JP6545033B2 - Three-dimensional temperature distribution display - Google Patents

Description

  The present invention relates to a three-dimensional temperature distribution display device capable of three-dimensionally displaying the surface temperature distribution of an object to be measured.

 Conventionally, as a display device for displaying the surface temperature distribution of the measurement object, for example, as shown in Patent Document 1, it is common to display the surface temperature distribution two-dimensionally.

Japanese Patent Application Publication No. 2001-249052

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

  Therefore, the present invention solves such a problem, and a three-dimensional temperature distribution display device capable of three-dimensionally and three-dimensionally displaying surface temperature distribution of a three-dimensional measurement object provided with three-dimensional CAD data. Intended to be provided.

  In order to achieve the above object, in the first invention, an image generation means (3, step 102) for generating a three-dimensional wireframe image (4) of a measurement object (1) from CAD data; Temperature measurement means (2A to 2C, 3, step 106) for remotely acquiring the two-dimensional temperature distribution image (6) of 1) and third order viewed from the installation point (Fa) of the temperature measurement means (2A to 2C) Overlaying display means (3, step 107) for overlaying and displaying the two-dimensional temperature distribution image (6) on the original wireframe image (4), and each pixel of the two-dimensional temperature distribution image (6) in the superimposed display state Correspondence determination means for determining the correspondence between each pixel (51) of the two-dimensional texture image (5) associated with each polygon (41) constituting the three-dimensional wireframe image (4) and (61) 3, step 108) Image completion means (3, step 109) for 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 attaching means (3, step 202) for attaching the completed two-dimensional texture image (5) to the polygon (41) corresponding thereto, wherein the attaching means (3, step 202) is a three-dimensional wire frame The completed two-dimensional texture image of the periphery is pasted to each polygon (41) which constitutes the image portion by which the two-dimensional temperature distribution image (6) by which overlapping display is carried out among images (4) is not obtained. The two-dimensional texture image (5) in which temperature information calculated in consideration of the thermal conductivity from the temperature information of the attached polygon (41) is applied to each pixel is pasted.

  In the first aspect of the invention, the texture image to which the temperature information of each pixel of the two-dimensional temperature distribution image is added is attached to each polygon of the three-dimensional wire frame image, and the surface temperature distribution of the measurement object is three-dimensional. As it is displayed, the actual temperature distribution with depth can be accurately indicated, and the temperature distribution can be accurately grasped. In addition, since a three-dimensional wireframe 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 polygons around the polygon is given to each polygon constituting the image part where the two-dimensional temperature distribution image (6) is not obtained because it becomes a blind spot of the temperature measuring means. Since the two-dimensional texture image is attached, it is possible to prevent the occurrence of a missing part in the three-dimensional surface temperature distribution display of the measurement object.

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

  In the second aspect of the invention, since the two images are superimposed and displayed by matching the feature points extracted respectively from the two-dimensional temperature distribution image and the three-dimensional wire frame image, the operation of overlapping display is simplified. It becomes easy to automate.

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

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

  The reference numerals in the parentheses indicate the correspondence with the specific means described in the embodiments to be described later.

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

It is a figure which shows the hardware constitutions of a 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 performed with a personal computer. It is a front view explaining the position shift of the color distribution picture on a monitor screen, and its amendment. It is a flowchart which shows the detail of outline matching operation. It is a conceptual diagram which shows the position of an infrared camera, the color distribution image, and the positional relationship of 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 performed with a personal computer. It is a front view at the time of displaying three-dimensionally displaying temperature distribution of vehicle parts on a monitor. It is a conceptual diagram which shows the position of an infrared camera, a color distribution image, and the positional relationship of a polygon. FIG. 2 is a conceptual perspective view of a wire frame image including a portion where a temperature distribution image can not be obtained. It is a conceptual diagram of an adjacent polygon. It is a front view at the time of two-dimensionally displaying temperature distribution of vehicle parts in a conventional example in a monitor.

  The embodiments described below are merely examples, and various design improvements made by those skilled in the art without departing from the scope of the present invention are also included in the scope of the present invention.

  FIG. 1 shows the entire configuration of the measuring apparatus. In FIG. 1, infrared cameras 2A, 2B and 2C constituting temperature measurement 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 facilitate the following description, in the present embodiment, the shape of the measurement object 1 is assumed to be a simple rectangular parallelepiped. The output image from each of the infrared cameras 2A, 2B, 2C is input to a personal computer 3 having a CPU 31, a memory, various interfaces and the like and a monitor 31 and a keyboard 32 through signal lines 21, 22, 23.

  The three-dimensional positions of the measurement object 1 and the infrared cameras 2A to 2C are set in the personal computer 3 in advance. The position of the measurement object 1 is set to a position substantially at the center, while the logical focal 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 focus position Fa is an intersection on the extension of the light L incident on the objective lens 24. Therefore, as shown in FIG. 3 (the figure shows the infrared camera 2A as an example), the line-of-sight direction of the infrared cameras 2A to 2C is a three-dimensional straight line vector connecting the camera position Fa and the position P of the measurement object 1 It is indicated by V. 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 FIG. 4, FIG. 6, and FIG. CAD data of the measurement object 1 is fetched from an external database or the like into the memory of the personal computer 3 (step 101), and a three-dimensional wireframe image of the measurement object 1 is generated from the CAD data (step 102) 31 is displayed (step 103). The wireframe 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 triangles in the present embodiment, and these polygons are triangle planes connecting three points in a three-dimensional space by straight lines. Each polygon is associated with a texture image of an isomorphic triangle in advance in software. That is, each texture image is a two-dimensional bit map, and each point on the polygon surface is associated with each pixel (pixel) on the texture image.

  A temperature distribution image of the measurement object 1 taken from three directions by each of the infrared cameras 2A to 2C is 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 is prepared 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 rectangular two-dimensional bit map according to the camera wide angle viewed from the camera gaze direction.

  The color distribution image 6 is displayed on the monitor 31 of the personal computer 3 (step 106). At this time, in the case where the measurement object 1 is conveyed on the line or the like, positional deviation may occur at the time of stop. Therefore, when the color distribution image 6 displayed on the screen of the monitor 31 is misaligned as shown in FIG. 5 (1), the misregistration shown in FIG. As shown in FIG. 5, positional deviation correction is performed so that the color distribution image 6 comes to a predetermined position (center in the present embodiment) on the monitor 31 (steps 107 and 108). As shown in FIG. 5 (2), this is a display frame of the monitor 31 while shifting display pixels and interpolating an insufficient area by image extension using the technique of electronic shake correction. The color distribution image 6 is moved to be displayed at a predetermined position on the monitor 31. In addition to the positional deviation at the time of stop of the measuring object 1, the color distribution image 6 may cause positional deviation, in addition to the case where the measuring object 1 vibrates. In addition to the method described above, the displacement amount and the displacement direction of the color distribution image 6 may be determined as vectors, and the color distribution image 6 may be returned to a predetermined position by the inverse vector.

  Thereafter, the three-dimensional wireframe 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) The outer shape of the wire frame image 4 is matched with the outer shape (step 109). At this time, as shown in steps 201 to 204 in FIG. 6, the outer shape matching operation (fitting) is performed by using a plurality of (for example, four or more) feature points (corner portions etc.) on the color distribution image 6 and the wire frame image 4 The same number of feature points above are specified manually, and camera parameters such as resolution calculated from the angle of view of the infrared camera and its arrangement are read out, and the above-mentioned features are calculated 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.

  A state in which the outline matching operation of the color distribution image 6 and the three-dimensional wire frame image 4 is finished is schematically shown in FIG. In FIG. 7, the surface of the wire frame image 4 is composed of a large number of two-dimensional triangular polygons 41. In the drawing, only the polygon 41 of one surface of the wire frame image 4 is drawn with the size thereof exaggerated for ease of understanding. Reference numeral 5 indicates a texture image corresponding to one of the polygons 41.

  In this state, a three-dimensional object coordinate system Co specifying each position on the infrared camera position Fa or the wire frame image 4 and a two-dimensional viewport coordinate system Cv specifying each position on the color distribution image 6 Software (eg, OpenGL) is associated (step 110). Therefore, when the camera position Fa and one of the pixels 61 of the color distribution image 6 are designated, the point 411 on the polygon 41 of the wire frame image 4 corresponding to this is determined. This will be schematically described with reference to FIG. 7. A point at which the extension of the line of sight from the camera position Fa to the pixel 61 on the color distribution image 6 is incident on the surface of the polygon 41 is the point 411. As described above, the pixels 61 on the color distribution image 6 and the points 411 on the surface of the polygon 41 correspond one to one, and as described above, each point 411 on the surface of the polygon 41 and on the texture image 5 Since each pixel 51 is also associated, each pixel 61 on the color distribution image 6 eventually corresponds to each pixel 51 on the texture image 5. If this correspondence is prepared in advance in the personal computer 3 by using, for example, a conversion table, the processing can be speeded up because the calculation is unnecessary.

  One or more pixels 51 of the texture image 5 corresponding to the point 411 are present. 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 color information of the pixel 61 in the square area S is Given. In this manner, for all the pixels 61 of the color distribution image 6, color information is given to the pixels 51 of the texture image 5 corresponding to the points 411 on the polygons 41 of the wire frame image 4 (step 111). A texture image corresponding to all of the polygons constituting the frame image is 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 temperature information of the temperature distribution image may be directly given to each pixel to complete the texture image without converting 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). Paste the completed texture image 5 corresponding to this (texture mapping, step 302). Thereby, the surface temperature distribution of the measurement object 1 is three-dimensionally displayed.

Here, FIG. 10 shows a three-dimensional display of the temperature distribution of the vehicle component which 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, since the actual distribution state with depth is accurately indicated, 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 attached to the polygon is also moved integrally, so it is necessary to change the viewpoint and examine the temperature distribution situation in detail. it can.

  The selection of polygons to be texture-mapped in the personal computer 3 when displaying the surface temperature distribution of the measurement object is performed as follows. That is, as shown in FIG. 11, one of the polygons 41A constituting the wireframe image is selected as the 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 to the coordinates of the point 62 on the color distribution image 6 of the viewport coordinate system Cv, and other polygons 41B and 41C exist on the extension of the line of sight from the camera position Fa to the point 62. It is determined whether or not. Then, texture mapping on the target polygon 41A is enabled only when the target polygon 41A is closest to the camera position Fa. Such determination is performed on all polygons.

  By the way, there is a case where a temperature distribution image of a part of the measurement object 1 can not be obtained due to a blind spot of the infrared cameras 2A to 2C. In this case, the completed two-dimensional texture image 5 (see FIG. 7) is obtained for each polygon 41y constituting the three-dimensional wireframe image 4 portion (the white portion in FIG. 12) where the temperature distribution image is not obtained. New wire information is calculated from the temperature information of the polygon 41x around which is attached 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 from which the temperature distribution image is not obtained, but the temperature information calculation method will be specifically described for one of the polygons 41y. Thus, from the temperature information t1 of the center of the triangular polygon 41x adjacent to the triangular polygon 41y, a two-dimensional texture in which the temperature information t2 calculated by the following equation (1) is given to each pixel in consideration of the thermal conductivity. An image 5 is created and attached to the polygon 41y.
t2 = t1 {1- (d2 · c1) / (d1 · c2)} (1)
Here, c1 is the thermal conductivity predetermined for the polygon 41x, c2 is the thermal conductivity predetermined for the polygon 41y, d1 is the distance from the center (center of gravity) of the polygon 41x to the boundary with the polygon 41y, d2 is the polygon 41y The distance from the center of the 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 these temperature information t2 are calculated. The averaged value is adopted as temperature information of the polygon 41y.

DESCRIPTION OF SYMBOLS 1 ... measurement object, 2A, 2B, 2C ... infrared camera (temperature measurement means), 3 ... personal computer, 4 ... wireframe image, 41 ... polygon, 5 ... texture image, 51 ... pixel (pixel), 6 ... color Distribution image (temperature distribution image), 61 ... pixel (pixel).

Claims (3)

An image generation means for generating a three-dimensional wireframe image of a measurement object from CAD data;
Temperature measurement means for remotely acquiring a two-dimensional temperature distribution image of the measurement object;
Overlay display means for overlaying the two-dimensional temperature distribution image on the three-dimensional wireframe image viewed from the installation point of the temperature measurement means;
Determination of correspondence between each pixel of the two-dimensional temperature distribution image in the superimposed display state and each pixel of the two-dimensional texture image associated with each polygon constituting the three-dimensional wireframe image Means,
An image completion means for giving temperature information at each pixel of the two-dimensional temperature distribution image to each pixel of the two-dimensional texture image to complete the texture image;
And attaching means for attaching the completed two-dimensional texture image to the corresponding polygon;
The pasting means is a completed two-dimensional texture image around each of polygons constituting an image portion of the three-dimensional wireframe image for which the two-dimensional temperature distribution image to be displayed is not obtained. A three-dimensional temperature distribution display device for pasting a two-dimensional texture image in which each pixel is given temperature information calculated in consideration of thermal conductivity from temperature information of a polygon to which is attached. The overlapping display means is configured to generate the two-dimensional temperature distribution image and the three-dimensional wire such 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 wireframe image. The three-dimensional temperature distribution display device according to claim 1, wherein the frame image is displayed in an overlapping manner. The three-dimensional temperature distribution display device according to claim 1, wherein the temperature measurement means performs positional deviation correction so that the acquired two-dimensional temperature distribution image comes to a predetermined position on the screen.