e.g., the non-imaging sensor(s) <NUM> (shown in <FIG>), in one or more MWIR wavebands, as shown with box <NUM>. In accordance with certain examples the non-imaging sensor detection state(s) are determined using electromagnetic radiation received at the non-imaging sensor in an ultraviolet waveband, as shown with box <NUM>. The non-imaging sensor analyzes the electromagnetic radiation received by the non-imaging sensor and determines the detection state of the non-imaging sensor, i.e., flame presence or absence state(s), as shown with box <NUM>. It is also contemplated that the non-imaging sensor detection state(s) can be gas presence or absence state(s), as shown with box <NUM>.

As shown with box <NUM>, the flame or gas detection method <NUM> also includes determining imaging sensor detection state(s), e.g., the imaging sensor detection state(s) <NUM> (shown in <FIG>). In certain examples the imaging sensor detection state(s) are determined using electromagnetic radiation received at imaging sensor(s), e.g., the imaging sensor(s) <NUM> (shown in <FIG>), in a visible waveband, as shown with box <NUM>. In accordance with certain examples the imaging sensor detection state(s) are determined using electromagnetic radiation received at the imaging sensor(s) in an infrared waveband, as shown with box <NUM>. The imaging sensor analyzes the electromagnetic radiation received by the non-imaging sensor and determines the detection state of the imaging sensor, i.e., flame presence or absence state(s), as shown with box <NUM>. It is also contemplated that the imaging sensor detection state(s) can be gas presence or absence state(s), as shown with box <NUM>.

As shown with box <NUM>, the flame or gas detection method <NUM> additionally includes deconflicting and validating one or more of the sensor detection state(s) and the non-imaging sensor detection state(s) with the other of the sensor detection state(s) and the imaging sensor detection state(s). When the non-imaging sensor detection state(s) agree with the imaging sensor detection state(s), the validated detection state is indicated at a user interface, e.g., the user interface <NUM> (shown in <FIG>), as a system flame or gas detection state, e.g., the system flame or gas detection state <NUM> (shown in <FIG>), as shown with boxes <NUM> and <NUM>. When the non-imaging detection state(s) disagree with the imaging sensor detection state(s) the disagreement is deconflicted, and the deconflicted detection state indicated at a user interface, e.g., the user interface <NUM> (shown in <FIG>), as a system flame or gas detection state, e.g., the system flame or gas detection state <NUM> (shown in <FIG>), as shown with boxes <NUM> and <NUM>. Indication can be accomplished, for example, visually or audibly. Deconfliction can be accomplished using one or more of a sensor health status, an imaging sensor health status, sensor reference data, imaging sensor reference data, and/or application of a keep-in or keep-out definition in conjunction with the imaging sensor data as described further below with reference to <FIG>.

For example, a scene of interest can be imaged and image divided into one or more image portions wherein indication of flame or gas is disregarded for purposes of determining the imaging sensor detection state, and into one or more image portion wherein indication of flame or gas is considered for purposes of the imaging sensor detection state. In certain examples the system flame or gas detection state is a flame detection state, as shown with box <NUM>. In accordance with certain examples the system flame or gas detection state is a gas detection state, as shown with box <NUM>.

With reference to <FIG>, a flame or gas detector <NUM> is shown. The flame or gas detector <NUM> is similar to the flame or gas detector <NUM> (shown in <FIG>) and additionally includes a plurality of non-imaging sensor systems, e.g., an MWIR non-imaging sensor system <NUM> and an ultraviolet non-imaging sensor <NUM>. The flame or gas detector <NUM> also includes a plurality of imaging sensor systems, e.g., an infrared imaging system <NUM> and a visible light imaging system <NUM>. The flame or gas detector <NUM> additionally includes a validation engine <NUM> for deconflicting and validating one or more of the non-imaging sensor detection state(s) <NUM> and the imaging sensor detection state(s) <NUM> against the other of the detection states <NUM> and <NUM>. Although a specific group of non-imaging sensor systems and imaging sensor systems are shown in the illustrated example it is to be understood that flame or gas detectors having different, fewer or additional non-imaging sensor systems and imaging sensor systems are within the scope of the present disclosure.

The MWIR non-imaging sensor system <NUM> includes an MWIR non-imaging sensor array <NUM>, an MWIR sensor signal buffer <NUM>, an MWIR sensor reference data module <NUM>, and an MWIR sensor detection state determination module <NUM>. The MWIR non-imaging sensor array <NUM> is configured to acquire MWIR non-imaging sensor data <NUM> of the scene of interest <NUM>. The MWIR sensor signal buffer <NUM> is disposed in communication with MWIR non-imaging sensor array <NUM> to receive therefrom the MWIR non-imaging sensor data <NUM>, and is further configured to buffer the MWIR non-imaging sensor data <NUM> according to a schedule in order to synchronize delivery of the MWIR non-imaging sensor data <NUM> to the validation engine <NUM> with the one or more data <NUM>, <NUM>, and/or <NUM> from the plurality of non-imaging sensor systems and/or the imaging sensor systems <NUM>, <NUM>, and/or <NUM> of the flame or gas detector <NUM>. The MWIR sensor detection state determination module <NUM> is disposed in communication with the MWIR sensor signal buffer <NUM> to receive therefrom the MWIR non-imaging sensor data <NUM> and is configured to determine an MWIR non-imaging sensor detection state <NUM> from the MWIR non-imaging sensor data <NUM>.

It is contemplated that the MWIR sensor reference data module <NUM> employ a process for verifying or adjusting algorithm parameters based on scene content. For example, a scene of interest having a known flame or gas condition (i.e. a flame or gas with known characteristics such as intensity and luminosity generated for the purpose of characterization) can be observed over a period of time while the MWIR non-imaging sensor system <NUM> executes flame or gas detection operations for the purpose of verifying the range of metrics associated with the known flame or gas condition. In one such case, the scene of interest is monitored by the MWIR non-imaging sensor system <NUM> for a period of time while no flame is present and metrics are calculated using the MWIR sensor data and recorded into a memory, such as memory <NUM>. The metrics are used to verify or adjust the detection threshold (or thresholds) and provide the MWIR non-imaging sensor system <NUM> a metrics-based definition of the scene of interest <NUM> when no flame is present. In another case the scene of interest <NUM> is observed over a period of time during which a known flame is within the scene of interest <NUM>, metrics recorded in a memory and calculated using the MWIR sensor data, and the calculated metrics are used to verify or adjust the detection threshold (or thresholds) and provide the MWIR non-imaging sensor system <NUM> a metrics-based definition of the scene of interest when a known flame is present.

The ultraviolet non-imaging sensor system <NUM> includes an ultraviolet non-imaging sensor <NUM>, an ultraviolet sensor signal buffer <NUM>, an ultraviolet non-imaging sensor reference module <NUM>, and an ultraviolet sensor detection state determination module <NUM>. The ultraviolet non-imaging sensor <NUM> is configured to acquire ultraviolet non-imaging sensor data <NUM> of the scene of interest <NUM>. The ultraviolet sensor signal buffer <NUM> is disposed in communication with the ultraviolet non-imaging sensor <NUM> to receive therefrom the ultraviolet non-imaging sensor data <NUM>, and is further configured to buffer the ultraviolet non-imaging sensor data <NUM> according to a schedule in order to synchronize delivery of the ultraviolet non-imaging sensor data <NUM> to the validation engine <NUM> with the one or more data <NUM>, <NUM>, and/or <NUM> from the plurality of non-imaging sensors and/or imaging sensors <NUM>, <NUM>, and/or <NUM> of the flame or gas detector <NUM>. The ultraviolet sensor detection state determination module <NUM> is disposed in communication with the ultraviolet sensor signal buffer <NUM> to receive therefrom the ultraviolet non-imaging sensor data <NUM> and is further configured to determine an ultraviolet non-imaging sensor detection state <NUM> from the ultraviolet non-imaging sensor data <NUM>.

The infrared imaging system <NUM> includes an infrared focal plane array <NUM>, an infrared imaging system frame buffer <NUM>, an infrared imaging system reference module <NUM>, and an infrared imaging system detection state determination module <NUM>. The infrared focal plane array <NUM> is configured to acquire infrared image data <NUM> of the scene of interest <NUM>. The infrared imaging system frame buffer <NUM> is disposed in communication with the infrared focal plane array <NUM> to receive therefrom the infrared image data <NUM>, and is further configured to buffer the infrared image data <NUM> according to a schedule in order to synchronize delivery of the infrared image data <NUM> to the validation engine <NUM> with the one or more data <NUM>, <NUM>, and/or <NUM> from the plurality of non-imaging sensors and/or imaging sensors <NUM>, <NUM>, and/or <NUM> of the flame or gas detector <NUM>. The infrared imaging system detection state determination module <NUM> is disposed in communication with the infrared imaging system frame buffer <NUM> to receive therefrom the infrared image data <NUM> and is configured to determine an infrared imaging system detection state <NUM> from the infrared image data <NUM>.

The visible light imaging system <NUM> includes a visible light focal plane array <NUM>, a visible light imaging system frame buffer <NUM>, a visible light imaging system reference module <NUM>, and a visible light imaging system detection state determination module <NUM>. The visible light focal plane array <NUM> is configured to acquire visible light imaging system data <NUM> of the scene of interest <NUM>. The visible light imaging system frame buffer <NUM> is disposed in communication with the visible light focal plane array <NUM> to receive therefrom the visible light imaging system data <NUM>, and is further configured to buffer the visible light imaging system data <NUM> according to a schedule in order to synchronize delivery of the visible light imaging system data <NUM> to the validation engine <NUM> with one or more data of data <NUM>, <NUM>, and/or <NUM> from the plurality of non-imaging sensors and/or imaging sensors <NUM>, <NUM>, and/or <NUM> of the flame or gas detector <NUM>. The visible light imaging system detection state determination module <NUM> is disposed in communication with the visible light imaging sensor frame buffer <NUM> to receive therefrom the visible light imaging system data <NUM> and is configured to determine a visible light imaging system detection state <NUM> from the visible light imaging system data <NUM>.

The validation engine <NUM> is further configured to determine the flame or gas detection state <NUM> using state-specific analysis and decision making according to associations of system state scenarios and validation engine actions stored in memory such as the memory <NUM>, for example, in a state table or other suitable storage format. <FIG> shows an illustrative example of association of system state scenarios <NUM> and validation engine actions <NUM>. In this respect the validation engine <NUM> is disposed in communication with each of the plurality of non-imaging sensors, e.g., the MWIR non-imaging sensor system <NUM> and the ultraviolet non-imaging sensor system <NUM>, to receive therefrom a health status (shown in <FIG>) and a detection status of the respective non-imaging system. In further respect the validation engine <NUM> is also disposed in communication with each of the plurality of imaging systems, e.g., the infrared imaging system <NUM> and the visible light imaging system <NUM>. The validation engine <NUM> is configured such that certain sub-systems take precedent, e.g., non-imaging systems and/or imaging systems with acceptable health states, in determining appropriate engine actions <NUM> according to scenarios which may be discerned from the full set of sub-system states. The set of example system states and appropriate actions in <FIG> are chosen according to known detection susceptibilities of each sub-system type such that the most robust flame or gas detection can occur, e.g., by validating an infrared flame candidate in infrared imagery using an infrared intensity associated with a frequency reported by the MWIR non-imaging sensor. In general, the validation engine actions <NUM> may be application-configurable according to known conditions (structures that emit at wavebands tending to provoke false alarms from one or more of the imaging sensors and non-imaging sensors) or predisposed hazards (potential location of flame or gas source) in the specific installation environment.

With reference to <FIG>, data flows through a portion of the flame or gas detector <NUM> are shown. As shown within the MWIR non-imaging sensor system <NUM>, an MWIR non-imaging sensor health status <NUM> and the MWIR non-imaging sensor detection state <NUM> are determined by the MWIR non-imaging sensor system <NUM>. The MWIR non-imaging sensor health status <NUM> in turn indicates whether the MWIR non-imaging sensor detection state <NUM> should be included or excluded (disregarded) by the validation engine <NUM> in determining the flame or gas detection state <NUM>. In certain examples an on-board diagnostics module can determine the MWIR non-imaging sensor health status <NUM>.

The MWIR non-imaging sensor detection state <NUM> is determined using MWIR non-imaging sensor data <NUM> acquired by the MWIR non-imaging sensor array <NUM> (shown in <FIG>) in conjunction with the MWIR sensor system reference data <NUM> received from the MWIR sensor reference module data <NUM> (shown in <FIG>). In certain examples the MWIR sensor system reference data <NUM> is user defined, e.g., thresholding information and /or frequency characterization received through a user interface, e.g., a user interface <NUM> (shown in <FIG>). In accordance with certain examples the MWIR sensor system reference data <NUM> may also be acquired by monitoring scene content as described above with respect to the process for verifying or adjusting algorithm parameters based on scene content.

As shown within the ultraviolet non-imaging sensor system <NUM>, an ultraviolet non-imaging sensor health status <NUM> and the ultraviolet non-imaging sensor detection state <NUM> are determined by the ultraviolet non-imaging sensor system <NUM>. The ultraviolet non-imaging sensor health status <NUM> indicates whether the ultraviolet non-imaging sensor detection state <NUM> should be included or excluded (disregarded) by the validation engine <NUM> in determining the flame or gas detection state <NUM>. In certain examples an on-board diagnostics module determines the ultraviolet non-imaging sensor health status <NUM>.

The ultraviolet non-imaging sensor detection state <NUM> is determined using the ultraviolet non-imaging sensor data <NUM>, which is acquired by the ultraviolet non-imaging sensor <NUM> (shown in <FIG>) in conjunction with the ultraviolet sensor system reference data <NUM> received from the ultraviolet non-imaging sensor reference module <NUM> (shown in <FIG>). In certain examples the ultraviolet sensor system reference data <NUM> is user defined, e.g., thresholding information and /or frequency characterization received through the user interface <NUM> (shown in <FIG>). In accordance with certain examples the ultraviolet sensor system reference data <NUM> may be acquired by monitoring scene content as described above with respect to the process for verifying or adjusting algorithm parameters based on scene content (which may be applied to ultraviolet non-imaging sensors in a similar manner as described for verifying or adjusting algorithm parameters for MWIR sensors).

As shown within the infrared imaging system <NUM>, an infrared imaging system health status <NUM> and the infrared imaging system detection state <NUM> are determined by the infrared imaging system <NUM>. The infrared imaging system health status <NUM> indicates whether the infrared imaging system detection state <NUM> should be included or excluded (disregarded) by the validation engine <NUM> in determining the flame or gas detection state <NUM>. In certain examples an on-board diagnostics module determines the infrared imaging system health status <NUM>.

The infrared imaging system detection state <NUM> is determined using the infrared image data <NUM> from the infrared focal plane array <NUM> (shown in <FIG>) in conjunction with infrared imaging system reference data <NUM>, an infrared imaging system keep-out definition <NUM>, and cross-referencing data <NUM>. The infrared imaging system reference data <NUM> is received from the infrared imaging system reference module <NUM> (shown in <FIG>) and may be received from a user interface, e.g., the user interface <NUM> (shown in <FIG>), and/or acquired using scene monitoring operations as described above with respect to the process for verifying or adjusting algorithm parameters based on scene content (which may be applied to infrared imaging system sensors in a similar manner as described for verifying or adjusting algorithm parameters for MWIR sensors). The infrared imaging system keep-out definition <NUM> demarcates, e.g., established during set up of the flame or gas detection system, image data frames received from the infrared imaging system frame buffer <NUM> (shown in <FIG>) into frame regions where flame indication is eligible for determining the flame or gas detection state <NUM> and frame regions where flame indication is ineligible for determining the flame or gas detection state <NUM>. The cross-referencing data <NUM> is received from one or more non-imaging sensor and/or imaging sensor and provides additional checks to the validity of the infrared imaging system detection state <NUM> specific to a given system/system pair and/or system/sensor pair, when the imaging system receives electromagnetic radiation in a waveband associated with false detection events is the non-imaging sensor.

As shown within the visible light imaging system <NUM>, a visible light imaging system health status <NUM> and the visible light imaging system detection state <NUM> are determined by the visible light imaging system <NUM>. The visible light imaging system health status <NUM> indicates whether the visible light imaging sensor detection state <NUM> should be included or excluded (disregarded) by the validation engine <NUM> in determining the flame or gas detection state <NUM>. In certain examples an on-board diagnostics module determines the visible light imaging system health status <NUM>.

The visible light imaging system detection state <NUM> is determined using the visible light imaging sensor data <NUM> from the visible light focal plane array <NUM> (shown in <FIG>) in conjunction with visible light imaging system reference data <NUM>, a visible imaging system keep-out definition <NUM>, and cross-referencing data <NUM>. The visible imaging system reference data <NUM> is received from the visible light imaging system reference module <NUM> (shown in <FIG>) and may be received from a user interface, e.g., the user interface <NUM> (shown in <FIG>), and/or acquired using scene monitoring operations as described above with respect to the process for verifying or adjusting algorithm parameters based on scene content (which may be applied to VL imaging system sensors in a similar manner as described for verifying or adjusting algorithm parameters for MWIR sensors). The visible imaging system keep-out definition <NUM> demarcates image data frames received from the visible light imaging system frame buffer <NUM> (shown in <FIG>) into frame region where flame indication is eligible for determining the flame or gas detection state <NUM> and frame regions where flame indication is ineligible for determining the flame or gas detection state <NUM>.

The present disclosure provides techniques for combining data from imaging systems (including visible light and infrared imaging sensors) with data from non-imaging systems (including mid-wave infrared non-imaging sensors) in order to more reliably detect and validate the occurrence of flame or gas, to indicate the flame or gas location via image data, to disregard flame or gas that is detected in areas that are meant to be unmonitored, (sometimes referred to as 'keep-out regions'), and to minimize the occurrence of false alarms as compared to a system that utilizes imaging or non-imaging technology exclusively.

Claim 1:
A flame or gas detection method (<NUM>), comprising:
determining (<NUM>) a non-imaging sensor system detection state (<NUM>; <NUM>, <NUM>) for a scene of interest (<NUM>);
determining (<NUM>) an imaging sensor system detection state (<NUM>; <NUM>, <NUM>) for the scene of interest;
validating (<NUM>) one of the non-imaging sensor system detection state and the imaging sensor system detection state with the other of the non-imaging sensor system detection state and the imaging sensor system detection state; and
indicating (<NUM>), at a user interface (<NUM>; <NUM>), a flame or gas detection system detection state (<NUM>; <NUM>, <NUM>) including the validated one of the non-imaging sensor system detection state and the imaging sensor system detection state,
wherein determining (<NUM>) the imaging sensor system detection state (<NUM>; <NUM>, <NUM>) includes:
receiving image data (<NUM>; <NUM>, <NUM>) from an imaging sensor (<NUM>; <NUM>, <NUM>) for the scene of interest (<NUM>);
receiving imaging sensor system reference data (<NUM>, <NUM>) for the scene of interest;
receiving an imaging sensor system keep-out definition (<NUM>, <NUM>) for the scene of interest, the keep-out definition demarcating image data frames of the image data into a frame region where flame indication is eligible for determining the flame or gas detection state and frame regions where flame indication is ineligible for determining the flame or gas detection state, the frame regions where flame indication is ineligible for determining the flame or gas detection state being unmonitored; and
determining the imaging sensor system detection state based on the image data from the imaging sensor, the imaging sensor system reference data, and the imaging sensor system keep-out definition for the scene of interest.