JP2008102063A - Vehicle wheel center position measuring device by image processing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle wheel center position measuring device by image processing capable of measuring accurately the shape center of a vehicle wheel. <P>SOLUTION: This vehicle wheel center position measuring device by image processing for measuring the shape center of the vehicle 2 wheel 21 at a performance test time of the vehicle 2 installed on a drum 1 has a constitution comprising a camera 3 for imaging a marker applied onto the rotation center of the wheel 21, and outputting the imaged image; and an image processing part 4 for extracting the marker from inside the image inputted from the camera 3 based on information of the marker registered beforehand, calculating the marker position on the wheel 21 surface from a position in the image of the extracted marker, and detecting the calculated marker position as the rotation center position of the wheel 21. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vehicle wheel center position measuring apparatus using image processing.

  There is a chassis dynamometer as a device for inspecting the engine performance of an automobile. The chassis dynamometer is a device for inspecting the performance of the vehicle by fixing the vehicle so that the wheel of the vehicle rides on a drum as a simulated running path and rotating the drum under various conditions.

  It is desirable that the vehicle disposed on the chassis dynamometer is provided with a foil just above the rotating shaft of the drum in order to simulate smooth road running. However, depending on various power performance tests, the vehicle may move in the front-rear direction on the drum due to vibration or force acting on the vehicle. Thus, if the position of the vehicle on the drum changes during the inspection, there is a problem that the vehicle cannot maintain a horizontal state and an error occurs in the performance inspection value.

For this reason, in order to correct the error of the performance inspection value, it is necessary to measure the wheel center of the vehicle in real time and with high accuracy, and there are the following techniques.
(1) The measurement technique using a mechanical sensor or an infrared sensor is a technique for detecting the position of a wheel using these sensors and detecting tire puncture.
(2) Patent Document 1 is a technique for acquiring an image of the outer periphery of a tire, a seam between a wheel and a tire, and a seam provided on a foil, measuring the center of the foil by image processing, and determining the installation state of the vehicle. . Since measurement of the foil center is difficult with other measurement means such as a laser, the measurement means using image processing is an effective method.

JP 2005-351730 A

  However, the technique (1) described above has the following problems. That is, since the mechanical sensor is a contact type, it is a problem that it is easily broken, and because it is an On / Off measurement, a detailed foil center position cannot be measured. In addition, the infrared sensor has an advantage that the foil position can be measured in a non-contact manner, but on the other hand, the resolution is rough and the foil center cannot be measured with high accuracy.

  Moreover, the following problems can be considered in the technique (2) described above. In other words, the film center is photographed small because the entire foil is photographed, and the foil center cannot be measured with high accuracy. Although the center of the foil is obtained from the foil shape, the shape center may be different from the actual rotation center. For example, the foil shape center having a wheel balance error and the actual dynamic rotation center are different in units of several mm. In some cases, the center of the shape is not an accurate center of rotation, and there is a problem that a deviation may cause an error in performance inspection.

  In view of the above, an object of the present invention is to provide a vehicle wheel center position measuring device by image processing that enables accurate measurement of the shape center of a vehicle foil.

  A vehicle wheel center position measuring apparatus according to the first image processing of the present invention for solving the above problems is an apparatus for measuring the center position of the wheel of the vehicle at the time of a performance test of the vehicle installed on the simulated traveling road. An image pickup unit that picks up an image of a marker applied to the rotation center of the wheel of the vehicle and outputs the picked up image, and the image input from the image pickup unit based on information of the marker registered in advance. Image processing means for extracting the marker from the inside, calculating the position of the marker on the surface of the foil from the position of the extracted marker in the image, and detecting the calculated position of the marker as the rotation center position of the foil; It is provided with.

  The vehicle wheel center position measuring apparatus according to the second image processing of the present invention is the vehicle wheel center position measuring apparatus according to the first image processing, wherein the imaging means includes the first marker as the marker and the foil. The image of the second marker that is spaced from the first marker on the surface is output and a calibration image sequence is output, and the image processing means is configured to input the calibration image sequence The angle between the reference line passing through the origin with the position of the first marker as the origin, the straight line connecting the origin and the second marker, and the center point of the first marker position are calculated in advance. A function of storing the offset amount calculated from the calculated angle and the position of the center point in a storage unit, and a function of calibrating the center position of the foil based on the offset amount during the performance test. And

  According to a third aspect of the present invention, there is provided a vehicle wheel center position measuring apparatus for measuring the center position of a wheel of a vehicle during a performance test of the vehicle installed on a simulated traveling road, wherein the wheel surface of the vehicle is measured. The image pickup means for picking up two markers provided at any position of the image, and outputting the picked up image, and extracting the marker based on the information of the marker registered in advance from the input image A plurality of rotation center candidate regions of the foil are set from the displacements of the positions of the markers in the image, the displacements of the rotation center candidate points constituting the candidate regions are respectively measured, and the point with the smallest locus deviation is determined. Image processing means for detecting the center position of the foil is provided.

  According to a fourth aspect of the present invention, there is provided a vehicle wheel center position measuring apparatus for measuring the center position of a wheel of a vehicle at the time of a performance test of the vehicle installed on a simulated running road, wherein the wheel surface of the vehicle is measured. An image pickup means for picking up an image of one marker provided at an arbitrary position and outputting the picked-up image, and extracting the marker based on information of the marker registered in advance from the input image And an image processing means having a function of calculating the rotation center position of the foil from the position of the marker and a function of calibrating the rotation center position of the foil.

  According to a fifth aspect of the present invention, there is provided a vehicle wheel center position measuring apparatus for measuring the center position of a wheel of a vehicle during a performance test of the vehicle installed on a simulated traveling road. Imaging means for capturing an image of a marker provided at any position of the at least one rotation of the foil and outputting the captured image, and based on information on the marker registered in advance from the input image A marker is extracted, a logical image is drawn that draws the locus of the marker from the extracted position of the marker, the locus of the marker is extracted as a circle from the logical image, a center position is calculated, and the calculated center position is calculated. Image processing means for setting the center position of the foil.

  According to a sixth image processing of the present invention, a vehicle wheel center position measuring device is a device for measuring the center position of a wheel of the vehicle at the time of a performance test of the vehicle installed on the simulated traveling road, and the wheel surface of the vehicle Imaging means for imaging a marker provided at an arbitrary position in an exposed state during at least one rotation of the foil and outputting the captured image, and a locus of the marker captured in the input image Image processing means for extracting a circle, calculating a center position, and setting the calculated center position as a center position of the foil is provided.

  According to the seventh image processing vehicle wheel center position measuring apparatus of the present invention, in the vehicle wheel center position measuring apparatus according to any one of the first to sixth image processing, the two image pickup means having synchronized image pickup periods. By means of the above, images of the markers respectively applied to the two foils positioned on both sides of one axle are captured, and the image processing means is configured to detect each of the foils from the images input from the two synchronized imaging means. In addition to calculating a rotation center position, a function of calculating a dynamic displacement of the axle from a correlation between the calculated rotation center positions is provided.

  According to an eighth aspect of the present invention, there is provided a vehicle wheel center position measuring device according to any one of the first to seventh image processing, wherein the vehicle wheel center position measuring device is applied to the front and side surfaces of the vehicle body. Each of the third markers is imaged, and two imaging units that synchronize an imaging cycle for outputting the captured vehicle image are provided, and the image processing unit is input from the two synchronized imaging units. A function of extracting the third marker based on the information of the third marker registered in advance from an image and calculating a movement amount of the vehicle from a correlation between the extracted positions of the third marker; It is characterized by that.

  According to a ninth aspect of the present invention, there is provided the vehicle wheel center position measuring device according to the seventh or eighth image processing of the vehicle wheel center position measuring device, wherein the wheel rotation center position calculated by the image processing means is calculated. Control means for controlling a position of the vehicle by adjusting a binding force to the vehicle based on information is provided.

  According to the tenth image processing vehicle wheel center position measuring apparatus of the present invention, the vehicle wheel center position measuring apparatus according to the seventh or eighth image processing is based on the rotation center position of the foil calculated by the image processing means. An acceleration is calculated, and the calculated acceleration is used for calculation of a measurement value in the vehicle performance inspection.

  According to the vehicle wheel center position measuring apparatus according to the first image processing of the present invention described above, the rotation center of the foil is non-contacted by using image processing as compared with the conventional contact-type measuring means such as a laser. The position can be measured, the center position can be measured by imaging the center of the foil without imaging the entire foil, and the center position of the foil can be measured with high resolution, for example, If the foil color is white, the marker color is black, and if the foil color is black, the marker color is castle. The effect that the center position of the foil can be measured robustly is obtained.

  According to the vehicle wheel center position measuring apparatus according to the second image processing of the present invention, even if it is difficult to apply the marker to the exact rotation center position of the foil, the rotation of the foil from the position of the two markers is performed. Since the center position can be calibrated, the rotation center position of the foil can be measured with higher accuracy.

  According to the vehicle wheel center position measuring apparatus according to the third image processing of the present invention, even if it is difficult to place a marker at the rotation center position of the foil, the wheel rotation center position is determined from the positions of the two markers. Can be calibrated, so that it is possible to accurately measure the rotational center position of the foil.

  According to the fourth to sixth image processing vehicle wheel center position measuring apparatus of the present invention, it is possible to accurately measure the rotation center position of the foil simply by applying one marker to any position on the foil surface. Therefore, the center position of the foil can be measured more easily.

  According to the vehicle wheel center position measuring device according to the seventh image processing of the present invention, in addition to the effects of the vehicle wheel center position measuring device according to the first to sixth image processing, the vehicle wheel center position measuring device can be It is possible to measure sequential positions.

  According to the vehicle wheel center position measuring device according to the eighth image processing of the present invention, in addition to the effects of the vehicle wheel center position measuring device according to the first to seventh image processing, the vehicle longitudinal direction, the vertical direction, Since the amount of movement in the left-right direction can be measured, the dynamic amount of movement of the vehicle can be measured without contact.

  According to the vehicle wheel center position measuring device of the ninth image processing of the present invention, in addition to the effect of the vehicle wheel center position measuring device of the seventh or eighth image processing, the control is performed according to the amount of movement of the vehicle. Since the vehicle position can be maintained in the initial state, the error of the performance inspection value can be reduced.

  According to the vehicle wheel center position measuring apparatus according to the tenth image processing of the present invention, the acceleration is calculated by second-order differentiation of the movement amount of the axle or the vehicle, and the calculated acceleration is reflected in the vehicle performance inspection. Further, it becomes possible to carry out the performance inspection of the vehicle with higher accuracy and with less error.

  Embodiments of the present invention will be described in detail with reference to the following examples.

  A first embodiment of the present invention will be described in detail with reference to FIG. FIG. 1 is a configuration diagram schematically showing a vehicle wheel center position measuring apparatus by image processing according to the present embodiment, and FIG. 2 is a schematic diagram showing an example of a marker.

  As shown in FIG. 1, in the vehicle wheel center position measuring apparatus by image processing according to the present embodiment, a camera 3 as an image pickup means is arranged on the side of a vehicle 2 installed on a drum 1 constituting a dynamometer. It is configured. Specifically, the camera 3 is arranged so that an image can be taken from a position facing at least the rotation center of the foil 21 to the surface of the foil 21. As shown in FIG. 2, a marker 51 is provided in advance at the rotational center position of the surface of the foil 21, and the camera 3 captures the marker 51 and uses the captured image data as an image processing unit 4. To output.

  Information such as the shape of the marker 51 is registered in the image processing unit 4 in advance as a registered marker. The image processing unit 4 uses the position of the marker 51 in the input image as the center coordinate of the foil 21 as a portion corresponding to the registered marker by the arithmetic processing such as pattern matching for the input image data (input image). To detect. Then, the position of the marker 51 detected in this way is used as the rotation center of the foil 21 for various vehicle performance inspections. For example, in this embodiment, a circular marker having a diameter of about 5 mm is applied as the marker 51.

  According to the vehicle wheel center position measuring apparatus using the image processing of the present embodiment, the measurement can be smoothly performed because of the non-contact type using the image processing with respect to the laser and the contact type measuring means.

  Furthermore, it is possible to measure the moving speed and acceleration of the wheel 21 center by differentiating the wheel 21 center position.

  Furthermore, since it is possible to detect the position by capturing an image of the marker 51 applied to the rotation center of the foil 21, it is not necessary to image the entire foil 21, and an image obtained by enlarging the rotation center of the foil 21 is obtained. The center of the foil 21 can be measured with high resolution.

  Further, for example, if the white foil 21 is used, the marker 51 is black. If the black foil 21 is used, the marker 51 is white. Thus, the center of the foil 21 can be measured robustly without being affected by the environment such as the dirt of the foil 21 or the lighting state at the time of measurement.

  In the present embodiment described above, an example in which the position of the marker 51 is detected by an arithmetic process such as pattern matching has been shown. However, for example, the marker 51 is extracted by a binarization process, and the center of gravity of the shape of the extracted marker 51 is calculated. Needless to say, various changes can be made without departing from the gist of the present invention, such as detection as the rotation center of the foil 21.

  A second embodiment of the present invention will be described with reference to the drawings. FIG. 3 is an explanatory diagram showing an example of the positional relationship between two markers. This embodiment is different from the first embodiment in that markers are provided at a total of two locations on the foil 21. Other configurations are substantially the same as those of the first embodiment. Therefore, the vehicle wheel center position measuring apparatus according to the image processing of the present embodiment will be described by taking the configuration shown in FIG. 1 as an example, and the description overlapping the above description will be omitted.

  In the present embodiment, markers 52 and 53 are provided on the surface of the foil 21 at approximately the rotation center position of the foil 21 and at a position having an arbitrary distance from the rotation center as shown in FIG.

  The camera 3 arrange | positions the markers 52 and 53 in the position facing the foil 21 surface so that imaging is possible. The foil 21 rotated at a constant speed by the camera 3 is imaged at a constant period, and the captured image is input to the image processing unit 4 as a calibration image sequence. The calibration image sequence is acquired by rotating the foil 21 at least once or more.

  Information such as the shapes of the markers 52 and 53 is registered in the image processing unit 4 in advance as registered markers. The image processing unit 4 performs arithmetic processing such as pattern matching on the calibration image sequence, extracts two markers 52 and 53 from one calibration image, and detects the respective positions (coordinates). Further, the coordinates of the markers 52 and 53 are detected in the same procedure in all the calibration images.

The procedure for calculating the rotation center of the foil 21 from the coordinates of the two markers 52 and 53 will be described below with reference to FIG. As shown in FIG. 3, the position of the marker 52 applied to the approximate rotation center of the foil 21 in the calibration image is set to m ₁ (x ₁ , y ₁ ), and the distance from the rotation center of the foil 21 is set. The position of the marker 53 is m ₂ (x ₂ , y ₂ ).

First, from the respective positions m ₁ (x ₁ , y ₁ ) and m ₂ (x ₂ , y ₂ ) of the detected two markers 52 and 53, the x axis as a reference line with the marker 52 as the origin, and m _An angle formed by a straight line connecting ₁ (x ₁ , y ₁ ) and m ₂ (x ₂ , y ₂ ), that is, a rotation angle θ of the wheel 21 is calculated. Further, the center point of the position m ₁ (x ₁ , y ₁ ) of the marker 52 is calculated from the calibration image sequence, and this is set as the true value of the rotation center.

Next, the difference between the true value and the position m ₁ (x ₁ , y ₁ ) of the marker 52 calculated from the calibration image sequence is calculated, and the offset amount for each rotation angle θ is (dx (θ), dy). (Θ)) is stored in advance in a storage means (not shown).

  Then, during various vehicle performance inspections, the center position of the foil 21 is calibrated with reference to the offset amount for each rotation angle θ stored in the storage means in the images obtained by capturing the markers 52 and 53 with the camera 3.

  The true value calculated in this way is used as the rotation center of the wheel 21 for various vehicle performance inspections. Note that the markers 52 and 53 in the calibration image sequence may be determined from, for example, a search position and a detection position.

  According to the vehicle wheel center position measuring apparatus using the image processing of the present embodiment, the coordinates of the rotation center of the foil 21 can be configured using the offset amount calculated by the image processing unit. In addition to the effect of 1, the rotation center of the foil 21 can be measured more precisely. In this embodiment, a circular shape having a diameter of about 5 mm is applied as an example of the markers 52 and 53.

  A third embodiment of the present invention will be described with reference to the drawings. FIG. 4 is an explanatory diagram showing an example of the positional relationship between two markers, and FIG. 5 is an explanatory diagram showing a locus of a point P described later. The present embodiment is an example in which the position where the marker is applied is different from that in the second embodiment. Other configurations are substantially the same as those of the second embodiment. Therefore, the vehicle wheel center position measuring apparatus according to the image processing of the present embodiment will be described by taking the configuration shown in FIG. 1 as an example, and the description overlapping the above description will be omitted.

  In this embodiment, the foil 21 is provided with two markers 54 and 55 as shown in FIG. 4 at arbitrary positions on the surface facing the camera 3 and having a distance from the rotation center. In the camera 3, the markers 54 and 55 are arranged on the same axis as the rotation center of the wheel 21 so as to be capable of imaging. The foil 21 rotated at a constant speed by the camera 3 is imaged at a constant period, and the captured image is input to the image processing unit 4 as a calibration image sequence. The calibration image sequence is acquired by rotating the foil 21 at least once or more.

  Information such as the shapes of the markers 54 and 55 is registered in the image processing unit 4 in advance as registered markers. The image processing unit 4 performs arithmetic processing such as pattern matching on the calibration image sequence, extracts two markers 54 and 55 from one calibration image, and detects the respective positions (coordinates). Further, the coordinates of the markers 54 and 55 are detected in the same procedure in all the calibration images.

Hereinafter, a procedure for calculating the rotation center of the foil 21 from the coordinates of the two markers 54 and 55 detected based on FIGS. 4 and 5 will be described. As shown in FIG. 4, the positions of the markers 54 and 55 in the calibration image are m ₃ (x ₃ , y ₃ ) and m ₄ (x ₄ , y ₄ ).

First, the marker coordinate axis (x, y) is set with the marker 54 in the calibration image as the origin and the vector from m ₃ (x ₃ , y ₃ ) to m ₄ (x ₄ , y ₄ ) as the x axis. And the rotation center candidate area | region 6 which includes a rotation center is set to this marker coordinate system.

Next, one point in the rotation center candidate area 6 is selected as the rotation center candidate point p, and a locus as shown in FIG. 5, that is, a locus drawn by the candidate point p on the coordinate system (u, v) of the calibration image sequence is shown. The deviation σu _p + σv _p between the u-axis and the v-axis of this locus is calculated. Similarly, deviations σu + σv at all points in the rotation center candidate region 6 are calculated, and a point p _{0 at} which the deviation is minimum is obtained as the rotation center of the wheel 21.

In this way, the calculated position p ₀ is used as the rotation center of the wheel 21 for various vehicle performance inspections.

  According to the vehicle wheel center position measuring apparatus according to the image processing of the present embodiment, in addition to the effects of the second embodiment described above, even if it is difficult to mark the rotation center of the foil 21, the foil 21 This makes it possible to accurately measure the center of rotation. For example, in the present embodiment, circular markers having a diameter of about 5 mm are applied as the markers 54 and 55.

  A fourth embodiment of the present invention will be described. The present embodiment differs from the first embodiment in the position where the marker is applied. Other configurations are substantially the same as those of the first embodiment. Therefore, the vehicle wheel center position measuring apparatus according to the image processing of the present embodiment will be described by taking the configuration shown in FIG. 1 as an example, and the description overlapping the above description will be omitted.

  In the present embodiment, one marker is provided on the surface of the foil 21 at an arbitrary position. The camera 3 is arranged at a position where the marker can be imaged from a position facing the surface of the foil 21. The foil 21 rotated at a constant speed by the camera 3 is imaged at a constant period, and the captured image is input to the image processing unit 4 as a calibration image sequence. The calibration image sequence is acquired by rotating the foil 21 at least once or more.

  Information such as the shape of the marker is registered in advance in the image processing unit 4 as a registered marker. The image processing unit 4 performs arithmetic processing such as pattern matching on the calibration image sequence, extracts a marker from one calibration image, and detects its position (coordinates). Further, the coordinates of the marker are detected in the same procedure in all the calibration images.

  In this embodiment, the average value of the detected marker coordinates is calculated, and this average value is used as the rotation center of the foil 21. Further, the rotation angle can be calculated by using the calculated rotation center of the foil 21 as the origin and comparing the origin with the marker position. In this way, the average value of the calculated marker coordinates is used as the rotation center of the foil 21 for various vehicle performance inspections.

  According to the wheel center position measuring apparatus for a vehicle by image processing according to the present embodiment, in addition to the effects of the first embodiment described above, even if it is difficult to place a marker at the rotation center of the foil 21, the foil 21. It becomes possible to measure the rotation center and rotation angle of the lens with high accuracy.

  A fifth embodiment of the present invention will be described. The present embodiment is different from the fourth embodiment in that the image processing unit 4 creates a logical image from the calibration image sequence and obtains the rotation center of the foil 21. Other configurations are substantially the same as those in the fourth embodiment. Therefore, the vehicle wheel center position measuring apparatus according to the image processing of the present embodiment will be described by taking the configuration shown in FIG. 1 as an example, and the description overlapping the above description will be omitted.

  In this embodiment, the image processing unit 4 creates a logical image from the calibration image sequence. Specifically, for example, when the foil 21 is black and the marker is white, a plurality of calibration image sequences are overlapped to enable the maximum pixel value in the same coordinates to create one logical image. As a result, a logical image in which the locus of the marker is a white circular circle is obtained.

  Further, when the foil 21 is white and the marker is black, a logical image is created by overlapping a plurality of calibration image sequences and enabling the minimum pixel value in the same coordinates, and the marker trajectory is black. A logical image that is a circle is obtained.

  The rotation center position of the wheel 21 can be obtained by performing arithmetic processing using the least square method or the like from the logical image thus obtained and calculating the center of the circle.

  According to the vehicle wheel center position measuring apparatus based on image processing of the present embodiment, in addition to the effects of the first embodiment described above, it is difficult to place a marker at the rotation center of the foil 21 as in the fourth embodiment. Even if it exists, it becomes possible to measure the rotation center and rotation angle of the foil 21 with high accuracy.

  A sixth embodiment of the present invention will be described. The present embodiment is different from the fourth embodiment in the method of capturing the marker by the camera 3. The marker 3 is captured by setting the exposure time of the camera 3 longer, the captured image is processed, and the rotation center of the foil 21 is processed. Is what you want. Other configurations are substantially the same as those in the fourth embodiment. Therefore, the vehicle wheel center position measuring apparatus according to the image processing of the present embodiment will be described by taking the configuration shown in FIG. 1 as an example, and the description overlapping the above description will be omitted.

  In the present embodiment, the camera 3 is disposed so as to face the surface of the wheel 21 of the vehicle 2, and is disposed so as to be able to image the rotation center of the wheel 21. Markers are provided in advance at arbitrary positions on the surface of the foil 21 facing the camera 3, and the camera 3 images the rotating foil 21 while being exposed, and outputs image data to the image processing unit 4. The camera 3 acquires an image by rotating the foil 21 at least once or more.

  For example, when the foil 21 is black and the marker is white from the input image input to the image processing unit 4 in this manner, a white circular circle is extracted as the marker locus, and the least square method or the like is used. An arithmetic operation is performed to calculate the center of the circle, which is used as the rotation center of the wheel 21. Further, when the foil 21 is white and the marker is black, a black circular circle is extracted as the locus of the marker, the center of the circle is calculated by calculation, and this is set as the rotation center of the foil 21.

  According to the wheel center position measuring apparatus for a vehicle by image processing according to the present embodiment, in addition to the effects of the first embodiment described above, even if it is difficult to place a marker at the rotation center of the foil 21, the foil 21. It becomes possible to measure the rotation center and rotation angle of the lens with high accuracy.

  The second embodiment of the present invention will be described in detail based on FIG. FIG. 6 is a block diagram schematically showing a vehicle wheel center position measuring apparatus using image processing according to the present embodiment.

  As shown in FIG. 6, the vehicle wheel center position measuring apparatus according to the image processing of the present embodiment is different from the first embodiment described above in that two cameras are used. In the following, the same members as those shown in FIG.

  In the present embodiment, cameras 31 and 32 are arranged on both sides of the vehicle 2 installed on the drum 1. Specifically, the camera 31 is arranged at a position facing the foil 22 so that the rotational center position of the surface of the foil 21 can be imaged. The camera 32 is disposed at a position facing the foil 22 so that the rotational center position of the surface of the foil 22 can be imaged.

  Markers as shown in FIG. 2 are provided in advance at the rotation centers of the wheels 21 and 22, and the cameras 31 and 32 respectively capture the markers and output the captured image data to the image processing unit 4. To do. Note that the two cameras 31 and 32 image the markers provided on the rotating wheels 21 and 22 in a state where the imaging cycles are synchronized.

  Information such as the shape of the marker is registered in advance in the image processing unit 4 as a registered marker. The image processing unit 4 detects the position of the marker in the input image as the center coordinates of the wheels 21 and 22 by performing arithmetic processing such as pattern matching on the input images captured by the cameras 31 and 32, for example. Furthermore, time-series fluctuating positions in the front-rear and vertical directions of the axle are calculated from marker position information detected from the input images from the synchronized cameras 31 and 32. The detected fluctuation position is used for various vehicle performance inspections. In the present embodiment, a circular marker having a diameter of about 5 mm is applied as an example of the marker.

  According to the vehicle wheel center position measuring apparatus according to the image processing of the present embodiment, in addition to the effects of the first embodiment described above, it is possible to calculate time-series fluctuation positions in the front-rear and vertical directions of the axle. It becomes possible to measure the center position fluctuation with higher accuracy.

  The eighth embodiment of the present invention will be described in detail based on FIG. FIG. 7 is a block diagram schematically showing a vehicle wheel center position measuring apparatus using image processing according to the present embodiment. The present embodiment is applied in addition to the configuration of any of the first to sixth embodiments described above, and some of the overlapping members are not shown. Further, the same members as those described in the first to sixth embodiments are denoted by the same reference numerals, and redundant description is omitted.

  As shown in FIG. 7, the vehicle wheel center position measuring apparatus according to the image processing of the present embodiment has a configuration in which cameras 33 and 34 are arranged in front and side of the vehicle 2 installed on the drum 1. Specifically, the camera 33 is arranged on the side of the vehicle 2 so that the vehicle can be imaged, and the camera 34 is arranged in front of (or behind) the vehicle so that the vehicle can be imaged. Markers 56 and 57 are provided in advance on the surface of the vehicle imaged by the cameras 33 and 34, and the cameras 33 and 34 image the markers 56 and 57, and the captured image data is sent to the image processing unit 4. Is output. Note that the two cameras 33 and 34 image the markers 56 and 57 in a state where the imaging cycles are synchronized.

  Information such as the shapes of the markers 56 and 57 is registered in the image processing unit 4 in advance as registered markers. The image processing unit 4 detects the positions of the markers 56 and 57 in the input image by an arithmetic process such as pattern matching for the input image. Specifically, the amount of movement of the vehicle in the left-right direction and the up-down direction is measured by the position of the marker 56, and the amount of movement of the vehicle in the front-rear direction and the up-down direction is measured by the position of the marker 57. Furthermore, by synchronizing the cameras 33 and 34, the amount of dynamic movement of the vehicle is calculated from the detected position information of the marker 56 and the marker 57.

  The dynamic movement amount of the vehicle from the positions of the markers 56 and 57 detected in this way is used for various vehicle performance inspections. In the present embodiment, a circular shape having a diameter of about 5 mm is applied as an example of the markers 56 and 57.

  According to the vehicle wheel center position measuring apparatus using the image processing of the present embodiment, in addition to the effects of the first embodiment, the dynamic movement amount of the vehicle can be calculated by non-contact measurement. It becomes possible to carry out with high precision.

  A ninth embodiment of the present invention will be described in detail based on FIG. FIG. 8 is a block diagram schematically showing a vehicle wheel center position measuring apparatus using image processing according to the present embodiment. The present embodiment is applied to the above-described seventh embodiment, and the description overlapping with the description shown in FIG. In FIG. 8, the camera 3 is omitted.

  As shown in FIG. 8, this embodiment is obtained by adding a control device 7 that controls the movement of the vehicle 2 in the front-rear direction based on information input from the image processing unit 4 to the configuration of the first embodiment. It is. The control device 7 controls movement of the vehicle 2 in the front-rear direction, for example, by connecting an elastic body such as a spring to the vehicle. Based on the movement amount of the axle calculated in the seventh embodiment, the control device 7 applies a restraining force to the vehicle 2. It is configured to be adjustable.

  That is, the present embodiment uses the movement amount of the axle calculated in the seventh embodiment and actively controls the restraining force by the control device 7, thereby suppressing the front-rear direction movement of the vehicle 2 on the drum 1. is there.

  As a means for adjusting the restraining force, for example, the restraining member that restrains the vehicle 2 is configured to be movable in the front-rear direction of the vehicle 2, or by controlling the spring coefficient of the control device, that is, the elastic force. it can.

  According to the vehicle wheel center position measuring apparatus using the image processing of the present embodiment, in addition to the effects of the seventh embodiment, the movement of the vehicle 2 is restrained, and the movement amount in the front-rear direction of the vehicle 2 is controlled. Thus, it is possible to reduce the error of the inspection value in various vehicle performance inspections.

  A tenth embodiment of the present invention will be described. In the present embodiment, the measurement value calculation of the drum 1 is performed using the movement amount of the axle calculated in the seventh embodiment. That is, the acceleration is calculated by second-order differentiation of the movement amount of the axle obtained in the seventh embodiment, and the measurement value calculation of the chassis dynamometer is performed so that the acceleration measurement in the front-rear direction can be performed similarly to the actual road. .

  According to the vehicle wheel center position measuring apparatus using the image processing of the present embodiment, in addition to the effects of the seventh embodiment, calculation of performance inspection can be performed in consideration of the movement of the vehicle 2 on the drum 1 in the front-rear direction. An effect is obtained.

  The present invention can be applied to a vehicle wheel center position measuring apparatus using image processing.

1 is a block diagram schematically showing a vehicle wheel center position measuring apparatus using image processing according to Embodiment 1 of the present invention. It is a schematic diagram which shows an example of the marker of the wheel center position measuring apparatus of the vehicle by the image processing which concerns on Example 1 of this invention. It is explanatory drawing which shows an example of the positional relationship of the two markers of the wheel center position measuring apparatus of the vehicle by the image processing which concerns on Example 2 of this invention. It is explanatory drawing which shows an example of the positional relationship of the two markers of the wheel center position measuring device of the vehicle by the image processing which concerns on Example 3 of this invention. It is explanatory drawing which shows the locus | trajectory of the point P shown in FIG. It is a block diagram which shows typically the wheel center position measuring apparatus of the vehicle by the image processing which concerns on Example 7 of invention. It is a block diagram which shows typically the wheel center position measuring apparatus of the vehicle by the image process which concerns on Example 8 of this invention. It is a block diagram which shows typically the wheel center position measuring apparatus of the vehicle by the image processing which concerns on Example 9 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Drum 2 Vehicle 21 Wheels 3, 31, 32, 33, 34 Camera 4 Image processing means 51, 52, 53, 54, 55, 56, 57 Marker 6 Rotation center candidate area 7 Controller

Claims (10)

A device for measuring the center position of the wheel of the vehicle at the time of a performance test of the vehicle installed on the simulated traveling road,
Imaging means for imaging a marker applied to the rotation center of the wheel of the vehicle and outputting the captured image;
Based on information of the marker registered in advance, the marker is extracted from the image input from the imaging unit, and the position of the marker on the foil surface is calculated from the extracted position of the marker in the image. And an image processing means for detecting the calculated position of the marker as the rotation center position of the foil. The imaging means captures a first marker that is the marker and a second marker that is spaced from the first marker on the surface of the foil and outputs a calibration image sequence. And
The image processing means includes an angle between a reference line passing through the origin with the position of the first marker as an origin, and a straight line connecting the origin and the second marker from the input calibration image sequence. And a function of storing a center point of the first marker position, storing the calculated offset amount and the offset amount from the position of the center point in a storage unit, and based on the offset amount during the performance test The wheel center position measuring device for a vehicle by image processing according to claim 1, comprising a function of calibrating the center position of the foil. A device for measuring the center position of the wheel of the vehicle at the time of a performance test of the vehicle installed on the simulated traveling road,
Imaging means for imaging two markers provided at arbitrary positions on the wheel surface of the vehicle, and outputting the captured image;
Extracting the marker based on the information of the marker registered in advance from the input image, set the rotation center candidate region of the plurality of foils from the displacement of the position of the extracted marker in the image, Image processing means for measuring the displacement of each rotation center candidate point constituting the candidate area and detecting the point having the smallest trajectory deviation as the center position of the foil. Wheel center position measuring device. A device for measuring the center position of the wheel of the vehicle at the time of a performance test of the vehicle installed on the simulated traveling road,
Imaging means for imaging one marker applied to an arbitrary position on the wheel surface of the vehicle and outputting the captured image;
A function of extracting the marker based on information of the marker registered in advance from the input image, calculating a rotation center position of the foil from the extracted position of the marker, and a rotation center position of the foil An image processing means having a function of calibrating the vehicle wheel center position measuring device by image processing. A device for measuring the center position of the wheel of the vehicle at the time of a performance test of the vehicle installed on the simulated traveling road,
Imaging means for imaging a marker provided at an arbitrary position on the surface of the wheel of the vehicle and outputting an image captured at least while the foil makes one rotation;
The marker is extracted based on the information of the marker registered in advance from the input image, and a logical image that draws the locus of the marker from the extracted marker position is created. An image processing means for extracting a locus as a circle, calculating a center position, and setting the calculated center position as a center position of the foil. A device for measuring the center position of the wheel of the vehicle at the time of a performance test of the vehicle installed on the simulated traveling road,
An image pickup means for outputting an image picked up in a state where a marker provided at an arbitrary position on the surface of the wheel of the vehicle is exposed for at least one rotation of the foil;
Image processing means for extracting a locus of the marker imaged in the input image as a circle, calculating a center position, and setting the calculated center position as a center position of the foil. The wheel center position measuring device of the vehicle by image processing. By the two imaging means having synchronized imaging cycles, the markers applied to the two foils located on both sides of one axle are imaged,
The image processing means calculates the rotation center position of the wheel from the images input from the two synchronized image pickup means, and the dynamics of the axle is calculated from the calculated correlation between the rotation center positions. The vehicle wheel center position measuring device by image processing according to any one of claims 1 to 6, further comprising a function of calculating a displacement. Two imaging means that synchronize the imaging cycle for imaging the third marker applied to the vehicle body front and the vehicle body side of the vehicle, respectively, and outputting the captured vehicle image,
The image processing means extracts the third marker based on information of the third marker registered in advance from the body image input from the two synchronized imaging means, and the extracted third marker The vehicle wheel center position measuring device by image processing according to any one of claims 1 to 7, further comprising a function of calculating a movement amount of the vehicle from a mutual relationship between positions of three markers.   9. The control device according to claim 7, further comprising: a control unit that adjusts a binding force with respect to the vehicle based on information on a rotation center position of the foil calculated by the image processing unit and controls the position of the vehicle. The wheel center position measuring device of the vehicle by the image processing described in 1.   The acceleration is calculated from the rotation center position of the foil calculated by the image processing means, and the calculated acceleration is used for the measurement value calculation of the vehicle performance inspection. The wheel center position measuring device of the vehicle by the image processing described.

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