Rolling angle measuring device

Abstract

To provide a rolling angle measurement apparatus which can measure a rolling angle of a mobile body without being restricted in the axial direction of a movement shaft.SOLUTION: A rolling angle measurement apparatus includes: a mobile body 20 which is moved in a first direction along a movement shaft S arranged in the first direction; a cylindrical lens 50 which is provided so as to be spaced in a second direction from the mobile body 20; a position sensitive detector (PSD) 60 which is provided between the mobile body 20 and the cylindrical lens 50; an illumination device 80 which emits linear light E that extends in the first direction toward an incidence surface 52 of the cylindrical lens 50; and a data processing device 90 which calculates a rolling angle of the mobile body 20 on the basis of a displacement amount Δ of a light reception position of light E received by the PSD 60 when the mobile body 20 moves in the first direction.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a rolling angle measuring device, and particularly to a rolling angle measuring device that measures the rolling angle of a moving body that linearly moves along a moving shaft.

Background Art

[0002] In devices provided with a moving shaft, such as machine tools or shape measuring devices (e.g., three-dimensional coordinate measuring devices), it is required to improve the positioning accuracy of a moving body that linearly moves along the moving shaft. To improve positioning accuracy, a correction function is installed in the controller of the above-mentioned device, and a correction amount is calculated based on, in addition to positioning deviation, the rotation angle (rolling angle, pitching angle and yawing angle) of the moving body, and the like.

[0003] Patent Document 1 discloses a rolling angle measuring device that uses a laser length measuring machine to measure the oscillating motion around the moving shaft of a moving body, that is, the rolling angle.

[0004] According to Patent Document 1, the rolling angle measuring device comprises: an angle interferometer orthogonally arranged on the optical axis of a laser head via a turning mirror and installed on a moving body that moves parallel to the optical axis; and an angle target prism that receives a laser beam emitted from the angle interferometer and reflects the laser beam toward the angle interferometer side. A configuration is disclosed in which the upper end of either one of the angle interferometer and the angle target prism is swingably connected and installed relative to the other, a braking damper is installed at the lower end of the swingably installed one, and the other side is fixedly arranged on the moving body.

Prior Art Literature

Patent Literature

[0005]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0006] The rolling angle measuring device described in Patent Document 1 has a configuration in which an angle target prism is suspended and supported in the vertical direction, and when a rolling component exists on the horizontal axis, which is the axis of movement, the angle target prism is swung around the horizontal axis using its own weight. For this reason, the rolling angle measuring device described in Patent Document 1 can measure the rolling angle of a moving body with the horizontal axis as the axis of movement, but it has the problem that it cannot measure the rolling angle of a moving body with the vertical axis as the axis of movement because it cannot utilize the weight of the angle target prism.

[0007] Thus, conventional rolling angle measuring devices have the problem that they cannot measure the rolling angle depending on the axial direction of the moving axis. Therefore, there is a need to realize a rolling angle measuring device that can measure the rolling angle of a moving body without being restricted by the axial direction of the moving axis.

[0008] This invention has been made in view of these problems, and aims to provide a rolling angle measuring device that can measure the rolling angle of a moving body without being restricted by the axial direction of the moving axis. [Means for solving the problem]

[0009] To achieve the objectives of the present invention, the rolling angle measuring device of the present invention comprises: a moving body that moves in a first direction along a moving axis arranged in a first direction; a condensing lens provided spaced apart from the moving body in a second direction perpendicular to the first direction and moving together with the moving body in the first direction, having an incident surface and an outgoing surface, with the outgoing surface facing the moving body; a light receiving means provided between the moving body and the condensing lens and moving together with the moving body in the first direction, receiving light emitted from the outgoing surface; an illumination means that emits linear light spreading in the first direction toward the incident surface; and an angle calculation means that calculates the rolling angle of the moving body based on the amount of displacement of the light receiving position of the light received by the light receiving means when the moving body moves in the first direction.

[0010] In one embodiment of the present invention, the focusing lens includes a first focusing lens provided on a first surface among the surfaces constituting the outer surface of the moving body, and a second focusing lens provided on a second surface opposite to the first surface; the light receiving means includes a first light receiving means for receiving light emitted from the emission surface of the first focusing lens, and a second light receiving means for receiving light emitted from the emission surface of the second focusing lens; the illumination means includes a first illumination means for emitting linear first light spreading in a first direction toward the incident surface of the first focusing lens, and a second illumination means for emitting linear second light spreading in a first direction toward the incident surface of the second focusing lens; and preferably, the angle calculation means calculates the rolling angle of the moving body based on the amount of displacement of the light receiving position of the first light received by the first light receiving means and the amount of displacement of the light receiving position of the second light received by the second light receiving means when the moving body moves in a first direction.

[0011] In one embodiment of the present invention, the focusing lens is a cylindrical lens having a convex cylindrical surface as the incident surface and a flat surface as the exit surface, and it is preferable that the exit surface is arranged parallel to the axis of the moving axis when the cylindrical lens is viewed from a third direction perpendicular to the first and second directions, respectively.

[0012] In one embodiment of the present invention, the light-receiving means is preferably a one-dimensional position detection element having a strip-shaped light-receiving surface extending in a third direction, and the angle calculation means calculates the displacement amount based on the output signal value from the position detection element.

[0013] In one embodiment of the present invention, it is preferable that the illumination means emits light toward the axis along a second direction. [Effects of the Invention]

[0014] According to the present invention, it is possible to measure the rolling angle of a moving body without being restricted by the axial direction of the moving axis. [Brief explanation of the drawing]

[0015] [Figure 1] This is an overall perspective view of the rolling angle measuring device according to an embodiment. [Figure 2]It is an explanatory diagram showing a moving shaft included in a shape measuring apparatus. [Figure 3] It is an explanatory diagram of the rolling angle measuring apparatus of Fig. 1 as viewed from the Z-axis direction. [Figure 4] It is an explanatory diagram showing the configuration of the illumination apparatus of Fig. 1 as viewed from the Z-axis direction. [Figure 5] It is a functional block diagram showing the configuration of the data processing apparatus of Fig. 1. [Figure 6] It is an explanatory diagram showing the initial setting completion state of the rolling angle measuring apparatus as viewed from the X-axis direction. [Figure 7] It is an explanatory diagram showing a state where rolling occurs in a moving body as viewed from the X-axis direction. [Figure 8] It is an explanatory diagram of the rolling angle measuring apparatus according to the second embodiment as viewed from the X-axis direction. [Figure 9] It is an explanatory diagram showing a state where rolling occurs in a moving body as viewed from the X-axis direction. [Figure 10] It is an explanatory diagram for supplementarily explaining the content of Expression 4. [Figure 11] It is a schematic diagram showing a state where a moving body is moved along a moving shaft as viewed from the Y-axis direction. [Figure 12] It is a graph showing changes in light collection coordinates when the moving body is moved under a condition where no rolling exists. [Figure 13] It is a plot diagram of light collection coordinates when rolling occurs in a moving body.

Mode for Carrying Out the Invention

[0016] Hereinafter, embodiments of the rolling angle measuring apparatus according to the present invention will be described with reference to the accompanying drawings.

[0017] [First Embodiment] Figure 1 is a perspective view showing the overall configuration of the rolling angle measuring device 10 according to the first embodiment. Figure 2 is an explanatory diagram showing a movable axis S of a shape measuring device (not shown), such as a three-dimensional coordinate measuring device, as an example. In Figure 2, the rolling angle (angle around the X axis), pitching angle (angle around the Y axis), and yawing angle (angle around the Z axis), which are the measurement elements of the movable body 20 that moves along the movable axis S, are schematically shown.

[0018] The rolling angle measuring device 10 shown in Figure 1 is a device for measuring the rolling angle, that is, the oscillation angle of the moving body 20 around the axis P of the moving axis S shown in Figure 2, among the various measuring elements of the moving axis S shown in Figure 2. Here, in this specification, a moving axis S arranged horizontally is given as an example, and the direction of the axis P of the moving axis S in the horizontal direction is referred to as the X-axis direction, the horizontal direction perpendicular to the X-axis direction is referred to as the Y-axis direction, and the vertical directions perpendicular to the X-axis direction and the Y-axis direction are referred to as the Z-axis direction. The X-axis direction, Y-axis direction and Z-axis direction correspond to the first direction, second direction and third direction and respectively of the present invention.

[0019] Furthermore, as will be described later, the rolling angle measuring device 10 in this example measures the rolling angle without utilizing the weight of the moving body 20. Therefore, it is not restricted by the direction of the moving axis, and can measure the rolling angle of the moving body not only with a moving axis S arranged horizontally as in this example, but also with a moving axis arranged vertically. The rolling angle measuring device 10 in this example will be described in detail below.

[0020] As shown in Figure 1, the rolling angle measuring device 10 comprises a moving body 20, a cylindrical lens 50, a PSD (Position Sensitive Detector) 60, an illumination device 80, and a data processing device 90.

[0021] The movable body 20 shown in Figure 1 is a member that moves in the X-axis direction along the movement axis S. In this example, for the sake of simplicity, a rectangular parallelepiped shape is shown as an example. The movable body 20 has an outer surface, which has a first surface 22 and a second surface 24 facing each other in the Y-axis direction, a third surface 26 and a fourth surface 28 facing each other in the X-axis direction, and an upper surface 30 and a lower surface 32 facing each other in the Z-axis direction. The movable body 20 is an example of the movable body of the present invention and is also referred to as a stage.

[0022] The cylindrical lens 50 is provided on the first surface 22 of the moving body 20, spaced apart in the Y-axis direction (second direction). The cylindrical lens 50 is fixed to the moving body 20 using, for example, a connecting device (not shown) such as a bracket, and moves together with the moving body 20 in the X-axis direction.

[0023] Figure 3 is an explanatory diagram of the rolling angle measuring device 10 shown in Figure 1 as viewed from the Z-axis direction. As shown in Figure 3, the cylindrical lens 50 has an incident surface 52 which is a convex cylindrical surface and an exit surface 54 which is a flat surface, with the exit surface 54 facing the moving body 20. Specifically, as shown in Figure 3, when the cylindrical lens 50 is viewed from the Z-axis direction, the incident surface 52 facing the illumination device 80 in the Y-axis direction is configured in an arc shape, and the exit surface 54 facing the moving body 20 in the Y-axis direction is configured in a straight line. Also, as shown in Figure 3, when the cylindrical lens 50 is viewed from the Z-axis direction (third direction), the exit surface 54 is arranged parallel to the axis P of the moving axis S (see Figure 2). Note that the cylindrical lens 50 is an example of a focusing lens of the present invention.

[0024] As shown in Figures 1 and 3, the PSD 60 is provided between the moving body 20 and the cylindrical lens 50. The PSD 60 is attached to the first surface 22 of the moving body 20 and moves in the X-axis direction together with the moving body 20 and the cylindrical lens 50.

[0025] The PSD60 has the function of receiving light E emitted from the illumination device 80 through the emission surface 54 of the cylindrical lens 50. The PSD60 has a structure similar to that of a PIN-type photodiode and measures the photocurrent at the incident position of light E by the photovoltaic effect to measure the centroid position of the light E (the part with the highest light intensity). In this example, as shown in Figure 1, a one-dimensional PSD with a strip-shaped light-receiving surface (also called a detection surface) 62 is used as the PSD60, and is attached to the moving body 20 in a position where the longitudinal direction of the light-receiving surface 62 coincides with the Z-axis direction. Light E emitted from the illumination device 80 is focused by the cylindrical lens 50 and received by the light-receiving surface 62 of the PSD60. The PSD60 is an example of a light-receiving means of the present invention.

[0026] Figure 4 is an explanatory diagram showing the configuration of the illumination device 80 shown in Figure 1, viewed from the Z-axis direction. As shown in Figure 4, the illumination device 80 includes a laser light source 82, a rod lens 84, and a collimating lens 86.

[0027] The laser light source 82, rod lens 84, and collimating lens 86 are arranged along the Y-axis. The laser light source 82 is positioned so that the laser light emitted from its output end 82A is emitted along the Y-axis and toward the axis P of the moving axis S (see Figure 1). In other words, the output end 82A of the laser light source 82 and the axis P are located on the same XY plane.

[0028] According to the illumination device 80 with the above configuration, the laser light emitted in the Y-axis direction from the output end 82A of the laser light source 82 is incident on the rod lens 84 and converted into a linear beam of light E that spreads in the X-axis direction by the rod lens 84. This beam of light E is incident on the collimating lens 86 and converted into parallel light by the collimating lens 86. This beam of light E is then emitted toward the incident surface 52 of the cylindrical lens 50 (see Figure 3).

[0029] Therefore, the illumination device 80 can emit linear light E that spreads in the X-axis direction toward the incident surface 52 of the cylindrical lens 50, and can also emit light E along the Y-axis toward the axis P of the moving axis S. The illumination device 80 is an example of the illumination means of the present invention.

[0030] Here, the light E incident on the cylindrical lens 50 in Figure 3 is focused by the cylindrical lens 50 and received as a spot of light on the light-receiving surface 62 of the PSD 60. Furthermore, the light E incident on the cylindrical lens 50 exists in a band shape along the X-axis direction, which is the direction of movement of the moving body 20. Therefore, assuming that no rolling occurs in the moving body 20 within its range of movement, the light E focused by the cylindrical lens 50 will always be focused at the same YZ coordinate position regardless of the moving position (X coordinate position) of the moving body 20.

[0031] Figure 5 is a functional block diagram showing the configuration of the data processing device 90 shown in Figure 1. As shown in Figure 5, the data processing device 90 has an arithmetic processing circuit 92 including a processor such as a CPU (central processing unit), and a memory 94 such as ROM (Read Only Memory) or RAM (Random Access Memory). The data processing device 90 executes a program stored in the memory 94 via the arithmetic processing circuit 92, realizing the functions of each part of the data processing device 90, namely the function of calculating the displacement amount of the light receiving position and the function of calculating the rolling angle. The arithmetic processing circuit 92 also acquires the output signal of the PSD 60 and acquires measurement data indicating the rolling angle corresponding to the output signal. This measurement data is output to the monitor 98 by the output circuit 96 of the data processing device 90 and displayed on the monitor 98.

[0032] Next, an example of the displacement calculation function and angle calculation function implemented by the data processing device 90 will be described with reference to Figures 6 and 7. Figure 6 is an explanatory diagram of the initial settings performed before measuring the rolling angle, viewed from the X-axis direction. Figure 7 is an explanatory diagram of the measurement state of the rolling angle of the moving body 20 when rolling occurs, viewed from the X-axis direction.

[0033] In the initial setup shown in Figure 6, the positions of each component of the rolling angle measuring device 10 are adjusted so that light E is received at the light-receiving position 64, which is a pre-set reference position S1, on the light-receiving surface 62 of the PSD 60. As an example, the above position adjustment is made by adjusting the mounting position of the PSD 60 in the Z-axis direction. Hereafter, the state shown in Figure 6 after the initial setup is completed will also be referred to as the state in which no rolling occurs in the moving body 20 (the state in which the rolling angle of the moving body 20 is 0 degrees).

[0034] The arithmetic processing circuit 92, after the initial setup shown in Figure 6 is complete, records the light reception position 64 of the light E, which is determined from the output signal value from the PSD 60, as the reference position S1 in the memory 94 (see Figure 5).

[0035] Next, the mobile body 20 is moved along the movement axis S in the X-axis direction to measure the rolling angle. That is, when the mobile body 20 moves from the position in Figure 6 (the position after initial setup) in the X-axis direction to the measurement point shown in Figure 7, the calculation processing circuit 92 determines the light reception position 66 of the light E from the output signal value input from the PSD 60 and records this light reception position 66 as the detection position D1 in the memory 94 (see Figure 5).

[0036] In other words, as shown in Figure 7, when rolling occurs in the moving body 20 at the measurement point, the incident position of the light E incident on the incident surface 52 of the cylindrical lens 50 changes, and as a result of this change in incident position, the light receiving position changes (displaces) from the light receiving position 64 (see Figure 6) to the light receiving position 66 (see Figure 7). Note that there is a correlation between the amount of displacement of the light receiving position and the rolling angle of the moving body 20.

[0037] Next, the arithmetic processing circuit 92 reads the reference position S1 and the detection position D1 from the memory 94 and calculates the displacement amount Δ of the light-receiving position (see Figure 7) based on the reference position S1 and the detection position D1. The displacement amount Δ is the distance from the reference position S1 to the detection position D1 on the light-receiving surface 62 of the PSD 60.

[0038] Next, the arithmetic processing circuit 92 calculates the rolling angle θ of the moving body 20 using the following equation 1, based on the displacement amount Δ and the distance L from the axis P of the moving body 20 to the PSD 60 (see Figure 6), that is, the distance L from the axis P to the light-receiving surface 62. Note that the distance L is data that is pre-stored in the memory 94 (see Figure 5).

[0039] Equation 1: θ = arctan(Δ / L) As a result, the rolling angle measuring device 10 of the first embodiment can measure the rolling angle θ of the moving body 20. The data processing device 90 is an example of the angle calculation means of the present invention.

[0040] Therefore, the rolling angle measuring device 10 of the first embodiment includes a moving body 20 that moves in a first direction along a moving axis S arranged in a first direction (e.g., the X-axis direction), a cylindrical lens 50 provided on the moving body 20 spaced apart in a second direction (e.g., the Y-axis direction), a PSD 60 provided between the moving body 20 and the cylindrical lens 50, an illumination device 80 that emits linear light E spreading in the first direction toward the incident surface 52 of the cylindrical lens 50, and a data processing device 90 that calculates the rolling angle θ based on the displacement amount Δ of the light receiving position of the light E received by the PSD 60 when the moving body 20 is moved along the first direction. As such, it is possible to measure the rolling angle θ without being constrained by the axial direction of the moving axis (X-axis direction, Y-axis direction, and Z-axis direction).

[0041] In other words, the rolling angle measuring device 10 of the first embodiment is capable of measuring the rolling angle without utilizing the weight of the moving body 20, and since it is simply a device that measures the oscillation angle around the axis P of the moving body 20, it is not restricted by the axial direction of the moving axis, and can measure the rolling angle even when the moving axis is arranged in the vertical direction.

[0042] Furthermore, as a method for acquiring the rolling angle using the rolling angle measuring device 10, it is preferable to set multiple measurement points in the direction of the axis P of the moving axis S and acquire the rolling angle at each of these measurement points. This makes it possible to understand the transition of the rolling angle in the direction of the axis P. The rolling angles acquired in this way are used, for example, as correction values ​​for correcting the shape measurement values ​​in the control controller of the shape measuring device.

[0043] [Second Embodiment] Figure 8 is an explanatory diagram of the rolling angle measuring device 100 according to the second embodiment, viewed from the X-axis direction. Figure 8 also shows the state in which the initial setup of the rolling angle measuring device 100 has been completed (the state in which the rolling angle of the moving body 20 is 0 degrees).

[0044] As shown in Figure 8, the rolling angle measuring device 100 of the second embodiment is configured by arranging rolling angle measuring devices 10A and 10B, which have the same configuration as the rolling angle measuring device 10 of the first embodiment, on both sides of the moving body 20 in the Y-axis direction. Furthermore, the two rolling angle measuring devices 10A and 10B are arranged symmetrically with respect to the moving body 20. When describing the rolling angle measuring device 100 below, the same reference numerals may be used for components that are the same as those in the rolling angle measuring device 10 of the first embodiment, with "A" or "B" added to the end of the reference numerals.

[0045] As shown in Figure 8, the cylindrical lens used in the rolling angle measuring device 100 includes a cylindrical lens 50A and a cylindrical lens 50B. The cylindrical lens 50A is one of the components of the rolling angle measuring device 10A and, similar to the first embodiment, is fixed to the moving body 20 using, for example, a connector (not shown) such as a bracket, and moves in the X-axis direction together with the moving body 20. The cylindrical lens 50B is one of the components of the rolling angle measuring device 10B and, similar to the first embodiment, is fixed to the moving body 20 using, for example, a connector (not shown) such as a bracket, and moves in the X-axis direction together with the moving body 20. The cylindrical lenses 50A and 50B are respectively provided at positions equidistant from the axis P of the moving body 20 in the Y-axis direction. The cylindrical lens 50A is an example of the first focusing lens of the present invention, and the cylindrical lens 50B is an example of the second focusing lens of the present invention.

[0046] Furthermore, the PSD used in the rolling angle measuring device 100 includes PSD60A and PSD60B. PSD60A is one of the components of the rolling angle measuring device 10A and is attached to the first surface 22 of the moving body 20. PSD60A receives light (first light) EA emitted from the emission surface 54A of the cylindrical lens 50A. PSD60B is one of the components of the rolling angle measuring device 10B and is attached to the second surface 24 of the moving body 20. PSD60B receives light (second light) EB emitted from the emission surface 54B of the cylindrical lens 50B. The respective light-receiving surfaces 62A and 62B of PSD60A and PSD60B are located at positions equidistant L from the axis P of the moving body 20 in the Y-axis direction. PSD60A is an example of the first light-receiving means of the present invention, and PSD60B is an example of the second light-receiving means of the present invention.

[0047] Furthermore, the illumination device used in the rolling angle measuring device 100 includes illumination device 80A and illumination device 80B. Illumination device 80A is one of the components of the rolling angle measuring device 10A and emits linear light EA that spreads in the X-axis direction toward the incident surface 52A of the cylindrical lens 50A. Illumination device 80B is one of the components of the rolling angle measuring device 10B and emits linear light EB that spreads in the X-axis direction toward the incident surface 52B of the cylindrical lens 50B. Illumination device 80A is an example of the first illumination means of the present invention, and illumination device 80B is an example of the second illumination means of the present invention.

[0048] Next, an example of a method for measuring the rolling angle using the rolling angle measuring device 100 will be described.

[0049] The arithmetic processing circuit 92 records the light receiving position 64A of the optical EA, which is determined from the output signal value from the PSD60A, as the first reference position S1A in the memory 94 (see Figure 5) in the state shown in Figure 8 (the state after initial setup is complete).

[0050] Furthermore, the arithmetic processing circuit 92 records the light reception position 64B of the optical EB, which is determined from the output signal value from the PSD60B in the state shown in Figure 8 (the state after initial setup is complete), as the second reference position S1B in the memory 94 (see Figure 5).

[0051] Figure 9 is an explanatory diagram viewed from the X-axis direction, showing the state when the moving body 20 moves along the movement axis S in the X-axis direction and reaches a predetermined measurement point. Figure 9 shows that the moving body 20 has moved parallel to the Z-axis direction (upward in Figure 9) from the position where the initial setup in Figure 8 is completed, and that rolling is occurring in the moving body 20. The moving body 20 referred to here includes the cylindrical lenses 50A, 50B and PSD60A, 60B. The position where the initial setup is completed in Figure 8 is the position where the rolling angle is 0 degrees and the axis P is located in the direction of propagation of the optical EA and EB in the Y-axis direction.

[0052] The arithmetic processing circuit 92 determines the light receiving position 66A of the optical EA from the output signal value input from the PSD60A at the rolling angle measurement position shown in Figure 9, and records this light receiving position 66A as the first detection position D1A in the memory 94 (see Figure 5).

[0053] Furthermore, the arithmetic processing circuit 92 determines the light receiving position 66B of the optical EB from the output signal value input from the PSD60B at the rolling angle measurement position shown in Figure 9, and records this light receiving position 66B as the second detection position D1B in the memory 94 (see Figure 5).

[0054] Next, the arithmetic processing circuit 92 reads the first reference position S1A and the first detection position D1A from the memory 94, and calculates the displacement amount Δ1 of the light-receiving position based on the first reference position S1A and the first detection position D1A. The displacement amount Δ1 is the distance from the first reference position S1A to the first detection position D1A on the light-receiving surface 62A of the PSD60A.

[0055] Furthermore, the arithmetic processing circuit 92 reads the second reference position S1B and the second detection position D1B from the memory 94 and calculates the displacement amount Δ2 of the light-receiving position based on the second reference position S1B and the second detection position D1B. The displacement amount Δ2 is the distance from the second reference position S1B to the second detection position D1B on the light-receiving surface 62B of the PSD60B.

[0056] Next, the arithmetic processing circuit 92 calculates the rolling angle θ of the moving body 20 using the following equation 2, based on the above-mentioned displacement amounts Δ1 and Δ2, and the respective distances L from the axis P of the moving body 20 to each light-receiving surface 62A and 62B.

[0057] Equation 2: θ = arctan((Δ1 - Δ2) / 2L) Figure 10 is an explanatory diagram to supplement the content of Equation 2 described above. Figure 10 shows that the rolling angle θ is calculated by Equation 2 (θ = arctan((Δ1-Δ2) / 2L)) based on the subtraction value (Δ1-Δ2) of the displacement Δ1 and the displacement Δ2, and the distance 2L. Thus, according to the rolling angle measuring device 100 of the second embodiment, the rolling angle θ is measured using the subtraction value (Δ1-Δ2) described above, so only the rolling angle θ can be measured, excluding the parallel movement component α in the Z-axis direction of the moving body 20.

[0058] Therefore, since the rolling angle measuring device 100 of the second embodiment has rolling angle measuring devices 10A and 10B with the same configuration as the rolling angle measuring device 10 of the first embodiment, it is possible to measure the rolling angle θ of the moving body 20 without being restricted by the axial direction of the moving axis (X-axis direction, Y-axis direction, and Z-axis direction), just like the rolling angle measuring device 10. Furthermore, as described above, even if a translation component α occurs in the moving body 20, it is possible to measure only the rolling angle θ while excluding that translation component α.

[0059] The following describes some modified examples of the present invention.

[0060] In the first and second embodiments, a cylindrical lens 50 was described as the focusing lens of the present invention, but the invention is not limited thereto. For example, a rod lens or a linear Fresnel lens may be used as the focusing lens.

[0061] In the first and second embodiments, a one-dimensional PSD was described as the light-receiving means of the present invention, but the invention is not limited thereto. For example, a one-dimensional image sensor such as a CCD (Charge Coupled Device) line sensor or a CMOS (Complementary Metal Oxide Semiconductor) line sensor, which has a structure in which a plurality of light-receiving elements (pixels) are arranged in a line, may be used as the light-receiving means. In this case, it is possible to obtain the amount of displacement of the light-receiving position based on the light-receiving position of the light-receiving element that detects the spot light among the plurality of light-receiving elements arranged in a line.

[0062] Furthermore, the system is not limited to the one-dimensional image sensor described above; a two-dimensional image sensor may also be used. However, one-dimensional image sensors, including one-dimensional PSDs, are more cost-effective than two-dimensional image sensors.

[0063] In the first and second embodiments, the illumination device 80 (80A, 80B) having a laser light source 82, a rod lens 84, and a collimating lens 86 was described as the illumination means of the present invention, but the invention is not limited to this configuration. In other words, any illumination device capable of emitting linear light E that spreads in the X-axis direction toward the incident surface 52 of the cylindrical lens 50 can be applied to the illumination means of the present invention.

[0064] As an example of the illumination means of the present invention, an illumination device comprising a tubular light source whose longitudinal axis is arranged along the X-axis direction, a light-shielding plate having a slit formed along the longitudinal axis (long side) along the X-axis direction, and a collimating lens (corresponding to the collimating lens 86 in the embodiment) may be applied. With this illumination device, unwanted light from the light source is shielded by the light-shielding plate, and the required light is irradiated from the slit toward the collimating lens. Even with such an illumination device configuration, linear light E spreading in the X-axis direction toward the incident surface 52 of the cylindrical lens 50 can be emitted.

[0065] Furthermore, in the first and second embodiments, the present invention has described lighting devices 80 (80A, 80B) configured to emit light E along the Y-axis towards the axis P as the lighting means of the present invention, but it is not limited thereto. For example, a lighting device configured to emit linear light inclined with respect to the X-axis when viewed from the Y-axis direction can also be applied. The following will be explained with reference to the drawings.

[0066] Figure 11 is a schematic diagram of the state in which the moving body 20 is moved along the moving axis S, as viewed from the Y-axis direction. In Figure 11, the linear light emitted toward the axis P along the Y-axis direction is shown as light E, and the linear light inclined with respect to the X-axis is shown as light EC. According to Figure 11, the focusing positions (also called Z-axis focusing coordinates or focusing point data) 63A, 63B, and 63C of light EC on the light-receiving surface 62 of the PSD 60 change depending on the movement position of the moving body 20.

[0067] Figure 12 is a graph showing the change in the Z-axis focusing coordinate when the moving body 20 is moved under conditions where rolling does not occur. The vertical axis represents the Z-axis focusing coordinate, and the horizontal axis represents the movement position of the moving body 20. According to Figure 12, the Z-axis focusing coordinate of light E, indicated by line R1, is always the same regardless of the movement position of the moving body 20, but the Z-axis focusing coordinate of light EC, indicated by line R2, changes linearly according to the movement position of the moving body 20.

[0068] Figure 13 is a plotted diagram showing the Z-axis focusing coordinates when rolling occurs in the moving body 20 when using an illumination device that emits optical emission (EC), with the "○" marks indicating the coordinates. As shown in Figure 13, when rolling occurs in the moving body 20, the Z-axis focusing coordinates shift vertically relative to the coordinates (line R2) when no rolling occurs.

[0069] Here, the coordinate position of the "○" mark shown in Figure 13 includes the amount of inclination relative to the X-axis. Therefore, when measuring the rolling angle, it is necessary to calculate the amount of inclination and correct the coordinate position of the "○" mark by the amount of inclination. The amount of inclination can be calculated using the least squares method from the light-gathering point data obtained at each position. This allows the coordinate position of the "○" mark to be corrected by the amount of inclination. As a result, the lighting device in this example can reduce the measurement error of the rolling angle caused by linear light EC inclined with respect to the X-axis.

[0070] Although an example of a rolling angle measuring device according to the present invention has been described above, the technology of the present invention is not limited to the embodiments, and several improvements or modifications may be made without departing from the spirit of the present invention. [Explanation of symbols]

[0071] 10...Rolling angle measuring device, 10A...Rolling angle measuring device, 10B...Rolling angle measuring device, 20...Moving body, 22...First surface, 24...Second surface, 26...Third surface, 28...Fourth surface, 30...Top surface, 32...Bottom surface, 50...Cylindrical lens, 50A...Cylindrical lens, 50B...Cylindrical lens, 52...Incident surface, 52A...Incident surface, 52B...Incident surface, 54...Output surface, 54A...Output surface, 54B...Output surface, 60...PSD, 60A...PSD, 60B...PSD, 62...Light receiving surface, 62A...Light receiving surface, 62B...Light receiving surface, 64 ...Light receiving position, 64A...Light receiving position, 64B...Light receiving position, 66...Light receiving position, 66A...Light receiving position, 66B...Light receiving position, 80...Illumination device, 82...Laser light source, 84...Rod lens, 86...Collimating lens, 90...Data processing device, 92...Calculation processing circuit, 94...Memory, 96...Output circuit, 98...Monitor, 100...Rolling angle measuring device, S...Moving axis, P...Axis center, E...Light, EA...Light, EB...Light, S1...Reference position, S1A...First reference position, S1B...Second reference position, D1...Detection position, D1A...First detection position, D1B...Second detection position

Claims

1. A moving body that moves in the first direction along a moving axis arranged in the first direction, A condensing lens provided on the moving body at intervals in a second direction perpendicular to the first direction and moved together with the moving body in the first direction, having an incident surface and an exit surface, wherein the exit surface is positioned opposite the moving body, A light-receiving means provided between the moving body and the focusing lens, which moves together with the moving body in the first direction, and which receives light emitted from the emission surface, An illumination means that emits linear light spreading in a first direction toward the incident surface, An angle calculation means for calculating the rolling angle of the moving body based on the amount of displacement of the light receiving position of the light received by the light receiving means when the moving body moves in the first direction, A rolling angle measuring device equipped with [a specific feature].

2. The condensing lens includes a first condensing lens provided on a first surface among the surfaces constituting the outer surface of the moving body, and a second condensing lens provided on a second surface opposite to the first surface. The light-receiving means includes a first light-receiving means that receives light emitted from the emission surface of the first condensing lens, and a second light-receiving means that receives light emitted from the emission surface of the second condensing lens. The illumination means includes a first illumination means that emits a linear first light beam that spreads in a first direction toward the incident surface of the first condensing lens, and a second illumination means that emits a linear second light beam that spreads in a first direction toward the incident surface of the second condensing lens. The angle calculation means calculates the rolling angle of the moving body based on the amount of displacement of the receiving position of the first light received by the first light receiving means and the amount of displacement of the receiving position of the second light received by the second light receiving means when the moving body moves in the first direction. The rolling angle measuring device according to claim 1.

3. The aforementioned focusing lens is a cylindrical lens in which the incident surface is a convex cylindrical surface and the exit surface is a flat surface. When the cylindrical lens is viewed from a third direction perpendicular to the first and second directions, the emission surface is arranged parallel to the axis of the moving axis. A rolling angle measuring device according to claim 1 or 2.

4. The light-receiving means is a one-dimensional position detection element having a strip-shaped light-receiving surface extending in the third direction, The angle calculation means calculates the displacement amount based on the output signal value from the position detection element. The rolling angle measuring device according to claim 3.

5. The illumination means emits the light toward the axis along the second direction, The rolling angle measuring device according to claim 4.

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