Vehicle inspection device

Abstract

To provide a vehicle inspection device that does not require multiple imaging means and is easy to handle. [Solution] The vehicle inspection device 1 comprises: an illumination means 2 that illuminates at least the left and right sides of the vehicle body surface of the vehicle 6 to be inspected; a controller 3 that controls the illuminance of the light emitted by the illumination means 2; an imaging means 4 that photographs the vehicle body surface illuminated by the illumination means 2; and an image processing means 5 that outputs inspection results regarding the quality of the vehicle body surface based on the output of the imaging means 4. The illumination means 2 has a pair of light-emitting surfaces 10 that sandwich the vehicle 6 from the left and right, and each light-emitting surface 10 is shorter than the total length of the vehicle 6 in the front-rear direction of the vehicle 6, taller than the total height of the vehicle 6 in the up-down direction of the vehicle 6, and curves concavely toward the vehicle 6. The controller 3 is capable of adjusting the illuminance of the light-emitting surface 10 for each of the multiple regions divided in the height direction of the light-emitting surface 10.

Description

Technical Field

[0001] The present invention relates to a vehicle inspection device.

Background Art

[0002] The inspection process in the vehicle manufacturing line includes surface inspection for inspecting the presence or absence of defects such as scratches on the painted surface of the vehicle body. Conventionally, this type of surface inspection has often been performed visually by an operator. The operator approaches the vehicle body while illuminating the side surface and roof of the vehicle to be inspected with lighting means, and observes the illuminated parts from various angles while looking closely at the vehicle body to determine the presence or absence of defects. In some cases, a large support such as a scaffold is constructed to support the lighting means at intervals from the positions on both sides and above the vehicle body so that the operator can approach the vehicle body for inspection.

[0003] On the other hand, in recent years, a technique has been proposed in which an imaging means is used to photograph the painted surface of a vehicle body to be inspected, and the presence or absence of defects is automatically determined based on the obtained image.

[0004] Patent Document 1 discloses a vehicle inspection device in which a plurality of imaging means are arranged vertically on both sides of a vehicle body, and in a state where the vehicle body to be inspected is illuminated with illumination light, the images obtained for each imaging means are subjected to image analysis to obtain inspection results regarding the presence or absence of defects on the painted surface.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] The vehicle inspection device described in Patent Document 1 is equipped with an illumination means that emits light with a uniform illuminance across the entire illumination surface to illuminate both sides of the vehicle body. However, it is generally difficult to make the distance between the vehicle body side, which has a complex shape, and the illumination surface of the illumination means uniform. Therefore, the vehicle inspection device described in Patent Document 1 installs multiple imaging means, each with a narrow field of view, in a vertical arrangement on both sides of the vehicle body, and performs imaging by adjusting the shooting settings for each of these imaging means and then dividing the imaging area among them. In this way, the vehicle inspection device described in Patent Document 1 obtains an image that is close to what would be obtained if the entire vehicle body were illuminated without unevenness. Consequently, a large number of imaging means are required, and the adjustment of the shooting settings for each of the numerous imaging means is necessary, which is excessively complicated.

[0007] The technology disclosed herein has been developed in view of the circumstances described above, and aims to provide a vehicle inspection device that does not require a large number of imaging means, and therefore eliminates the hassle of adjusting the shooting settings for each of the numerous imaging means, thereby simplifying its operation. [Means for solving the problem]

[0008] One vehicle inspection apparatus according to the present disclosure includes: an illumination means for illuminating at least the left and right sides of the vehicle body surface of a vehicle to be inspected; a controller for controlling the illuminance of the light emitted by the illumination means; an imaging means for photographing the vehicle body surface illuminated by the illumination means; and an image processing means for outputting an inspection result regarding the quality of the vehicle body surface based on the output of the imaging means. The illumination means has a pair of light-emitting surfaces that sandwich the vehicle from the left and right, and each of the light-emitting surfaces is shorter than the overall length of the vehicle in the front-rear direction of the vehicle, taller than the overall height of the vehicle in the vertical direction of the vehicle, and curved concavely toward the vehicle. The controller can adjust the illuminance of the light-emitting surface for each of a plurality of regions divided in the height direction of the light-emitting surface. [Effects of the Invention]

[0009] One vehicle inspection device in this disclosure allows for adjustment of the illuminance for each of the multiple regions divided in the height direction of the light-emitting surface of the lighting means. Therefore, the brightness of the vehicle illuminated by the lighting means is adjusted to be uniform in the height direction. This eliminates the need to arrange a large number of imaging means in a line in the height direction, making it possible to realize a vehicle inspection device that is easy to handle. [Brief explanation of the drawing]

[0010] [Figure 1] This is a front view showing the vehicle inspection device of this disclosure. [Figure 2] Figure 1 is a side view of the vehicle inspection device. [Figure 3] This is a functional block diagram showing the vehicle inspection device disclosed herein. [Figure 4] Figure 3 shows the division of the image area to be evaluated by the lighting controller. [Figure 5] This figure shows the data structure of the table data stored in the table data storage unit in Figure 3. [Modes for carrying out the invention]

[0011] A vehicle inspection device according to one aspect of this disclosure will be described with reference to the drawings. In Figures 1 to 3, which are referenced below, corresponding parts are denoted by the same reference numerals.

[0012] Figure 1 is a front view of a vehicle inspection device 1 according to one aspect of this disclosure, Figure 2 is a side view of the vehicle inspection device 1, and Figure 3 is a functional block diagram of the vehicle inspection device 1.

[0013] The vehicle inspection device 1 comprises a lighting means 2, a controller 3, an imaging means 4, and an image processing means 5.

[0014] The vehicle 6 to be inspected by the vehicle inspection device 1 is placed on a belt conveyor 7 installed on the production line and moves at a constant speed in the forward and backward direction.

[0015] The lighting means 2 includes a light source 8, such as an LED, and a diffuser plate 9, such as one made of acrylic resin, provided on the light-emitting side of the light source 8. The diffuser plate 9 has a surface facing the light source 8 and a light-emitting surface 10 on the back of this surface, which faces the vehicle 6 to be inspected and irradiates the vehicle 6 with light. The lighting means 2 also includes a support body 11 (Figure 2) that faces the diffuser plate 9 and supports the light source 8 and the diffuser plate 9. The light source 8 is positioned between the diffuser plate 9 and the support body 11.

[0016] The lighting means 2 in the vehicle inspection apparatus 1 of this disclosure does not require a worker to stand between the vehicle body of the vehicle to be inspected and the lighting means 2 to perform a visual inspection, as in conventional systems. It does not require securing space for a worker to stand between the vehicle body and the lighting means 2, and the distance between the vehicle body and the lighting means 2 can be made relatively narrow, resulting in an overall compact size. Such a lighting means 2 can take the form of a portable unit that can be moved together with the support body 11. When made portable, it has the advantage of being able to be moved and used, for example, on an adjacent production line.

[0017] The light-emitting surface 10 includes a pair of light-emitting surfaces 10a and 10b that sandwich the vehicle 6 from the left and right. As shown in Figure 1, each of the light-emitting surfaces 10a and 10b is curved concavely toward the vehicle 6. Also, as can be easily understood by referring to Figure 2, each of the light-emitting surfaces 10a and 10b is shorter than the total length of the vehicle 6 in the front-rear direction and taller than the total height of the vehicle 6 in the up-down direction. The length of the light-emitting surfaces 10a and 10b in the front-rear direction of the vehicle 6 is, for example, about 1000 millimeters. Although the length of the light-emitting surfaces 10a and 10b in the front-rear direction of the vehicle 6 is shorter than the total length of the vehicle 6, the vehicle 6 is placed on the belt conveyor 7 and moves at a constant speed, so its entire length is illuminated by the lighting means 2 in such a way that it is scanned by the movement.

[0018] In this disclosure, the diffuser plate 9 has a pair of light-emitting surfaces 10a and 10b and is connected in a continuous line above the vehicle 6. However, it is not necessary for the diffuser plate 9 to be connected in a continuous line in this way, and it may be interrupted.

[0019] The imaging means 4 captures an image of the body surface of the vehicle 6 illuminated by the illumination means 2. The imaging means 4 in the present disclosure includes a left camera 4a arranged so as to include an area on the left side surface of the vehicle 6 illuminated by the light irradiation surface 10a within the imaging field of view, and a right camera 4b arranged so as to include an area on the right side surface of the vehicle 6 illuminated by the light irradiation surface 10b within the imaging field of view.

[0020] Both the left camera 4a and the right camera 4b are line cameras having line sensors arranged in a single row in the vertical direction. Similar to a general line camera, the imaging fields of view of the left camera 4a and the right camera 4b are ranges determined by the vertical viewing angle in the vertical direction and cover the entire vertical direction of the side surface of the vehicle 6. The imaging field of view in the scan direction orthogonal to the vertical direction is the relative movement range with respect to the vehicle 6 as the subject. Since the vehicle 6 is placed on the belt conveyor 7 and moves at a constant speed, as a result, the left camera 4a and the right camera 4b cover the entire length of the vehicle 6 within the imaging field of view in the scan direction. That is, the left camera 4a and the right camera 4b include the area illuminated by the illumination means 2 within the imaging field of view. The left camera 4a and the right camera 4b perform line scan processing on the image data obtained by the imaging operation for such an imaging field of view to obtain the image data constituting the subsequent frames.

[0021] The illumination means 2 is capable of adjusting the illuminance of the light irradiation surface 10 for each of a plurality of regions divided in the height direction of the light irradiation surface 10. The adjustment of the illuminance is performed under the control of the controller 3. The light irradiation surface 10 in the illumination means 2 of the present disclosure is divided into a lower region RE1, a middle region RE2, and an upper region RE3 in order from bottom to top in the height direction. A lower region light source 8a is arranged corresponding to the lower region RE1, a middle region light source 8b is arranged corresponding to the middle region RE2, and an upper region light source 8c is arranged corresponding to the upper region RE3. The lower region light source 8a, the middle region light source 8b, and the upper region light source 8c are each composed of, for example, a plurality of LEDs.

[0022] By the way, in the vehicle inspection device 1 of the present disclosure, the light irradiation surface 10 including the lower region RE1, the middle region RE2, and the upper region RE3 is curved concave toward the vehicle 6.

[0023] Here, for example, let's assume a light source with a non-curved light-emitting surface that extends straight from bottom to top. Generally, the side of a vehicle body, although there are some differences depending on the vehicle model, has a curved surface that bulges outward in the width direction. As a result, the diffusion distance and incident angle of light emitted from a flat light source differ depending on the location in the vertical direction within the side of the vehicle body, causing uneven brightness and inconsistencies on the side of the vehicle body.

[0024] In contrast, in the vehicle inspection device 1 of this disclosure, the light irradiation surface 10, which includes the lower region RE1, the middle region RE2, and the upper region RE3 of the light source 8, is curved concavely toward the vehicle 6. As a result, the degree to which the light diffusion distance and incident angle differ depending on the location in the vertical direction within the side of the vehicle body is reduced compared to conventional light sources. As a result, the brightness of the side of the vehicle body becomes nearly uniform and unevenness is reduced.

[0025] Furthermore, because the light-emitting surface is curved, even the complex shapes of the vehicle body sides, including uneven surfaces, will have uniform brightness regardless of their vertical position. For example, even the upward-facing surface near the side window of the vehicle body can be illuminated from a direction relatively close to the normal direction by illumination light from the upper region RE3, which is the part of the light-emitting surface 10 that is relatively close to directly above this surface. As a result, even the complex shapes of the vehicle body sides, including uneven surfaces, will have uniform brightness regardless of their vertical position. Therefore, the entire left and right sides of the vehicle body can be inspected under uniform conditions using a single imaging device.

[0026] Generally, when a surface illuminated by a light source has an angle θ with respect to the direction of light propagation (corresponding to the angle with the normal to the surface), the illuminance on that surface decreases to a value obtained by multiplying the illuminance when the light is incident in a direction directly facing the surface by the cosine of θ. In the vehicle inspection device 1 of this disclosure, even upward-facing surfaces as exemplified above are illuminated from a direction that is nearly directly facing the surface among the curved light-emitting surfaces 10, so such surfaces do not become too dark. As a result, the brightness unevenness across the entire left and right sides of the vehicle body is reduced.

[0027] As described above, in the vehicle inspection device 1 of this disclosure, the brightness of the vehicle body side becomes substantially uniform regardless of location in the vertical direction, resulting in less unevenness. Therefore, the entire left and right sides of the vehicle body can be inspected under uniform conditions using a single imaging device.

[0028] Furthermore, in the vehicle inspection device 1 of this disclosure, the lower region RE1 curves concavely toward the vehicle 6, with its lower end extending downward to the lower part of the side of the vehicle body 6. Therefore, the area up to the lower part of the side of the vehicle body can be illuminated with the necessary illumination for inspection, and it is possible to perform a proper inspection up to this range.

[0029] The vehicle inspection device 1 of this disclosure will be further described with reference to the functional block diagram in Figure 3.

[0030] In Figure 3, the system controller 12 receives the imaging output from the left camera 4a and the right camera 4b, which are the imaging means 4, and supplies output to control the illuminance of the light sources 8, which are the lower region light source 8a, the middle region light source 8b, and the upper region light source 8c. As a result, the illuminance of the lower region RE1, the middle region RE2, and the upper region RE3 of the light-illuminated surface 10 is adjusted, and the body of the vehicle 6 becomes uniformly bright regardless of its vertical position, as described above.

[0031] The system controller 12 includes a lighting controller 13 as a controller 3 for the lighting means 2, and an image processing unit 15 as an image processing means 5 that outputs an inspection output related to the quality of the vehicle body surface of the vehicle 6 to the display unit 14 based on the output of the imaging means 4. The image processing unit 15 performs calculation processing for the inspection output related to the quality of the vehicle body surface of the vehicle 6 based on the outputs of the left camera 4a and the right camera 4b, which are the imaging means 4. The calculation processing for such vehicle appearance inspection is a general one.

[0032] In order to perform a uniform external inspection of the entire vehicle body of vehicle 6, it is necessary to adjust how the vehicle body is illuminated by the light source 8 so that the brightness is uniform regardless of the vertical position of the vehicle body. For this adjustment, the lighting controller 13 controls the illuminance of the lower area light source 8a, the middle area light source 8b, and the upper area light source 8c of the light source 8. The illuminance control by the lighting controller 13 is performed based on a predetermined reference luminous emission illuminance data SD. The hardware used to construct the reference luminous emission illuminance data SD and its operation will be described next. Note that the construction of the reference luminous emission illuminance data SD is performed in advance, separately from the control of the illuminance of the light source 8 itself.

[0033] The image processing unit 15 supplies at least one frame of image data from the output of the left camera 4a and the right camera 4b to the lighting controller 13. The lighting controller 13 evaluates the signal level of the video signal (luminance signal) for each image region divided into multiple sections in the height direction for each frame of image from the output of the left camera 4a and the right camera 4b.

[0034] The signal level of the video signal (luminance signal) for each image region corresponds to the brightness of the vehicle body surface when the vehicle body surface of the subject of the left camera 4a and the right camera 4b is illuminated by the lighting means 2.

[0035] In the above-described configuration, image data from at least one frame from the left camera 4a and the right camera 4b is supplied to the lighting controller 13 via the image processing unit 15. Alternatively, image data from at least one frame from the left camera 4a and the right camera 4b can be supplied to the lighting controller 13 without going through the image processing unit 15. In either configuration, the lighting controller 13 is supplied with image data from the left camera 4a and the right camera 4b.

[0036] When dividing a single frame of an image into multiple image regions in the height direction, one possible approach is to divide the output image of a certain frame from both the left camera 4a and the right camera 4b into lower image regions, middle image regions, and upper image regions, sequentially from bottom to top in the height direction.

[0037] Figure 4 conceptually illustrates, as described above, how the output image of a single frame from the left camera 4a and the right camera 4b is divided sequentially from bottom to top in the height direction into the lower image region 16, the middle image region 17, and the upper image region 18, using a single frame output image 19 based on the output of the left camera 4a as a representative example.

[0038] The control of the lighting controller 13 over the lighting means 2 when the image area is set as shown in Figure 4 above will be explained in more detail.

[0039] The vehicle inspection device 1 of this disclosure photographs the left and right sides of the vehicle 6, which is illuminated by the lighting means 2, with a left camera 4a and a right camera 4b, which are line cameras, respectively, and inspects the quality of the vehicle body surface based on the images obtained from these photographs. As a condition for performing this inspection, it is desirable that the vehicle body is illuminated by the lighting means 2 in such a way that the brightness is as uniform as possible from the bottom to the top of the vehicle body, so that inspection results can be obtained under uniform conditions for the entire vehicle body.

[0040] Image processing for inspection by the image processing unit 15 is performed on the left and right sides of the vehicle 6 captured in the images obtained by the left camera 4a and the right camera 4b. If one frame of the captured image is divided into three image regions from bottom to top as shown in Figure 4, and the illumination by the lighting means 2 is adjusted so that the video signal levels of each image region are close, then the brightness from the bottom to the top of the vehicle body can be considered to be approximately uniform, which is the condition for inspection.

[0041] On the other hand, if the paint specifications are different, the brightness of the vehicle body surface will show different values ​​even if the lighting means 2 illuminates it with the same illuminance. For example, the brightness of so-called solid color paints and metallic color paints will differ even if illuminated with the same illuminance from the lighting means 2. Also, since the three-dimensional shape of the side of the vehicle body differs depending on the vehicle model, even if the paint specifications are the same, the video signal levels (signal levels corresponding to brightness) in the three image areas of Figure 4 will differ slightly from vehicle model to vehicle model. Hereafter, paint specifications will be referred to as paint colors as appropriate.

[0042] Here, the lower image region 16, the middle image region 17, and the upper image region 18 do not correspond one-to-one with the lower region RE1, the middle region RE2, and the upper region RE3 in the illumination means 2.

[0043] For the vehicle body portion corresponding to the middle image region 17, the light emitted from the middle region RE2, which is located relatively close together, contributes relatively highly to illuminating this portion. On the other hand, the light emitted from the lower region RE1 and the upper region RE3 also illuminate the same portion of the vehicle body, although their contributions are relatively low. In other words, for the vehicle body portion corresponding to the middle image region 17, the light emitted from the lower region RE1 and the upper region RE3, in addition to the light emitted from the middle region RE2, overlaps and illuminates the vehicle body portion corresponding to the middle image region 17, although their respective contributions differ. In other words, the video signal level (luminance signal level) for the middle image region 17 reflects the state in which the light emitted from the middle region RE2, the lower region RE1, and the upper region RE3 of the illumination means 2 overlaps and illuminates the vehicle body portion corresponding to the middle image region 17.

[0044] Thus, the video signal level (luminance signal level) for a single image region reflects the state in which the vehicle body portion corresponding to that image region is illuminated by light from the middle region RE2, lower region RE1, and upper region RE3 of the lighting means 2, each contributing to the illumination in an overlapping manner, as is the case with the lower image region 16 and upper image region 18 described above.

[0045] The reference luminescence illuminance data SD was created by taking the above into consideration and determining the illuminance settings for the lower area RE1, middle area RE2, and upper area RE3 of the lighting means 2 when the brightness (video signal level) of the lower image area 16, middle image area 17, and upper image area 18 are close to the above values ​​for each paint color. This was done by aggregating data from numerous experiments and was compiled into a lookup table for illuminance adjustment.

[0046] The lighting controller 13 controls the lighting means 2 based on the reference luminescence illuminance data SD. The reference luminescence illuminance data SD is a tabular information (table data) that pre-determines the illuminance of the lighting means 2 for each of the multiple image regions, divided into multiple image regions in the height direction, so that when the vehicle 6 is illuminated by the lighting means 2, the brightness between each image region takes a similar value.

[0047] The control of the lighting means 2 as described above by the lighting controller 13 is performed by the calculation processing unit 20 of the lighting controller 13 referring to the data in the table data storage unit 21 which stores the table data of the reference luminous intensity data SD. The structure and usage of the reference luminous intensity data SD will be described in detail below with reference to Figure 5.

[0048] Figure 5 shows the data structure of the reference luminescence illuminance data SD stored in the table data storage unit 21. The reference luminescence illuminance data SD has a corresponding "set illuminance value" for each of the 15 "paint colors": four paint colors A1-A4, one paint color B1, two paint colors C1-C2, four paint colors D1-D4, and four paint colors E1-E4, which is the illuminance set for the upper area RE3, middle area RE2, and lower area RE1 of the lighting means 2.

[0049] In Figure 5, the "set illuminance values" for the upper area RE3, middle area RE2, and lower area RE1 of the lighting means 2 are labeled as "upper," "middle," and "lower."

[0050] The "illuminance setting value" to be set is divided into "R illuminance," which is the illuminance of the part of the lighting means 2 that illuminates the right side of the vehicle 6, and "L illuminance," which is the illuminance of the part of the lighting means 2 that illuminates the left side of the vehicle 6. In the notation in Figure 5, the values ​​of "R illuminance" and "L illuminance" are symbolically shown by numbers preceded by α. Note that different numbers may correspond to the same illuminance value.

[0051] The brightness of the vehicle body when illuminated by lighting means 2 at the set illuminance value is shown as "Brightness" for each paint color, and is categorized by vehicle type. There are four vehicle types: "Vehicle Type 1," "Vehicle Type 2," "Vehicle Type 3," and "Vehicle Type 4." For each vehicle type, "Brightness" is shown for both the illuminance on the right side of the vehicle body ("R") and the illuminance on the left side of the vehicle body ("L").

[0052] In detail, the brightness of "R" and "L" are shown for each of the "vehicle type 1," "vehicle type 2," "vehicle type 3," and "vehicle type 4," categorized by "paint color" and by the "upper," "middle," and "lower" lighting area 2. For each vehicle type, the brightness of "R" and "L" are shown in three sections corresponding to the upper image area 18, middle image area 17, and lower image area 16 in Figure 4.

[0053] In Figure 5, the brightness values ​​for "R" and "L" are symbolically represented by numbers preceded by β. Note that different numbers may correspond to the same brightness value.

[0054] If the brightness levels corresponding to the upper image area 18, the middle image area 17, and the lower image area 16 are approximately equal, inspection can be performed under uniform conditions across the entire side of the vehicle body, regardless of the vertical position. The reference luminescence data SD indicates the "upper," "middle," and "lower" illuminance levels of the lighting means 2 for performing inspection under uniform conditions across the entire side of the vehicle body of the "paint color" to be inspected.

[0055] Therefore, as a result of the lighting means 2 illuminating the vehicle body from the upper region RE3, the middle region RE2, and the lower region RE1 with illuminance values ​​based on the reference luminescence data SD, the brightness values ​​between the three sections corresponding to the upper image region 18, the middle image region 17, and the lower image region 16 are close.

[0056] In the process of creating standard luminescence illuminance data SD through repeated experiments, the illuminance of the upper region RE3, middle region RE2, and lower region RE1 of the lighting means 2 is adjusted. As a result, when the brightness corresponding to the upper image region 18, middle image region 17, and lower image region 16 becomes close to the same value, the illuminance values ​​for "upper," "middle," and "lower" are determined as "illuminance setting values."

[0057] As a specific example, let's focus on the "R" side of vehicle 6 of "Vehicle Type 1" whose "paint color" is A1. When the illuminance of the upper area RE3, middle area RE2, and lower area RE1 of the lighting means 2 is changed, the brightness β101, β102, and β103 of the upper image area 18, middle image area 17, and lower image area 16 related to the "R" side change. The illuminance α101, α102, and α103 of the upper area RE3, middle area RE2, and lower area RE1 when the brightness β101, β102, and β103 are close to the values ​​of the "upper," "middle," and "lower" areas are defined as the "illuminance setting values."

[0058] Regarding the above, "close values" means values ​​that are close enough that it can be experimentally confirmed that the brightness values ​​β101, β102, and β103 can be inspected under approximately uniform conditions across the entire area from the top to the bottom of the vehicle's side.

[0059] The process for determining the "illumination setting value" is the same for the "L" side of vehicle 6 of the same "Vehicle Type 1". Similarly, the same applies to the "R" side and "L" side of vehicle 6 of "Vehicle Type 2", "Vehicle Type 3", and "Vehicle Type 4".

[0060] As a result, for all of "Vehicle Model 1" to "Vehicle Model 4," the brightness values ​​on both the "R" and "L" sides are close to the values ​​of the three brightness groups from top to bottom. For example, on the "R" side of "Vehicle Model 1," the values ​​are close to the brightness groups β101, β102, β103, β104, β105, β106, β107, β108, β109, and so on.

[0061] For each of these groups, there are corresponding sets of illuminances α101, α102, α103, α104, α105, α106, α107, α108, α109, etc., for the upper region RE3, middle region RE2, and lower region RE1 of the lighting means 2. These illuminances are the "set illuminances" for the lighting means 2.

[0062] By preparing reference luminescence illuminance data SD based on experiments, it is possible to determine the "R illuminance" and "L illuminance" for the upper region RE3, middle region RE2, and lower region RE1 that should be set in the lighting means 2, by referring to the reference luminescence illuminance data SD in relation to the "paint color".

[0063] The system controller 12 in Figure 3 receives management command information from a higher-level system (not shown). The management command information includes, at a minimum, paint information representing the paint color applied to the vehicle 6 to be inspected.

[0064] The lighting controller 13 decodes the aforementioned paint information in the calculation processing unit 20 and refers to the reference illuminance data SD, which is a lookup table stored in the table data storage unit 21. That is, the calculation processing unit 20 reads the illuminance setting values ​​for the upper area RE3, middle area RE2, and lower area RE1 of the lighting means 2, which are associated with the paint color based on the decoded paint information.

[0065] The lighting controller 13 adjusts the illuminance of the upper region RE3, middle region RE2, and lower region RE1 of the lighting means 2 to match the illuminance set value according to the reference illuminance data SD. This adjustment is performed by adjusting the light emission of the upper region light source 8c, the middle region light source 8b, and the lower region light source 8a.

[0066] As a result, the side of the vehicle body has a nearly uniform brightness from the upper part to the lower part. In conventional systems, if the brightness differs partially depending on the location from the upper to the lower part of one side of the vehicle body, it is not possible to inspect the entire side of the vehicle body under uniform conditions unless multiple imaging means are used, each with different settings and a narrow field of view according to the brightness. In the vehicle inspection device 1 of this disclosure, since the side of the vehicle body has a nearly uniform brightness from the upper part to the lower part, the entire side of the vehicle body can be inspected under uniform conditions by photographing one side of the vehicle body with a single imaging means. In other words, it is not necessary to individually adjust and use multiple imaging means, and handling is simplified.

[0067] The configurations and effects of each embodiment of the vehicle inspection device described herein are summarized below.

[0068] (1) The vehicle inspection device 1 of the present disclosure includes an illumination means 2 that illuminates at least the left and right sides of the vehicle body surface of a vehicle 6 to be inspected, a controller 3 that controls the illuminance of the light emitted by the illumination means 2, an imaging means 4 that photographs the vehicle body surface illuminated by the illumination means 2, and an image processing means 5 that outputs an inspection result regarding the quality of the vehicle body surface based on the output of the imaging means 4. The illumination means 2 has a pair of light-emitting surfaces 10a and 10b that sandwich the vehicle 6 from the left and right, and each light-emitting surface 10a and 10b is shorter than the total length of the vehicle 6 in the front-rear direction of the vehicle 6, higher than the total height of the vehicle 6 in the up-down direction of the vehicle 6, and curves concave toward the vehicle 6, and the controller 3 can adjust the illuminance of the light-emitting surfaces 10a and 10b for each of the multiple regions (lower region RE1, middle region RE2, and upper region RE3) divided in the height direction of the light-emitting surfaces 10a and 10b.

[0069] In the vehicle inspection device 1 described in (1) above, the controller 3 adjusts the illuminance of multiple regions divided in the height direction of the light-emitting surfaces 10a and 10b, so that the vehicle body surface has a uniform brightness regardless of the position in the height direction. Therefore, without using multiple imaging means with different settings and narrow imaging fields to match different brightness levels, the entire side of the vehicle body can be inspected under uniform conditions by photographing one side of the vehicle body with a single imaging means. This simplifies handling compared to using multiple imaging means individually. Furthermore, because the light-emitting surfaces 10a and 10b are curved concavely toward the vehicle 6, it is easy to adjust the illuminance of the lighting means 2 to achieve uniform brightness regardless of the position in the vertical direction, even for vehicle bodies with complex shapes that include curved surfaces or uneven surfaces that bulge outward in the width direction.

[0070] (2) One embodiment of the vehicle inspection device 1 described in (1) above is such that the multiple regions of the light irradiation surface 10a, 10b include a lower region RE1, a middle region, and an upper region RE3 in the height direction of the light irradiation surface 10a, 10b, from bottom to top in sequence.

[0071] In the vehicle inspection device 1 described in (2) above, the light-emitting surfaces 10a and 10b of the lighting means 2 are sequentially divided from bottom to top into a lower region RE1, a middle region, and an upper region RE3. By adjusting the illuminance for each of these divided regions, the side of the vehicle body 6 to be inspected can be made to have a uniform brightness regardless of its position in the vertical direction.

[0072] (3) One embodiment of the vehicle inspection device 1 described in (1) above is in which the light irradiation surfaces 10a and 10b are diffusers 9.

[0073] In the vehicle inspection device 1 described in (3) above, even when using multiple light sources, the diffuser plate 9 allows for the irradiation of uniform light that spreads evenly in a planar manner. As a result, the sides of the vehicle body 6 to be inspected can be illuminated with uniform light with minimal unevenness from the light irradiation surfaces 10a and 10b, resulting in uniform brightness on the sides of the vehicle body 6 to be inspected, regardless of its vertical position.

[0074] (4) In one embodiment of the vehicle inspection device 1 described in (1) above, the imaging means 4 is a camera (left camera 4a, right camera 4b) positioned to capture the area illuminated by the illumination means 2 within its imaging field of view.

[0075] In the vehicle inspection device 1 described in (4) above, the area illuminated by the lighting means 2 falls within the imaging field of the cameras (left camera 4a, right camera 4b), so the entire inspection area of ​​the vehicle 6 can be inspected without any omissions while keeping the positions of the cameras (left camera 4a, right camera 4b) fixed.

[0076] (5) In one embodiment of the vehicle inspection device 1 described in (1) above, the controller 3 (lighting controller 13) controls the illuminance for each of the multiple areas (lower area RE1, middle area RE2, upper area RE3) according to the paint specifications of the vehicle 6.

[0077] In the vehicle inspection device 1 described in (5) above, conventionally, depending on the paint specifications, the surface of the vehicle under inspection may show different brightness levels even when illuminated with the same illuminance from the lighting means 2. However, the controller 3 (lighting controller 13) controls the illuminance for each of the multiple regions (lower region RE1, middle region RE2, upper region RE3) according to the paint specifications of the vehicle 6, so that the illuminance of the lighting means 2 can be adjusted so that the surface of the vehicle shows a brightness level suitable for inspection.

[0078] (6) In one embodiment of the vehicle inspection device 1 described in (5) above, the controller 3 (lighting controller 13) controls the illuminance of each of the multiple regions (lower region RE1, middle region RE2, upper region RE3) of the lighting device 2, which are divided into multiple image regions (lower image region 16, middle image region 17, upper image region 18) in the height direction when the vehicle 6 is illuminated by the lighting device 2, based on standard luminescence illuminance data SD determined for each paint color of the vehicle body surface, so that the brightness between each image region takes a similar value.

[0079] In the vehicle inspection device 1 described in (6) above, the controller 3 (lighting controller 13) controls the lighting means 2 based on standard luminous intensity data SD defined for each paint color of the vehicle 6 to be inspected. Therefore, once the paint color is identified, the illuminance in each of the multiple regions of the lighting means 2 (lower region RE1, middle region RE2, upper region RE3) can be appropriately adjusted. As a result, the side of the vehicle body of the vehicle 6 to be inspected will have uniform brightness regardless of its vertical position, and the entire inspection area can be inspected under uniform conditions.

[0080] (7) In one embodiment of the vehicle inspection device 1 described in (6) above, the multiple image regions are the lower image region 16, the middle image region 17, and the upper image region 18, which are sequential image regions obtained by dividing the output image of the imaging means 4 from bottom to top in the height direction.

[0081] In the vehicle inspection device 1 described in (7) above, the brightness of the vehicle body surface can be evaluated from the output image of the imaging means 4 according to the divisions into the lower image area 16, the middle image area 17, and the upper image area 18. Therefore, the brightness of the vehicle body surface can be appropriately evaluated with a simple configuration.

[0082] (8) In one embodiment of the vehicle inspection device 1 described in (6) above, the controller 3 (lighting controller 13) has a table data storage unit 21 that holds table data of the reference luminescence illuminance data SD.

[0083] In the vehicle inspection device 1 described in (8) above, the controller 3 (lighting controller 13) refers to the reference luminescence illuminance data SD in the memory unit 21 and obtains illuminance setting values ​​for the lower area RE1, middle area RE2, and upper area RE3 of the lighting means 2, respectively, without any separate calculation processing. This enables rapid illuminance adjustment of the lighting means 2.

[0084] The vehicle inspection device 1 of this disclosure is not limited to the embodiments described above. For example, the lower region RE1, middle region RE2, and upper region RE3 of the lighting means 2, whose illuminance can be individually adjusted, may be connected without gaps as shown in Figure 1, or they may have overlapping portions. Alternatively, the lower region RE1, middle region RE2, and upper region RE3 may be somewhat separated in the vertical direction.

[0085] The lower image region 16, middle image region 17, and upper image region 18, which individually evaluate the brightness of the output image of one frame from the left camera 4a and the right camera 4b, may be continuous without gaps as shown in Figure 4, or they may have overlapping parts. Alternatively, the lower image region 16, middle image region 17, and upper image region 18 may be slightly separated in the vertical direction.

[0086] It is also possible to use more general area cameras instead of line cameras for the left camera 4a and the right camera 4b.

[0087] The aforementioned lighting controller 13, acting as controller 3, controls the lighting means 2 by referring to table data, which is the reference luminescence illuminance data SD. However, the form of controller 3 is not limited to this. For example, it may be in the form of a dimmer that adjusts the illuminance of the lower region RE1, middle region RE2, and upper region RE3 of the lighting means 2 according to the operator's operation. In this case, a PWM type dimmer, which is common in LED lighting and supplies power to the light source with a duty cycle corresponding to the operator's operation, can be used. [Explanation of Symbols]

[0088] RE1…Lower area RE2…middle area RE3... Upper area SD...Standard Luminous Illuminance Data 1... Vehicle inspection device 2...Lighting means 3…Controller 4…Imaging means 4a... Left camera 4b... Right-side camera 5…Image processing means 6…Vehicles 7...Conveyor belt 8…Light source 8a…Lower area light source 8b…middle area light source 8c…Upper area light source 9... Diffuser 10, 10a, 10b...Light irradiation surface 11...Support 12…System Controller 13…Lighting controller 14...Display section 15…Image Processing Unit 16…Lower image area 17…Middle image area 18…Upper image area 19...Output image of 1 frame 20… Processing Unit 21...Table data storage unit

Claims

1. A lighting means that illuminates at least the left and right sides of the vehicle body surface of the vehicle to be inspected, A controller that controls the illuminance of the light emitted by the lighting means, An imaging means for photographing the surface of the vehicle body illuminated by the aforementioned lighting means, The system includes an image processing means that outputs an inspection result relating to the quality of the vehicle body surface based on the output of the imaging means, The lighting means has a pair of light-emitting surfaces that sandwich the vehicle from the left and right, Each of the aforementioned light-irradiated surfaces is, In the longitudinal direction of the vehicle, the length is shorter than the overall length of the vehicle. In the vertical direction of the vehicle, it is higher than the overall height of the vehicle and curves concavely toward the vehicle, The controller is capable of adjusting the illuminance of the light-emitting surface for each of the multiple regions divided in the height direction of the light-emitting surface. Vehicle inspection equipment.

2. The aforementioned multiple regions include a lower region, a middle region, and an upper region, sequentially arranged from bottom to top in the height direction of the light irradiation surface. The vehicle inspection device according to claim 1.

3. The light irradiation surface is a diffuser plate. The vehicle inspection device according to claim 1.

4. The imaging means is a camera positioned to capture the area illuminated by the illumination means within its imaging field of view. The vehicle inspection device according to claim 1.

5. The controller controls the illumination level for each of the multiple areas according to the paint specifications of the vehicle. The vehicle inspection device according to claim 1.

6. The controller controls the illuminance of each of the multiple regions of the lighting means, which is obtained by dividing the output image of the imaging means into multiple image regions in the height direction, based on reference emission illuminance data defined for each paint color of the vehicle body surface, such that the brightness of each image region is close to that value. The vehicle inspection device according to claim 5.

7. The aforementioned plurality of image regions are the lower image region, the middle image region, and the upper image region, which are sequential image regions obtained by dividing the output image of the imaging means from bottom to top in the height direction. The vehicle inspection device according to claim 6.

8. The controller has a table data storage unit that holds table data of the reference illuminance data. The vehicle inspection device according to claim 6.

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