MEASURING PANEL FOR VEHICLE MEASUREMENT

Abstract

A measurement panel (8) for the optical measurement or calibration of a vehicle component, in particular a wheel system or driver assistance system, comprises at least one optical feature (30, 32) and at least one optically detectable information carrier (34) of measurement panel information relating to the measurement panel (8) itself. The at least one optical feature (30, 32) is formed on or attached to a front side of the measurement panel (8), and the at least one optically detectable information carrier (34) is formed on or attached to a rear side of the measurement panel (8).

Claims

1. A measurement panel for the optical measurement or calibration of a vehicle component, in particular of a wheel system or driver assistance system, the measurement panel comprising: at least one optical feature; and at least one optically detectable information carrier of measurement panel information relating to the measurement panel itself; characterized in that the at least one optical feature is formed on or attached to a front side of the measurement panel; and the at least one optically detectable information carrier is formed on or attached to a rear side of the measurement panel.

2. The measurement panel according to claim 1, characterized in that the measurement panel information is at least one of a group comprising: an individual identifier of the measurement panel, geometric dimensions of the measurement panel, geometric dimensions of optical features formed on the measurement panel, parameters of the measurement panel and/or the optical features formed thereon, optical properties of the measurement panel and/or the optical features, formed thereon.

3. The measurement panel according to claim 1, characterized in that the measurement panel information is encoded in the at least one optically detectable information carrier, the measurement panel information being encoded in the at least one optically detectable information carrier in particular in compressed form.

4. The measurement panel according to claim 3, characterized in that the measurement panel information is encoded in a machine-readable form in the at least one optically detectable information carrier, the machine-readable form including at least one element of the group comprising: alphanumeric symbols or the like, a one-dimensional code, in particular a bar code, or a two-dimensional code, in particular a QR code, or a combination thereof.

5. The measurement panel according to claim 1, wherein at least one identification pattern is additionally formed on the front side of the measurement panel, which identification pattern enables the measurement panel to be identified by means of an image recording device directed towards the front side of the measurement panel.

6. The measurement panel according to claim 5, wherein the identification pattern comprises a plurality of geometric identification elements, in particular circles or polygons, wherein the identification pattern comprises in particular a plurality of like geometric identification elements.

7. The measurement panel according to claim 6, wherein the identification elements are formed on the measurement panel in a measurement panel-specific number and/or are arranged on the measurement panel in a measurement panel-specific arrangement, wherein the identification elements are arranged on the measurement panel in particular in a vertically or horizontally or diagonally or obliquely aligned row.

8. The measurement panel according to claim 5, wherein the measurement panel comprises a first measurement panel element and a second measurement panel element formed separately from the first measurement panel element, wherein the at least one optical feature and the at least one optically detectable information carrier are formed on the first measurement panel element, and wherein the identification pattern is formed on the second measurement panel element.

9. The measurement panel according to claim 8, wherein the measurement panel comprises a measurement panel element carrier adapted to receive the first and second measurement panel elements; wherein the first and second measurement panel elements are attachable to and detachable from the measurement panel element carrier independently of each other.

10. A wheel adapter, comprising a measurement panel according to claim 1, wherein the wheel adapter is configured to be attached to a wheel of a motor vehicle.

11. A device for the optical measurement and/or calibration of a vehicle component, in particular a wheel system or driver assistance system, comprising: at least one image recording device, at least one image processing unit and at least one measurement panel according to claim 1, wherein the at least one measurement panel can be attached to a wheel of a motor vehicle, in particular by means of a wheel adapter, and wherein the at least one image recording device is configured to capture an image of the optically detectable information carrier of the at least one measurement panel and to transmit the captured image to the at least one image processing unit, and wherein the at least one image processing unit is adapted to decode the measurement panel information from the captured image of the optically detectable information carrier by means of image processing and to use the decoded measurement panel information in a subsequent measurement and/or calibration.

12. The device according to claim 11, wherein the device comprises a mobile image recording device adapted to capture an image of the optically detectable information carrier.

13. A method for the optical measurement or calibration of a vehicle component, in particular a wheel system or driver assistance system, using at least one measurement panel according to claim 1, the method comprising the steps of: attaching the at least one measurement panel to a wheel of a motor vehicle or to a measuring means required for the calibration of a driver assistance system; capturing an image of the at least one optically detectable information carrier ; recognizing and decoding the measurement panel information contained in the image of the at least one optically detectable information carrier, capturing at least one image of the at least one optical feature; and using the measurement panel information in the measurement or calibration of the vehicle component by means of the at least one captured image of the at least one optical feature.

14. The method according to claim 13, wherein the method comprises capturing the at least one image of the at least one optical feature by means of a stationary image recording device of a device for the optical measurement and/or calibration of a vehicle component.

15. The method according to claim 13, wherein the method comprises capturing the at least one image of the at least one optically detectable information carrier by means of a stationary image recording device of a device for the optical measurement and/or calibration of a vehicle component or by means of a mobile image recording device, in particular a camera of a mobile operating device, such as a smartphone or a tablet PC.

16. The method according to claim 13, wherein the method comprises furthermore: assigning the measurement panel information contained in the optically detectable information carrier to an identification pattern; capturing an image of the identification pattern; identifying the at least one measurement panel by means of the captured image of the identification pattern; and assigning the measurement panel information contained in the optically detectable information carrier to the measurement panel identified by means of the identification pattern.

17. The method according to claim 14, wherein the method comprises furthermore: assigning the measurement panel information contained in the optically detectable information carrier to an identification pattern; capturing an image of the identification pattern; identifying the at least one measurement pane by means of the captured image of the identification pattern; and assigning the measurement panel information contained in the optically detectable information carrier to the measurement panel identified by means of the identification pattern.

18. The measurement panel according to claim 2, characterized in that the measurement panel information is encoded in the at least one optically detectable information carrier, the measurement panel information being encoded in the at least one optically detectable information carrier in particular in compressed form.

19. The measurement panel according to claim 2, wherein at least one identification pattern is additionally formed on the front side of the measurement panel, which identification pattern enables the measurement panel to be identified by means of an image recording device directed towards the front side of the measurement panel.

20. A wheel adapter, comprising a measurement panel according to claim 2, wherein the wheel adapter is configured to be attached to a wheel of a motor vehicle.

Description

[0053] In the following, an exemplary embodiment of the invention will be explained in more detail with reference to the accompanying figures.

[0054] FIG. 1 shows a perspective view of a motor vehicle standing on a lifting platform with measurement panels attached to the wheels of the motor vehicle and a measuring head mounted laterally next to the running rails.

[0055] FIG. 2 shows an enlarged front view of a measurement panel according to the invention attached to a wheel of a motor vehicle by means of a wheel adapter.

[0056] FIG. 3 shows an enlarged rear view of the measurement panel according to the invention attached to a wheel of a motor vehicle by means of a wheel adapter.

[0057] FIG. 4 shows an enlarged front view of the measurement panel according to the invention.

[0058] FIG. 5 shows an enlarged rear view of the measurement panel according to the invention.

[0059] FIG. 1 shows a perspective view of a measuring station 1 equipped with a lifting platform 2 with a motor vehicle 6 standing thereon.

[0060] The lifting platform 2 has four columns 3a, 3b, namely two rear columns 3a and two front columns 3b, a rear cross member 5a and a front cross member 5b, each extending between the two front and the two rear columns 3a, 3b. A left and a right running rail 4a, 4b rest on the cross members 5a, 5b. By lifting the cross members 5a, 5b, the running rails 4a, 4b and the motor vehicle 6 standing thereon can be raised.

[0061] A measurement panel 8 designed according to the invention is attached to each of the four wheels 7 of the motor vehicle 6 by means of a wheel adapter 18. In the perspective view of FIG. 1, only two wheels 7 of the motor vehicle 6, namely the two wheels 7 on the right side of the motor vehicle 6, and three of the four measurement panels 8 are visible.

[0062] The front wheels 7 of the motor vehicle 6 are positioned on turn plates 16, which allow steering angles of the front wheels 7.

[0063] A measuring head 10 is mounted on each of the right (outer) side of the right-hand running rail 4b (and likewise on the outer left side of the left-hand running rail 4a, which is, however, concealed by the motor vehicle 6).

[0064] The measuring heads 10 are attached to the two running rails 4a, 4b of the lifting platform 2 by means of suitable attachment means 14. The measuring heads 10 can be attached to the running rails 4a, 4b, for example, by sliding them onto a respective outwardly directed holding device 14 that is attached to the respective running rail 4a, 4b.

[0065] The measuring head 10 is mounted in an approximately central position with respect to the longitudinal direction of the running rail 4a, 4b and the vehicle 6, so that a front (non-visible) image recording device of the measuring head 10 can capture an image of the respective measurement panel 8 on the front wheel 7 and a rearwardly directed image recording device 12 of the measuring head 10 can capture an image of the respective measurement panel 8 on the rear wheel 7 of the motor vehicle 6. The image recording devices 12 of the measuring heads 10 may be designed, in particular, as low-cost 2D cameras.

[0066] The measuring head 10 also comprises an image processing unit 13 which is designed for processing and evaluating the images captured or recorded by the image recording devices 12.

[0067] A reference system comprising a transverse camera and an optically detectable element is provided on the inner sides of the two measuring heads 10 facing the motor vehicle 6, i.e. on the side of each measuring head 10 facing the opposite measuring head 10. Via the reference systems of the two measuring heads 10 located opposite each other in the transverse direction, the measuring heads 10 reference each other in the transverse direction below the motor vehicle 6. Thus, the position and orientation of the measuring heads 10 with respect to each other can be determined, and the recorded images of the measurement panels 8 from both measuring heads 10 can be brought into a common coordinate system.

[0068] In addition to the measuring heads 10, a mobile and/or a stationary operating device 40 may be provided, which allows parameters and commands to be input and transferred to the measuring heads 10. The operating device 40 may also comprise a display device 42 that is designed to display measurement results, operating instructions, error messages and/or other information that has been transmitted from the measuring heads 10 to the operating device 40.

[0069] In particular, the operating device 40 may have a touch-sensitive screen (“touchscreen”) that can be used both as an input device and as a display device 42. Alternatively, the operating device 40 may be formed with a display device (screen) 42 and an input device separate therefrom, for example a keyboard, a mouse and/or a trackball.

[0070] The operating device 40 may be equipped furthermore with an image recording device (camera) 44 as well. One possible use of such an image recording device 44 within the scope of the invention will be explained further below.

[0071] The operating device 40 may be, for example, a smartphone or tablet PC and communicate with the measuring heads 10 and/or a central computer not shown in the figures via a wired or wireless connection, for example a WLAN or Bluetooth connection. The central computer may be a conventional personal computer or a single board computer, e.g. “Raspberry Pi”. The central computer can be designed to be operated as a web server to enable information to be displayed, in particular measurement results, to be displayed through a web browser. In this manner, commercially available devices, in particular smartphones and tablet PCs, can be used as operating and display devices 40.

[0072] Although the measuring station 1 shown in FIG. 2 is equipped with a lifting platform 2, measurement panels 8 formed according to the invention can also be used at measuring stations 1 that are not equipped with a lifting platform 2. In particular, the measuring heads 10 can also be attached to running rails 4a, 4b installed on the floor of a measuring station 1 or placed next to the motor vehicle 6 on the floor of the measuring station 1.

[0073] FIGS. 2 and 3 show enlarged views of a measurement panel 8 attached to a wheel 7 of the motor vehicle 6 by means of a wheel adapter 18 from the front (FIG. 2) and from the rear (FIG. 3).

[0074] FIGS. 4 and 5 show enlarged views of a measurement panel 8 according to the invention from the front (FIG. 4) and from the rear (FIG. 5).

[0075] The measurement panel 8 has a frame-shaped measurement panel element carrier 20 which can be connected, for example by means of a pluggable connection, to the wheel adapter 18 in order to support the measurement panel 8 on a wheel 7 of the motor vehicle 6.

[0076] The measurement panel element carrier 20 carries a first measurement panel element 22 and a second measurement panel element 24. In the exemplary embodiment shown in the figures, the first measurement panel element 22 has a larger surface area than the second measurement panel element 24.

[0077] The two measuring panel elements 22, 24 shown in the figures are plate-shaped, i.e. the width B.sub.1, B.sub.2 and the height H.sub.1, H.sub.2 of the two measurement panel elements 22, 24 are considerably larger than their thickness, so that the measurement panel elements 22, 24 can be regarded as substantially two-dimensional measurement panel elements 22, 24.

[0078] For example, the first measurement panel element 22 has a width B.sub.1 and height H.sub.1 of between 10 cm and 30 cm each, in particular a width B.sub.1 and height H.sub.1 of between 15 cm and 25 cm; and the second measurement panel element has a height (length) H.sub.2 of between 10 cm and 30 cm and a width B.sub.2 of between 5 cm and 10 cm.

[0079] The thickness of the measurement panel elements 22, 24 is typically less than 1 cm, in particular less than 0.6 cm.

[0080] The first measurement panel element 22 shown in the figures is octagonal in shape with slightly rounded corners. The first measurement panel element 22 is not formed as an equilateral octagon in the shape of a stop sign. Rather, the vertical sides of the first measurement panel element 22 are longer than its horizontal sides. However, the first measurement panel element 22 may have other geometries not shown in the figures.

[0081] The second measurement panel element 24 is substantially rectangular in shape with two chamfered corners 26 and a longitudinally central indentation 28.

[0082] The measurement panel element carrier 20 is configured such that the second measurement panel element 24 can be disposed in the measurement panel element carrier 20 only in the orientation shown, due to the chamfered corners 26 and the indentation 28. In particular, a protrusion may be formed on the measurement panel element carrier 20, which is arranged in the central indentation 28 when the second measurement panel element 24 is disposed in the measurement panel element carrier 20 in the orientation shown in FIGS. 2 and 4.

[0083] The two measurement panel elements 22, 24 can be independently mounted in and removed from the measurement panel element carrier 20. As a result, different first and second measurement panel elements 22, 24 can be combined in arbitrary manner in a measurement panel element carrier 20 to form a measurement panel 8.

[0084] For example, the measurement panel elements 22, 24 can be slidably inserted into the measurement panel element carrier 20 and/or locked in place in the measurement panel element carrier 20 using snap-in connections.

[0085] A two-dimensional measurement mark pattern 31 comprising a number of two-dimensional optical features, e.g. measurement marks, 30, 32, is formed on the front side of the first measurement panel element 22 visible in FIGS. 2 and 4, which faces one of the measuring heads 10 during measuring operation. The optical features 30, 32 can be formed, for example, as bright measurement marks 30, 32, in particular as light-reflecting retro-reflective marks, on a black background.

[0086] In the exemplary embodiment shown in the figures, the optical features 30, 32 are formed in a circular or disk-shaped configuration. However, other optical features not shown in the figures are possible as well. The only condition for an optical feature or a measurement mark pattern is that its parameters, such as a position, can be determined algorithmically upon optical detection.

[0087] In order to be able to perform the wheel alignment measurement with the required accuracy, certain parameters of the optical features 30, 32, such as their positions, must be known with high accuracy. Since the measurement mark patterns 31 can be manufactured with certain tolerances only, the required accuracy in the manufacture of the measurement mark patterns 31 cannot be guaranteed. Therefore, the measurement mark patterns 31 are measured with high accuracy after the first measuring panel elements 22 are manufactured, so that the parameters of the measurement mark patterns 31 can be provided with the required accuracy.

[0088] The parameters of the measurement mark patterns 31 thus determined are encoded in an optically detectable information carrier 34, in particular in a bar code or QR code 34. The optically detectable information carrier 34 thus generated is attached to or formed on the rear side of the respective first measurement panel element 22, as can be seen in FIGS. 3 and 5.

[0089] The optically detectable information carrier 34 may be applied, for example, as a sticker to the rear side of the respective first measurement panel element 22 or may be printed directly on the rear side of the respective first measurement panel element 22.

[0090] The parameters of the measurement mark patterns 31 can be determined, in particular, in the form of the deviations (differences) of the measured parameters from predetermined reference parameters and can thus be encoded in the optically detectable information carrier 34 in a space-saving manner.

[0091] By reading-in the optically detectable information carrier 34, the parameters of the measurement mark patterns 31 of the first measurement panel element 22 can be made known to the measuring heads 10.

[0092] In an exemplary embodiment, the measurement panels 8 or first measurement panel elements 22 are positioned in front of a measuring head 10 for this purpose before the start of the actual measurement such that the optically detectable information carrier 34 formed on the rear side of the respective first measurement panel element 22 can be optically detected by an image recording device 12 of the measuring head 10. The optically detectable information carrier 34 can then be read and evaluated by the measuring head 10.

[0093] Alternatively, the optically detectable information carrier 34 can be detected and evaluated by an external/mobile image recording device 44, in particular by means of the camera 44 of a mobile operating device 40 (see FIG. 1).

[0094] Since the optically detectable information carrier 34 is formed on the rear side of the respective first measurement panel element 22 according to the invention, the optically detectable information carrier 34 does not overlap with the measurement mark pattern 31 formed on the front side of the respective first measurement panel element 22 and does not take up any additional space on the front side of the respective first measurement panel element 22.

[0095] Therefore, the optically detectable information carrier 34 and the measurement mark pattern 31 can be formed on the measurement panel element 22 independently of each other, and the optically detectable information carrier 34 can be formed in a size that is advantageous for encoding the parameters and for good recognizability of the optically readable code 34, without the dimensions of the first measurement panel element 22 having to be increased for this purpose or space being lost for the measurement mark pattern 31 formed on the front surface of the respective first measurement panel element 22.

[0096] For avoiding that the optically detectable information carrier 34 has to be read in again before each vehicle measurement in order to transmit the parameters of the measurement mark pattern 31 of the respective measurement panel element 22 to the measuring head 10, the parameters of the measurement mark pattern 31 stored in the optically detectable information carrier 34 can be assigned to an identification pattern 52 formed on a second measurement panel element 24.

[0097] For this purpose, the optically detectable information carrier 34, as described above, is first optically detected by an image recording device 12, 44, in particular the image recording device 12, 44 of a measuring head 10 or a mobile operating device 40. Then, the parameters encoded in the optically detectable information carrier 34 are assigned to the identification pattern 52 of a second measuring element 24 associated with the first measuring element 22 and arranged together with the first measuring element 22 in the same measuring element carrier 20.

[0098] This assignment may be effected by also detecting the identification pattern 52 of the second measurement panel element 24 associated with the first measurement panel element 22 by means an image recording device 12, 44. This image recording device 12, 44 may be the same image recording device 12, 44 that previously detected the optically detectable information carrier 34. However, two different image recording devices 12, 44 may be used for optically detecting the identification pattern 52 and for detecting the optically detectable information carrier 34.

[0099] As an alternative, the parameters encoded in the optically detectable information carrier 34 can be assigned to the identification pattern 52 of a second measurement panel element 24 by manually entering a code 50 uniquely identifying the second measurement panel element 24, in particular a number or letter formed on the second measurement panel element 24, into the operating device 40.

[0100] For each subsequent measurement of the motor vehicle 6, the identification pattern 52 formed on the second measurement panel element 24 is then optically detected by an image recording device 12 of the measuring head 10, so that the measuring head 10 can use the detected identification pattern 52 to access the parameters of the first measurement panel element 22 associated with the detected identification pattern 52 that are stored for the detected identification pattern 52.

[0101] As long as the mutual assignment of the first and second measurement panel elements 22, 24 and thus the assignment of the parameters of the measurement panel patterns 31 formed on the first measurement panel elements 22 to the associated identification patterns 52 is maintained, the measurement panels 8 can be attached in any permutation to the wheels 7 of the motor vehicle 6. Based on the identification patterns detected by the cameras 12 of the measuring heads 10, the measuring heads 10 can recognize which measurement panel 8 is mounted on which wheel 7 of the motor vehicle 6 and thus retrieve the parameters stored for the measurement mark pattern 31 of the respective measurement panel 8 and use them in the subsequent wheel alignment measurement.

[0102] It is also possible to provide more than four different measurement panels 8 with different identification patterns 52 for one or more measuring stations 1, with the measurement mark pattern 31 of each measurement panel 8 being assigned to a different identification pattern 52. In this way, more than four different measurement panel elements 22 can be used at one or more measuring stations 1, for example adjacent to each other, without an incorrect assignment of the first measurement panel elements 22 and thus incorrect measurement results being caused.

[0103] In the exemplary embodiment shown in the figures, the identification pattern 52 comprises a number of identification pattern marks 54 arranged equidistantly, i.e. at equal distances from each other, along a row. Like the optical features 30, 32, the identification pattern marks 54 may be light-reflective retro-reflective marks.

[0104] In the exemplary embodiment shown in the figures, the identification pattern marks 54 are formed as squares and arranged in a vertical row on an outer side of the measurement panel 8 facing away from the vehicle 6.

[0105] The identification pattern marks 54 may also have other geometric shapes, for example rectangles, squares or ellipses. It is advantageous if the identification pattern marks 54 have a different geometric shape and/or size than the optical features 30, 32 formed on the first measurement panel elements 22, so that they can be clearly distinguished therefrom.

[0106] The identification pattern marks 54 may also be arranged in a different geometric arrangement than in a vertical row, for example in a horizontal row above or below the first measurement panel element 22, or in any other arrangement.

[0107] In the exemplary embodiment shown in the figures, the second measurement panel elements 24 are uniquely encoded in that at least one of the identification pattern marks 54 is missing from the equidistant row of identification pattern marks 54. In this way, the second measurement panel elements 24 can be uniquely and reliably encoded, recognized and identified. However, other types of arrangement/coding of the identification pattern marks 54 are also possible, which enable the second measurement panel elements 24 to be uniquely identified and distinguished.

[0108] The proposed design of the measurement panels 8 with two, first and second, measurement panel elements 22, 24 that can be combined with each other as desired enables flexible handling of the measurement panel elements 22 in workshop use. In particular, the first measurement panel elements 22, during manufacture and measurement thereof, do not yet have to be assigned to one of the wheels 7 (front/rear, right/left) of a motor vehicle 6 to be measured.

[0109] First measurement panel elements 22 according to the invention are precisely measured after their manufacture, and the parameters of the measurement panel pattern 31 formed on the respective first measurement panel element 22 are stored in an optically readable code formed on the rear side of the first measurement panel element 22.

[0110] Only at the place of use/measuring station 1 does the above-described assignment of the first measurement panel elements 22 to one of the second measurement panel elements 24 take place. The pairs of mutually assigned first and second measurement panel elements 22, 24 are arranged together in a measurement panel element carrier 20 and thus form a measurement panel 8 which can be used for vehicle measurement.

[0111] Due to the flexible assignment of the first and second measurement panel elements 22, 24, which does not take place during manufacture but only at the measurement station 1, measurement panel elements 22, 24 can be easily exchanged, for example when they are damaged or are to be replaced by measurement panel elements 22, 24 with other measurement mark patterns 31 due to changed requirements.

TABLE-US-00001 List of reference numerals 1 measuring station 2 lifting platform 3a rear column 3b front column 4a right running rail 4a left running rail 5a rear cross member 5b front cross member 6 motor vehicle 7 wheel 8 measurement panel 10 measuring head 12 image recording device 13 image processing unit 14 holding device 16 turn plate 18 wheel adapter 20 measurement panel element carrier 22 first measurement panel element 24 second measurement panel element 26 chamfered corner 28 central indentation 30 optical feature 31 measurement mark pattern 32 optical feature 34 optically detectable information carrier 40 operating device 42 display device 44 mobile image recording device 50 identifier 52 identification pattern 54 identification elements