JP2017040488A - Three-dimensional temperature distribution display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily display surface temperature distribution of a three-dimensional measurement object comprising three-dimensional CAD data in a three-dimensional state.SOLUTION: The invention comprises plural infrared cameras 2A-2C, and a personal computer 3 creates a three-dimensional wire frame image of a measurement object 1 from CAD data, superposes and displays a two-dimensional temperature distribution image to the three-dimensional wire frame image which is viewed from installation points of the infrared cameras 2A-2C, then determines correspondence of respective pixels of the two-dimensional temperature distribution image and respective pixels of the two-dimensional texture image corresponding to respective polygons forming the three-dimensional wire frame image, then completes the texture image by applying temperature information on respective pixels of the two-dimensional temperature distribution image to respective pixels of the two-dimensional texture image, then sticks the completed two-dimensional texture image to the corresponding polygons. To respective polygons forming an image part on which the two-dimensional temperature distribution image is not acquired, the two-dimensional texture image in which temperature information calculated from temperature information of the polygons to which the completed two-dimensional texture image is stuck in the surrounding, is applied to respective pixels, is stuck.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a three-dimensional temperature distribution display device that can three-dimensionally display a surface temperature distribution of a measurement object.

 Conventionally, as a display device for displaying the surface temperature distribution of the measurement object, for example, as disclosed in Patent Document 1, a display device that displays the surface temperature distribution two-dimensionally is usually used.

JP2001-249052

  However, when the measurement target is a three-dimensional object having a depth, it is difficult to accurately grasp the actual distribution state having a depth even if the surface temperature distribution is displayed two-dimensionally. On the other hand, when the measurement object is a machine part or the like, precise three-dimensional CAD data of the measurement object is often prepared.

  Therefore, the present invention solves such a problem, and provides a three-dimensional temperature distribution display device that can easily display a three-dimensional surface temperature distribution of a three-dimensional measurement object having three-dimensional CAD data. The purpose is to provide.

  In order to achieve the above object, in the first invention, an image generating means (3, step 102) for generating a three-dimensional wire frame image (4) of a measurement object (1) from CAD data, and a measurement object ( The temperature measurement means (2A to 2C, 3, step 106) for remotely acquiring the two-dimensional temperature distribution image (6) of 1) and the third order viewed from the installation point (Fa) of the temperature measurement means (2A to 2C) Overlay display means (3, step 107) for superimposing and displaying the two-dimensional temperature distribution image (6) on the original wire frame image (4), and each pixel of the two-dimensional temperature distribution image (6) in the overlaid state Correspondence determination means (61) for determining the correspondence between each pixel (51) of the two-dimensional texture image (5) associated with each polygon (41) constituting the three-dimensional wire frame image (4). 3, step 108) and Image completion means (3, step 109) which completes the texture image by giving temperature information in each pixel (61) of the two-dimensional temperature distribution image (6) to each pixel (51) of the two-dimensional texture image (5). And a pasting means (3, step 202) for pasting the completed two-dimensional texture image (5) to the corresponding polygon (41). The pasting means (3, step 202) is a three-dimensional wire frame. Of the image (4), the completed two-dimensional texture image is pasted to each polygon (41) constituting the image portion where the two-dimensional temperature distribution image (6) to be displayed is not obtained. A two-dimensional texture image (5) in which temperature information calculated in consideration of thermal conductivity from the temperature information of the attached polygon (41) is added to each pixel is pasted.

  In the first invention, a texture image to which temperature information of each pixel of the two-dimensional temperature distribution image is attached is attached to each polygon of the three-dimensional wire frame image, and the surface temperature distribution of the measurement object is three-dimensional. Since it is displayed, the actual temperature distribution state with depth is accurately shown, and the temperature distribution can be accurately grasped. Further, since a three-dimensional wire frame image generated from CAD data is used, three-dimensional display of the surface temperature distribution can be easily performed. Furthermore, the temperature information calculated from the temperature information of the surrounding polygons is given to each polygon constituting the image portion where the two-dimensional temperature distribution image (6) is not obtained as a blind spot of the temperature measuring means. Since the two-dimensional texture image is pasted, it is possible to prevent a missing portion from appearing in the three-dimensional surface temperature distribution display of the measurement object.

  In the second invention, the overlapping display means (3, step 107) has the same number of feature points extracted from the two-dimensional temperature distribution image (6) extracted from the three-dimensional wire frame image (4). The two-dimensional temperature distribution image (6) and the three-dimensional wire frame image (4) are displayed so as to coincide with the feature points.

  In the second aspect of the present invention, since both images are displayed in an overlapping manner by matching the feature points extracted from the two-dimensional temperature distribution image and the three-dimensional wire frame image, the operation of overlapping display is simplified. Automation becomes easy.

  In the third aspect of the invention, the temperature measuring means (2A to 2C, 3, step 106) corrects misalignment so that the acquired two-dimensional temperature distribution image (6) comes to a predetermined position on the screen. .

  In the third aspect of the invention, since the positional shift of the two-dimensional temperature distribution image acquired by moving the measurement object is corrected, the subsequent overlay display with the three-dimensional wire frame image is performed reliably.

  In addition, the code | symbol in the said parenthesis shows the correspondence with the specific means as described in embodiment mentioned later for reference.

  As described above, according to the three-dimensional temperature distribution display device and the like of the present invention, the surface temperature distribution of a three-dimensional measurement object having three-dimensional CAD data can be easily displayed three-dimensionally.

It is a figure which shows the hardware constitutions of the three-dimensional temperature distribution display apparatus in one Embodiment of this invention. It is a conceptual diagram explaining the camera position of an infrared camera. It is a conceptual diagram explaining the gaze direction of an infrared camera. It is a flowchart which shows the process sequence of the processing program run with a personal computer. It is a front view explaining the position shift of the color distribution image on the monitor screen and its correction. It is a flowchart which shows the detail of outline matching operation. It is a conceptual diagram which shows the positional relationship of the position of an infrared camera, a color distribution image, and a wire frame image. It is a conceptual enlarged view of a texture image. It is a flowchart which shows the process sequence of the processing program run with a personal computer. It is a front view at the time of displaying the temperature distribution of vehicle components on a monitor three-dimensionally. It is a conceptual diagram which shows the position relationship of an infrared camera position, a color distribution image, and a polygon. It is a conceptual perspective view of the wire frame image containing the part from which a temperature distribution image is not obtained. It is a conceptual diagram of an adjacent polygon. It is a front view at the time of displaying the temperature distribution of the vehicle components in a two-dimensional display on a monitor in a conventional example.

  The embodiment described below is merely an example, and various design improvements made by those skilled in the art without departing from the gist of the present invention are also included in the scope of the present invention.

  FIG. 1 shows the overall configuration of the measuring apparatus. In FIG. 1, infrared cameras 2A, 2B, and 2C constituting temperature measuring means for sensing infrared rays emitted from the measurement object 1 are installed at three locations so as to surround the three-dimensional measurement object 1. . In addition, in order to make the following description easy, in this embodiment, the shape of the measuring object 1 is assumed to be a simple rectangular parallelepiped. Output images from the infrared cameras 2A, 2B, and 2C are input to a personal computer 3 that includes a CPU 31, a memory, various interfaces, and the like and includes a monitor 31 and a keyboard 32 through signal lines 21, 22, and 23.

  The three-dimensional positions of the measuring object 1 and the infrared cameras 2A to 2C are set in the personal computer 3 in advance. The position of the measuring object 1 is set at the substantially center position, while the logical focus position Fa shown in FIG. 2 is set as the position of each of the infrared cameras 2A to 2C. In FIG. 2, reference numeral 24 denotes an objective lens of the infrared cameras 2A to 2C, reference numeral 25 denotes an imaging sensor, and reference numeral Fb denotes an actual focal position. The logical focal position Fa is an intersection point on the extension line of the light L incident on the objective lens 24. Therefore, the line-of-sight directions of the infrared cameras 2A to 2C are three-dimensional linear vectors that connect the camera position Fa and the position P of the measurement object 1, as shown in FIG. 3 (the figure shows the infrared camera 2A as an example). Indicated by V. Note that the number of infrared cameras installed is not limited to three.

  Hereinafter, the processing procedure of the processing program executed by the personal computer 3 will be described with reference to the flowcharts of FIGS. 4, 6, and 9. The CAD data of the measurement object 1 is taken into the memory of the personal computer 3 from an external database or the like (step 101), and a three-dimensional wire frame image of the measurement object 1 is generated from the CAD data (step 102). 31 is displayed (step 103). The wire frame image can be translated, vertically rotated, horizontally rotated, zoomed in, and zoomed out on the monitor 31. The polygons constituting the wire frame image are all triangular in this embodiment, and these polygons are triangular planes connecting three points in a three-dimensional space with straight lines. Each polygon is preliminarily associated with the same triangular texture image in software. That is, each texture image is a two-dimensional bitmap, and each point on the polygon surface is associated with each pixel on the texture image.

  Temperature distribution images of the measuring object 1 photographed from the three directions by the infrared cameras 2A to 2C are taken into the personal computer 3 (step 104). A temperature color table in which a temperature and a color corresponding to the temperature are set in advance in the personal computer 3, and a color distribution image (thermal image) 6 is created from the temperature distribution image with reference to the temperature color table ( Step 105). This color distribution image is a quadrangular two-dimensional bitmap corresponding to the camera wide angle viewed from the camera viewing direction.

  The color distribution image 6 is displayed on the monitor 31 of the personal computer 3 (step 106). At this time, when the measuring object 1 is transported on the line or the like, there may be a positional deviation at the time of stopping. Therefore, when the color distribution image 6 displayed on the screen of the monitor 31 is misaligned as shown in FIG. 5A, the color distribution image 6 shown in FIG. As shown in FIG. 5, the positional deviation correction is performed so that the color distribution image 6 comes to a predetermined position on the monitor 31 (center in this embodiment) (steps 107 and 108). As shown in FIG. 5 (2), the electronic image stabilization technique is used to shift the display pixel and interpolate the lacking area by extending the image (shaded area in the figure). The color distribution image 6 is displayed at a predetermined position on the monitor 31 by being moved. Note that the cause of the positional deviation of the color distribution image 6 may be the case where the measuring object 1 is vibrating other than the positional deviation when the measuring object 1 is stopped. In addition to the above method for correcting the positional deviation, the moving amount and moving direction of the color distribution image 6 may be obtained as a vector, and the color distribution image 6 may be returned to a predetermined position by the inverse vector.

  Thereafter, the three-dimensional wire frame image displayed on the monitor 31 is translated, rotated, zoomed in, zoomed out, etc., and the measurement object 1 on the color distribution image 6 (hereinafter simply referred to as a color distribution image) is displayed. The outer shape of the wire frame image 4 is matched with the outer shape (step 109). In this case, the contour matching operation (fitting) includes a plurality of (for example, four or more) feature points (for example, four or more points) on the color distribution image 6 and the wire frame image 4 as shown in steps 201 to 204 in FIG. The same number of feature points above are manually specified, camera parameters such as resolution calculated from the angle of view of the infrared camera and its arrangement are read, and each of the above features is based on the deformation parameters obtained from this. The wire frame image 4 is automatically translated, rotated, zoomed in, zoomed out, etc. so that the points coincide.

  FIG. 7 schematically shows a state where the outer shape matching operation between the color distribution image 6 and the three-dimensional wire frame image 4 is finished. In FIG. 7, the surface of the wire frame image 4 is composed of a number of two-dimensional triangular polygons 41. In the figure, only the polygon 41 on one surface of the wire frame image 4 is drawn with exaggerated size for easy understanding. Reference numeral 5 denotes a texture image corresponding to one of the polygons 41.

  In this state, a three-dimensional object coordinate system Co for specifying each position on the infrared camera position Fa and the wire frame image 4 and a two-dimensional viewport coordinate system Cv for specifying each position on the color distribution image 6 are provided. It is associated with software (for example, OpenGL) (step 110). Therefore, when the camera position Fa and one of the pixels 61 of the color distribution image 6 are designated, the corresponding point 411 on the polygon 41 of the wire frame image 4 is determined. When this is schematically described with reference to FIG. 7, the point 411 is a point where an extended line of sight from the camera position Fa to the pixel 61 on the color distribution image 6 is incident on the polygon 41 surface. In this way, the pixels 61 on the color distribution image 6 and the points 411 on the polygon 41 surface have a one-to-one correspondence, and as described above, the points 411 on the polygon 41 surface and the points on the texture image 5 Since each pixel 51 is also associated, after all, each pixel 61 on the color distribution image 6 and each pixel 51 on the texture image 5 correspond. If this correspondence is prepared in advance in the personal computer 3 by using, for example, a conversion table, it is possible to speed up the processing because no calculation is required.

  There are one or a plurality of pixels 51 of the texture image 5 corresponding to the point 411. This is determined by comparing the two-dimensional sizes of the color distribution image 6 and the texture image 5. In the present embodiment, for example, a plurality of pixels 51 in the square area S of the texture image 5 shown in FIG. 8 correspond to one pixel 61 on the color distribution image 6, and the color information of the pixel 61 is stored in this square area S. Given. In this way, color information is given to the pixels 51 of the texture image 5 corresponding to the points 411 on each polygon 41 of the wire frame image 4 for all the pixels 61 of the color distribution image 6 (step 111), and the wire Texture images corresponding to all the polygons constituting the frame image are completed (step 112). The above procedure is performed for each color distribution image 6 converted from the temperature distribution images obtained by all the infrared cameras 2A to 2C (step 113). Note that the texture image may be completed by directly giving the temperature information of the temperature distribution image to each pixel without converting to the color distribution image.

  When displaying the surface temperature distribution of the measurement object 1, as shown in FIG. 9, the three-dimensional wire frame image 4 of the measurement object 1 is displayed on the monitor 31 (step 301). The completed texture image 5 corresponding to this is pasted (texture mapping, step 302). Thereby, the surface temperature distribution of the measuring object 1 is displayed three-dimensionally.

Here, FIG. 10 shows a three-dimensional display of the temperature distribution of the vehicle component that is the measurement object 1. On the other hand, FIG. 14 shows a conventional two-dimensional display of the temperature distribution of the same vehicle component. In the three-dimensional display of the surface temperature distribution, the actual distribution state with depth is accurately shown, so that the temperature distribution state can be accurately grasped. At this time, if the posture of the measurement object 1 in the screen is changed according to the viewpoint, the texture image pasted on the polygon also moves together, so it is possible to examine the temperature distribution situation in detail by changing the viewpoint. it can.

  In addition, when displaying the surface temperature distribution of the measurement object, the polygon to be texture-mapped in the personal computer 3 is selected as follows. That is, as shown in FIG. 11, one polygon 41A constituting the wire frame image is selected and set as a target polygon, and the coordinates of the center 412 of the target polygon 41A in the object coordinate system Co are calculated. The coordinates of the center 412 are converted into the coordinates of the point 62 on the color distribution image 6 in the viewport coordinate system Cv, and other polygons 41B and 41C exist on the extended line of sight from the camera position Fa to the point 62. It is determined whether or not. Only when the target polygon 41A is closest to the camera position Fa, texture mapping for the target polygon 41A is enabled. Such a determination is performed for all polygons.

  By the way, the temperature distribution image of a part of the measuring object 1 may not be obtained due to the blind spots of the infrared cameras 2A to 2C. In this case, the completed two-dimensional texture image 5 (see FIG. 7) is applied to each polygon 41y constituting the four-dimensional three-dimensional wire frame image 4 portion (outlined portion in FIG. 12) from which no temperature distribution image is obtained. A new temperature information is calculated from the temperature information of the surrounding polygon 41x to which the) is pasted, and the wire frame image 4 is completed.

In the wire frame image shown in FIG. 12, there are a plurality of polygons constituting a portion where a temperature distribution image is not obtained. A method for calculating temperature information for one of the polygons 41y will be described in detail. As described above, the two-dimensional texture in which the temperature information t2 calculated by the following equation (1) is given to each pixel from the temperature information t1 of the triangle polygon 41x adjacent to the triangle polygon 41y in consideration of the thermal conductivity. An image 5 is created and pasted on the polygon 41y.
t2 = t1 {1- (d2 · c1) / (d1 · c2)} (1)
Here, c1 is a predetermined thermal conductivity for the polygon 41x, c2 is a predetermined thermal conductivity for the polygon 41y, d1 is a distance from the center (center of gravity) of the polygon 41x to the boundary with the polygon 41y, and d2 is a polygon 41y. The distance from the center to the boundary with the polygon 41x. When there are a plurality of polygons 41x adjacent to the polygon 41y (two in the example shown in FIG. 13), the temperature information t2 obtained from the above equation (1) is calculated for each polygon 41x, and the temperature information t2 is calculated. The average value is adopted as the temperature information of the polygon 41y.

DESCRIPTION OF SYMBOLS 1 ... Measurement object, 2A, 2B, 2C ... Infrared camera (temperature measurement means), 3 ... Personal computer, 4 ... Wire frame image, 41 ... Polygon, 5 ... Texture image, 51 ... Pixel (pixel), 6 ... Color Distribution image (temperature distribution image), 61... Pixel (pixel).

Claims (3)

Image generating means for generating a three-dimensional wire frame image of a measurement object from CAD data;
Temperature measuring means for remotely acquiring a two-dimensional temperature distribution image of the measurement object;
An overlapping display means for displaying the two-dimensional temperature distribution image on the three-dimensional wire frame image viewed from the installation point of the temperature measuring means;
Correspondence determination for determining the correspondence between each pixel of the two-dimensional temperature distribution image in the overlaid state and each pixel of the two-dimensional texture image associated with each polygon constituting the three-dimensional wire frame image Means,
Image completion means for completing the texture image by giving temperature information in each pixel of the two-dimensional temperature distribution image to each pixel of the two-dimensional texture image;
A pasting means for pasting the completed two-dimensional texture image to the polygon corresponding thereto,
The pasting means is a completed two-dimensional texture image around each polygon constituting an image portion in which the two-dimensional temperature distribution image to be displayed is not obtained in the three-dimensional wire frame image. A three-dimensional temperature distribution display device for pasting a two-dimensional texture image in which temperature information calculated in consideration of thermal conductivity from temperature information of a polygon to which is attached is applied to each pixel. The overlapping display means includes the two-dimensional temperature distribution image and the three-dimensional wire so that a plurality of feature points extracted from the two-dimensional temperature distribution image coincide with the same number of feature points extracted from the three-dimensional wire frame image. The three-dimensional temperature distribution display device according to claim 1, wherein the three-dimensional temperature distribution display device displays the frame images in an overlapping manner. The three-dimensional temperature distribution display device according to claim 1, wherein the temperature measuring unit corrects misalignment so that the acquired two-dimensional temperature distribution image comes to a predetermined position on the screen.