JP2013101028A - Oil leakage detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oil leakage detector which detects leakage of oil by simple structure regarding the oil leakage detector which detects oil leakage from equipment.SOLUTION: An oil leakage detector is constituted by including: a light source part 2 for detection, which projects light of which the attenuation to water has wavelength larger than that of the attenuation to oil to a detection object area of oil leakage; and a determination part 4 which determines the presence/absence of the oil leakage on the basis of reflected light projected from the light source part 2 for detection and reflected on the detection object area.

Description

  The present invention relates to an oil leak detection device that detects an oil leak from a device, and relates to an oil leak detection device that detects an oil leak with a simple configuration.

  2. Description of the Related Art Conventionally, an apparatus for detecting leakage of oil filled in equipment has been known. As this type of oil leakage detection device, for example, the one described in Patent Document 1 is known. This oil leakage detection device is configured to detect oil leakage by, for example, previously dissolving SF6 gas as an oil leakage index substance in oil and detecting this gas.

Japanese Patent Laid-Open No. 06-213758

  However, since the oil leak detection device described in Patent Document 1 is configured to detect an oil leak by detecting a gas that has been dissolved in oil in advance, the device to be inspected for an oil leak is in response to the gas. It needs to be airtight. Therefore, it is difficult for the conventional oil leak detection device to detect an oil leak from a device that is not airtight with respect to the gas. Moreover, since it is necessary to dissolve gas in oil beforehand, it takes time and effort.

  In addition, there is a case where a device to be inspected for oil leakage is installed outdoors, and in such a case, it may get wet with rainwater, so it is necessary to distinguish between water and oil and detect the oil leakage.

  Accordingly, there is a need for an oil leak detection device that can detect oil leaks from equipment with a simple configuration even when the equipment to be inspected for oil leaks is installed in an environment where the equipment is wet with water.

  The present invention has been made paying attention to the above problems, and provides an oil leak detection device having a simple configuration and capable of detecting an oil leak even when the device is wet with water. With the goal.

  In order to achieve the above object, an oil leak detection apparatus according to an aspect of the present invention includes a light source unit for detection that projects light having a wavelength at which attenuation with respect to water is greater than attenuation with respect to oil onto a detection target region of oil leak. And a determination unit that determines the presence or absence of the oil leakage based on the reflected light projected from the detection light source unit and reflected by the detection target region.

  According to the oil leakage detection device according to one aspect of the present invention, light having an attenuation with respect to water having a wavelength larger than that with respect to oil is projected to the detection target region of the oil leakage, and reflected light reflected in the detection target region is reflected. Based on the configuration to determine the presence or absence of oil leakage, even if the equipment subject to detection of oil leakage is installed in an environment that gets wet with water, oil leakage is detected by distinguishing between water and oil Can do. Moreover, since it is the structure which determines the presence or absence of oil leak based on reflected light without requiring expensive apparatuses, such as a gas detector, oil leak can be detected with a simple structure.

1 is a block diagram illustrating a first embodiment of an oil leak detection device according to the present invention. It is an example of the image of the detection object area | region which has only the water droplet imaged by the imaging part for a detection in the said embodiment. It is an example of the image of the detection object area | region where only oil is imaged by the imaging part for a detection in the said embodiment. It is an example of the image of the detection object area | region to which the oil and water drop are imaged by the imaging part for a detection in the said embodiment. It is the figure which showed the image of the said FIG. 4 in the contour figure. FIG. 6 is a diagram showing the frequency distribution of the luminance of the divided image of the oil droplet area shown in FIG. 5, (a) is a diagram of address 5-5, (b) is a diagram of address 6-3, and (a) is an address FIG. 6-5 is a diagram. 5A and 5B are diagrams showing the luminance frequency distribution of the divided image of the water droplet area shown in FIG. 5, in which FIG. 5A is a diagram at address 5-7, and FIG. 5A and 5B are diagrams showing the luminance frequency distribution of the divided image of the painted surface area shown in FIG. 5, where FIG. 5A is a diagram of addresses 0-0, FIG. 5B is a diagram of addresses 4-2, and FIG. It is a figure of 4-4. It is a flowchart explaining operation | movement of the said 1st Embodiment. It is a block diagram which shows 2nd Embodiment of the oil leak detection apparatus by this invention.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 is a block diagram showing a first embodiment of an oil leakage detection apparatus according to the present invention.
In FIG. 1, an oil leakage detection device 10 of the present embodiment detects oil leakage from a device in which oil is enclosed, and includes a control unit 1, a detection light source unit 2, and a visual recognition light source unit 3. The determination unit 4, the recording unit 5, the display unit 6, and the I / F unit 7 are provided.

  The control unit 1 controls the entire apparatus, and performs, for example, lighting switching control of a detection light source unit 2 and a visual light source unit 3 described later.

  The detection light source unit 2 projects light having a wavelength that is greater in attenuation than water than that of oil into an oil leakage detection target region. For example, as shown in FIG. It is configured. In the present embodiment, the light source unit 2 for detection is configured to project light having an infrared wavelength, for example, a wavelength λ of 940 nm. The light of this wavelength (940 nm) has a particularly large attenuation with respect to water and a very small attenuation with respect to oil.

  For example, as illustrated in FIG. 1, the light source unit 2 for detection is disposed so as to project light having the above-described wavelength (940 nm) from an oblique direction with respect to the normal line of the light reflection surface R in the detection target region. ing.

  The visual light source unit 3 projects a light having a wavelength in the visible region onto the detection target region so that the detection target region can be viewed, and is a general visible light illuminator. When the light projected from the detection light source unit 2 is invisible light such as light having a wavelength in the infrared region as in the present embodiment, an oil leak inspector or the like is illuminated at night by illumination by the visual light source unit 3. Thus, the detection target area can be visually confirmed.

  For example, at the timing when the detection light source unit 2 is turned on, a detection imaging unit 4a described later captures an image and acquires image data. In other cases, the visual recognition light source unit 3 is turned on. As described above, the light source units 2 and 3 and the detection imaging unit 4a are synchronized, and the light source is switched at high speed, so that both the visibility of the detection target region and the detection of the oil leakage can be achieved.

  The determination unit 4 determines the presence or absence of oil leakage based on the reflected light projected from the detection light source unit 2 and reflected from the detection target region. For example, the detection imaging unit 4a and the image analysis unit 4b and a luminance determination unit 4c.

  The detection imaging unit 4a captures a detection target region and acquires an image based on reflected light, and is, for example, an image sensor that receives only light having a wavelength of 940 nm.

  Here, equipment such as industrial equipment that is an imaging target of the imaging unit 4a for detection is generally painted with a general paint that does not include pearl, metallic, or the like, such as a gray system. As a result, the light incident on the surface (reflection surface R) of the device to be imaged is scattered. Therefore, since light from the surface of the device that is not wet with rain or oil has a large amount of diffused scattered light components, the frequency distribution of the luminance of the image acquired by the imaging unit for detection 4a is narrowed and the standard deviation is small. It becomes. In addition, as described above, the detection target region is illuminated with light having a wavelength that is particularly attenuated with respect to water. Therefore, the light from the wet part of the device is attenuated and darkened as shown in FIG. On the other hand, the light incident on the oil surface is reflected in a direction according to the incident angle without being scattered. Thus, the light reflected from the surface of the oil is non-scattered light (that is, light that is not scattered but is reflected in a direction corresponding to the incident angle). Therefore, when there is a portion wetted with oil in the detection target region, the light from this region is mixed with scattered light from the painted surface and non-scattered light from the oil surface, as shown in FIG. Since the non-scattered light is brighter than the scattered light, the frequency distribution of the luminance of the image acquired by the detection imaging unit 4a becomes wide and has a large standard deviation. Although light from the surface of water is also non-scattered light, it is attenuated and darkened, so that as can be seen from FIG. 4 to be described later, non-scattered light from water and non-scattered light from oil can be easily distinguished. can do.

  In addition, the detection imaging unit 4a is disposed so as to be able to receive light projected from the detection light source unit 2 and regularly reflected by the reflection surface R in the detection target region. That is, the detection light source unit 2 is configured such that the angle formed between the normal line of the reflecting surface R and the optical axis L1 of the detection light source unit 2 is equal to the angle formed between the normal line and the axis L2 of the detection image capturing unit 4a. And an image pickup unit 4a for detection. By arranging in this way, the detection imaging unit 4a is incident light obliquely with respect to the normal line of the light reflection surface R in the detection target region and reflected by the reflection surface R as shown in FIG. Since an image based on (non-scattered light) can be acquired, the difference between the non-scattered light and the scattered light is easily understood.

  The image analysis unit 4b calculates the luminance of the image acquired by the detection imaging unit 4a. The image analysis unit 4b is configured to select, for example, a partial region of the image acquired by the detection imaging unit 4a and calculate the luminance of the image in the selected region.

  For example, as shown in FIG. 4, the image analysis unit 4 b is an image of an image of the reflection surface R (see FIG. 1) of the detection target region where oil (old oil, new oil) and water droplets are attached from the detection imaging unit 4 a. When data is input, as shown in FIG. 5, the result of calculating the luminance of the image of FIG. 4 is converted into a contour (contour line) diagram, and the information of the contour diagram is output to the recording unit 5 and the display unit 6. Record and display. In FIG. 4, the reflecting surface R (for example, the surface of the plate) is painted with a general paint that does not contain pearl, metallic, etc. For example, the size of the oil droplet is about 5 mm in diameter and the size of the water droplet. The diameter is about 2 mm. Further, for example, as illustrated in FIG. 5, the image analysis unit 4 b divides the entire image captured by the detection imaging unit 4 a into a plurality of small blocks, and the recording unit 5 divides the plurality of small blocks. The data (file) of the divided image is stored for each address (AB) represented by the vertical and horizontal coordinates of the image, the divided image is selected in the order of address, and the luminance of each pixel of the divided image is calculated. This luminance information is output to the luminance determination unit 4c for each divided image.

  The luminance determination unit 4c determines the presence or absence of oil leakage based on the luminance calculated by the image analysis unit 4b. The luminance determination unit 4c is configured to determine the presence or absence of oil leakage based on, for example, the frequency distribution state for the luminance calculated by the image analysis unit 4b. The determination result by the luminance determination unit 4c is output to, for example, the recording unit 5 and the display unit 6 through the image analysis unit 4b. Several examples of the frequency distribution state will be described below.

  6A and 6B are diagrams showing the frequency distribution of the luminance of the divided image of the oil droplet area shown in FIG. 5A, FIG. 6A is a diagram of the address 5-5, FIG. 6B is a diagram of the address 6-3, c) is a diagram of addresses 6-5. As can be seen from these frequency distribution states, since the image of the region including the oil droplets includes non-scattered light, the luminance distribution of the image includes a region with high luminance. FIGS. 7A and 7B are diagrams showing the luminance frequency distribution of the divided image of the water droplet area shown in FIG. 5, wherein FIG. 7A is a diagram of address 5-7 and FIG. 7B is a diagram of address 5-8. . As can be seen from these frequency distribution states, since the image of the region including water droplets includes a portion where light reflection is small, the luminance distribution of the image includes a low luminance region. FIG. 8 is a diagram showing the luminance frequency distribution of the divided image of the painted surface area shown in FIG. 5, where (a) is a diagram of address 0-0 and (b) is a diagram of address 4-2. (C) is a diagram of an address 4-4. As can be seen from these frequency distribution states, the image of the area that does not contain water droplets or oil droplets, that is, the image of the painted surface that does not contain pearl or metallic, is often due to diffuse scattered light, so the luminance distribution of that image Becomes narrow and has a small standard deviation.

  As described above, the luminance determination unit 4c uses the fact that the luminance frequency distribution state differs between when oil leaks and when it enters wet with water and when it does not wet with oil or water, The presence or absence of oil is detected by distinction. Specifically, for example, the luminance determination unit 4c calculates the frequency distribution of the luminance of the divided image, and determines that there is no oil or water when the standard deviation is equal to or less than a predetermined threshold. On the other hand, when the standard deviation exceeds the threshold value and the average luminance value is equal to or less than the predetermined threshold value, it is determined that there is water (wet only in water), and the standard deviation is the threshold value. If the average value of the luminance exceeds a predetermined threshold, it is determined that there is oil (no water).

  The recording unit 5 records and holds data such as luminance information by the image analysis unit 4b, contour diagram information, divided image information, and determination results by the luminance determination unit 4c.

  The display unit 6 displays an image (monochrome image) or a divided image (monochrome image) of the entire detection target area imaged by the detection imaging unit 4a, or a contour of luminance calculated by the image analysis unit 4b. The figure, the determination result of the luminance determination unit 4c, and the image etc. that identifies and highlights the oil leak location are displayed, and this makes it possible to visually provide information such as oil leak to the operator. it can.

  The I / F unit 7 outputs oil leakage detection result data to the outside. For example, the I / F unit 7 is connected to the determination unit 4 (image analysis unit 4b) and outputs the determination result data to the outside. Is configured to do.

  Next, operation | movement of the oil leak detection apparatus 10 of this embodiment is demonstrated based on FIG.

  First, in STEP 1, the detection light source unit 2 projects light of a specific wavelength (940 nm) in the infrared region onto the oil leak detection target region, and the detection imaging unit 4a images the oil leak detection target region, The image data is output to the image analysis unit 4b.

  In STEP 2, the image analysis unit 4 b divides the entire image captured by the detection imaging unit 4 a into a plurality of small blocks, and the recording unit 5 stores data (files) of the plurality of divided images divided into the small blocks. Saved for each address (A-B) expressed in vertical and horizontal coordinates of the image.

  In STEP 3, the image analysis unit 4b selects divided images in the order of addresses, and in STEP 4, the image analysis unit 4b calculates the luminance of each pixel of the divided image. This luminance information is output to the luminance determination unit 4c for each divided image.

  In STEP 5, the luminance determination unit 4c obtains the frequency distribution of the luminance of the divided image, and in STEP 6, determines whether the standard deviation is equal to or less than a predetermined threshold value. When it determines with a standard deviation being below a threshold value (STEP5: Yes), it determines with neither oil nor water (STEP6a), and progresses to STEP10. On the other hand, when it is determined that the standard deviation is not less than the threshold value (STEP 5: No), the process proceeds to the next STEP 7, where it is determined whether or not the average luminance value is less than or equal to a predetermined threshold value. When it is determined that the average value of the luminance is equal to or less than the threshold (STEP 7: Yes), the presence of water (wet only in water) is detected (STEP 7a), and the process proceeds to STEP 10. On the other hand, when it determines with the average value of brightness | luminance not being below a threshold value (STEP7: No), presence of oil (no water) is detected (STEP8), and it progresses to the next STEP9.

  In STEP 9, the luminance determination unit 4c specifies, for example, a pixel position whose luminance is equal to or higher than a predetermined threshold as an oil leakage location, and the display unit 6 sets the pixel of the oil leakage location specified by the luminance determination unit 4c to high. A warning action is performed by displaying the light.

  In STEP 10, the recording unit 5 records and holds the luminance information by the image analysis unit 4b, the contour diagram information and the divided image information, the determination result of the luminance determining unit 4c, and the like, and proceeds to the next STEP11.

  In STEP 11, the luminance determination unit 4c determines whether or not all of the plurality of divided images have been analyzed by the image analysis unit 4b. If it is determined that all of the divided images have been analyzed (STEP 11: Yes), the process proceeds to STEP 12. When it is determined that not all have been analyzed (STEP 11: No), the process returns to STEP 3 and the operations from STEP 3 to STEP 11 are performed.

  In STEP 12, the display unit 6 reads all the information on the oil leak points specified for each divided image from the recording unit 5, highlights all the oil leak points in the entire image before the division, and displays the entire inspection result. And the oil leakage inspection is completed.

  According to the above embodiment, light having a wavelength that is greater than the attenuation with respect to water is projected onto the detection target area of the oil leak, and the presence or absence of the oil leak is determined based on the reflected light reflected by the detection target area. Since it is the structure to determine, even if it is the case where the apparatus of the detection target of oil leak is installed in the environment where it gets wet with water, oil leak can be detected by distinguishing water and oil. In addition, an expensive device such as a gas detector is not required, and the oil leakage can be detected with a simple configuration because the configuration simply determines the presence or absence of oil leakage by image processing.

FIG. 10 is a block diagram showing a second embodiment of the oil leak detection apparatus according to the present invention. Here, the same elements as those in the first embodiment of FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted, and only different parts will be described. Since operations other than the recording image pickup unit 8 described below are the same as those in the first embodiment, description thereof will be omitted.
In the present embodiment, a recording imaging unit 8 is provided.

  The recording imaging unit 8 receives light having a wavelength in the visible region and images the detection target region for recording. For example, the recording imaging unit 8 is a general one that can output captured color image data to the outside. is there. The recording imaging unit 8 is controlled by the control unit 1 so as to perform an imaging operation in synchronization with the visual light source unit 3, for example, and the captured color image data is captured by the recording unit 5 by the detection imaging unit 4a. Stored in association with the monochrome image data.

  According to the above embodiment, since the recording imaging unit 8 is provided, the detection image (black and white image) can be recorded in association with the visible image (color image). The image can be confirmed not only as a black and white image but also as a color image (visible image).

  In the present embodiment, the recording imaging unit 8 has been described as being provided separately from the detection imaging unit 4a as shown in FIG. 10, but this is not a limitation, and although not illustrated, one imaging unit is provided. Thus, the detection imaging unit 4a and the recording imaging unit 8 may be configured to be used together. For example, the detection imaging unit 4a and the recording imaging unit 8 are configured to be shared by a single imaging unit provided with a filter capable of switching the wavelength range of light that can be received at high speed.

  In the first and second embodiments, the image analysis unit 4b selects a partial area of the image and calculates the luminance for the image in the selected area. However, the present invention is not limited to this. The luminance of each pixel may be calculated for the entire image without dividing the image.

  In the first and second embodiments, the luminance determination unit 4c has been described in the case of determining the presence or absence of oil leakage based on the frequency distribution state for the luminance calculated by the image analysis unit 4b. However, the present invention is not limited to this, and it may be configured to simply determine that oil is leaking when the luminance calculated by the image analysis unit 4b is equal to or higher than a predetermined threshold.

  In the said 1st and 2nd embodiment, although demonstrated in the case where the light source part 3 for visual recognition was provided, it does not need to provide not only this but. Further, the wavelength of the light projected from the detection light source unit 2 is the wavelength in the infrared region, particularly 940 nm. However, the wavelength is not limited to this, and if the attenuation with respect to water is larger than the attenuation with respect to oil, Any wavelength range may be used.

  In the first and second embodiments, the determination unit 4 captures the detection target region and acquires an image based on the reflected light, and the luminance of the image acquired by the detection imaging unit 4a. In the above description, the image analysis unit 4b for calculating the image and the luminance determination unit 4c for determining the presence or absence of oil leakage based on the luminance calculated by the image analysis unit 4b are described. As long as it is the structure which determines the presence or absence of an oil leak based on the reflected light which was projected from the light source part 2 and reflected in the detection object area | region, what kind of structure may be sufficient. Specifically, for example, the determination unit 4 includes a light receiving unit that measures the received light intensity of the reflected light and an intensity determination unit that determines the presence or absence of oil leakage based on the intensity of the reflected light.

2 ... Light source for detection 3 ... Light source for visual recognition 4 ... Determining part 4a ... Detecting imaging part 4b ... Image analyzing part 4c ... Luminance judging part 8 ... Recording imaging part 10 ..Oil leak detector

Claims (9)

A light source unit for detection that projects light having a wavelength that is greater than the attenuation of oil to water to the detection target region of oil leakage;
A determination unit that determines the presence or absence of the oil leakage based on the reflected light that is projected from the detection light source unit and reflected by the detection target region;
An oil leak detection device comprising:   The determination unit includes a detection imaging unit that images the detection target region and acquires an image based on the reflected light, an image analysis unit that calculates luminance of the image acquired by the detection imaging unit, and the image The oil leakage detection device according to claim 1, further comprising: a luminance determination unit that determines presence or absence of the oil leakage based on the luminance calculated by the analysis unit.   The oil leak detection device according to claim 2, wherein the brightness determination unit determines the presence or absence of the oil leak based on a frequency distribution state of the brightness calculated by the image analysis unit.   The oil leakage detection device according to claim 2, wherein the luminance determination unit determines that the oil is leaking when the luminance calculated by the image analysis unit is equal to or greater than a predetermined threshold.   The oil leakage detection according to any one of claims 2 to 4, wherein the image analysis unit selects a partial region of the image and calculates the luminance for the image of the selected region. apparatus. The detection light source unit is arranged so as to project light of the wavelength from an oblique direction with respect to a normal line of a light reflection surface in the detection target region,
The said detection imaging part is arrange | positioned so that the light projected from the said light source part for detection and the regular reflection by the said reflective surface in the said detection object area | region can be received. The oil leak detection apparatus according to one.   The oil leak detection device according to claim 1, wherein the wavelength is an infrared wavelength.   The light source part for visual recognition which light-projects the light of the wavelength of a visible region to the said detection object area | region, and makes the said detection object area | region visible is provided, The one of Claims 1-7 characterized by the above-mentioned. Oil leak detection device.   The oil leakage detection device according to claim 8, further comprising a recording imaging unit that receives light having a wavelength in the visible region and images the detection target region for recording.