Measurement system, measurement program, and measurement method

Abstract

To easily obtain information which expresses a posture of a wheel.SOLUTION: A measurement system comprises: a processing circuit; and a storage device including at least one memory so as to store pattern information including information for defining a shape of a measurement pattern which is positioned with respect to a wheel attached to a vehicle body of a vehicle. The processing circuit performs: acquiring a measurement pattern image to be obtained by photographing the measurement pattern; and generating wheel posture information which expresses the posture of the wheel with the use of the information on the shape of the measurement pattern in the measurement pattern image and the pattern information.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a measurement system, a measurement program, and a measurement method. [Background technology]

[0002] Japanese Patent Publication No. 2020-118506 discloses a wheel alignment measuring device that enables verification of wheel alignment taking into account the state of the vehicle while it is running. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-118506 Summary of the Invention [Problem to be solved by the invention]

[0004] In these fields, it is desirable to be able to obtain measurement results easily. For example, if specialized equipment is used to measure wheel alignment, the introduction costs of the equipment can be high and specialized knowledge is required to use the equipment. As a result, for example, vehicle inspections and maintenance can be delayed, which can hinder the smooth operation of traffic and logistics.

[0005] Therefore, one aspect of the present disclosure aims to make it possible to easily obtain information representing the attitude of a wheel. [Means for solving the problem]

[0006] A measurement system according to one aspect of the present disclosure includes a processing circuit and a storage device including at least one memory that stores pattern information including information defining the shape of a measurement pattern positioned relative to a wheel attached to a vehicle body. The processing circuit is configured to acquire a measurement pattern image obtained by photographing the measurement pattern, and to generate wheel attitude information representing the attitude of the wheel using information on the shape of the measurement pattern in the measurement pattern image and the pattern information.

[0007] A measurement program according to one aspect of the present disclosure causes a computer system including at least one computer to execute the following steps: store measurement pattern information including information defining the shape of a measurement pattern positioned relative to a wheel attached to a vehicle body, acquire a measurement pattern image obtained by photographing the measurement pattern, and generate wheel attitude information representing the attitude of the wheel using information on the shape of the measurement pattern in the measurement pattern image and the pattern information. The program can be stored in a computer-readable, non-transitory, and tangible storage medium.

[0008] A measurement method according to one aspect of the present disclosure is a measurement method using a computer system including at least one computer, and includes storing measurement pattern information in the computer system that defines the shape of a measurement pattern positioned relative to a wheel attached to a vehicle body, photographing the measurement pattern, and using information on the shape of the measurement pattern captured in the measurement pattern image obtained by photographing and the measurement pattern information to generate wheel attitude information representing the attitude of the wheel in the computer system. [Effects of the Invention]

[0009] According to one aspect of the present disclosure, information representing the attitude of a wheel attached to a vehicle body can be easily obtained. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram of a measurement system according to the first embodiment. [Figure 2] Fig. 2A is a plan view of a vehicle for explaining the toe angle of the wheels of the vehicle, and Fig. 2B is a front view of the vehicle for explaining the camber angle of the wheels of the vehicle. [Figure 3] Figure 3A is a front view of a wheel showing the placement of a measurement pattern and a reference pattern when measuring a camber angle, and Figure 3B is a side view of the wheel showing the placement of the measurement pattern of Figure 3A. [Figure 4] Figure 4A is a front view of a wheel showing the placement of a measurement pattern and a reference pattern when measuring toe angles, and Figure 4B is a side view of the wheel showing the placement of the measurement pattern of Figure 4A. [Figure 5] FIG. 5 is a block diagram showing the hardware of the computer system of FIG. [Figure 6] FIG. 6 is a functional block diagram of the computer system of FIG. [Figure 7] FIG. 7 is a schematic diagram showing the arrangement of the measurement pattern, the reference pattern, and the camera. [Figure 8] FIG. 8 is a conceptual diagram showing the measurement principle in the arrangement of FIG. [Figure 9] FIG. 9 is a flowchart illustrating a measurement process based on the measurement principle of FIG. [Figure 10] FIG. 10 is a diagram showing a captured image including a measurement pattern image and a reference pattern image. [Figure 11] FIG. 11 is a schematic diagram showing the arrangement of a measurement pattern, a reference pattern, and a camera in a measurement system according to a first modified example of the first embodiment. [Figure 12] FIG. 12 is a conceptual diagram showing the measurement principle in the arrangement of FIG. [Figure 13] Figure 13A is a plan view of the positioning tool, and Figure 13B is a partially cross-sectional side view of the positioning tool of Figure 13A. [Figure 14]FIG. 14 is a schematic diagram showing the arrangement of the measurement pattern, the reference pattern, and the camera in the measurement system according to the second modified example of the first embodiment. [Figure 15] FIG. 15 is a conceptual diagram showing the measurement principle in the arrangement of FIG. [Figure 16] FIG. 16 is a schematic diagram showing the arrangement of measurement patterns and mobile terminals in the measurement system according to the second embodiment. [Figure 17] FIG. 17 is a conceptual diagram showing the measurement principle in the arrangement of FIG. [Figure 18] FIG. 18 is a flowchart illustrating a measurement process based on the measurement principle of FIG. [Figure 19] FIG. 19 is a diagram showing the screen of a mobile terminal that captures an image of a measurement pattern. [Figure 20] FIG. 20 is a diagram showing the screen of a mobile terminal that captures an image of a measurement pattern in a measurement system according to a first modified example of the second embodiment. [Figure 21] FIG. 21 is a schematic diagram showing a measurement pattern and an arrangement of cameras in a measurement system according to a second modified example of the second embodiment. [Figure 22] FIG. 22 is a conceptual diagram showing the measurement principle in the arrangement of FIG. [Figure 23] Fig. 23A is a front view of a wheel showing the placement of a measurement pattern in a measurement system according to Embodiment 3. Fig. 23B is a side view of the wheel showing the placement of the measurement pattern of Fig. 23A. [Figure 24] FIG. 24 is a schematic diagram showing the arrangement of the measurement pattern, reference pattern, and camera in FIG. [Figure 25] FIG. 25 is a conceptual diagram showing the measurement principle in the arrangement of FIG. [Figure 26] FIG. 26 is a flowchart illustrating a measurement process based on the measurement principle of FIG. [Figure 27] FIG. 27 is a diagram showing a captured image including a measurement pattern image and a reference pattern image. [Figure 28]FIG. 28 is a diagram for explaining the projective transformation regarding the reference pattern. [Figure 29] FIG. 29 is a diagram for explaining the projective transformation regarding the measurement pattern. [Figure 30] FIG. 30 is a schematic diagram showing the arrangement of the measurement pattern, the reference pattern, and the camera in the measurement system according to the first modified example of the third embodiment. [Figure 31] FIG. 31 is a conceptual diagram showing the measurement principle in the arrangement of FIG. [Figure 32] FIG. 32 is a schematic diagram showing the measurement pattern and the arrangement of cameras in the measurement system according to the fourth embodiment. [Figure 33] FIG. 33 is a conceptual diagram showing the measurement principle in the arrangement of FIG. [Figure 34] FIG. 34 is a flowchart illustrating a measurement process based on the measurement principle of FIG. [Figure 35] FIG. 35 is a diagram showing the screen of a mobile terminal that captures an image of a measurement pattern. [Figure 36] FIG. 36 is a schematic diagram showing a measurement pattern and an arrangement of cameras in a measurement system according to a modified example of the fourth embodiment. [Figure 37] FIG. 37 is a conceptual diagram showing the measurement principle in the arrangement of FIG. [Figure 38] FIG. 38 is a functional block diagram of the measurement system according to the fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment will be described with reference to the drawings.

[0012] [First embodiment] FIG. 1 is a schematic diagram of a measurement system 10 according to a first embodiment. As shown in FIG. 1, the measurement system 10 is a device that measures the camber angle and toe angle of a wheel 3 for wheel alignment of a vehicle 1. The vehicle 1 includes a vehicle body 2 and a plurality of wheels 3 attached to the vehicle body 2 so as to support the vehicle body 2. The plurality of wheels 3 include a pair of left and right wheels 3 spaced apart from each other in the width direction of the vehicle 1. Each of the wheels 3 includes a wheel body 4 and a tire 5 attached to the outer periphery of the wheel body 4. A measurement pattern Pm is positioned on the side of the wheel body 4 via a jig 6.

[0013] The measurement system 10 includes a computer system 11 and a camera 12. The camera 12 is a digital camera. The camera 12 is connected to the computer system 11 via wired or wireless communication. The camera 12 captures an image of the measurement pattern Pm and sends the captured image to the computer system 11.

[0014] FIG. 2A is a plan view of the vehicle 1 illustrating the toe angle θz of the wheel 3 of the vehicle 1. FIG. 2B is a front view of the vehicle 1 illustrating the camber angle θy of the wheel 3 of the vehicle 1. For example, the width direction of the vehicle 1 is defined as the X direction, the longitudinal direction of the vehicle 1 is defined as the Y direction, and the height direction of the vehicle 1, which is perpendicular to the reference plane 8, which is the road surface, is defined as the Z direction. As shown in FIG. 2A, when the vehicle 1 is viewed from above in a straight-traveling state with the wheel 3 not steered, the angle of the wheel 3 with respect to the Y direction is referred to as the toe angle θz. As shown in FIG. 2B, when the vehicle 1 is viewed from the front in a straight-traveling state with the wheel 3 not steered, the angle of the wheel 3 with respect to the Z direction is referred to as the camber angle θy. In this embodiment, the reference plane 8 is the plane on which the vehicle 1 is placed, but it may be a different plane. The reference plane 8 is typically a horizontal plane, but it does not have to be a horizontal plane.

[0015] FIG. 3A is a front view of the wheel 3 showing the placement of the measurement pattern Pm and the reference pattern Pr when measuring the camber angle θy. FIG. 3B is a side view of the wheel 3 showing the placement of the measurement pattern Pm of FIG. 3A. As shown in FIGS. 3A and 3B, a jig 6 is fixed to the wheel body 4 of the wheel 3, and the measurement pattern Pm is fixed to the jig 6. The measurement pattern Pm is, for example, a two-dimensional code such as a QR code (registered trademark). When measuring the camber angle θy, the measurement pattern Pm is positioned so that it faces forward of the vehicle 1. The horizontal axis direction of the measurement pattern Pm is positioned parallel to the direction in which the rotation axis L of the wheel 3 extends.

[0016] For example, the measurement pattern Pm is printed on an adhesive sheet, and the adhesive sheet having the measurement pattern Pm is attached to the jig 6. Note that the measurement pattern Pm may be formed directly on the jig 6 or the wheel body 4 by printing or laser marking.

[0017] The shape of the reference pattern Pr is different from the shape of the measurement pattern Pm. The reference pattern Pr is, for example, a two-dimensional code such as a QR code (registered trademark). In this embodiment, the measurement pattern Pm and the reference pattern Pr are both QR codes (registered trademark), but the shapes of the information display portions of the two patterns are different from each other.

[0018] The reference pattern Pr is fixed to an installation base 7 placed on the reference surface 8. In other words, the reference pattern Pr is positioned with respect to the reference surface 8. The installation base 7 has, for example, a base 7a placed on the reference surface 8 and a box 7b placed on the upper surface of the base 7a so that they can be separated. The reference pattern Pr is fixed to one surface of the box 7b. The reference pattern Pr is placed so that it faces the same direction as the measurement pattern Pm. In other words, the box 7b is placed on the base 7a so that the reference pattern Pr faces forward of the vehicle 1. The horizontal axis direction of the reference pattern Pr is placed parallel to the reference surface 8.

[0019] The reference pattern Pr is printed on an adhesive sheet, and the adhesive sheet having the reference pattern Pr is attached to the installation base 7. The reference pattern Pr may also be formed directly on the installation base 7 by printing or laser marking.

[0020] The shapes of the measurement pattern Pm and the reference pattern Pr may be rotationally asymmetric within the expected range of angles measured in this embodiment, for example, within the range of 0° to 45°. The measurement pattern Pm and the reference pattern Pr may be a one-dimensional code or pattern, or may be a partial or entire shape of the wheel 3 itself.

[0021] When measuring the camber angle θy, the camera 12 captures the reference pattern Pr and the measurement pattern Pm from the front side of the vehicle 1 so that the optical axis of the light incident side of the camera 12 is parallel to the normal vectors of the reference pattern Pr and the measurement pattern Pm. In the following explanation, it is assumed that the optical axis of the light incident side of the camera 12 is perpendicular to the sensor surface on which the light receiving elements are arranged in the image sensor.

[0022] FIG. 4A is a front view of the wheel 3 showing the placement of the measurement pattern Pm and reference pattern Pr when measuring the toe angle θz. FIG. 4B is a side view of the wheel showing the placement of the measurement pattern Pm of FIG. 4A. As shown in FIGS. 4A and 4B, when measuring the toe angle θz, the measurement pattern Pm and reference pattern Pr are positioned so that they face upward toward the vehicle 1. This state can be achieved, for example, by changing the angle of the jig 6 shown in FIG. 3A around the rotation axis L of the wheel 3 and re-fixing it to the wheel body 4.

[0023] The reference pattern Pr is arranged so that it faces the same direction as the measurement pattern Pm. This state can be achieved, for example, by moving the box 7b shown in FIG. 3B upward from the base 7a, rotating it 90 degrees, and then placing it back on the top surface of the base 7a so that the reference pattern Pr faces upward toward the vehicle 1. The horizontal axis direction of the reference pattern Pr is arranged parallel to the width direction of the vehicle 1. The horizontal axis direction of the measurement pattern Pm is arranged parallel to the direction in which the rotation axis L of the wheel 3 extends.

[0024] When measuring the toe angle θz, the camera 12 photographs the reference pattern Pr and the measurement pattern Pm from above the vehicle 1 so that the normal vector of the sensor surface of the image sensor of the camera 12 is parallel to the normal vectors of the reference pattern Pr and the measurement pattern Pm.

[0025] Fig. 5 is a block diagram showing the hardware of computer system 11 in Fig. 1. As shown in Fig. 5, computer system 11 includes at least one computer 15. In this embodiment, computer system 11 is a single computer 15. Computer system 11 may include multiple computers connected directly to each other, or may include multiple computers connected to each other via a network.

[0026] In terms of hardware, the computer 15 includes a processing circuit 20. Specifically, the computer 15 includes a processor 21, a system memory 22, a storage memory 23, a user interface 25, and a communication interface 26. The processor 21 may include a central processing unit (CPU). The system memory 22 may include random access memory (RAM). The storage memory 23 may include a hard disk, a flash memory, or a combination thereof. The storage memory 23 stores a measurement program 24. A configuration in which the processor 21 executes the measurement program 24 read from the storage memory 23 to the system memory 22 is an example of a processing circuit 20.

[0027] The user interface 25 includes an input interface through which a user can input information. The user interface 25 includes devices such as a keyboard, a mouse, a touch panel, or a microphone. The user interface 25 may also include an output interface through which information can be output to the user. The user interface 25 may also include devices such as a display or a speaker. The communication interface 26 is connected to the camera 12 via wired or wireless communication. The communication interface 26 may also include an interface for connecting to a network such as the Internet.

[0028] The processor 21 may be distributed among multiple processors connected via a network. The storage memory 23 may be distributed among multiple memories connected via a network. In this case, a group of multiple memories constitutes a storage device. The communication interface 26 may be connected to a network such as the Internet so that the computer 15 can communicate with a server. A part or all of the measurement program 24 may be executed by a processor of a server connected to the computer 15 via the network.

[0029] Fig. 6 is a functional block diagram of the computer system 11 of Fig. 5. As shown in Fig. 6, in terms of functionality, the computer system 11 includes a storage unit 31, an acquisition unit 32, an information generation unit 33, and an identification information specification unit 34. The storage unit 31 is realized by the storage memory 23. The acquisition unit 32 is realized by the interface 25. The information generation unit 33 and the identification information specification unit 34 are realized by the processor 21, the system memory 22, and the measurement program 24.

[0030] The memory unit 31 stores pattern information 31a. The pattern information 31a includes information that defines the shapes of the reference pattern Pr and the measurement pattern Pm. If the reference pattern Pr and the measurement pattern Pm are QR Codes (registered trademark), the pattern information 31a includes information related to a finder pattern definition, an alignment pattern definition, a timing pattern definition, and the like. If the reference pattern Pr and the measurement pattern Pm are simply patterns, the pattern information 31a includes information indicating the shape of the patterns. The memory unit 31 also stores wheel attitude information calculated by the information generation unit 33, which will be described later.

[0031] The acquisition unit 32 acquires captured images obtained by the camera 12 capturing images of the measurement pattern Pm and the reference pattern Pr from the camera 12. The image capturing trigger for the camera 12 may be a user's operation of the camera 12, or a command from the computer system 11. The information generation unit 33 generates wheel attitude information that represents the attitude of the wheel 3 using information indicating the shapes of the measurement pattern Pm and the reference pattern Pr in the acquired captured images and pattern information 31a.

[0032] The identification information specifying unit 34 reads the measurement pattern Pm and the reference pattern Pr captured in the captured image received by the acquisition unit 32 from the camera 12 through image processing, thereby specifying the identification information of the measurement pattern Pm and the reference pattern Pr, respectively.

[0033] An example of determining the camber angle θy of the wheel 3 will be described below. FIG. 7 is a schematic diagram showing the arrangement of the measurement pattern Pm, reference pattern Pr, and camera 12. As shown in FIG. 7, the wheel 3 supporting the vehicle body 2 is placed on a reference surface 8, and the measurement pattern Pm is positioned on the wheel 3. The reference pattern Pr is positioned on the reference surface 8 via the installation base 7 shown in FIG. 3A. The camera 12 captures the measurement pattern Pm and the reference pattern Pr so that both the measurement pattern Pm and the reference pattern Pr are included in a single captured image.

[0034] FIG. 8 is a conceptual diagram showing the measurement principle in the arrangement of FIG. 7. As shown in FIG. 8, the attitude of the wheel 3 relative to the vehicle body 2 is unknown, and the goal is to ultimately determine this. For example, the underside of the vehicle body 2 is disposed parallel to a reference plane 8, and a vertical line extending in the height direction of the vehicle body 2 is perpendicular to the reference plane 8. In other words, the angle of the vehicle body 2 relative to the reference plane 8 is zero. Therefore, the attitude of the vehicle body 2 relative to the reference plane 8 is known.

[0035] The horizontal axis direction of the reference pattern Pr is arranged parallel to the reference plane 8 via the installation stand 7 shown in FIG. 3A. In other words, the reference pattern Pr is positioned relative to the vehicle body 2. The angle of the horizontal axis direction of the reference pattern Pr relative to the reference plane 8 is zero, and therefore the angle of the horizontal axis direction of the reference pattern Pr relative to the vehicle body 2 is also zero. Therefore, the orientation of the reference pattern Pr relative to the reference plane 8 is known.

[0036] The measurement pattern Pm is positioned relative to the wheel 3. The horizontal axis direction of the measurement pattern Pm is arranged parallel to the direction in which the rotation axis L of the wheel 3 extends. The angle between the direction in which the rotation axis L of the wheel 3 extends and the horizontal axis direction of the measurement pattern Pm is zero. Therefore, the orientation of the measurement pattern Pm relative to the wheel 3 is known.

[0037] The attitude of the measurement pattern Pm relative to the reference pattern Pr is measured based on the image 40 captured by the camera 12, as will be described later. If the attitude of the measurement pattern Pm relative to the reference pattern Pr is known by this measurement, the attitude of the wheel 3 relative to the vehicle body 2, i.e., the camber angle θy, can be known.

[0038] Fig. 9 is a flowchart explaining the measurement process based on the measurement principle of Fig. 8. Fig. 10 is a drawing showing a captured image 40 including a measurement pattern image 42 and a reference pattern image 41. Below, the measurement process will be explained along the flow of Fig. 9 with reference to Figs. 6, 7, 10, etc. In response to a user's operation of the camera 12 or a command from the computer system 11, the camera 12 captures the reference pattern Pr and the measurement pattern Pm together to generate one captured image 40. The acquisition unit 32 of the computer system 11 acquires the captured image 40 from the camera 12 (step S1).

[0039] As shown in FIG. 10 , both the measurement pattern Pm and the reference pattern Pr are captured within the angle of view of the captured image 40. In this embodiment, a reference pattern image 41 obtained by capturing the measurement pattern Pm and a measurement pattern image 42 obtained by capturing the reference pattern Pr are defined as partial regions of the captured image 40. Therefore, the coordinate systems of the reference pattern image 41 and the measurement pattern image 42 are the same as the coordinate system of the captured image 40. That is, the coordinate system of the reference pattern image 41 and the coordinate system of the measurement pattern image 42 have a predetermined relationship in which they are the same. Here, the coordinate system of the image is based on the pixel array direction. For example, the horizontal axis direction of the coordinate system is the horizontal scanning direction of the image, and the vertical axis direction of the coordinate system is the vertical scanning direction of the image.

[0040] Note that, as long as the coordinate system of reference pattern image 41 and the coordinate system of measurement pattern image 42 have a predetermined relationship, reference pattern image 41 and measurement pattern image 42 may be images captured separately. For example, if reference pattern image 41 and measurement pattern image 42 are captured separately with the attitude of camera 12 fixed, the coordinate system of measurement pattern image 42 is the same as the coordinate system of reference pattern image 41.

[0041] The coordinate system of measurement pattern image 42 and the coordinate system of reference pattern image 41 may be different as long as they have a predetermined relationship. By establishing a predetermined relationship between the orientation of camera 12 when photographing measurement pattern Pm and the orientation of camera 12 when photographing reference pattern Pr, the coordinate system of measurement pattern image 42 and the coordinate system of reference pattern image 41 will have a predetermined relationship. By using this difference in orientation of camera 12 to correct the coordinate system of measurement pattern image 42 with respect to the coordinate system of reference pattern image 41, it is possible to compare measurement pattern Pm captured in measurement pattern image 42 with reference pattern Pr captured in reference pattern image 41.

[0042] Here, a brief explanation of QR Code (registered trademark) will be given with reference to the reference pattern Pr in Fig. 10. QR Code (registered trademark) has a finder pattern Q1, an alignment pattern Q2, a timing pattern Q3, etc. The finder pattern Q1 is a position detection pattern arranged at each of the three corners of the QR Code (registered trademark). The alignment pattern Q2 is a pattern for correcting misalignment of each cell caused by distortion. The timing pattern Q3 is an alternating arrangement of white and black cells, and is a pattern for determining coordinates within the code.

[0043] The information generating unit 33 of the computer system 11 identifies the shape of the reference pattern Pr in the reference pattern image 541 based on the pattern information 31a, and calculates the orientation of the reference pattern Pr in the reference pattern image 41 (step S2). The orientation of the reference pattern Pr calculated here is the orientation in the rotation direction along the pixel array surface of the reference pattern image 41. A reference pattern direction Dr indicating the orientation of the reference pattern Pr in the reference pattern image 41 is an example of the orientation of the reference pattern Pr in the rotation direction. The captured image direction Di shown in FIG. 10 is the horizontal axis direction in the coordinate system of the captured image 40. Because no effort has been made to align the orientation of the camera 12 with the orientation of the reference pattern Pr, the reference pattern direction Dr does not necessarily coincide with the captured image direction Di.

[0044] The reference pattern direction Dr is a direction defined using feature points included in the shape of the reference pattern Pr in the reference pattern image 41. Information indicating the definitions of the feature points is included in the pattern information 31a stored in the storage unit 31. The feature points are points identified by recognizing the shape of the reference pattern Pr in the reference pattern image 41 through image processing. The feature points are selected from the finder pattern Q1, alignment mark Q2, timing pattern Q3, etc. of the QR code (registered trademark). When the QR code (registered trademark) is in an upright position, i.e., a non-tilted position, the finder pattern Q1 is located at the top right corner, top left corner, and bottom left corner of the rectangular outline of the QR code (registered trademark).

[0045] 10, the reference pattern direction Dr is a direction parallel to a line passing through the top two finder patterns Q1 in the QR code (registered trademark). In other words, it is a direction parallel to the bottom side of the rectangular outline of the QR code (registered trademark). That is, the reference pattern direction Dr is the horizontal axis direction of the reference pattern Pr of the reference pattern image 41.

[0046] The information generation unit 33 of the computer system 11 calculates the orientation of the measurement pattern Pm shown in the measurement pattern image 42 (step S3). The orientation of the measurement pattern Pm calculated here is the orientation in the rotation direction along the pixel array surface of the measurement pattern image 42. The measurement pattern direction Dp, which indicates the orientation of the measurement pattern Pm shown in the measurement pattern image 42, is an example of the orientation of the measurement pattern Pm in the rotation direction. The measurement pattern direction Dp is a direction defined using the feature points of the measurement pattern Pm in the measurement pattern image 42.

[0047] The method for determining the measurement pattern direction Dp is the same as the method for determining the reference pattern direction Dr, so a detailed description will be omitted. In the example of FIG. 10, the measurement pattern direction Dp is the horizontal axis direction of the measurement pattern Pm in the measurement pattern image 42. The reference pattern direction Dr and the measurement pattern direction Dp are not limited to those described above, and may be other directions as long as they can identify the orientations of the reference pattern Pr and the measurement pattern Pm. Note that the order of execution of steps S2 and S3 may be reversed, or steps S2 and S3 may be executed in parallel.

[0048] The information generation unit 33 of the computer system 11 generates wheel attitude information 31b representing the attitude of the wheel 3 using the attitudes of the reference pattern Pr and the measurement pattern Pm in the captured image 40 (step S4). The information generation unit 33 stores the generated wheel attitude information 31b in the storage unit 31. Specifically, the information generation unit 33 calculates the angle θ of the measurement pattern direction Dp with respect to the reference pattern direction Dr as the attitude of the measurement pattern Pm with respect to the reference pattern Pr.

[0049] When the captured image 40 is an image of the reference pattern Pr and the measurement pattern Pm in FIGS. 3A and 3B captured by the camera 12 from the front side of the vehicle 1, the wheel attitude information 31b indicates the camber angle θy.

[0050] As shown in Figure 8, if the angle θ of the measurement pattern Pm relative to the reference pattern Pr is known, the angle of the wheel 3 relative to the vehicle body 2 can be determined. In this embodiment, the angle of the measurement pattern Pm relative to the wheel 3 and the angle of the reference pattern Pr relative to the vehicle body 2 are both zero, so the angle θ of the measurement pattern Pm relative to the reference pattern Pr can be considered to be the angle of the wheel 3 relative to the vehicle body 2. If the captured image 40 is an image of the reference pattern Pr and measurement pattern Pm in Figures 3A and 3B taken from the front side of the vehicle 1 by the camera 12, the calculated angle θ can be considered to be the camber angle θy.

[0051] Although the camber angle θy has been described, the toe angle θz can also be calculated using a similar principle. If the captured image 40 is an image of the reference pattern Pr and the measurement pattern Pm in Figures 4A and 4B captured by the camera 12 from above the vehicle 1, the calculated angle θ can be considered to be the toe angle θz. The camber angle θy and toe angle θz calculated in this manner constitute the wheel posture information 31b.

[0052] According to the measurement system 10 described above, the camber angle θy and toe angle θz of the wheel 3 can be easily inspected without requiring the user to have specialized knowledge, while suppressing the introduction cost.

[0053] (First Modification) FIG. 11 is a schematic diagram showing the arrangement of the measurement pattern Pm, reference pattern Pr, and camera 12 in a measurement system 110 according to a first modified example of the first embodiment. Note that components common to the previously described embodiments are assigned the same reference numerals and will not be described again. As shown in FIG. 11, a wheel 3 supporting a vehicle body 2 is located on a reference surface 8, and the measurement pattern Pm is positioned on the wheel 3. The reference pattern Pr is positioned by a positioning tool 150 installed on the reference surface 8. The camera 12 captures the measurement pattern Pm and the reference pattern Pr so that both the measurement pattern Pm and the reference pattern Pr are included in a single captured image.

[0054] Fig. 12 is a conceptual diagram showing the measurement principle in the arrangement of Fig. 11. As shown in Fig. 12, for example, the underside of the vehicle body 2 is arranged parallel to the reference plane 8, and a vertical line extending in the height direction of the vehicle body 2 is perpendicular to the reference plane 8. In other words, the angle of the vehicle body 2 with respect to the reference plane 8 is zero. Therefore, the orientation of the vehicle body 2 with respect to the reference plane 8 is known. The positioning tool 150 is installed on the reference plane 8. The orientation of the positioning tool 150 with respect to the reference plane 8 is known.

[0055] The reference pattern Pr is positioned by the positioning tool 150. In other words, the reference pattern Pr is positioned relative to the vehicle body 2 via the positioning tool 150. For example, the horizontal axis direction of the reference pattern Pr is arranged parallel to the upper surface of the positioning tool 150. The angle of the reference pattern Pr relative to the reference plane 8 can be zero or a measured value. Therefore, the orientation of the reference pattern Pr relative to the vehicle body 2 is known.

[0056] The measurement pattern Pm is positioned relative to the wheel 3. The horizontal axis direction of the measurement pattern Pm is arranged parallel to the direction in which the rotation axis L of the wheel 3 extends. The angle between the direction in which the rotation axis L of the wheel 3 extends and the horizontal axis direction of the measurement pattern Pm is zero. Therefore, the orientation of the measurement pattern Pm relative to the wheel 3 is known. The orientation of the measurement pattern Pm relative to the reference pattern Pr is measured based on the image 40 captured by the camera 12, as described above with reference to Figure 10. Once the orientation of the measurement pattern Pm relative to the reference pattern Pr is known, the orientation of the wheel 3 relative to the vehicle body 2 can be determined.

[0057] Fig. 13A is a plan view of positioning tool 150. Fig. 13B is a partially cross-sectional side view of positioning tool 150 of Fig. 13A. As shown in Figs. 13A and 13B, positioning tool 150 includes a base 151 and a table 152. Base 151 includes a plurality of legs 151a and a spherical portion 151b. The plurality of legs 151a are placed on reference surface 8 and support spherical portion 151b. Spherical portion 151b has a vertical through-hole 151c that extends vertically.

[0058] The table 152 includes a cover portion 152a, multiple roller portions 152b, a rod portion 152c, and a weight portion 152d. The cover portion 152a is disposed above the base 151. The multiple roller portions 152b support the cover portion 152a and rotatably contact the upper hemispherical surface of the spherical portion 151b from above. The multiple roller portions 152b are at least three rollers arranged at equal intervals around the center of the spherical portion 151b in a plan view of the positioning tool 150. In this embodiment, the number of roller portions 152b is four. The rod portion 152c is fixed to the cover portion 152a, hangs down from the center of the cover portion 152a, and is inserted through a vertical through-hole 151c in the spherical portion 151b. The weight portion 152d is attached to the lower end of the rod portion 152c.

[0059] Because roller portion 152b can roll on the surface of spherical portion 151b, the gravitational effect of weight portion 152d maintains the posture of rod portion 152c extended in the vertical direction. As a result, even if reference surface 8 on which base 151 is placed is not horizontal, top surface HS of cover portion 152a is kept horizontal. A reference pattern Pr is positioned on the horizontal top surface HS of cover portion 152a. For example, reference pattern Pr is positioned on top surface HS of cover portion 152a so that its horizontal axis direction is horizontal. Note that, as long as the relative angle between top surface HS of positioning tool 150 and reference surface 8 is known, the top surface HS of positioning tool 150 may be fixed or not.

[0060] Returning to FIG. 12, if the reference plane 8 is horizontal or approximately horizontal, the posture of the reference pattern Pr can be considered to be the same as the posture of the vehicle body 2. If the reference plane 8 is not horizontal or approximately horizontal and the relative angle between the reference plane 8 and the horizontal plane is known by measurement, the relative angle between the reference pattern Pr and the vehicle body 2 is known. Therefore, as explained in FIG. 10, if the angle θ of the measurement pattern Pm relative to the reference pattern Pr is known, the angle of the wheel 3 relative to the vehicle body 2 can be determined. The camber angle θy and toe angle θz calculated in this manner constitute wheel posture information 31b. Note that other configurations are similar to those of the previously described embodiment, and therefore will not be described here.

[0061] (Second Modification) FIG. 14 is a schematic diagram showing the arrangement of the measurement pattern Pm, reference pattern Pr, and camera 12 in a measurement system 210 according to a second modified example of the first embodiment. Note that components common to the previously described embodiments are given the same reference numerals and will not be described again. As shown in FIG. 14, a wheel 3 supporting a vehicle body 2 is located on a reference surface 8. The measurement pattern Pm is positioned on the wheel 3. The reference pattern Pr is positioned on the vehicle body 2. The camera 12 captures the measurement pattern Pm and the reference pattern Pr so that both the measurement pattern Pm and the reference pattern Pr are included in a single captured image.

[0062] Fig. 15 is a conceptual diagram showing the measurement principle in the arrangement of Fig. 14. As shown in Fig. 15, the reference pattern Pr is positioned on the vehicle body 2. For example, the underside of the vehicle body 2 is disposed parallel to the reference plane 8, and the horizontal axis direction of the reference pattern Pr is parallel to the reference plane 8. In other words, the angle of the reference pattern Pr with respect to the vehicle body 2 is zero. Therefore, the attitude of the reference pattern Pr with respect to the vehicle body 2 is known.

[0063] The measurement pattern Pm is positioned relative to the wheel 3. The horizontal axis direction of the measurement pattern Pm is arranged parallel to the direction in which the rotation axis L of the wheel 3 extends. The angle between the direction in which the rotation axis L of the wheel 3 extends and the horizontal axis direction of the measurement pattern Pm is zero. Therefore, the orientation of the measurement pattern Pm relative to the wheel 3 is known. The orientation of the measurement pattern Pm relative to the reference pattern Pr is measured based on the image 40 captured by the camera 12, as described above with reference to FIG. 10. Once the orientation of the measurement pattern Pm relative to the reference pattern Pr is known, the orientation of the wheel 3 relative to the vehicle body 2 can be determined. The camber angle θy and toe angle θz calculated in this manner constitute wheel orientation information 31b. Note that the other configurations are the same as those in the previously described embodiment, and therefore description thereof will be omitted.

[0064] [Second embodiment] FIG. 16 is a schematic diagram showing the arrangement of a measurement pattern Pm and a mobile terminal 316 in a measurement system 310 according to the second embodiment. Note that components common to the first embodiment described above are given the same reference numerals and will not be described again. As shown in FIG. 16, a wheel 3 supporting a vehicle body 2 is located on a reference plane 8. The measurement pattern Pm is positioned on the wheel 3 as shown in FIG. 3A. In this example, no reference pattern is used, and only the measurement pattern Pm is used.

[0065] The mobile terminal 316 includes a camera 12 and a gyro sensor 317. The gyro sensor 317 may be any other type of sensor as long as it can detect a physical quantity correlated with the direction of the Earth's gravity acting on the camera 12 (hereinafter referred to as the gravity direction). The mobile terminal 316 is not particularly limited, but may be, for example, a smartphone. The mobile terminal 316 is a computer included in the computer system 11 (see FIG. 6). In other words, the mobile terminal 316 can be said to be the computer 15 shown in FIG. 5 to which the camera 12 and the gyro sensor 317 have been added. Note that a camera 12 with a gyro sensor 317 connected to the computer system 11 may also be used.

[0066] FIG. 17 is a conceptual diagram showing the measurement principle in the arrangement of FIG. 16. As shown in FIG. 17, for example, the underside of the vehicle body 2 is arranged parallel to the reference plane 8, and a vertical line extending in the height direction of the vehicle body 2 is perpendicular to the reference plane 8. In other words, the angle of the vehicle body 2 with respect to the reference plane 8 is zero. Therefore, the posture of the vehicle body 2 with respect to the reference plane 8 is known. The relative angle between the reference plane 8 and the horizontal plane HS is measured in advance and is known. For example, the reference plane 8 itself can be the horizontal plane.

[0067] The measurement pattern Pm is positioned relative to the wheel 3. The horizontal axis direction of the measurement pattern Pm is arranged parallel to the direction in which the rotation axis L of the wheel 3 extends. The angle between the direction in which the rotation axis L of the wheel 3 extends and the horizontal axis direction of the measurement pattern Pm is zero. Therefore, the orientation of the measurement pattern Pm relative to the wheel 3 is known.

[0068] As will be described later, the measurement pattern Pm is positioned relative to the camera 12 when the measurement pattern Pm is photographed. Therefore, the orientation of the measurement pattern Pm relative to the camera 12 is known. The orientation of the camera 12 relative to the horizontal plane HS is measured based on the detection value of the gyro sensor 317, as will be described later. In this way, the orientation of the wheel 3 relative to the vehicle body 2 can be calculated.

[0069] FIG. 18 is a flowchart explaining measurement processing based on the measurement principle of FIG. 17. FIG. 19 is a drawing showing the screen of mobile terminal 316 that captures measurement pattern Pm. Below, the measurement processing will be explained along the flow of FIG. 18 with reference to FIGS. 16, 17, 19, etc. Guide marks 319 for positioning the display of measurement pattern Pm are displayed on screen 318 of mobile terminal 316. The user displays measurement pattern Pm on screen 318 of mobile terminal 316. When measurement pattern Pm is positioned on screen 318 along guide marks 319 without distortion, the user operates mobile terminal 316 to capture measurement pattern Pm with camera 12, and generates measurement pattern image 342 (step S11).

[0070] Alternatively, when the measurement program 24 (see FIG. 5) of the mobile terminal 316 detects that the outer shape of the measurement pattern Pm is a square on the screen 318 and that the measurement pattern Pm has been arranged along the guide marks 319 without distortion, the camera 12 may capture an image of the measurement pattern Pm in accordance with commands from the measurement program 24 to generate the measurement pattern image 342. Alternatively, if there is distortion in the shape of the measurement pattern Pm shown in the measurement pattern image 342, the mobile terminal 316 may correct the distortion using pattern information 31a including a QR code (registered trademark) alignment pattern. Then, an image in which the corrected measurement pattern Pm is arranged along the guide marks 319 may be used as the measurement pattern image 342.

[0071] As shown in FIG. 19, camera orientation direction D1, which indicates the orientation of camera 12, has a predetermined relationship with measurement pattern direction D2, which indicates the orientation of measurement pattern Pm captured in measurement pattern image 342. For example, camera orientation direction D1 is the up-and-down direction of mobile terminal 316. Measurement pattern direction D2 indicates the orientation in the rotation direction along the pixel array surface of measurement pattern image 342. In the example of FIG. 19, measurement pattern direction D2 is the vertical axis direction of measurement pattern Pm in measurement pattern image 342. In other words, measurement pattern direction D2 is the same as camera orientation direction D1.

[0072] The gyro sensor 317 detects the attitude of the camera 12 with respect to the reference plane 8 at the time when the measurement pattern Pm was captured by the camera 12 as camera attitude information (step S12). Specifically, the gyro sensor 317 detects the direction of gravity G relative to the camera 12 at the time when the measurement pattern Pm was captured. The normal direction of the reference plane 8 (see FIG. 16) has a predetermined relationship with the direction of gravity G. For example, the normal direction of the reference plane 8 is the same as the direction of gravity G. The mobile terminal 316 calculates the relative angle α between the camera attitude direction D1 and the direction of gravity G at the time when the measurement pattern Pm was captured. This relative angle α is synonymous with the relative angle between the left-right direction of the camera 12 and the horizontal plane HS at the time when the measurement pattern Pm was captured.

[0073] The attitude of the camera 12 is detected, for example, as follows: The camera 12 repeatedly captures images at a predetermined frame rate and outputs each captured image together with the capture time. The gyro sensor 317 repeatedly detects the attitude at a predetermined sampling rate and outputs the detection result together with the detection time. The measurement program 24 identifies, from among the multiple captured images, an image in which the correlation coefficient between the guide 319 in the image and the outer shape of the measurement pattern Pm is equal to or greater than a threshold (for example, an image in which the correlation coefficient is equal to or greater than a threshold and is the largest). The measurement program 24 determines the detection result of the gyro sensor 317 corresponding to the capture time of the identified image as the attitude of the camera 12. The detection result of the gyro sensor 317 corresponding to the capture time may be a value obtained from the detection result at the detection time closest to the capture time, or may be a value obtained by interpolating the detection results at detection times before and after the capture time.

[0074] 17, for example, if the attitude of the wheel 3 and the attitude of the measurement pattern Pm are the same, the attitude of the measurement pattern Pm and the attitude of the camera 12 are the same, and the attitude of the vehicle body 2 and the reference plane 8 are horizontal, the relative angle α becomes the camber angle θy of the wheel 3. In this case, the mobile terminal 316 generates the relative angle α meaning the camber angle θy as wheel attitude information (step S13).

[0075] If the mobile terminal is equipped with a direction sensor, the toe angle θx can also be calculated using the same principle. For example, the first mobile terminal 316 is placed so that the vertical or thickness direction of the screen 318 of the first mobile terminal 316 is parallel to the longitudinal direction of the vehicle 1, and the direction sensor detects the direction of the vehicle 1. The camera of the second mobile terminal captures the measurement pattern Pm, and the direction sensor of the second mobile terminal detects the direction of the second mobile terminal. The difference between the direction of the first mobile terminal and the direction of the second mobile terminal can be calculated as the toe angle θx. The direction sensor may be, for example, a geomagnetic sensor, or a gyro sensor that detects the Coriolis force due to the Earth's rotation and calculates the direction.

[0076] (First Modification) FIG. 20 is a diagram showing the screen of a mobile terminal 316 that captures a measurement pattern Pm in a measurement system according to a first modified example of the second embodiment. Note that components common to the previously described embodiment are assigned the same reference numerals and will not be described again. As shown in FIG. 20 , a measurement pattern image 342 may be obtained by capturing the measurement pattern Pm with the camera 12 without regard to the orientation of the measurement pattern Pm on the screen 318. If the measurement pattern direction D2 deviates from the camera orientation direction D1 in the rotation direction along the pixel array surface of the measurement pattern image 342 by a relative angle β with respect to the camera orientation direction D1, the mobile terminal 316 determines the camber angle θy of the wheel 3 to be the angle obtained by adding the relative angle α between the camera orientation direction D1 and the direction of gravity G to the relative angle β between the measurement pattern direction D2 and the camera orientation direction D1. Note that other components are similar to those of the previously described embodiment and will not be described again.

[0077] (Second Modification) FIG. 21 is a schematic diagram showing the arrangement of the measurement pattern Pm and the camera 12 in a measurement system 410 according to a second modified example of the second embodiment. Note that components common to the above-described embodiments are given the same reference numerals and will not be described again. As shown in FIG. 21, the wheel 3 supporting the vehicle body 2 is located on a reference surface 8, and the measurement pattern Pm is positioned on the wheel 3 as shown in FIG. 3A. The camera 12 is positioned by a positioning tool 450 installed on the reference surface 8. The camera 12 captures the measurement pattern Pm.

[0078] Fig. 22 is a conceptual diagram showing the measurement principle in the arrangement of Fig. 21. As shown in Fig. 22, for example, the underside of the vehicle body 2 is arranged parallel to the reference plane 8, and a vertical line extending in the height direction of the vehicle body 2 is perpendicular to the reference plane 8. Therefore, the orientation of the vehicle body 2 with respect to the reference plane 8 is known. The positioning tool 450 is installed on the reference plane 8. The orientation of the positioning tool 450 with respect to the reference plane 8 is known.

[0079] The camera 12 is positioned by the positioning tool 450. In other words, the camera 12 is positioned relative to the vehicle body 2 via the positioning tool 450. Therefore, the posture of the camera 12 relative to the vehicle body 2 is known. Note that the camera 12 may also be positioned on the reference plane 8 without the positioning tool 450.

[0080] The measurement pattern Pm is positioned relative to the wheel 3. The horizontal axis direction of the measurement pattern Pm is arranged parallel to the direction in which the rotation axis L of the wheel 3 extends. The angle between the direction in which the rotation axis L of the wheel 3 extends and the horizontal axis direction of the measurement pattern Pm is zero. Therefore, the orientation of the measurement pattern Pm relative to the wheel 3 is known. The orientation of the measurement pattern Pm relative to the camera 12 is measured based on the measurement pattern image 342 captured by the camera 12, as described above with reference to Figures 19 and 20. Once the orientation of the measurement pattern Pm relative to the camera 12 is known, the orientation of the wheel 3 relative to the vehicle body 2 can be determined. Note that other configurations are the same as those in the above-described embodiment, so description thereof will be omitted.

[0081] [Third embodiment] FIG. 23A is a front view of the wheel 3 showing the installation of the measurement pattern Pm in the measurement system 510 according to the third embodiment. FIG. 23B is a side view of the wheel 3 showing the installation of the measurement pattern Pm in FIG. 23A. Note that the same reference numerals are used for configurations that are common to the above-described embodiments, and descriptions thereof will be omitted. As shown in FIGS. 23A and 23B, the measurement pattern Pm is fixed to the wheel body 4 of the wheel 3 via a jig. The normal direction of the surface of the measurement pattern Pm is the same as the direction in which the rotation axis L of the wheel 3 extends. In other words, the measurement pattern Pm faces in the direction in which the rotation axis L of the wheel 3 extends.

[0082] FIG. 24 is a schematic diagram showing the arrangement of the measurement pattern Pm, reference pattern Pr, and camera 12 in FIG. 23. Note that components common to the above-described embodiment are given the same reference symbols and will not be described. As shown in FIG. 24, the wheel 3 supporting the vehicle body 2 is located on a reference plane 8. The measurement pattern Pm is positioned on the wheel 3 so as to face in the direction in which the rotation axis L of the wheel 3 extends. The reference pattern Pr is positioned on the side of the vehicle body 2. Both the reference pattern Pr and the measurement pattern Pm face outward in the width direction of the vehicle 1.

[0083] The normal direction to the surface of the reference pattern Pr and the posture of the vehicle body 2 have a predetermined relationship. In this embodiment, the normal direction to the surface of the reference pattern Pr is parallel to the direction in which the reference plane 8 extends. The normal direction to the surface of the reference pattern Pr extends in the width direction of the vehicle 1 and is perpendicular to the fore-and-aft direction of the vehicle 1. The camera 12 captures the measurement pattern Pm and the reference pattern Pr so that both the measurement pattern Pm and the reference pattern Pr are included in a single captured image. The camera 12 is connected to a computer system 11 as shown in FIG. 6.

[0084] FIG. 25 is a conceptual diagram showing the measurement principle in the arrangement of FIG. 24. As shown in FIG. 25, the reference pattern Pr is positioned on the vehicle body 2. For example, the horizontal axis direction of the reference pattern Pr is parallel to the reference plane 8, and the vertical axis direction of the reference pattern Pr is parallel to a direction perpendicular to the reference plane 8. Therefore, the orientation of the reference pattern Pr relative to the vehicle body 2 is known. The measurement pattern Pm is positioned with respect to the wheel 3. Therefore, the orientation of the measurement pattern Pm relative to the wheel 3 is known. The orientation of the measurement pattern Pm relative to the reference pattern Pr is measured based on the image 540 captured by the camera 12. If the orientation of the measurement pattern Pm relative to the reference pattern Pr is known, the orientation of the wheel 3 relative to the vehicle body 2 can be determined.

[0085] FIG. 26 is a flowchart illustrating measurement processing based on the measurement principle of FIG. 25. FIG. 27 is a drawing showing a captured image 540 including a measurement pattern image 542 and a reference pattern image 541. Below, the measurement processing will be described along the flow of FIG. 26 with reference to FIGS. 23 to 25 and 27 to 29, etc. In response to a user's operation of the camera 12 or a command from the computer system 11, the camera 12 captures the reference pattern Pr and the measurement pattern Pm together to generate one captured image 540. The acquisition unit 32 of the computer system 11 acquires the captured image 540 from the camera 12 (step S21). The captured image 540 includes the reference pattern image 541 and the measurement pattern image 542.

[0086] 27, the information generating unit 33 of the computer system 11 identifies the shape of the reference pattern Pr captured in the reference pattern image 541 based on the pattern information 31a and calculates the orientation of the reference pattern Pr captured in the reference pattern image 541 (step S22). The calculated orientation of the reference pattern Pr includes the orientation in a first out-of-plane direction about a first axis AX1 extending along the pixel array surface of the reference pattern image 541 and the orientation in a second out-of-plane direction about a second axis AX2 extending along the pixel array surface of the reference pattern image 541. The first axis AX1 and the second axis AX2 are perpendicular to each other. The first axis AX1 is the horizontal centerline of the reference pattern Pr captured in the reference pattern image 541, and the second axis AX2 is the vertical centerline of the reference pattern Pr captured in the reference pattern image 541. Note that when the normal direction of the sensor surface of the camera 12 coincides with the normal direction of the surface of the reference pattern Pr, the reference pattern Pr captured in the reference pattern image 541 is free from distortion.

[0087] 27, it is assumed that the reference pattern Pr reflected in the reference pattern image 541 is distorted. That is, the reference pattern Pr reflected in the reference pattern image 541 is angularly displaced about the first axis line AX1 and about the second axis line AX2. The information generator 33 calculates an angle θ1 about the first axis line AX1 and an angle θ2 about the second axis line AX2 for the reference pattern Pr reflected in the reference pattern image 541. To calculate the orientation from the distortion of the reference pattern Pr reflected in the reference pattern image 541, for example, projective transformation can be used, but other methods may also be used.

[0088] Fig. 28 is a diagram illustrating the projective transformation regarding the reference pattern Pr. As shown in Fig. 28, the projective transformation between the surface of the reference pattern Pr and the sensor surface SS of the image sensor of the camera 12 is expressed by Equation (1) and Equation (2).

[0089]

number

[0090]

number

[0091] The perspective viewpoint is the origin, a point on the surface of the actual reference pattern Pr is point P'(x',y'), and a point on the sensor surface SS of the camera 12 is point P(x,y,z). The coefficients a0, a1, a2, b0, b1, b2, c0, c1, and c2 are unknown. The coordinates (x',y') of the feature points of the actual reference pattern Pr are obtained from the pattern information 31a. The coordinates (x,y) of the corresponding feature points on the sensor surface SS of the camera 12 can be identified by image recognition of the reference pattern image 541. The projection transformation formula can be determined if there are four pairs of feature points (x',y') and feature points (x,y). In the case of a QR code (registered trademark), the four feature points can be, for example, three finder patterns and one alignment pattern.

[0092] The information generator 33 calculates a normal vector V1 of the surface of the reference pattern Pr by projective transformation determined by the coordinates (x, y) of the four feature points on the reference pattern image 541 and the coordinates (x', y') of the four feature points defined in the pattern information 31a. Note that the normal vector V0 of the sensor surface SS of the image sensor of the camera 12 is a direction determined by the attitude of the camera 12.

[0093] Next, the information generation unit 33 of the computer system 11 identifies the shape of the measurement pattern Pm reflected in the measurement pattern image 542 based on the pattern information 31a, and calculates the orientation of the measurement pattern Pm reflected in the measurement pattern image 542 (step S23). Note that the order of execution of steps S22 and S23 may be reversed, or steps S22 and S23 may be executed in parallel.

[0094] The orientation of the measurement pattern Pm calculated here includes an orientation in a third out-of-plane direction about a third axis AX3 extending along the pixel array surface of the measurement pattern image 542, and an orientation in a fourth out-of-plane direction about a fourth axis AX4 extending along the pixel array surface of the measurement pattern image 542. The third axis AX3 passes through the center of the measurement pattern image 542 and is parallel to the first axis AX1. The fourth axis AX4 passes through the center of the measurement pattern image 542 and is parallel to the second axis AX2.

[0095] 27, the measurement pattern Pm shown in measurement pattern image 542 is distorted. That is, the measurement pattern Pm shown in measurement pattern image 542 is angularly displaced about the third axis AX3 and about the fourth axis AX4. The method for calculating the actual orientation of the measurement pattern Pm from the distortion of the measurement pattern Pm shown in measurement pattern image 542 can use projective transformation as described above in step S22, but other methods may also be used.

[0096] FIG. 29 is a diagram illustrating projective transformation for measurement pattern Pm. As shown in FIG. 29, the coordinates (x', y') of feature points of the actual measurement pattern Pm are obtained from pattern information 31a. The coordinates (x, y) of the corresponding feature points on the sensor surface SS of the image sensor of camera 12 can be identified by image recognition of measurement pattern image 542. In the case of a QR code (registered trademark), the four feature points may be, for example, three finder patterns and one alignment pattern.

[0097] The information generation unit 33 calculates a normal vector V2 of the surface of the measurement pattern Pm by projective transformation determined by the coordinates (x, y) of the four feature points on the measurement pattern image 542 and the coordinates (x', y') of the four feature points defined in the pattern information 31a. Note that the normal vector V0 of the sensor surface SS of the image sensor of the camera 12 is a direction determined by the attitude of the camera 12.

[0098] The information generation unit 33 generates wheel attitude information 31b using the attitude of the reference pattern Pr and the attitude of the measurement pattern Pm (step S24). Specifically, the information generation unit 33 calculates the relative angle between the calculated normal vector V1 to the surface of the reference pattern Pr and the calculated normal vector V2 to the surface of the measurement pattern Pm. The relative angle of the normal vector V2 with respect to the normal vector V1 around the horizontal line corresponds to the camber angle θy. The relative angle of the normal vector V2 with respect to the normal vector V1 around the vertical line corresponds to the toe angle θz. In this way, the camber angle θy and the toe angle θz are calculated as wheel attitude information 31b.

[0099] (First Modification) FIG. 30 is a schematic diagram showing the arrangement of the measurement pattern Pm, reference pattern Pr, and camera 12 in a measurement system 610 according to a first modified example of the third embodiment. Note that components common to the previously described embodiments are assigned the same reference numerals and will not be described again. As shown in FIG. 30, a wheel 3 supporting a vehicle body 2 is located on a reference surface 8, and the measurement pattern Pm is positioned on the wheel 3. The reference pattern Pr is positioned by a positioning tool 450 installed on the reference surface 8. The camera 12 captures the measurement pattern Pm and the reference pattern Pr so that both the measurement pattern Pm and the reference pattern Pr are included in a single captured image 540.

[0100] Fig. 31 is a conceptual diagram showing the measurement principle in the arrangement of Fig. 30. As shown in Fig. 31, for example, the underside of the vehicle body 2 is arranged parallel to the reference plane 8, and a vertical line extending in the height direction of the vehicle body 2 is perpendicular to the reference plane 8. Therefore, the orientation of the vehicle body 2 with respect to the reference plane 8 is known. The positioning tool 150 is installed on the reference plane 8. The orientation of the positioning tool 150 with respect to the reference plane 8 is known.

[0101] The reference pattern Pr is positioned by the positioning tool 150. In other words, the reference pattern Pr is positioned relative to the vehicle body 2 via the positioning tool 150. The angle of the horizontal axis direction of the reference pattern Pr relative to the reference plane 8 can be zero or a measured value. Therefore, the orientation of the reference pattern Pr relative to the vehicle body 2 is known. The measurement pattern Pm is positioned relative to the wheel 3. The normal direction to the surface of the measurement pattern Pm is parallel to the direction in which the rotation axis L of the wheel 3 extends. Therefore, the orientation of the measurement pattern Pm relative to the wheel 3 is known. The orientation of the measurement pattern Pm relative to the reference pattern Pr is measured based on the captured image 540 of the camera 12, as described above with reference to FIG. 27. Once the orientation of the measurement pattern Pm relative to the reference pattern Pr is known, the orientation of the wheel 3 relative to the vehicle body 2 can be determined. Note that the other configurations are the same as those in the previously described embodiment, and therefore will not be described again.

[0102] [Fourth embodiment] 32 is a schematic diagram showing the arrangement of the measurement pattern Pm and the camera 12 in the measurement system 710 according to the fourth embodiment. Note that the same reference numerals are used for components common to the above-described embodiments, and their description will be omitted. The wheel 3 supporting the vehicle body 2 is located on the reference plane 8. The measurement pattern Pm is positioned on the wheel 3. The mobile terminal 316 includes the camera 12 and a gyro sensor 317. In this example, no reference pattern is used, and only the measurement pattern Pm is used.

[0103] Figure 33 is a conceptual diagram showing the measurement principle in the arrangement of Figure 32. As shown in Figure 33, for example, the underside of the vehicle body 2 is arranged parallel to the reference plane 8, and a vertical line extending in the height direction of the vehicle body 2 is perpendicular to the reference plane 8. Therefore, the posture of the vehicle body 2 with respect to the reference plane 8 is known. The relative angle between the reference plane 8 and the horizontal plane HS is measured in advance and is known. For example, the reference plane 8 itself can be the horizontal plane.

[0104] The measurement pattern Pm is positioned relative to the wheel 3 as shown in Figure 23A. Therefore, the orientation of the measurement pattern Pm relative to the wheel 3 is known. The orientation of the camera 12 relative to the horizontal plane HS is measured based on the detection value of the gyro sensor 317. The orientation of the measurement pattern Pm relative to the camera 12 is measured based on the captured image 540 of the camera 12. Once the orientation of the measurement pattern Pm relative to the camera 12 is known, the orientation of the wheel 3 relative to the reference plane 8 can be determined.

[0105] Figure 34 is a flowchart explaining the measurement process based on the measurement principle of Figure 33. Figure 35 is a drawing showing the screen of the mobile terminal 316 that captures the measurement pattern Pm. Below, the measurement process will be explained along the flow of Figure 34 with reference to Figures 32, 33, 35, etc. The camera 12 of the mobile terminal 316 captures the measurement pattern Pm from the side of the vehicle 1 with the optical axis of the camera 12 facing in the width direction of the vehicle 1. The acquisition unit 32 of the computer system 11 acquires the measurement pattern image 742 obtained thereby from the camera 12 (step S31).

[0106] 35, the information generation unit 33 of the computer system 11 identifies the shape of the measurement pattern Pm captured in the measurement pattern image 742 based on the pattern information 31a, and calculates the orientation of the measurement pattern Pm captured in the measurement pattern image 742 (step S32). The orientation of the measurement pattern Pm calculated here includes the orientation in the out-of-plane direction around an axis AX5 extending along the horizontal direction. The axis AX5 passes through the center of the measurement pattern Pm captured in the measurement pattern image 742 and extends in the horizontal direction perpendicular to the direction of gravity G detected by the gyro sensor 317 at the time the measurement pattern Pm was captured. Using the projective transformation described above, the angle θ5 of the actual measurement pattern Pm around the axis AX5 relative to the camera 12 is calculated from the distortion of the measurement pattern Pm captured in the measurement pattern image 742.

[0107] Based on the detection signal of the gyro sensor 317, the information generation unit 33 calculates the attitude of the camera 12 with respect to the reference plane 8 at the time when the measurement pattern Pm was photographed by the camera 12 as camera attitude information (step S33). Specifically, the gyro sensor 317 detects the direction of gravity G based on the camera 12 at the time when the measurement pattern Pm was photographed. The direction of gravity G is the same as the normal direction to the horizontal plane HS. The mobile terminal 316 calculates the relative angle α about the axis AX5 between the camera attitude direction D1 and the direction of gravity G at the time when the measurement pattern Pm was photographed.

[0108] 33, once the angle θ5 of the measurement pattern Pm relative to the camera 12 and the angle α of the camera 12 relative to the horizontal plane HS are calculated, it becomes possible to calculate the camber angle θy of the wheel 3 relative to the vehicle body 2. For example, if the angle between the rotation axis L of the wheel 3 and the normal to the surface of the measurement pattern Pm is zero, the angle between the underside of the vehicle body 2 and the reference plane 8 is zero, and the reference plane 8 is horizontal, the information generator 33 regards the angle θ5 plus the angle α as the camber angle θy and generates wheel attitude information indicating this camber angle θy (step S33).

[0109] If the mobile terminal is equipped with a direction sensor, the toe angle θx can also be calculated using the same principle. For example, the first mobile terminal 316 is placed so that the vertical or thickness direction of the screen 318 of the first mobile terminal 316 is parallel to the longitudinal direction of the vehicle 1, and the direction sensor detects the direction of the vehicle 1. The camera of the second mobile terminal captures the measurement pattern Pm, and the direction sensor of the second mobile terminal detects the direction of the second mobile terminal. The difference between the direction of the first mobile terminal and the direction of the second mobile terminal can be calculated as the toe angle θx. The direction sensor may be, for example, a geomagnetic sensor, or a gyro sensor that detects the Coriolis force due to the Earth's rotation and calculates the direction.

[0110] (Variation) FIG. 36 is a schematic diagram showing the arrangement of the measurement pattern Pm and the camera 12 in a measurement system 810 according to a modified example of the fourth embodiment. Note that components common to the above-described embodiments are given the same reference numerals and will not be described again. As shown in FIG. 36, the wheel 3 supporting the vehicle body 2 is located on a reference surface 8, and the measurement pattern Pm is positioned on the wheel 3. The camera 12 is positioned by a positioning tool 450 installed on the reference surface 8. The camera 12 captures the measurement pattern Pm.

[0111] Fig. 37 is a conceptual diagram showing the measurement principle in the arrangement of Fig. 36. As shown in Fig. 37, for example, the underside of the vehicle body 2 is arranged parallel to the reference plane 8, and a vertical line extending in the height direction of the vehicle body 2 is perpendicular to the reference plane 8. Therefore, the orientation of the vehicle body 2 with respect to the reference plane 8 is known. A positioning tool 450 is installed on the reference plane 8. The orientation of the positioning tool 450 with respect to the reference plane 8 is known.

[0112] The camera 12 is positioned by the positioning tool 450. In other words, the camera 12 is positioned relative to the vehicle body 2 via the positioning tool 450. Therefore, the attitude of the camera 12 relative to the vehicle body 2 is known. For example, the normal direction of the sensor surface of the image sensor of the camera 12 is parallel to the reference plane 8 and perpendicular to the fore-and-aft direction of the vehicle 1. Note that the camera 12 may be positioned on the reference plane 8 without the positioning tool 450.

[0113] The measurement pattern Pm is positioned relative to the wheel 3. The normal direction of the measurement pattern Pm is parallel to the direction in which the rotation axis L of the wheel 3 extends. Therefore, the orientation of the measurement pattern Pm relative to the wheel 3 is known. The orientation of the measurement pattern Pm relative to the camera 12 is measured based on the measurement pattern image 342 captured by the camera 12, as described above with reference to FIG. 35. Once the orientation of the measurement pattern Pm relative to the camera 12 is known, the orientation of the wheel 3 relative to the vehicle body 2 can be calculated. In this example, the normal direction to the sensor surface of the image sensor of the camera 12 is perpendicular to the fore-and-aft direction of the vehicle 1, and the orientation relative to the fore-and-aft direction of the vehicle 1 is known, so the toe angle θz can also be calculated using the same principle as the camber angle θy. Note that the other configurations are the same as those in the first embodiment, and therefore description thereof will be omitted.

[0114] [Fifth embodiment] Fig. 38 is a functional block diagram of a measurement system 910 according to a fifth embodiment. As shown in Fig. 37, the measurement system 910 includes a camera 12 and a computer system 911. The computer system 911 is connected to another detection system 1000. The detection system 1000 includes a sensor 960 different from the camera 12, a memory unit 961 that stores detection data of the sensor 960, and a processing circuit including a processor connected to the sensor 960 and the memory unit 961. The sensor 960 may be mounted on the vehicle 1 or may be located outside the vehicle 1. The sensor 960 is not particularly limited, and may be, for example, a sensor that detects wear of a tire 5 on a wheel 3.

[0115] When the sensor 960 detects wear of the tire 5 on the wheel 3, the identification information of the wheel 3 is also read. The detection result D of the sensor 960 is stored in the storage unit 961 in association with the corresponding identification information. The identification information of the wheel 3 may be read from a measurement pattern Pm provided on the wheel 3, may be read from an IC chip provided on the wheel 3, or may be read by image recognition from an image obtained by photographing the identification number marked on the wheel 3.

[0116] The information generation unit 33 of the computer system 911 generates wheel attitude information θy, θz according to any of the above-described embodiments and modifications. At this time, the identification information specification unit 34 of the computer system 911 specifies the identification information of the measurement pattern Pm by reading the measurement pattern Pm provided on the wheel 3. The storage unit 31 stores the wheel attitude information θy, θz generated by the information generation unit 33 in association with the corresponding identification information.

[0117] The computer system 911 is communicatively connected to the detection system 1000. The acquisition unit 32 of the computer system 911 acquires the detection result D and the corresponding identification information from the detection system 1000. For the same wheel 3, the identification information stored in the memory unit 961 of the detection system 1000 and the identification information stored in the memory unit 31 of the measurement system 910 are the same. The acquisition unit 32 of the measurement system 910 stores the detection result D and wheel attitude information θy, θz of the detection system 1000, which are associated with the same identification information, in association with each other in the memory unit 31.

[0118] The computer system 911 can provide the external system 962 with not only the wheel attitude information θy, θz but also the detection result D as information about one wheel 3. The identification information may be associated with vehicle model information. This makes it possible to take measures such as arranging for an inspection of a specific vehicle model when an abnormality is found in the specific vehicle model. The identification information may also be associated with the vehicle's movement history. This makes it possible to arrange for an inspection of other vehicles that share a movement history with the vehicle that had the abnormality.

[0119] Note that, for the same vehicle 1, the identification information stored in the storage unit 961 of the detection system 1000 may be different from the identification information stored in the storage unit 31 of the computer system 911. For example, the storage unit 31 may store reference information that associates the identification information acquired by photographing with the camera 12 with the identification information stored in the storage unit 961 of the detection system 1000. The acquisition unit 32 may identify the identification information associated in the reference information with the identification information stored in the storage unit 31, and use the identified information to search for the detection results stored in the storage unit 961. The storage unit 961 does not have to be part of the detection system 1000, and may be part of a system different from the detection system 1000.

[0120] As described above, the above-described embodiments have been described as examples of the technology disclosed in this application. However, the technology disclosed herein is not limited to these embodiments and can be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are made as appropriate. Furthermore, the components described in the above-described embodiments can be combined to create new embodiments. For example, a portion of the configuration or method of one embodiment or variant may be applied to another embodiment or variant, and a portion of the configuration of an embodiment or variant may be separated from the other configurations and arbitrarily extracted. Furthermore, the components described in the accompanying drawings and detailed description include not only components essential for solving the problem, but also components that are not essential for solving the problem, and are used to illustrate the technology.

[0121] The functions of the elements disclosed herein can be performed using circuits or processing circuits, including general-purpose processors, special-purpose processors, integrated circuits, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), graphics processing units (GPUs), conventional circuits, and / or combinations thereof, configured or programmed to perform the disclosed functions. Processors are considered processing circuits or circuits because they include transistors and other circuitry. In this disclosure, a circuit, unit, or means is hardware that performs the recited functions or hardware that is programmed to perform the recited functions. The hardware may be hardware disclosed herein or other known hardware that is programmed or configured to perform the recited functions. Where the hardware is a processor, which is considered a type of circuit, the circuit, means, or unit is a combination of hardware and software, and the software is used to configure the hardware and / or processor.

[0122] [Aspect] The above-described embodiments are examples of the following aspects.

[0123] (Aspect 1) a processing circuit; a storage device including at least one memory that stores pattern information including information defining the shape of a measurement pattern positioned relative to a wheel attached to a body of a vehicle; The processing circuitry acquiring a measurement pattern image obtained by photographing the measurement pattern; generating wheel attitude information representing an attitude of the wheel using information on the shape of the measurement pattern in the measurement pattern image and the pattern information; a measurement system configured to:

[0124] (Aspect 2) the pattern information includes information defining a shape of a reference pattern positioned with respect to the vehicle body; the processing circuitry is configured to acquire a reference pattern image obtained by photographing the reference pattern, the reference pattern image having a coordinate system that has a predetermined relationship with a coordinate system of the measurement pattern image, Generating the wheel attitude information includes: calculating the orientation of the reference pattern shown in the reference pattern image using the pattern information; Calculating the orientation of the measurement pattern shown in the measurement pattern image using the pattern information; generating, as the wheel attitude information, information representing a relative attitude between the vehicle body and the wheel, using the calculated attitude of the measurement pattern and the attitude of the reference pattern. 2. The measurement system according to embodiment 1.

[0125] (Aspect 3) calculating the orientation of the reference pattern includes calculating the orientation of the reference pattern in a rotation direction along a pixel array plane of the reference pattern image; calculating the orientation of the measurement pattern includes calculating the orientation of the measurement pattern in a rotation direction along a pixel array plane of the measurement pattern image. 3. The measurement system according to embodiment 2.

[0126] (Aspect 4) calculating the orientation of the reference pattern includes calculating, using a shape of the reference pattern defined by the pattern information and a shape of the reference pattern captured in the reference pattern image, an orientation of the reference pattern in an out-of-plane direction around an axis extending along a pixel array surface of the reference pattern image; calculating the orientation of the measurement pattern includes calculating the orientation of the measurement pattern in an out-of-plane direction around an axis extending along a pixel array surface of the measurement pattern image, using the shape of the measurement pattern defined by the pattern information and the shape of the measurement pattern shown in the measurement pattern image. 4. The measurement system according to embodiment 2 or 3.

[0127] (Aspect 5) calculating the orientation of the reference pattern includes calculating the orientation of the reference pattern in a first out-of-plane direction about a first axis extending along a pixel array surface of the reference pattern image, and calculating the orientation of the reference pattern in a second out-of-plane direction about a second axis extending along the pixel array surface of the reference pattern image and perpendicular to the first axis; calculating an orientation of the measurement pattern in a third out-of-plane direction about a third axis line that extends along the pixel array surface of the measurement pattern image and has a predetermined relationship with the first axis line, and calculating an orientation of the measurement pattern in a fourth out-of-plane direction about a fourth axis line that extends along the pixel array surface of the measurement pattern image and is perpendicular to the third axis line, Generating the wheel attitude information includes: generating information indicating a camber angle of the wheel using the calculated orientation of the reference pattern in the first out-of-plane direction and the calculated orientation of the measurement pattern in the third out-of-plane direction; generating information indicating a toe angle of the wheel using the calculated orientation of the reference pattern in the second out-of-plane direction and the calculated orientation of the measurement pattern in the fourth out-of-plane direction. 5. The measurement system according to embodiment 4.

[0128] (Aspect 6) A plane that is a reference for the attitude of the vehicle is defined as a reference plane, the processing circuit is configured to acquire camera attitude information indicating the attitude of the camera with respect to the reference plane at the time when the measurement pattern image was captured by the camera, generating the wheel attitude information includes generating, as the wheel attitude information, information representing a relative attitude between the vehicle body and the wheel, using the camera attitude information; 2. The measurement system according to embodiment 1.

[0129] (Aspect 7) acquiring the measurement pattern image includes acquiring the measurement pattern image obtained by photographing the measurement pattern image with the camera having a predetermined orientation with respect to the measurement pattern. 7. The measurement system according to embodiment 6.

[0130] (Aspect 8) Generating the wheel attitude information includes: correcting distortion of the shape of the measurement pattern shown in the measurement pattern image using the pattern information, and calculating the attitude of the measurement pattern in a rotation direction along the pixel array plane of the measurement pattern image using the corrected shape of the measurement pattern; generating information representing a relative attitude between the vehicle body and the wheel as the wheel attitude information using the calculated attitude of the measurement pattern and the camera attitude information. 8. The measurement system according to embodiment 6 or 7.

[0131] (Aspect 9) Generating the wheel attitude information includes: calculating an orientation of the measurement pattern in an out-of-plane direction around an axis extending along a pixel array surface of the measurement pattern image, using a shape of the measurement pattern defined by the pattern information and a shape of the measurement pattern captured in the measurement pattern image; generating information representing a relative attitude between the vehicle body and the wheel as the wheel attitude information using the calculated attitude of the measurement pattern and the camera attitude information; 7. The measurement system according to embodiment 6.

[0132] (Aspect 10) calculating the orientation of the measurement pattern includes calculating the orientation of the measurement pattern in a first out-of-plane direction about a first axis extending along a pixel array surface of the measurement pattern image, and calculating the orientation of the measurement pattern in a second out-of-plane direction about a second axis extending along the pixel array surface of the measurement pattern image and perpendicular to the first axis, Generating the wheel attitude information includes: generating information indicating a camber angle of the wheel using the calculated orientation of the measurement pattern in the first out-of-plane direction; and generating information indicating a toe angle of the wheel using the calculated orientation of the measurement pattern in the second out-of-plane direction. 7. The measurement system according to embodiment 6.

[0133] (Aspect 11) the measurement pattern includes identification information; The processing circuitry Identifying the identification information included in the measurement pattern from the measurement pattern image; storing the wheel attitude information in association with the identification information in the storage device; and further configured to: A measurement system according to any one of aspects 1 to 10.

[0134] (Aspect 12) The processing circuitry acquiring a second detection result obtained by detecting the vehicle by a sensor different from the camera using the identification information; storing the second detection result in the storage device in association with the wheel attitude information using the identification information; and further configured to: 12. The measurement system according to claim 11.

[0135] (Aspect 13) storing measurement pattern information including information defining the shape of the measurement pattern positioned relative to a wheel mounted on a body of a vehicle; acquiring a measurement pattern image obtained by photographing the measurement pattern; generating wheel attitude information representing an attitude of the wheel using information on the shape of the measurement pattern in the measurement pattern image and the measurement pattern information; A measurement program that causes a computer system including at least one computer to execute the above.

[0136] (Aspect 14) A measurement method using a computer system including at least one computer, storing metrology pattern information in the computer system defining the shape of a metrology pattern positioned relative to a wheel mounted on a vehicle body; taking an image of the measurement pattern; and causing the computer system to generate wheel attitude information representing the attitude of the wheel using information on the shape of the measurement pattern captured in the measurement pattern image obtained by photographing and the measurement pattern information. [Explanation of symbols]

[0137] 1 vehicle 2. Body 3 wheels 8 Reference plane 10,110,210,310,410,510,610,710,810,910 Measurement System 11,911 computer systems 12 Camera 15. Computer 20 Processing circuit 24 Measurement Program 31a Pattern Information 31b Wheel attitude information 40,540 images taken 41,541 reference pattern images 42,342,542,742 measurement pattern images 317 Gyro Sensor 960 Sensors

Claims

1. a processing circuit; a storage device including at least one memory that stores pattern information including information defining the shape of a measurement pattern positioned relative to a wheel attached to a body of a vehicle; The processing circuitry acquiring a measurement pattern image obtained by photographing the measurement pattern; generating wheel attitude information representing an attitude of the wheel using information on the shape of the measurement pattern in the measurement pattern image and the pattern information; a measurement system configured to:

2. the pattern information includes information defining a shape of a reference pattern positioned with respect to the vehicle body; the processing circuitry is configured to acquire a reference pattern image obtained by photographing the reference pattern, the reference pattern image having a coordinate system that has a predetermined relationship with a coordinate system of the measurement pattern image, Generating the wheel attitude information includes: calculating the orientation of the reference pattern shown in the reference pattern image using the pattern information; Calculating the orientation of the measurement pattern shown in the measurement pattern image using the pattern information; generating, as the wheel attitude information, information representing a relative attitude between the vehicle body and the wheel, using the calculated attitude of the measurement pattern and the attitude of the reference pattern. The measurement system of claim 1 .

3. calculating the orientation of the reference pattern includes calculating the orientation of the reference pattern in a rotation direction along a pixel array plane of the reference pattern image; calculating the orientation of the measurement pattern includes calculating the orientation of the measurement pattern in a rotation direction along a pixel array plane of the measurement pattern image. The measurement system of claim 2 .

4. calculating the orientation of the reference pattern includes calculating, using a shape of the reference pattern defined by the pattern information and a shape of the reference pattern captured in the reference pattern image, an orientation of the reference pattern in an out-of-plane direction around an axis extending along a pixel array surface of the reference pattern image; calculating the orientation of the measurement pattern includes calculating the orientation of the measurement pattern in an out-of-plane direction around an axis extending along the pixel array surface of the measurement pattern image, using the shape of the measurement pattern defined by the pattern information and the shape of the measurement pattern shown in the measurement pattern image. The measurement system of claim 2 .

5. calculating the orientation of the reference pattern includes calculating the orientation of the reference pattern in a first out-of-plane direction about a first axis extending along a pixel array surface of the reference pattern image, and calculating the orientation of the reference pattern in a second out-of-plane direction about a second axis extending along the pixel array surface of the reference pattern image and perpendicular to the first axis; calculating an orientation of the measurement pattern in a third out-of-plane direction about a third axis line that extends along a pixel array surface of the measurement pattern image and has a predetermined relationship with the first axis line, and calculating an orientation of the measurement pattern in a fourth out-of-plane direction about a fourth axis line that extends along the pixel array surface of the measurement pattern image and is perpendicular to the third axis line, Generating the wheel attitude information includes: generating information indicating a camber angle of the wheel using the calculated orientation of the reference pattern in the first out-of-plane direction and the calculated orientation of the measurement pattern in the third out-of-plane direction; generating information indicating a toe angle of the wheel using the calculated orientation of the reference pattern in the second out-of-plane direction and the calculated orientation of the measurement pattern in the fourth out-of-plane direction. The measurement system according to claim 4 .

6. A plane that is a reference for the attitude of the vehicle is defined as a reference plane, the processing circuit is configured to acquire camera attitude information indicating the attitude of the camera with respect to the reference plane at the time when the measurement pattern image was captured by the camera, generating the wheel attitude information includes generating, as the wheel attitude information, information representing a relative attitude between the vehicle body and the wheel, using the camera attitude information; The measurement system of claim 1 .

7. acquiring the measurement pattern image includes acquiring the measurement pattern image obtained by photographing the measurement pattern image with the camera having a predetermined orientation with respect to the measurement pattern. The measurement system of claim 6 .

8. Generating the wheel attitude information includes: correcting distortion of the shape of the measurement pattern shown in the measurement pattern image using the pattern information, and calculating the attitude of the measurement pattern in a rotation direction along the pixel array plane of the measurement pattern image using the corrected shape of the measurement pattern; generating information representing a relative attitude between the vehicle body and the wheel as the wheel attitude information using the calculated attitude of the measurement pattern and the camera attitude information. The measurement system of claim 6 .

9. Generating the wheel attitude information includes: calculating an orientation of the measurement pattern in an out-of-plane direction around an axis extending along a pixel array surface of the measurement pattern image, using a shape of the measurement pattern defined by the pattern information and a shape of the measurement pattern captured in the measurement pattern image; generating information representing a relative attitude between the vehicle body and the wheel as the wheel attitude information using the calculated attitude of the measurement pattern and the camera attitude information; The measurement system of claim 6 .

10. calculating the orientation of the measurement pattern includes calculating the orientation of the measurement pattern in a first out-of-plane direction about a first axis extending along a pixel array surface of the measurement pattern image, and calculating the orientation of the measurement pattern in a second out-of-plane direction about a second axis extending along the pixel array surface of the measurement pattern image and perpendicular to the first axis, Generating the wheel attitude information includes: generating information indicating a camber angle of the wheel using the calculated orientation of the measurement pattern in the first out-of-plane direction; generating information indicating a toe angle of the wheel using the calculated orientation of the measurement pattern in the second out-of-plane direction; The measurement system of claim 6 .

11. the measurement pattern includes identification information; The processing circuitry Identifying the identification information included in the measurement pattern from the measurement pattern image; storing the wheel attitude information in association with the identification information in the storage device; and further configured to: The measurement system of claim 1 .

12. The processing circuitry acquiring a second detection result obtained by detecting the vehicle by a sensor different from the camera using the identification information; storing the second detection result in the storage device in association with the wheel attitude information using the identification information; and further configured to: The measurement system of claim 11.

13. storing measurement pattern information including information defining the shape of the measurement pattern positioned relative to a wheel mounted on a body of a vehicle; acquiring a measurement pattern image obtained by photographing the measurement pattern; generating wheel attitude information representing an attitude of the wheel using information on the shape of the measurement pattern in the measurement pattern image and the measurement pattern information; A measurement program that causes a computer system including at least one computer to execute the above.

14. A measurement method using a computer system including at least one computer, storing metrology pattern information in the computer system defining the shape of a metrology pattern positioned relative to a wheel mounted on a vehicle body; taking an image of the measurement pattern; and causing the computer system to generate wheel attitude information representing the attitude of the wheel using information on the shape of the measurement pattern captured in the measurement pattern image obtained by photographing and the measurement pattern information.

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