Leak detection using reflection-based imaging

Abstract

The invention relates to leak detection using reflection-based imaging. A leak detection system includes a transmitter, a detector, and an electronic control unit (ECU). The emitter directs electromagnetic energy having a predetermined wavelength range, such as infrared energy, towards the surface of the product. The product defines a closed chamber containing a trace amount of gas. The detector is located between the emitter and the product at an offset distance from the surface. The detector detects reflected energy. The ECU receives a signal from the detector indicative of an energy spectrum of the reflected energy and identifies a detected leak in the product. This includes comparing an energy spectrum of the reflected energy to a predetermined energy spectrum of the trace gas. The trace gas has a wavelength within a predetermined wavelength range of the emitter. The ECU generates an output signal in response to the leakage, wherein the output signal identifies the presence and location of the leakage.

Description

Background Technology

[0001] Leak testing of manufactured products may involve introducing an inert gas into the product's void volume, such as an inner cavity, chamber, fluid passage, or pipe. The gas is carefully sealed within the cavity. Several different methods are then used to detect leaks. For example, pressure decay within the void volume can be monitored over time, and detected pressure decay may indicate the presence of a leak. Another technique, known as "helium sniffing," involves filling the void volume with pressurized helium. A mass spectrometer is then used to detect the presence of helium in the surrounding air. While effective in some applications, these and other leak detection techniques are still not optimal when performing leak tests with high repeatability and precise resolution of leak location. Summary of the Invention

[0002] The following describes a reflection-based system and method for the precise detection and localization of leaks in products with defined internal volumes. During leak testing, this volume or enclosed chamber may be filled with trace amounts of a gas suitable for the application, such as carbon dioxide or helium. While countless consumer, transport, and industrial products possess such enclosed chambers, products used in non-limiting battery applications include battery trays, welded cold plates, battery covers, battery packs, battery cells, and various other objects of interest. Other non-battery vehicle products that will benefit from the leak testing and leak localization methods described in this paper include internal combustion engines, heat exchangers, and a wide range of non-vehicle products as well. If the enclosed chamber experiences a leak, a certain amount of the aforementioned trace gas will escape into the surrounding atmosphere. Therefore, the reflection-based leak testing solution presented herein aims to detect the presence of such leaks while precisely locating potential leak points. In response to the detection and localization of the leak, subsequent corrective actions can be taken as needed.

[0003] Specifically, a leak detection system according to a representative embodiment includes an emitter, a detector, and an electronic control unit (ECU), wherein “a” and “an” mean “at least one” or “one or more”, unless otherwise specified. During a leak test, the emitter, such as an infrared (IR) emitter or an array thereof, directs electromagnetic energy toward the surface of the product, wherein the energy has a predetermined wavelength range. As envisioned herein, the product defines the aforementioned enclosed chamber, which is filled with a desired trace amount of gas during the leak test. A detector configured to detect reflected energy from the product / its surface is positioned between the emitter and the product at a specific offset distance from the surface of the product.

[0004] In this exemplary configuration, the ECU receives an electronic input signal from the detector. This electronic input signal indicates / describes the spectrum of the reflected energy, and in particular, the wavelength / multiple wavelengths it detects. The ECU also identifies detected leaks in the product by comparing the spectrum of the reflected energy with a predetermined spectrum of a trace gas. This trace gas has wavelengths that fall within a predetermined wavelength range of the energy from the emitter. In one or more embodiments, this predetermined wavelength range is from approximately 2 micrometers (μm) to approximately 10 μm, while other possible wavelength ranges may be used in other applications of this teaching.

[0005] The ECU also generates an electronic output signal in response to a detected leak. This electronic output signal identifies both the presence and location of the leak. This information can be used by the ECU and / or production operators / maintenance personnel, for example, to correct the leak or perform root cause analysis. In one or more embodiments, the ECU can detect the presence and location of a leak by analyzing the difference in contrast between the energy spectrum of the reflected energy and a predetermined energy spectrum of the trace gas.

[0006] For certain constructions of the product, including exemplary battery components used in battery electric vehicles (BEVs), hybrid electric vehicles (HEVs), plug-in HEVs (PHEVs), or other vehicle or mobility systems, the predetermined offset distance from the surface of the product may be from approximately 0.25 meters (m) to approximately 5 meters, or approximately 10-200 inches.

[0007] The detector may include an image filter having a bandwidth covering the wavelengths of trace gases and energy from the emitter. In various embodiments, the emitter, which may be fixed or movable relative to the product, may comprise an array of emitters positioned or arranged near the product. In such embodiments, each respective emitter in the array is configured to illuminate the product from a different angle.

[0008] In one or more embodiments, the leak detection system may include a robot and / or an elevated gantry system (“gantry”). A detector may be attached to the robot, which is configured to move the detector relative to the product. In this or other embodiments, the gantry may be used to position the transmitter relative to the product. Optionally, a three-dimensional (3D) laser scanner that may be attached to the gantry may also be used as part of the leak detection system to scan the surface of the product and output a 3D scan file indicating the contour of the surface. In such an embodiment, the ECU may compare the contour of the surface with a calibration baseline contour to determine the surface distortion level of the product. The ECU may then generate an electronic output signal in part by using the surface distortion level.

[0009] This document also describes a leak detection method. One embodiment of such a method includes using an emitter to direct electromagnetic energy within a predetermined wavelength range toward a surface of a product. The method may include detecting the reflected energy by a detector, as described above, positioned between the emitter and the product surface at an offset distance. As part of the method, an ECU receives an electronic input signal from the detector, wherein the signal indicates the energy spectrum of the reflected energy. The method further includes identifying a detected leak in the product by the ECU. This action may include comparing the energy spectrum of the reflected energy with a predetermined energy spectrum of a trace gas. The trace gas, by its very nature, has wavelengths falling within the predetermined wavelength range of the emitter. The method also includes generating an electronic output signal in response to a detected leak, wherein the output signal identifies the presence and location of the leak.

[0010] A leak detection system according to another disclosed embodiment includes an IR emitter array configured to direct an IR energy beam in the wavelength range of approximately 2 μm to approximately 10 μm toward a surface of a product, wherein the product defines the aforementioned enclosed chamber. In this particular embodiment, the chamber contains carbon dioxide as a trace gas. An IR detector array is positioned between the IR emitter array and the product at an offset distance of less than approximately 5 m from the surface of the product. The IR detector array is configured to detect reflected IR energy during leak testing of the product. A 3D laser scanner and an ECU are also used as part of this non-limiting embodiment.

[0011] The ECU is configured to receive an electronic input signal from an IR detector array, indicating the energy spectrum of reflected IR energy. The ECU also commands a 3D scanner to generate a 3D scan file indicating the contour of a surface and compares this contour to a calibration baseline contour to determine the level of surface deformation in the product. Additionally, the ECU uses the surface deformation and compares the energy spectrum of reflected energy with a predetermined energy spectrum of trace gases to identify detected leaks in the product. Finally, the ECU generates an electronic output signal in response to a detected leak, identifying the presence and location of the leak.

[0012] This invention also includes the following technical solutions:

[0013] Option 1. A leak detection system, comprising:

[0014] A transmitter configured to direct electromagnetic energy within a predetermined wavelength range toward the surface of a product, the product defining a closed chamber containing trace amounts of gas;

[0015] A detector, positioned between the transmitter and the product at an offset distance from the surface of the product, wherein the detector is configured to detect reflected energy during a leakage test of the product; and

[0016] An electronic control unit (ECU) communicating with the detector, the ECU being configured to:

[0017] Receive an electronic input signal from the detector, the electronic input signal indicating the energy spectrum of the reflected energy;

[0018] Identifying a detected leak in the product includes comparing the energy spectrum of the reflected energy with a predetermined energy spectrum of the trace gas, wherein the wavelength of the trace gas falls within the predetermined wavelength range of the electromagnetic energy from the transmitter; and generating an output signal in response to the detected leak, the output signal identifying the presence and location of the leak.

[0019] Option 2. The leak detection system according to Option 1, wherein the transmitter includes an infrared (IR) transmitter.

[0020] Option 3. The leak detection system according to Option 2, wherein the predetermined wavelength range of the electromagnetic energy is from approximately 2 micrometers (μ) to approximately 10 μ.

[0021] Option 4. The leak detection system according to Option 1, wherein the offset distance from the surface of the product is approximately 0.25 meters (m) to approximately 5 meters.

[0022] Option 5. The leak detection system according to Option 1, wherein the detector includes a filter having a bandwidth covering the wavelength of the trace gas and the predetermined wavelength range of the electromagnetic energy from the transmitter.

[0023] Option 6. The leak detection system according to Option 1, wherein the ECU is configured to detect the presence and location of the leak by analyzing the difference in contrast between the energy spectrum of the reflected energy and the predetermined energy spectrum of the trace gas.

[0024] Option 7. The leak detection system according to Option 1, wherein the detector comprises a detector array located near the product, and wherein each corresponding detector in the detector array is configured to detect the reflected energy from a different angle.

[0025] Option 8. The leak detection system according to Option 1, wherein the transmitter is configured to move relative to the product.

[0026] Option 9. The leak detection system according to Option 1 further includes:

[0027] A robot, wherein the detector is connected to the robot, and wherein the robot is configured to move the detector relative to the product.

[0028] Option 10. The leak detection system according to Option 9 further includes:

[0029] A gantry configured to position the transmitter relative to the product.

[0030] Option 11. The leak detection system according to Option 1 further includes:

[0031] A three-dimensional (3D) laser scanner configured as follows:

[0032] Scan the surface of the product;

[0033] The 3D scan file is output to the ECU, the 3D scan file indicating the contour of the surface;

[0034] The surface profile is compared to a calibration baseline profile to determine the level of surface deformation of the product; and

[0035] The electronic output signal is generated using the surface deformation level.

[0036] Option 12. A leak detection method, comprising:

[0037] Electromagnetic energy within a predetermined wavelength range is directed to the surface of a product via an emitter, the product defining a closed chamber containing trace amounts of gas;

[0038] The reflected energy is detected by a detector, which is located between the emitter and the product at an offset distance from the surface of the product.

[0039] The electronic input signal is received from the detector by an electronic control unit (ECU), wherein the electronic input signal indicates the energy spectrum of the reflected energy;

[0040] Identifying a detected leak in the product via the ECU includes comparing the energy spectrum of the reflected energy with a predetermined energy spectrum of the trace gas, wherein the wavelength of the trace gas falls within the predetermined wavelength range of the electromagnetic energy from the transmitter; and

[0041] An electronic output signal is generated in response to the detected leak, the output signal identifying the presence and location of the leak.

[0042] Option 13. The leakage detection method according to Option 12, wherein:

[0043] The transmitter includes an infrared (IR) transmitter; and

[0044] Guiding the electromagnetic energy within the predetermined wavelength range includes guiding IR energy having wavelengths in the range of approximately 750 nanometers (nm) to approximately 10 micrometers (μ).

[0045] Option 14. The leakage detection method according to Option 13, wherein:

[0046] The trace gases include carbon dioxide; and

[0047] Guiding IR energy with wavelengths in the range of approximately 750 nm to approximately 10 μm includes guiding IR energy with wavelengths in the range of approximately 2 μm to approximately 10 μm.

[0048] Option 15. The leak detection method according to Option 13, wherein the offset distance from the surface of the product is approximately 0.25 meters (m) to approximately 5 meters.

[0049] Option 16. The leakage detection method according to Option 12, wherein guiding the electromagnetic energy within the predetermined wavelength range includes guiding the electromagnetic energy toward a vehicle component.

[0050] Option 17. The leak detection method according to Option 12, wherein identifying the detected leak includes analyzing the difference in contrast between the energy spectrum of the reflected electromagnetic energy and the predetermined energy spectrum of the trace gas.

[0051] Option 18. The leakage detection method according to Option 12 further includes:

[0052] The surface of the product is scanned using a three-dimensional (3D) laser scanner;

[0053] The 3D laser scanner outputs a 3D scan file to the ECU, the 3D scan file indicating the contour of the surface;

[0054] The surface profile is compared to a calibration baseline profile to determine the level of surface deformation of the product; and

[0055] The surface deformation level is used to generate the inspection output signal.

[0056] Option 19. A leak detection system, comprising:

[0057] An infrared (IR) emitter array configured to direct IR energy in the wavelength range of approximately 2 micrometers (μ) to approximately 10 μ to the surface of a product defining a closed chamber containing carbon dioxide as a trace gas;

[0058] An IR detector array is located between the IR transmitter array and the product at an offset distance of less than approximately 5 meters (m) from the surface of the product, wherein the IR detector array is configured to detect reflected IR energy during a leakage test of the product;

[0059] 3D laser scanner; and

[0060] An electronic control unit that communicates with the IR detector array is configured to:

[0061] Receive an electronic input signal from the IR detector array, the electronic input signal indicating the energy spectrum of the reflected IR energy;

[0062] The command instructs the 3D laser scanner to generate a 3D scan file indicating the contour of the surface;

[0063] The surface profile is compared with the calibration baseline profile to determine the level of surface deformation of the product;

[0064] Detected leaks in the product are identified by using surface deformation and comparing the energy spectrum of the reflected IR energy with a predetermined energy spectrum of the trace gas; and

[0065] An electronic output signal is generated in response to the detected leak, the electronic output signal identifying the presence and location of the leak.

[0066] Option 20. The leak detection system according to Option 19 further includes:

[0067] A robot configured to move the IR detector array relative to the product; and

[0068] A gantry configured to position the IR emitter array and the 3D laser scanner relative to the product.

[0069] The foregoing features and advantages, as well as other features and accompanying advantages, of this disclosure will become apparent when taken in conjunction with the accompanying drawings and the appended claims, through the following detailed description of illustrative examples and models for carrying out this disclosure. Furthermore, this disclosure expressly includes combinations and sub-combinations of the elements and features presented above and below. Attached Figure Description

[0070] Figure 1 This is a diagram of a reflection-based leak detection system constructed as described in this article.

[0071] Figure 1A The illustration shows a portion of a leak detection system according to a possible implementation.

[0072] Figure 2 and Figure 3 The diagram shows... Figure 1 and Figure 1A An alternative construction for leak detection systems.

[0073] Figure 4 This is a flowchart illustrating a robot-assisted leak detection method according to one aspect of the present disclosure.

[0074] This disclosure may be modified or implemented in alternative forms, wherein representative embodiments are shown in the accompanying drawings and described in detail below. The inventive step of this disclosure is not limited to the disclosed embodiments. Rather, this disclosure is intended to cover alternatives that fall within the scope of this disclosure as defined by the appended claims. Detailed Implementation

[0075] Referring to the accompanying drawings, the same reference numerals throughout several views denote the same features. Figure 1 A leak detection system 10 is illustrated, operable for precisely detecting and locating leaks in product 11. In a non-limiting use case, product 11 may be a component of vehicle 12. For example, vehicle 12 may be implemented as a battery electric vehicle (BEV), plug-in hybrid electric vehicle (PHEV), hybrid electric vehicle (HEV), range-extended electric vehicle (EREV), or another vehicle or other mobility system. In such embodiments, product 11 may include vehicle components such as battery trays, welded cold plates, battery covers, or other components of the vehicle battery. However, product 11 may include vehicle or non-vehicle components requiring leak testing and leak location as described herein, such as internal combustion engines, heat exchangers, etc. Therefore, other embodiments of product 11 are contemplated within the scope of this disclosure, and thus, the vehicle and mobility embodiments described herein represent only the teachings and not their limitations.

[0076] Figure 1 Product 11 has a surface 16 and defines a closed chamber 14. The closed chamber 14 can be implemented in various ways as a void volume, such as in the form of a cavity, tube, reservoir, etc. During a leak test of product 11, the closed chamber 14 is filled with a trace gas 18 suitable for the application, such that the closed chamber 14 contains the trace gas 18 during the leak test. The composition of the trace gas 18 can vary depending on the intended application. Exemplary inert gas compositions include, but are not limited to, carbon dioxide (CO2) and helium.

[0077] Figure 1The leak detection system 10 is based on the principle of energy reflection and imaging of the reflected energy spectrum of the escaping gas cloud from product 11 and / or trace gas 18. To this end, the leak detection system 10 includes an emitter 20 configured to direct light or other electromagnetic radiation (hereinafter referred to as emitted energy 120) of a predetermined wavelength range, either as a single beam, multiple beams, or a scanning beam, toward the surface 16 of product 11. In one or more representative embodiments, emitted energy 120 may be infrared (IR) energy, and emitter 20 may include an IR emitter. As used herein, the IR spectrum may encompass: energy having wavelengths from approximately 750 nanometers (nm) to approximately 1.4 micrometers (μm), i.e., near-infrared; energy having wavelengths from approximately 1.4 μm to approximately 3 μm (mid-infrared); and / or energy having wavelengths from approximately 3 μm to approximately 1 millimeter (mm), i.e., far-infrared. Non-IR wavelengths of emitted energy 120 may be used in other embodiments, such as visible light, ultraviolet energy, etc., and therefore, the infrared embodiments are illustrative of aspects of this teaching and not its limitation. When the emission energy 120 includes IR energy, the predetermined wavelength range of the emission energy 120 from the transmitter 20 may be from about 2 μ to about 10 μ, but this does not limit this teaching to such a range.

[0078] Additionally, the leak detection system 10 includes at least one detector 22. Each detector 22 is offset from the surface 16 by a distance (D). S The offset distance is located between the transmitter 20 and the product 11. This offset distance can vary within the scope of this disclosure depending on the construction of the product 11, wherein, according to embodiments, an offset distance of approximately 0.25 meters (m) to approximately 5 meters (approximately 10 inches to approximately 200 inches) is possible. When the product 11 is constructed as a battery tray as described above, the optimal separation distance can be approximately 1.1 meters to approximately 1.65 meters (approximately 45 inches to approximately 65 inches). The transmitter 20 is also offset relative to the detector 22 at an offset angle (θ). S The arrangement of detectors 22 varies depending on the intended application and the number of detectors 22 used in the construction of the leak detection system 10.

[0079] Figure 2 The detector 22 shown is configured to detect reflected energy 120R during a leak test of product 11, wherein reflected energy 120R returns to detector 22 when reflected from product 11 and / or a gas cloud composed of trace gases 18. Although for simplicity of illustration, detector 22 is... Figure 1 The diagram shows a pair of detectors 22, but in other embodiments, more or fewer detectors 22 may be used, as described below. Each detector 22 may include a filter 23 having a bandwidth covering the wavelengths of trace gas 18 and reflected energy 120R, thereby allowing these wavelengths and blocking other wavelengths.

[0080] Furthermore, according to this disclosure, the corresponding detector 22, as used herein, is configured to transmit an electronic input signal 122 to an electronic control unit (ECU) 50. The ECU 50 communicates with the detector 22 wirelessly and / or via physical transmission, and is therefore configured to receive the electronic input signal 122 from the detector 22. The electronic input signal 122, in itself, is an electrical signal indicating or describing the energy spectrum of the reflected energy 120R.

[0081] The ECU 50 in the various embodiments described below is equipped in hardware and programmed in software, i.e., configured to identify leaks detected in product 11. The ECU 50 achieves this by comparing the energy spectrum of the reflected energy 120R with a predetermined energy spectrum of the trace gas 18, for example, with a predetermined energy spectrum previously stored in the memory 54 of the ECU 50. The ECU 50 can also be configured to detect the presence and location of a leak by analyzing the difference in contrast between the energy spectrum of the reflected energy 120R and the predetermined energy spectrum of the trace gas 18. The trace gas 18 has wavelengths falling within a predetermined wavelength range of the detector 22. The ECU 50 is also configured to generate an output signal 500 in response to a detected leak, wherein the output signal 500 identifies the presence and location of the leak.

[0082] ECU 50 may be implemented as one or more computer devices and therefore includes hardware in the form of one or more application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), electronic circuitry, a central processing unit such as a microprocessor or processor 52, and associated computer-readable storage media, including memory 54. Instructions and other methods for implementing method 100 are executed by processor 52 from memory 54, which may be, for example, magnetic or optical media, CD-ROMs, and / or solid-state / semiconductor memories, such as random access memory (RAM) or read-only memory (ROM). Examples of method 100 are referred to below accordingly. Figure 4 The non-transitory components of the memory 54 used herein are capable of storing machine-readable instructions in the form of one or more software or firmware programs or routines, combinational logic circuits, input / output circuits and devices, signal conditioning and buffering circuits, and other components accessible by one or more processors to provide the functions described herein.

[0083] Brief Reference Figure 1A , Figure 1The leak detection system 10 can optionally be implemented using fixed components. In other words, no component of the leak detection system 10 is configured to move relative to other components. For example, in the illustrated configuration, product 11A, in the exemplary form of a welded cold plate having surface 16A, can be positioned relative to detector 22, while in other configurations, more than one detector 22 is possible. As described above, transmitter 20 can emit one or more beams of emission energy 120 toward surface 16A, wherein each beam has a [missing information - likely a specific energy level]. Figure 1 Trace gases of the same wavelength or wavelength range as 18. Figure 1A In the example of non-restricted welded cold plates, Figure 1 A trace amount of gas 18 can be inserted into product 11A as indicated by arrow AA. Subsequently, the trace amount of gas 18 can flow through a closed chamber 140, which is in the form of a meandering flow channel formed in the welded cold plate. The trace amount of gas 18 in this configuration eventually exits product 11A as indicated by arrow BB.

[0084] refer to Figure 2 , Figure 1 Product 11 can alternatively be constructed as a battery tray as described above. Such product 11B can be positioned near the aforementioned transmitter 20 on the fixing device 34 (see...). Figure 3 On the surface, the fixing device 34 is, for example, a fixing surface or a moving platform, such as a conveying device. Figure 2 In a representative embodiment, the emitter 20 is a scanning emitter, such as an IR scanner. Whether configured as a single device or multiple emitters 20, emitted energy 120, such as multiple energy beams as shown, illuminates the product 11B. Subsequently, the reflected energy 120R is detected by a detector array 22A collectively positioned near the product 11B. Each corresponding detector 22 in the detector array 22A is configured to detect the reflected energy 120R from the product 11B and / or trace gas 18 from a different angle.

[0085] Figure 3 The diagram illustrates an alternative leak detection system 10A. Figure 1 The leak detection system 10 includes a transmitter 20 configured to move relative to a product 11, which is shown in this example as... Figure 2 The representative product 11B. In this configuration, the leak detection system 10A may include one or more robots 32, such as a six-degree-of-freedom (6-DOF) industrial robot as shown. In this dynamic embodiment, the detector 22 is connected to the robot 32, wherein the robot 32 is configured to move the detector 22 relative to the product 11B as needed, for example in response to a leak from... Figure 1The command of ECU 50. Product 11B may be located in / on a fixture 34 as shown, wherein fixture 34 is configured differently as a fixed platform or table, or in different embodiments may be configured as a manual or automatic conveying device.

[0086] As part of this method, or perhaps without the use of robot 32, gantry 24 may be configured to position launcher 20 relative to product 11B. Gantry 24 may include various beams 25, horizontal rails 26, and upright support columns 27. Although omitted for simplicity, gantry 24 will be coupled to a motorized drive unit, drive belt, or another drive system operable for translating launcher 20 relative to product 11A. In various embodiments, ECU 50 may be assigned to control the motion of gantry 24 and / or robot 32, or such motion may be controlled by another computer system, such as a programmable logic controller, as is recognized in the art.

[0087] exist Figure 1 Leak detection system 10 or Figure 3 In a possible configuration of the leak detection system 10A, a three-dimensional (3D) laser scanner 30 can be connected to a gantry 24 via a rod 29 as shown, or to a robot 32 or another fixed / static or moving structure. The 3D laser scanner 30 can be configured to scan the surface 16 of the product 11. Figure 1 ), and then output the 3D scan file 300 to Figure 1 The ECU 50. The 3D scan file 300 indicates the contour of surface 16. The ECU 50 can compare the contour of surface 16 with a calibration baseline contour, for example, with a contour recorded in Figure 1 The calibration baseline profile in its memory 54 is compared to determine the surface deformation level of product 11. Then, ECU 50 can use the surface deformation level to generate... Figure 1 The electronic output signal 500 indicates that the level of surface deformation can be determined using an optional 3D laser scanner 30, for example, by taking this deformation into account when locating a leak, or for identifying the root cause of the leak.

[0088] This disclosure is also suitable for implementing automated reflection-based leak detection methods. Figure 1 The ECU 50 can be programmed using instructions that implement this method, wherein an optional robot-assisted version of method 100 is available. Figure 4 As shown in the diagram. For clarity, the following description is based on algorithm code segments or logic blocks. Figure 4 Unless otherwise stated, each block may be executed from memory 54 by processor 52 of ECU 50.

[0089] Generally, leak detection as described herein involves detecting the leakage from transmitter 20 (e.g., Figure 1The emitted energy 120 of the emitter 20 is directed toward the surface 16 of the product 11, and the emitted energy 120 has a predetermined wavelength range. The product 11 defines a closed chamber 14, which in turn contains a trace gas 18. Leak detection also includes detecting reflected energy 120R via detectors 22, wherein each detector 22 is offset from the surface 16 by an offset distance D between the emitter 20 and the product 11. The method described herein includes identifying a detected leak in the product 11 via an ECU 50. This may include comparing the energy spectrum of the detected reflected energy 120R with a predetermined energy spectrum of the trace gas 18. The trace gas 18, as described above, has wavelengths falling within the maximum and minimum limits of the predetermined wavelength range of the emitter 20. The ECU 50 then generates a gas in response to the detected leak. Figure 1 The electronic output signal 500 identifies the presence and location of the leak.

[0090] Regardless of whether or not Figure 3 With the assistance of robot 32, the methods envisioned herein may include directing the emitted energy 120 as IR energy having a wavelength in the range of approximately 750 nm to approximately 10 μm. For example, when the trace gas 18 includes CO2, this may require directing IR energy having a wavelength range of approximately 2 μm to approximately 10 μm, which may have an offset distance D of approximately 0.25 m to approximately 5 m. Directing the emitted energy 120 within the predetermined wavelength range may optionally include, in possible use cases as described above, directing the emitted energy 120 toward a battery tray, welding cold plate, or a cover for a vehicle battery.

[0091] Figure 4 The diagram illustrates the use of in Figure 3 An embodiment of method 100 for performing a leak test on product 11B with the assistance of robot 32 is shown. After initialization at block B101, for example, by starting a program on ECU 50, method 100 proceeds to block B102.

[0092] At block B102, robot 32 loads product 11B (i.e., the battery tray in this example) onto fixture 34. Therefore, block B102 requires placing product 11B in leak testing system 10A in preparation for leak testing. Method 100 then proceeds to block B104.

[0093] At block B104, ECU 50 controls the position of gantry 24, causing 3D laser scanner 30 to move to a horizontally elevated position relative to product 11B. Method 100 then proceeds to block B106.

[0094] Figure 4Block B106 requires the use of ECU 50 to command 3D laser scanner 30 to scan the outer perimeter and surface 16 of product 11B. Subsequently, 3D laser scanner 30 outputs a 3D scan file 300 to ECU 50, wherein the 3D scan file indicates the contour of surface 16 as described above. Method 100 then proceeds to block B107.

[0095] At block B107 Figure 1 The ECU 50 can predict surface deformation of product 11B based on the contents of 3D scan file 300. For example, the ECU 50 can compare the contour of surface 16 with a baseline to determine the level of surface deformation of product 11B. The deformation level can be saved and referenced later when determining the location and / or root cause of a detected leak. Method 100 then proceeds to block B108.

[0096] Figure 4 Block B108 may include moving the gantry 24 to a vertical position so that the movement of the robot 32 is unimpeded. Then, at block B110, the robot 32 may place a cover (not shown) on the fixture 34 for leak testing purposes. Once the cover is in place, the gantry 24 may be commanded to move back to a horizontal position at block B112. The leak test is then ready to begin.

[0097] Still referencing Figure 4 At block B114, ECU 50 can activate transmitter 20, which in this embodiment is positioned directly above product 11B. Once this occurs, method 100 proceeds to block B116, where robot 32 (or a group of cooperating robots or "cobots") uses the described method to scan product 11B for leaks. That is, detector 22 detects reflected energy 120R from its position between transmitter 20 and product 11B. Method 100 then proceeds to block B118.

[0098] At block B118, ECU 50 notifies or otherwise identifies the location of the leak in some way. For example, block B118 may include identifying the location of the leak on a display screen or in a data file, possibly with added audio broadcast. Method 100 then proceeds to block B120.

[0099] Figure 4 Block B120 includes repairing the identified leak. For example, an operator may enter the work cell and repair the identified leak. Method 100 then proceeds to block B121.

[0100] Block B121 includes determining whether the identified leak has been repaired. For example, options for block B121 include repeating the leak test, or performing another leak test online or offline. When the leak has not been repaired, method 100 may repeat block B116, while when the leak has been repaired, method 100 alternatively continues to block B122.

[0101] exist Figure 4 At block B122 of method 100 shown, ECU 50 can shut off the power to transmitter 20 before proceeding to block B124. There, ECU 50 can command gantry 24 to return to the vertical position (similar to block B108) and then proceed to block B126.

[0102] At block B126, ECU 50 commands robot 32 to remove the cap applied at block B110. Thereafter, method 100 continues to block B128, where robot 32 is commanded to... Figure 3 The fixing device 34 removes product 11B. Method 100 is completed at block B129. As will be readily recognized by those skilled in the art, other embodiments may be assisted by robot 32 with or without the aid of gantry 24.

[0103] Therefore, the above reference Figure 1-4 The described teachings enable optimal reflection-based imaging for leak detection in a wide variety of applications. Compared to prior art leak detection systems, these leak detection systems 10 and 10A do not require positioning the emitter 20 behind the trace gas 18 for radiation absorption before detection by the detector 22. Such as Figure 3 Embodiments of the method may be robot-assisted, wherein certain components of the leak detection systems 10 and 10A may be movable relative to the product 11. Optional scanning of the product 11, combined with surface profile data representing deformation, can be used to improve the accuracy of the disclosed leak detection results. These and other potential benefits will be readily apparent to those skilled in the art in light of this disclosure.

[0104] This disclosure allows for numerous different embodiments. Representative examples of this disclosure are shown in the accompanying drawings and described in detail herein as non-limiting examples of the disclosed principles. Therefore, elements and limitations described in the abstract, background, summary, and detailed description sections but not expressly set forth in the claims should not be incorporated into the claims, alone or collectively, by implication, inference, or otherwise.

[0105] For the purposes of this description, unless otherwise stated, the singular form is used to include the plural and vice versa; the terms “and” and “or” should be both conjunctions and adversative conjunctions; “any” and “all” should both mean “any and all”; and the terms “including,” “contains,” “comprising,” “containing,” “having,” etc., should mean “including but not limited to.” Furthermore, approximate terms such as “approximately,” “almost,” “substantially,” “roughly,” and “approximately” may be used herein in the sense of “being, near, or almost being” or “within 0-5% of it” or “within acceptable manufacturing tolerances” or logical combinations thereof.

[0106] Detailed descriptions and drawings or figures are provided to support and describe this teaching, but the scope of this teaching is defined only by the claims. While some best modes and other embodiments for carrying out this teaching have been described in detail, various alternative designs and embodiments exist for practicing the teaching as defined in the appended claims. Moreover, this disclosure expressly includes combinations and sub-combinations of the elements and features presented above and below.

Claims

1. A leak detection system, comprising: A transmitter configured to direct electromagnetic energy within a predetermined wavelength range toward the surface of a product, the product defining a closed chamber containing trace amounts of gas; A detector, positioned between the transmitter and the product at an offset distance from the surface of the product, wherein the detector is configured to detect reflected energy during a leakage test of the product; and An electronic control unit (ECU) communicating with the detector, the ECU being configured to: Receive an electronic input signal from the detector, the electronic input signal indicating the energy spectrum of the reflected energy; Identifying a detected leak in the product includes comparing the energy spectrum of the reflected energy with a predetermined energy spectrum of the trace gas, wherein the trace gas has a wavelength that falls within the predetermined wavelength range of the electromagnetic energy from the emitter; and An output signal is generated in response to the detected leak, the output signal identifying the presence and location of the leak.

2. The leak detection system according to claim 1, wherein, The transmitter includes an infrared (IR) transmitter.

3. The leak detection system according to claim 2, wherein, The predetermined wavelength range of the electromagnetic energy is from about 2 micrometers (μ) to about 10 μ.

4. The leak detection system according to claim 1, wherein, The offset distance from the surface of the product is approximately 0.25 meters (m) to approximately 5 meters (m).

5. The leak detection system according to claim 1, wherein, The detector includes a filter having a bandwidth covering the wavelength of the trace gas and the predetermined wavelength range of the electromagnetic energy from the transmitter.

6. The leak detection system according to claim 1, wherein, The ECU is configured to detect the presence and location of the leak by analyzing the difference in contrast between the energy spectrum of the reflected energy and the predetermined energy spectrum of the trace gas.

7. The leak detection system according to claim 1, wherein, The detector includes an array of detectors located near the product, wherein each corresponding detector in the array is configured to detect the reflected energy from a different angle.

8. The leak detection system according to claim 1, wherein, The transmitter is configured to move relative to the product.

9. The leak detection system according to claim 1, further comprising: A robot, wherein the detector is connected to the robot, and wherein the robot is configured to move the detector relative to the product.

10. The leak detection system according to claim 9, further comprising: A gantry configured to position the transmitter relative to the product.

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