Optical gas imaging system for leak detection during battery manufacturing

Abstract

A leak detection system for a battery housing of one of a rechargeable energy storage system, a battery cell, a battery module, and / or a battery pack includes a gas delivery system configured to selectively provide a tracer gas to the battery housing. A first optical gas imaging sensor is configured to generate an image of a surface of the battery housing after the gas delivery system fills the battery housing with the tracer gas. The image is used to selectively detect a gas cloud adjacent a surface of the battery housing. The gas cloud is used to determine a location of a gas leak on a surface of the battery housing.

Description

[0001] introduce

[0002] The information provided in this section is for the purpose of generally presenting the context of the present disclosure. The work of the inventors currently listed (to the extent that it is described in this section) and aspects of the description that may not have been prior art at the time of filing are neither explicitly nor implicitly admitted as prior art against the present disclosure.

[0003] The present disclosure relates to gas leak detection of a housing of a rechargeable energy storage system (RESS), battery cell, battery module, or battery pack during manufacturing.

[0004] An electric vehicle (EV) such as a battery electric vehicle (BEV), a hybrid vehicle, and / or a fuel cell vehicle includes one or more motors and a RESS or battery system including one or more battery cells, battery modules, and / or battery packs. Each battery cell includes a battery cell stack including an anode electrode, a cathode electrode, and a separator that generates exhaust gas during cycling. A power control system is used to control the charging and / or discharging of the battery system during charging and / or driving.

[0005] The RESS, battery cells, battery modules and / or battery packs are typically housed in a hermetically sealed RESS, battery cell, module or pack housing, respectively. Current processes for detecting housing leaks are expensive, time consuming and / or fail to identify the specific location of the gas leak. Failure to locate the gas leak(s) during repair increases the labor cost of the repair. The battery pack housing may have to go through 2-3 repair processes to repair the leak, which increases the labor cost. Summary of the invention

[0006] A leak detection system for an enclosure includes a gas delivery system configured to selectively provide a tracer gas to the enclosure. A first optical gas imaging sensor is configured to generate an image of a surface of the enclosure after the gas delivery system fills the enclosure with the tracer gas. The image is used to selectively detect a gas cloud adjacent to the surface of the enclosure. The gas cloud is used to determine a location of a gas leak on the surface of the enclosure.

[0007] In other features, the positioning device is configured to position the first optical gas imaging sensor and the housing relative to one of the first optical gas imaging sensor and the housing. The surface of the housing is disposed between the first optical gas imaging sensor and the temperature controlled screen.

[0008] In other features, the outer surface of the temperature controlled screen is black. The temperature controlled screen is heated to a temperature in the range of 10°F to 100°F above ambient temperature. The gas delivery system includes a tracer gas source and a valve fluidly connecting the tracer gas source to the housing. The gas delivery system includes a pump and a valve fluidly connecting the pump to the housing.

[0009] In other features, the gas delivery system supplies a tracer gas selected from the group consisting of carbon dioxide (CO2), hydrocarbons, volatile organic compounds (VOC), methane, carbon monoxide (CO), helium (He), molecular hydrogen (H2), and / or combinations thereof. The first optical gas imaging sensor includes a gas filter having a predetermined passband around an absorption wavelength of the tracer gas.

[0010] In other features, the controller is configured to communicate with the first optical gas imaging sensor, detect a gas cloud adjacent to a surface of the housing, and determine a location of a gas leak in response to the gas cloud.

[0011] In other features, the first optical gas imaging sensor is configured to capture a first image of a surface of the housing before a gas delivery system supplies a tracer gas, and to capture a second image of the surface of the housing after the tracer gas is supplied to the housing. The first optical gas imaging sensor is configured to reduce a field of view of the first optical gas imaging sensor after the second image in response to a gas cloud being identified and to capture a third image using the reduced field of view, wherein a location of the gas leak is based on the third image. The first optical gas imaging sensor generates an image from a first portion of the surface of the housing, and also includes a second optical gas imaging sensor configured to generate an image of the surface of the housing.

[0012] A method for detecting a gas leak in an enclosure comprises: selectively providing a tracer gas to the enclosure; after filling the enclosure with the tracer gas, generating an image of a surface of the enclosure using a first optical gas imaging sensor; selectively detecting a gas cloud adjacent to the surface of the enclosure; and in response to detecting the gas cloud, determining a location of the gas leak on the surface of the enclosure.

[0013] In other features, the method includes positioning the first optical gas imaging sensor and the housing relative to one of the first optical gas imaging sensor and the housing. The method includes disposing the housing between the temperature controlled screen and the first optical gas imaging sensor.

[0014] In other features, the outer surface of the temperature controlled screen is black, and the temperature controlled screen is heated to a temperature in the range of 10°F to 100°F above ambient temperature.

[0015] In other features, the tracer gas is selected from the group consisting of carbon dioxide (CO2), hydrocarbons, volatile organic compounds (VOC), methane, carbon monoxide (CO), helium (He), molecular hydrogen (H2), and / or combinations thereof. The method includes using a gas filter having a predetermined passband around an absorption wavelength of the tracer gas.

[0016] In other features, the method includes: capturing a first image of the surface of the housing using a first optical gas imaging sensor before supplying the tracer gas; capturing a second image of the surface of the housing using the first optical gas imaging sensor after supplying the tracer gas to the housing; reducing a field of view after the second image in response to a gas cloud being identified; and capturing a third image using the first optical gas imaging sensor using the reduced field of view, wherein a location of the gas leak is determined in response to the third image.

[0017] One aspect of the present disclosure relates to a leak detection system for a housing, comprising:

[0018] a gas delivery system configured to selectively provide a tracer gas to the housing; and

[0019] a first optical gas imaging sensor configured to generate an image of a surface of the enclosure after the gas delivery system fills the enclosure with a tracer gas,

[0020] wherein the image is used to selectively detect a gas cloud adjacent to a surface of the housing, and

[0021] The gas cloud is used to determine the location of a gas leak on the surface of the housing.

[0022] The leak detection system according to one aspect of the present disclosure further includes a positioning device configured to position the other of the first optical gas imaging sensor and the housing relative to the other of the first optical gas imaging sensor and the housing.

[0023] The leak detection system according to one aspect of the present disclosure further includes a temperature controlled screen, wherein the surface of the housing is disposed between the first optical gas imaging sensor and the temperature controlled screen.

[0024] According to an aspect of the present disclosure, the leak detection system, wherein an outer surface of the temperature-controlled screen is black.

[0025] According to an aspect of the present disclosure, the leak detection system wherein the temperature controlled screen is heated to a temperature in the range of 10°F to 100°F above ambient temperature.

[0026] According to an aspect of the present disclosure, the leak detection system comprises a tracer gas source and a valve fluidly connecting the tracer gas source to the housing.

[0027] According to an aspect of the present disclosure, the leak detection system comprises a pump and a valve fluidically connecting the pump to the housing.

[0028] According to an aspect of the present disclosure, the gas delivery system supplies a tracer gas selected from the group consisting of carbon dioxide (CO2), hydrocarbons, volatile organic compounds (VOCs), methane, carbon monoxide (CO), helium (He), molecular hydrogen (H2), and / or combinations thereof.

[0029] According to an aspect of the present disclosure, the leak detection system, wherein the first optical gas imaging sensor comprises a gas filter having a predetermined passband around an absorption wavelength of the tracer gas.

[0030] The leak detection system according to one aspect of the present disclosure further includes a controller configured to communicate with the first optical gas imaging sensor, detect a gas cloud adjacent to the surface of the housing, and determine a location of a gas leak in response to the gas cloud.

[0031] In a leak detection system according to one aspect of the present disclosure, the first optical gas imaging sensor is configured to capture a first image of a surface of the housing before the gas delivery system supplies a tracer gas, and to capture a second image of the surface of the housing after the tracer gas is supplied to the housing.

[0032] In a leak detection system according to an aspect of the present disclosure, the first optical gas imaging sensor is configured to: reduce a field of view of the first optical gas imaging sensor in response to a gas cloud being identified after the second image and to capture a third image using the reduced field of view, wherein the location of the gas leak is based on the third image.

[0033] According to an aspect of the disclosure, the leak detection system comprises a first optical gas imaging sensor that generates an image from a first portion of a surface of the housing, and further comprises a second optical gas imaging sensor that is configured to generate an image of the surface of the housing.

[0034] Another aspect of the present disclosure provides a method for detecting a gas leak in an enclosure, comprising:

[0035] selectively providing a tracer gas to the housing;

[0036] generating an image of a surface of the enclosure using a first optical gas imaging sensor after filling the enclosure with the tracer gas;

[0037] selectively detecting a gas cloud adjacent a surface of the housing; and

[0038] In response to detecting the gas cloud, a location of a gas leak on a surface of the enclosure is determined.

[0039] The method according to another aspect of the present disclosure further includes positioning one of the first optical gas imaging sensor and the housing relative to the other of the first optical gas imaging sensor and the housing.

[0040] The method according to another aspect of the present disclosure further includes disposing the housing between a temperature controlled screen and a first optical gas imaging sensor.

[0041] A method according to another aspect of the present disclosure, wherein:

[0042] The outer surface of the temperature controlled screen is black, and

[0043] The temperature controlled screen is heated to a temperature in the range of 10°F to 100°F above ambient temperature.

[0044] According to another aspect of the present disclosure, the method is characterized in that the tracer gas is selected from the group consisting of: carbon dioxide (CO2), hydrocarbons, volatile organic compounds (VOCs), methane, carbon monoxide (CO), helium (He), molecular hydrogen (H2), and / or combinations thereof.

[0045] The method according to another aspect of the present disclosure further includes using a gas filter having a predetermined passband around an absorption wavelength of the tracer gas.

[0046] The method according to another aspect of the present disclosure further includes:

[0047] capturing a first image of a surface of the housing using a first optical gas imaging sensor prior to supplying the tracer gas;

[0048] after supplying the tracer gas to the housing, capturing a second image of the surface of the housing using a first optical gas imaging sensor;

[0049] reducing the field of view after the second image in response to the gas cloud being identified; and

[0050] A third image is captured using the first optical gas imaging sensor using a reduced field of view, wherein a location of the gas leak is determined in response to the third image.

[0051] Further areas of applicability of the present disclosure will become apparent from the detailed description, claims and drawings.The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] The present disclosure will be more fully understood from the detailed description and accompanying drawings, in which:

[0053] Figure 1 is a functional block diagram of an example of a leak detection system for a housing of a rechargeable energy storage system, battery pack, battery module, and / or battery cell according to the present disclosure;

[0054] Figure 2A is a method for detecting a leak in a housing of a rechargeable energy storage system, a battery cell, a battery module and / or a battery pack according to the present disclosure;

[0055] Figure 2B illustrates an example of background radiation traveling from a heated black screen to an optical gas imaging sensor during leak testing of an enclosure in accordance with the present disclosure;

[0056] Figure 3 illustrates an example of a weld on a housing and a gas cloud created by a leaking weld that has a crack that may or may not leak;

[0057] Figure 4 is a graph illustrating an example of transmittance and absorbance of background radiation from a screen as a function of wavelength of a gas filter detector of an optical gas imaging sensor according to the present disclosure; and

[0058] Figure 5 and Figure 6 is an example of a leak detection system according to the present disclosure that includes more than one thermal imaging system.

[0059] Among the drawings, reference numerals may be repeated to identify similar and / or identical elements. DETAILED DESCRIPTION

[0060] Although the leak detection system according to the present disclosure is described below with respect to a housing for a rechargeable energy storage system (RESS), a battery pack, a battery module, and / or a battery cell, the leak detection system may be used in other applications.

[0061] The leak detection system and method according to the present disclosure accurately identify gas leaks in the housing of the RESS, battery cells, battery modules and / or battery packs. The housing should be hermetically sealed during manufacturing. The leak detection system and method also determine the location of (one or more) leaks on the housing. In some examples, the leak detection system also quantitatively determines the leak rate based on the size of the tracer gas cloud in one or more directions. In other words, larger gas leaks will produce large gas clouds, and smaller leaks will produce smaller gas clouds (assuming the same tracer gas fill pressure).

[0062] The leak detection systems and methods include an optical gas imaging sensor having a field of view directed toward a surface of the RESS, battery cell, battery module, or battery pack. In some examples, the leak test is performed in a chamber that includes an exhaust system to allow for exhaust of tracer gas. To provide a consistent temperature gradient background for gas imaging, the housing is disposed between a temperature controlled screen and the field of view of the optical gas imaging sensor. In some examples, the optical gas imaging sensor and screen move relative to the housing being tested. In some examples, the housing moves relative to the optical gas imaging sensor and screen.

[0063] In some examples, one or more first images are collected before the tracer gas is supplied to the enclosure. Then, after the enclosure is filled with the tracer gas, the optical gas imaging sensor collects one or more second images. An image processor uses the first and second images to identify the shape of the tracer gas emission cloud and estimate the specific location of the leak on the enclosure. The identification of the tracer gas cloud and the specific location is based on macroscopic scale (due to the large contrast between the tracer gas and the background) to identify the portion of the image that contains the leak. In some examples, the field of view of the camera is directed or refocused to a narrower field of view to generate one or more third images with finer resolution to help identify the specific location of the leak.

[0064] Reference now Figure 1 , the leak detection system 100 tests the housing 110 for gas leaks. For example, the housing 110 can surround a RESS, a battery cell, a battery module, or a battery pack. In some examples, a positioning device 112 is used to position the housing 110 during the leak test. The positioning device 112 selectively moves the housing 110 in one or more directions before, during, or after the leak test. In other examples, the housing 110 is stationary during the leak test.

[0065] During the manufacture of the housing, the outer surface of the housing 110 is welded at one or more welding locations 114-1, 114-2, ..., and 114-N, where N is an integer. In some examples, one or more welding locations 114 may include a weld having a crack or defect that causes one or more gas leaks (e.g., at 118 above the welding location 114-N). Since the housing 110 should be airtight, the housing needs to be repaired before use. During the repair, it is difficult to locate the location of the gas leak source (one or more) and repair the gas leak source (one or more) without knowing the location of the gas leak (one or more).

[0066] In some examples, the leak detection system 100 also includes a gas delivery system 119 for selectively delivering a tracer gas to the housing 110. In some examples, the gas delivery system 119 includes a tracer gas source 120, a valve 122, a pump 124, and a valve 126. The tracer gas source 120 and the valve 122 selectively supply the tracer gas to the housing 110. In some examples, the tracer gas is selected from the group consisting of carbon dioxide (CO2), hydrocarbons, volatile organic compounds (VOC), methane, carbon monoxide (CO), helium (He), molecular hydrogen (H2), and / or combinations thereof.

[0067] Pump 124 and valve 126 are used to increase the pressure within housing 110. If housing 110 has a leaking weld location, tracer gas in housing 110 is ejected through the leak at the weld and is sensed by the optical gas imaging sensor and / or identified using image processing as described herein.

[0068] The leak detection system 100 also includes a screen 130 for increasing the reliability of sensing. In some examples, the temperature of the screen is controlled to a temperature higher than the ambient temperature. The screen introduces a temperature difference between the tracer gas and the background provided by the screen 130. In some examples, the screen 130 has a black outer surface for increasing emissivity. In some examples, the screen 130 includes a heater 134 (e.g., a resistive heater) for allowing the temperature of the screen 130 to be different from the surrounding environment.

[0069] The heater 134 includes one or more heating zones. In some examples, the temperature controller 136 controls the temperature of the screen 130 to a predetermined temperature range. In some examples, the temperature controller 136 receives the output of one or more temperature sensors 137 and adjusts the power output to the heater 134 based on the output. In some examples, each zone of the heater 134 includes a corresponding temperature sensor 137. In some examples, the screen 130 is heated to a temperature in the range of 10°F to 100°F higher than the ambient temperature of the housing or the location where the leak test is performed. In other examples, the screen 130 is heated to a temperature in the range of 10°F to 40°F (e.g., 25°F) higher than the ambient temperature of the housing or the location where the leak test is performed.

[0070] In some examples, a positioning device 138 is used to position the temperature controller 136 and the screen 130. The positioning device 138 selectively moves the temperature controller 136 and the screen 130 in one or more directions. In other examples, the screen is stationary. The pressure sensor 142 monitors the pressure in the housing 110. When the pressure reaches a predetermined pressure in the housing 110, the valves 122 and / or 126 are closed and a second and / or third image for a leak test is generated.

[0071] Optical gas imaging sensor 150 performs optical gas imaging of the surface of housing 110. In some examples, optical gas imaging sensor 150 is a specialized version of an infrared or thermal imaging sensor. Optical gas imaging sensor 150 includes a lens, a detector, electronics for processing signals from the detector, and a viewfinder or screen for a user to view images produced by optical gas imaging sensor 150. In some examples, the detector includes an indium antimonide (InSb) detector.

[0072] In some examples, leak detection testing is performed on the top surface of the housing and the edges between the top surface and the sides. In some examples, a positioning device 152 is used to position the optical gas imaging sensor 150. The positioning device 152 selectively moves the optical gas imaging sensor 150 in one or more directions during the leak test. In other examples, leak detection is performed on the bottom surface and the edges between the bottom surface and the sides. In some examples, the top surface is checked for gas leaks, the housing is turned over, and then the bottom surface is checked for gas leaks. In other examples, separate optical gas imaging sensors are used to check the top and bottom surfaces, and the housing is held from the side surfaces during leak detection.

[0073] In some examples, controller 160 includes an image processor 164 for performing image processing on the images output by optical gas imaging sensor 150. Image processor 164 receives images generated by optical gas imaging sensor 150 and identifies when a tracer gas cloud is present near the enclosure and the location of the tracer gas cloud on the enclosure (corresponding to the leak location). The location of the gas leak can be provided to a repair operation to enable a more efficient repair. In other examples, the location of the gas leak can be provided to a robotic welding machine to allow for automated repair.

[0074] As can be appreciated, one or more of the positioning devices 112, 138, and / or 152 can be omitted if the corresponding structure (e.g., the housing or the optical gas imaging sensor and screen) does not need to move. In some examples, the controller 160 is also used to control one or more of the positioning devices 112, 138, and / or 152. For example, the optical gas imaging sensor 150 and the temperature controller 136 and the screen 130 can move relative to the housing 110. In other examples, the housing 110 can move relative to the optical gas imaging sensor 150 and the temperature controller 136 and the screen 130. In some examples, the controller 160 monitors the pressure sensor 142 and controls one or more of the valve 122, the valve 126, and the pump 124 to close the flow of tracer gas into the housing when a predetermined pressure is reached.

[0075] In some examples, the plurality of housings 110 move relative to the leak detection system 100 along a conveyor or a moving frame connected to a moving track or conveyor. In other examples, the optical gas imaging sensor 150 and the screen 130 and the temperature controller 136 move relative to the housing 110. In still other examples, both the leak detection system 100 and the housing 110 move relative to each other. In yet other examples, both the leak detection system 100 and the housing 110 are stationary during leak detection.

[0076] In some examples, screen 130 is made of a rigid material or includes a flexible material supported by a frame. In some examples, screen 130 is rigid enough to allow movement integrally with optical gas imaging sensor 150. In some examples, screen 130 covers at least a portion of an upper portion of housing 110 and / or a side of housing 110. Depending on the position of screen 130, screen 130 also helps prevent measurement contamination from one sensing location to another sensing location (e.g., see Figure 6 ).

[0077] Reference now Figure 2A, an example of a leak detection method 180 is shown. At 182, the method determines whether a test of the enclosure is required. If 182 is true, the method positions the enclosure relative to one or more optical gas imaging sensors and (one or more) temperature-controlled black screens at 184 (or vice versa). At 186, the method generates one or more first images to measure background radiation (using one or more optical gas imaging sensors with a first field of view setting). After completing 186, the method pressurizes the enclosure with a gas including a tracer gas to a predetermined pressure at 188.

[0078] At 190, the method generates one or more second images measuring background radiation (using the one or more optical gas imaging sensors having the first field of view). At 192, the method determines whether a tracer gas cloud is detected based on a comparison of the one or more first images to the one or more second images. In some examples, the presence of a gas cloud and the location of a gas leak are determined at this time. In other examples, the field of view is reduced to improve resolution based on the estimated location of the gas cloud and / or gas leak.

[0079] If 192 is true, the method optionally changes the first field of view to a second field of view (narrower than the first field of view) based on the estimated location of the gas cloud and / or gas leak. In other words, the optical gas imaging sensor 150 is pointed or focused on the estimated location of the gas leak or gas cloud and takes one or more third images with finer resolution. At 196, the method determines the presence of a gas cloud and the location of the gas leak based on the difference between the background radiation measurements before and after filling the enclosure with the tracer gas and / or further based on the one or more third images taken after changing the field of view.

[0080] In some examples, screen 130 is painted black and optionally heated to a predetermined temperature above ambient temperature during leak testing to increase emissivity and provide temperature contrast between the unheated tracer gas cloud and the heated background provided by screen 130 .

[0081] Reference now Figure 2B , the background radiation 210 generated by the screen 130 combines with the transmitted radiation 220 and / or the emitted radiation 222 as it travels toward the optical gas imaging sensor 150. If the background radiation generated by the screen 130 does not pass through the tracer gas cloud, it will remain relatively unchanged. If the background radiation passes through the tracer gas in the gas cloud, the background radiation 230 received by the optical gas imaging sensor 150 is different due to the absorption that occurs when passing through the tracer gas cloud (and / or the temperature contrast between the unheated gas cloud and the heated screen).

[0082] A portion of the background radiation 210 is absorbed within a predetermined wavelength range that is characteristic of the tracer gas from the tracer gas source. The optical gas imaging sensor 150 filters the received background radiation (passing through the tracer gas cloud, if present) using a filter. The filter includes a bandpass region around a wavelength corresponding to the absorption wavelength characteristic of the tracer gas supplied by the tracer gas source.

[0083] For example, when using carbon dioxide (CO2), wavelengths from 4.2 μm to 4.4 μm may be used. When the absorbance is high and the transmittance is low, tracer gas from the tracer gas source is present. When the absorbance is low and the transmittance is high, tracer gas from the tracer gas source is not present. The optical gas imaging sensor 150 uses this information to determine the shape and size of the tracer gas cloud, the exact location of the leak on the enclosure, the gas leak rate, and / or the size of the crack or defect based on the gas leak rate.

[0084] Reference now Figure 3 , various examples of welds (e.g., welds 1, 2, and 3) are shown at 240 and 242 and their corresponding tracer gas clouds (if leaking) at 244. Although weld 1 appears to have no surface cracks, weld 1 leaks and produces a tracer gas cloud. Weld 2 has surface cracks but does not leak. Weld 3 has a higher amount of leakage than weld 1 due to the greater number of cracks and / or defects connecting the outer surface to the interior location of weld 3. As can be appreciated, it may be difficult to determine where a gas leak is located using surface inspection.

[0085] Reference now Figure 4 , shows an example of the response of a tracer gas filter of an optical gas imaging sensor. The tracer gas filter is a bandpass filter including a bandpass region 250 arranged to pass wavelengths corresponding to the absorption wavelengths of the tracer gas species supplied by the tracer gas source. When a tracer gas cloud is present, the tracer gas in the tracer gas cloud absorbs background radiation (absorption 252 increases) and transmittance 256 decreases. In addition, the temperature difference of the screen 130 provides additional contrast to allow the optical gas imaging sensor to sense the position, shape and size of the tracer gas cloud.

[0086] The leak detection system may have various numbers of optical gas imaging sensors positioned and / or moved in various ways. Figure 5, a plurality of housings 310-1, 310-2, ..., and 310-C are moved by a positioning device 320 (e.g., a conveyor) (where C is an integer greater than 1). In other examples, the plurality of housings are held from the side to allow leak detection from the top and bottom sides of the housings simultaneously or sequentially. In other examples, the positioning device 138 of the screen 130 and the temperature controller 136 and / or the optical gas imaging sensor 150 are connected to a moving frame and move together relative to one or more surfaces of a stationary or moving housing.

[0087] For example, the leak detection system includes a first optical gas imaging sensor 340 and a screen 342 arranged along a first edge of the housing 310. The leak detection system includes a second optical gas imaging sensor 344 and a screen 346 arranged along a second edge of the housing 310. The second optical gas imaging sensor 344 and the screen 346 are arranged at an angle relative to the first optical gas imaging sensor 340 and the screen 342. In some examples, the angle is in a range from 45° to 135° (e.g., 90°). In this example, leak detection is performed at an orthogonal angle.

[0088] In some examples, moving frame 348 is connected to screens 342, 346 and optical gas imaging sensors 340 and 344. Positioning device 349 is connected to frame 348 to move frame 348 relative to housing 310 along a track or rail.

[0089] Reference now Figure 6 , a plurality of package shells 350-1, 350-2, ... (collectively referred to as package shells 350) are moved by a positioning device 320 such as a conveyor. In some examples, the package shell 350 includes rails 352-1, 352-2, ..., and 352-R protruding upward from the upper surface and / or lower surface of the shell. The rail 352 includes welding points on both sides thereof. The leak detection system includes one or more first optical gas imaging sensors (optical gas imaging sensors 350-1 and 350-2 are shown), arranged above (and / or below) the package shell 350 and facing one side of the screen 356 (e.g., along a first direction).

[0090] The leak detection system includes one or more second optical gas imaging sensors (optical gas imaging sensors 354-1 and 354-2 are shown) facing the opposite side of the screen (or a side of another screen) (e.g., along a second direction) above (and / or below) the package housing 350. In some examples, the first direction and the second direction are opposite to each other. Due to this orientation, the package housing 350 can be checked for weld leaks on both sides of the track 352 using a single pass (without contaminating measurements from the other side of the track).

[0091] In some examples, screen 356 is arranged parallel to track 352 and moves in a lateral direction of track 352. As can be appreciated, a similar Figure 5 The mobile frame and positioning device are used to replace the positioning device 320 or as a supplement to the positioning device 320.

[0092] The foregoing description is essentially merely illustrative and is in no way intended to limit the present disclosure, its application or use. The broad teachings of the present disclosure can be implemented in a variety of forms. Therefore, although the present disclosure includes specific examples, the true scope of the present disclosure should not be so limited, because other modifications will become apparent after studying the drawings, descriptions and appended claims. It should be understood that one or more steps in the method can be performed in different orders (or simultaneously) without changing the principles of the present disclosure. In addition, although each embodiment is described as having specific features above, any one or more of those features described with respect to any embodiment of the present disclosure can be implemented in any other embodiment and / or combined with the features of any other embodiment, even if the combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and the arrangement of one or more embodiments to each other is still within the scope of the present disclosure.

[0093] The spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.) are described using various terms, including "connected," "engaged," "coupled," "adjacent," "next to," "on top of," "above," "below," and "disposed." Unless explicitly described as "directly," when describing the relationship between a first element and a second element in the above disclosure, the relationship can be a direct relationship, in which there are no other intermediate elements between the first element and the second element, but can also be an indirect relationship, in which there are one or more intermediate elements (spatially or functionally) between the first and second elements. As used herein, the phrase "at least one of A, B, and C" should be interpreted to mean a logical (A or B or C), using a non-exclusive logical "or," and should not be interpreted to mean "at least one of A, at least one of B, and at least one of C."

[0094] In the drawings, the direction of the arrows, as indicated by the arrows, generally demonstrates the flow of information (e.g., data or instructions) of interest to the illustration. For example, when component A and component B exchange various information, but the information transmitted from component A to component B is relevant to the illustration, the arrow may be directed from component A to component B. This unidirectional arrow does not mean that no other information is transmitted from component B to component A. In addition, for information sent from component A to component B, component B may send a request or a receipt confirmation of the information to component A.

[0095] In this application, including the definitions below, the term "module" or the term "controller" may be replaced with the term "circuit". The term "module" may refer to, be part of, or include: an application specific integrated circuit (ASIC); a digital, analog, or mixed analog / digital discrete circuit; a digital, analog, or mixed analog / digital integrated circuit; a combinational logic circuit; a field programmable gate array (FPGA); a processor circuit (shared, dedicated, or group) that executes code; a memory circuit (shared, dedicated, or group) that stores code executed by the processor circuit; other suitable hardware components that provide the described functionality; or a combination of some or all of the above, such as in a system on a chip.

[0096] The module may include one or more interface circuits. In some examples, the interface circuit may include a wired or wireless interface connected to a local area network (LAN), the Internet, a wide area network (WAN), or a combination thereof. The functions of any given module of the present disclosure may be distributed between multiple modules connected via the interface circuit. For example, multiple modules may allow load balancing. In a further example, a server (also referred to as a remote or cloud) module may perform some functions on behalf of a client module.

[0097] The term "code" as used above may include software, firmware, and / or microcode, and may refer to a program, a routine, a function, a class, a data structure, and / or an object. The term "shared processor circuit" encompasses a single processor circuit that executes some or all of the code from multiple modules. The term "group processor circuit" encompasses a processor circuit that executes some or all of the code from one or more modules in combination with an additional processor circuit. References to multiple processor circuits encompass multiple processor circuits on discrete dies, multiple processor circuits on a single die, multiple cores of a single processor circuit, multiple threads of a single processor circuit, or a combination of the above. The term "shared memory circuit" encompasses a single memory circuit that stores some or all of the code from multiple modules. The term "group memory circuit" encompasses a memory circuit that stores some or all of the code from one or more modules in combination with additional memory.

[0098] The term "memory circuit" is a subset of the term "computer-readable medium". As used herein, the term "computer-readable medium" does not cover transient electrical or electromagnetic signals propagated through a medium (such as on a carrier wave); therefore, the term "computer-readable medium" may be considered to be tangible and non-transitory. Non-limiting examples of non-transitory, tangible computer-readable media are non-volatile memory circuits (such as flash memory circuits, erasable programmable read-only memory circuits, or mask read-only memory circuits), volatile memory circuits (such as static random access memory circuits or dynamic random access memory circuits), magnetic storage media (such as analog or digital magnetic tape or hard disk drives), and optical storage media (such as CDs, DVDs, or Blu-ray discs).

[0099] The apparatus and methods described in this application may be implemented in part or in whole by a special purpose computer created by configuring a general purpose computer to perform one or more specific functions embodied in a computer program. The above-mentioned function blocks, flow chart components and other elements serve as software specifications, which can be translated into a computer program by routine work of a skilled technician or programmer.

[0100] The computer program includes processor executable instructions stored on at least one non-transitory tangible computer readable medium. The computer program may also include or rely on stored data. The computer program may include a basic input / output system (BIOS) that interacts with the hardware of the special-purpose computer, device drivers that interact with specific devices of the special-purpose computer, one or more operating systems, user applications, background services, background applications, etc.

[0101] A computer program may include: (i) descriptive text to be parsed, such as HTML (Hypertext Markup Language), XML (Extensible Markup Language), or JSON (JavaScript Object Notation), (ii) assembly code, (iii) object code generated by a compiler from source code, (iv) source code for execution by an interpreter, (v) source code for compilation and execution by a just-in-time compiler, etc. By way of example only, the source code may be written using syntax from a language including: C, C++, C#, Objective C, Swift, Haskell, Go, SQL, R, Lisp, Fortran, Perl, Pascal, Curl, OCaml, HTML5 (Hypertext Markup Language Fifth Edition), Ada, ASP (Active Server Pages), PHP (PHP: Hypertext Preprocessor), Scala, Eiffel, Smalltalk, Erlang, Ruby, Visual Lua, MATLAB, SIMULINK, and

Claims

1. A leak detection system for a housing, comprising: a gas delivery system configured to selectively provide a tracer gas to the housing; and a first optical gas imaging sensor configured to generate an image of a surface of the enclosure after the gas delivery system fills the enclosure with a tracer gas, wherein the image is used to selectively detect a gas cloud adjacent to a surface of the housing, and The gas cloud is used to determine the location of a gas leak on the surface of the housing. 2 . The leak detection system of claim 1 , further comprising a positioning device configured to position one of the first optical gas imaging sensor and the housing relative to the other of the first optical gas imaging sensor and the housing. 3 .

3. The leak detection system of claim 1, further comprising a temperature controlled screen, wherein the surface of the housing is disposed between the first optical gas imaging sensor and the temperature controlled screen.

4. The leak detection system of claim 3, wherein an outer surface of the temperature controlled screen is black.

5. The leak detection system of claim 3, wherein the temperature controlled screen is heated to a temperature in the range of 10°F to 100°F above ambient temperature.

6. The leak detection system of claim 1, wherein the gas delivery system comprises a tracer gas source and a valve fluidly connecting the tracer gas source to the housing.

7. The leak detection system of claim 6, wherein the gas delivery system comprises a pump and a valve fluidly connecting the pump to the housing.

8. The leak detection system of claim 1, wherein the gas delivery system supplies a tracer gas selected from the group consisting of carbon dioxide (CO2), hydrocarbons, volatile organic compounds (VOCs), methane, carbon monoxide (CO), helium (He), molecular hydrogen (H2), and / or combinations thereof.

9. The leak detection system of claim 1, wherein the first optical gas imaging sensor comprises a gas filter having a predetermined passband around an absorption wavelength of the tracer gas.

10. The leak detection system of claim 1, further comprising a controller configured to communicate with the first optical gas imaging sensor, detect a gas cloud adjacent to a surface of the housing, and determine a location of a gas leak in response to the gas cloud.

Images