X-ray measurement system

Abstract

To provide an X-ray measurement system capable of easily measuring measurement objects formed in a variety of shapes.SOLUTION: An X-ray measurement system (1) comprises: a rail part (30) extending along an X-axis; and a measurement part (40) movably connected to the rail part, measuring a distance to a measurement object (2) in a Z-axis direction, irradiating the object in the Z-axis direction with X-ray, and detecting an X-ray diffracted on the measurement object. The X-ray measurement system further comprises a grip part (11) holding one end of the measurement object, and a grip part (21) holding the other end of the measurement object, the grip parts being capable of changing position and inclination. The X-ray measurement system further comprises a control device (50) that obtains an inclination and measurement result of distance of the two grip parts to a Y-axis direction, and determining the position and inclination based on the obtained information. The control device controls operations of the two grip parts so that they are positioned and inclined as determined, and controls operations of the measurement part to perform X-ray irradiation and detection.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an X-ray measurement system. [Background technology]

[0002] 2. Description of the Related Art Conventionally, X-ray measurement systems have been known that utilize the diffraction phenomenon of X-rays to measure the residual stress, half-value width, amount of retained austenite, etc. of an object to be measured.

[0003] In this regard, Patent Document 1 discloses a spring shape measuring device that includes a holding jig that holds a coil spring so that both ends are positioned on its axis, and a non-contact displacement meter that can measure the surface shape of the coil spring held by the holding jig. Patent Document 1 also discloses that the spring shape measuring device further includes a relative position adjustment mechanism that moves the non-contact displacement meter linearly along the axial direction of the coil spring and rotates the non-contact displacement meter around the axis of the coil spring relative to the coil spring. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6613128 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the technology described in Patent Document 1 does not take into consideration the possibility that the spring-like object to be measured may be bent. Therefore, the technology described in Patent Document 1 has a problem in that if the object to be measured has variations in shape, such as being bent, errors may occur in the measurement of the object to be measured.

[0006] The present invention has been made in view of the above problems, and its object is to provide an X-ray measurement system that can easily perform measurements even when the shape of an object to be measured varies. [Means for solving the problem]

[0007] In order to solve the above problem, the sensor system of the present invention comprises a rail section extending along a first direction, a distance sensor connected to the rail section so as to be able to move in the first direction and measuring the distance to a spring-shaped object to be measured in a second direction perpendicular to the first direction, and a measurement section having a detection section which irradiates X-rays in the second direction and detects X-rays diffracted from the object to be measured, a first gripping section whose position and inclination are variable and which holds one end of the object to be measured, a second gripping section whose position and inclination are variable and which holds the other end of the object to be measured, and a control device which acquires the inclination of the first gripping section and the second gripping section with respect to the second direction and the measurement results of the distance sensor, determines the position and inclination from the acquired inclination and measurement results, controls the operation of the first gripping section and the second gripping section so as to achieve the determined position and inclination, and controls the operation of the detection section to irradiate and detect X-rays.

[0008] The control device also calculates a degree of curvature indicating the degree of bending of the object to be measured from the acquired inclination and measurement results, and determines the position and inclination from the calculated degree of curvature.

[0009] In addition, the control device controls the operation of the first gripping unit, the second gripping unit, and the measurement unit to perform a measurement process including obtaining the tilt and the measurement results, determining the position and tilt, and irradiating and detecting X-rays for multiple measurement points defined from one end to the other end of the object to be measured.

[0010] In addition, during the measurement process, the control device controls the operation of the first gripping unit and the second gripping unit to rotate the measurement point of the object to face the measurement unit, with the normal direction of the gripping surface as the rotation axis, and controls the movement operation of the measurement unit.

[0011] The first gripping portion is provided at the tip of a first arm of an articulated type, and the second gripping portion is provided at the tip of a second arm of an articulated type different from the first arm. [Effects of the Invention]

[0012] According to the present invention, the X-ray measurement system can easily perform measurements even when there is variation in the shape of the object to be measured. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a diagram showing the overall configuration of an X-ray measurement system according to an embodiment of the present invention. [Figure 2] 2 is a view of a gripping portion of the X-ray measurement system shown in FIG. 1, viewed from the direction of the tip. [Figure 3] 2 is a cross-sectional view taken along line II-II of the X-ray measurement system shown in FIG. 1. [Figure 4] 2 is a flowchart showing an example of a processing flow of the X-ray measurement system shown in FIG. [Figure 5A] 2 is a front view of the X-ray measurement system when the gripping part shown in FIG. 1 is tilted with respect to the Z-axis direction. [Figure 5B] 2 is a front view of the X-ray measurement system when the gripping part shown in FIG. 1 is parallel to the Z-axis direction. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, an embodiment of the present invention (hereinafter referred to as "the present embodiment") will be described with reference to the accompanying drawings. To facilitate understanding of the description, the same components and steps in each drawing will be designated by the same reference numerals as much as possible, and redundant description will be omitted.

[0015] FIG. 1 is a diagram showing the overall configuration of an X-ray measurement system 1 according to this embodiment. As shown in FIG. 1, the X-ray measurement system 1 is mainly configured to include robots 10 and 20, a rail unit 30, a measurement unit 40, and a control device 50. In FIG. 1, the Z-axis direction is defined as the direction from bottom to top when the X-ray measurement system 1 is viewed from the front. In FIG. 1, the X-axis direction is defined as the direction perpendicular to the Z-axis direction and from left to right when the X-ray measurement system 1 is viewed from the front. In FIG. 1, the Y-axis direction is defined as the direction perpendicular to the Z-axis direction and from the front to the rear when the X-ray measurement system 1 is viewed from the front. The X-axis direction, Y-axis direction, and Z-axis direction are perpendicular to one another.

[0016] The robots 10 and 20 are robots having an articulated arm that movably and rotatably grips the object to be measured 2. The main part of the robot 10 includes, for example, a gripping unit 11, a wrist 12, an arm 13, and a base 14. The main part of the robot 20 includes, for example, a gripping unit 21, a wrist 22, an arm 23, and a base 24. The robots 10 and 20 are installed on an installation surface (not shown) in a positional relationship such that the gripping unit 11 can grip one end of the spring-like object to be measured 2, and the gripping unit 21 can grip the other end of the object to be measured 2.

[0017] The gripping portion 11 is formed in a cylindrical shape with the axis B as its central axis, and its bottom surface is fixedly connected to the other end of the wrist portion 12, and a gripping surface opposite the bottom surface grips one end of the object to be measured 2. The position and inclination of the gripping portion 11 can be changed by the movement of the wrist portion 12 and the arm portion 13.

[0018] Here, with reference to FIG. 2, the structure of the gripping unit 11 will be described in detail. FIG. 2 is a view of the gripping unit 11 of the X-ray measurement system 1 shown in FIG. 1 as viewed from the tip. As shown in FIG. 2, the gripping unit 11 has a convex portion 110 and a groove portion 111 on the gripping surface. The convex portion 110 is provided near the outer periphery of the gripping surface and is formed in a rectangular parallelepiped shape so as to receive one end of the object to be measured 2 on a side surface along the radial direction of the gripping surface. The groove portion 111 is formed as a recessed portion that extends from the side surface of the gripping surface along the circumferential direction of the gripping surface. The groove portion 111 functions as a guide to suppress shaking of the object to be measured 2 when the object to be measured 2 is gripped by the gripping unit 11.

[0019] 1, one end of the wrist 12 is connected to the tip of the arm 13 so as to be rotatable about an imaginary central axis extending from one end of the wrist 12 to the other end. The other end of the wrist 12 is fixedly connected to the grip 11. The rotation axis of the wrist 12 is parallel to the normal to the grip surface of the grip 11 and passes through the center of the grip surface.

[0020] The arm unit 13 is, for example, an articulated movable arm, and its main part is made up of multiple arms and multiple drive units. One end of the arm unit 13 is connected to the base unit 14, and the other end of the arm unit 13 is connected to the wrist unit 12.

[0021] The base unit 14 is a base for supporting the arm unit 13, and is installed so as to be in contact with an installation surface (not shown) of the robot 10. The base unit 14 is connected to the arm unit 13. The base unit 14 is also connected to the control device 50 so as to be able to communicate with it.

[0022] The components of the robot 20, namely, the gripper 21, the wrist 22, the arm 23, and the base 24, are similar to those of the robot 10, and therefore will not be described here. The gripper 21 has a protrusion 210 and a groove 211, but these are similar to those of the gripper 11, and therefore will not be described here.

[0023] The rail section 30 is a guide for the movement of the measuring section 40, and is provided above the robot 10 (on the Z-axis side) so as to extend along the X-axis direction.

[0024] The measuring unit 40 is connected to the rail unit 30 so as to be movable in the X-axis direction, and measures the object to be measured 2. The measuring unit 40 is mainly composed of, for example, a distance sensor 41 and a detection unit 42.

[0025] The distance sensor 41 is, for example, an optical, electromagnetic wave, or ultrasonic sensor, and measures the distance to the object 2 downward (the direction opposite to the Z-axis direction). Here, the distance between the distance sensor 41 and the object 2 will be described with reference to FIG. 3. FIG. 3 is a cross-sectional view of the X-ray measurement system 1 taken along line II-II of FIG. 1. As shown in FIG. 3, the distance sensor 41 measures the distance d between the distance sensor 41 and the object 2.

[0026] 1, the detection unit 42 irradiates X-rays downward (the direction opposite to the Z-axis direction) and detects the X-rays diffracted by the object under test 2. The detection unit 42 calculates the measurement results of each measurement item related to the object under test 2 from the detection results.

[0027] The control device 50 controls the movement and measurement operations of the measurement unit 40 and various operations of the robot 10. Specifically, the control device 50 acquires the inclination of the gripper 11 of the robot 10 and the gripper 21 of the robot 20 with respect to the Z-axis direction and the measurement results of the distance sensor 41. The control device 50 determines the position and inclination of the grippers 11 and 21 from the acquired inclination of the grippers 11 and 21 and the measurement results of the distance sensor 41. Furthermore, the control device 50 controls the operation of the grippers 11 and 21 so that they are at the determined position and inclination. The control device 50 then controls the operation of the detection unit 42 so that X-ray measurement is performed on the object 2 to be measured.

[0028] The above has described the overall configuration of the X-ray measurement system 1. Next, the operation of the X-ray measurement system 1 will be described with reference to Fig. 4. Fig. 4 is a flowchart showing an example of the processing flow of the X-ray measurement system 1 shown in Fig. 1.

[0029] (Step SP10) The X-ray measurement system 1 adjusts the angle between the gripper 11 of the robot 10 and the gripper 21 of the robot 20. Here, angle adjustment will be described with reference to FIG. 5A. FIG. 5A is a front view of the X-ray measurement system 1 when the grippers 11 and 21 shown in FIG. 1 are tilted with respect to the Z-axis direction. In FIG. 5A, a virtual axis extending from the measurement unit 40 along the Z-axis direction is defined as axis A. In FIG. 5A, a virtual axis in the normal direction passing through the center of the wrist 12 is defined as axis B. In FIG. 5A, a virtual axis in the normal direction passing through the center of the wrist 22 is defined as axis C. The gripping surface of the gripper 11 is tilted leftward (opposite the X-axis direction) by angle α with respect to axis A. The gripping surface of the gripper 21 is tilted rightward (in the X-axis direction) by angle β1 with respect to axis A. The acute angle between axis B and axis C is angle θ.

[0030] 4, in the processing of step SP10, the X-ray measurement system 1 adjusts the rotation angle of the gripper 11 of the robot 10 when axis B is the rotation axis so that measurement point P, which is the measurement location of the object 2, faces upward (in the Z-axis direction) toward the measurement unit 40. Similarly to the robot 10, the X-ray measurement system 1 also adjusts the rotation angle of the robot 20 when axis C of the gripper 21 is the rotation axis. Then, the processing proceeds to the processing of step SP12.

[0031] (Step SP12) The X-ray measurement system 1 uses the distance sensor 41 of the measurement unit 40 to measure the distance d between the distance sensor 41 and the measurement point P of the object to be measured 2. Here, when measuring the distance d, the X-ray measurement system 1 moves the measurement unit 40 along the rail unit 30, for example, and measures the distance d between the object to be measured 2 and the distance sensor 41 every predetermined distance. Then, the processing proceeds to the processing of step SP14.

[0032] (Step SP14) The X-ray measurement system 1 acquires, via the control device 50, information indicating the inclination of the gripping surface of the gripper 11 with respect to the axis A (i.e., angle α) from the robot 10. Also, the X-ray measurement system 1 acquires, via the control device 50, information indicating the inclination of the gripping surface of the gripper 21 with respect to the axis A (i.e., angle β1) from the robot 20. Then, the process proceeds to step SP16.

[0033] (Step SP16) The X-ray measurement system 1 calculates a curvature indicating the degree of torsion of the object 2 based on information about the inclination of the grippers 11 and 21 acquired from the robots 10 and 20 and the measurement results measured by the distance sensor 41. Specifically, the X-ray measurement system 1 generates shape data of the object 2 from the measurement results of the distance sensor 41 at each measurement point between the grippers 11 and 21. The shape data is, for example, an approximate curve generated to include the measurement point P for each measurement point on a virtual plane including the X-axis direction, the Z-axis direction, and the rail portion 30. The X-ray measurement system 1 calculates a curvature indicating the degree of torsion at the measurement point from the acquired angles α and β1 and the shape data. Here, the curvature is, for example, the angle between the gripping surface of the gripper 11 and the tangent to the measurement point P at the measurement point. Note that the X-ray measurement system 1 may also calculate the angle θ between the axes B and C from the angles α and β1, which are information about the inclination of the grippers 11 and 21. Furthermore, the X-ray measurement system 1 may calculate the curvature at the measurement point from the angle θ and the shape data. Alternatively, the X-ray measurement system 1 may calculate the curvature at the measurement point simply from the shape data. Furthermore, if shape data has already been generated for the object 2 to be measured, the process of generating the shape data may be omitted. Then, the process proceeds to step SP18.

[0034] (Step SP18) The X-ray measurement system 1 determines the position and inclination of the gripping surfaces of the gripping units 11 and 21 using the control device 50 from the curvature of the object 2 calculated in the processing of step SP16. Specifically, the X-ray measurement system 1 determines the position and inclination of the gripping surfaces of the gripping units 11 and 21 using the control device 50 so that the X-rays irradiated from the measurement unit 40 along the axis A are incident at a predetermined angle of incidence with respect to the measurement point P of the measurement location on the object 2. In this embodiment, the predetermined angle of incidence is a right angle. Then, the processing proceeds to the processing of step SP20.

[0035] (Step SP20) The X-ray measurement system 1 adjusts the positions and inclinations of the grippers 11 and 21 by the control device 50 so that the grippers 11 and 21 are at the positions and inclinations determined in the processing of step SP18. Here, with reference to FIG. 5B, the adjustment of the positions and inclinations of the grippers 11 and 21 will be described. FIG. 5B is a front view of the X-ray measurement system 1 when the gripper 11 shown in FIG. 1 is parallel to the Z-axis direction. As shown in FIG. 5B, the X-ray measurement system 1 adjusts the positions and inclinations of the grippers 11 and 21 so that, when X-rays are irradiated along the axis A, the X-rays are incident at a right angle on the measurement point P. In FIG. 5B, when the angle between the measurement point P and the X-ray irradiation direction is a right angle, the gripping surface of the gripper 11 becomes parallel to the axis A, so the angle of the gripping surface of the gripper 11 is adjusted so that it becomes parallel to the axis A. Furthermore, the position of the gripping surface of the gripper 11 is adjusted so that the X-ray irradiation dose is appropriate. As a result, the angle between the grip portion 21 and the axis A becomes angle β2. Returning to FIG. 4, the process proceeds to step SP22.

[0036] (Step SP22) The X-ray measurement system 1 causes the measurement unit 40 to irradiate X-rays toward the measurement point P of the object to be measured 2. Then, the process proceeds to step SP24.

[0037] (Step SP24) The X-ray measurement system 1 detects the X-rays diffracted by the object to be measured 2 by the measurement unit 40. Then, the process proceeds to step SP26.

[0038] (Step SP26) The X-ray measurement system 1 calculates the measurement results of each measurement item by using the measurement unit 40 to substitute the X-ray detection results by the measurement unit 40 into a derivation formula associated with each measurement item. Here, the measurement items for the object 2 to be measured are, for example, residual stress, half-value width, amount of retained austenite, etc. Then, the process proceeds to step SP28.

[0039] (Step SP28) The X-ray measurement system 1 determines whether or not all measurement locations to be measured on the object to be measured 2 have been measured. If the determination is negative, the X-ray measurement system 1 sets the unmeasured measurement location as the next measurement location, and the process returns to step SP10. On the other hand, if the determination is positive, the series of processes shown in FIG. 4 ends.

[0040] <Effects> As described above, in this embodiment, the X-ray measurement system 1 includes a rail unit 30 extending along the X-axis direction (first direction). The X-ray measurement system 1 also includes a measurement unit 40 movably connected to the rail unit 30, a distance sensor 41 that measures a distance d to the spring-shaped object under test 2 in the direction opposite to the Z axis (second direction), and a detection unit 42 that irradiates X-rays and detects X-rays diffracted by the object under test 2. The X-ray measurement system 1 also includes a gripping unit 11 (first gripping unit) whose position and tilt are variable and that grips one end of the object under test 2, and a gripping unit 21 (second gripping unit) whose position and tilt are variable and that grips the other end of the object under test 2. The X-ray measurement system 1 also includes a control device 50 that acquires the tilt of the gripping units 11 and 21 with respect to the Z-axis direction and the measurement result of the distance sensor 41, and determines the position and tilt from the acquired tilt and measurement result. Furthermore, the control device 50 controls the operation of the gripping units 11 and 21 so that they are at the determined position and inclination, and controls the operation of the detection unit 42 so that they irradiate and detect X-rays. Therefore, the X-ray measurement system 1 determines the position and inclination of the gripping units 11 and 21 that grip the object 2 to be measured according to the position and inclination of the gripping units 11 and 21 and the distance d, and therefore can easily perform measurement using X-rays even when there is variation in the shape of the object 2 to be measured.

[0041] Furthermore, in this embodiment, the control device 50 calculates the degree of curvature indicating the degree of torso bending of the object 2 from the acquired inclination and measurement results, and determines the position and inclination from the calculated curvature. Therefore, the X-ray measurement system 1 determines the position and inclination of the gripping units 11 and 21 taking into account the degree of torso bending of the object 2, so that even if there is variation in the shape of the object 2, measurement using X-rays can be performed easily and with high accuracy.

[0042] Furthermore, in this embodiment, the control device 50 controls the operations of the gripping units 11 and 21 and the measurement unit 40 so as to perform a measurement process for a plurality of measurement points defined from one end to the other end of the object 2. Here, the measurement process includes obtaining the tilt and measurement results, determining the position and tilt, and irradiating and detecting X-rays. Therefore, the X-ray measurement system 1 can easily perform X-ray measurement even when the shape of the object 2 varies and multiple measurement points on the object 2 are to be measured.

[0043] Furthermore, in this embodiment, in the measurement process, the control device 50 controls the operation of the gripping units 11 and 21 to rotate the measurement point of the object 2 under test around the normal direction of the gripping surface as the rotation axis so that the measurement point of the object 2 under test faces the measurement unit 40, and controls the movement of the measurement unit 40. Therefore, the X-ray measurement system 1 controls the operation of the gripping units 11 and 21 and the measurement unit 40 to perform an operation suitable for the object 2 under test, which is formed in a spring shape, and therefore can perform X-ray measurement easily and with high accuracy even when the shape of the object 2 under test varies.

[0044] In this embodiment, the gripper 11 is provided at the tip of an articulated arm 13 (first arm). The gripper 21 is provided at the tip of an articulated arm 23 (second arm) that is different from the arm 13. Therefore, in the X-ray measurement system 1, the grippers 11 and 21 are provided on the articulated arm 13 or 23, so that even when the shape of the object 2 to be measured varies, X-ray measurement can be performed easily and with high accuracy.

[0045] <Modification> The present invention is not limited to the above-described embodiments. In other words, variations of the above-described embodiments, which are appropriately modified by a person skilled in the art, are also included within the scope of the present invention as long as they include the features of the present invention. Furthermore, the elements of the above-described embodiments and the modifications described below can be combined to the extent technically possible, and such combinations are also included within the scope of the present invention as long as they include the features of the present invention.

[0046] For example, in this embodiment, the X-ray measurement system 1 grips the object 2 under measurement using grippers 11 and 21 as shown in FIGS. 1 and 2 , but is not limited to this. The X-ray measurement system 1 may have any structure as long as its position and inclination are variable and it can grip both ends of the object 2 under measurement. For example, the X-ray measurement system 1 may grip one end of the object 2 under measurement by pinching it with a plurality of movable finger-like structures, and grip the other end of the object 2 under measurement by pinching it with a plurality of movable finger-like structures. With this configuration, the X-ray measurement system 1 can easily perform X-ray measurement even when there are various structures for gripping the object 2 under measurement and the shape of the object 2 under measurement varies.

[0047] Furthermore, in this embodiment, the X-ray measurement system 1 has the measurement unit 40 move along the rail unit 30 extending in the X-axis direction, but this is not limited to this. The X-ray measurement system 1 may be provided in any manner as long as the measurement unit 40 is movable on a virtual plane extending in the X-axis direction and the Y-axis direction. For example, the X-ray measurement system 1 may have the measurement unit 40 held by a robot having an articulated arm that is movable above the robots 10 and 20, or provided at the tip of the arm of the robot. With this configuration, the X-ray measurement system 1 can easily perform X-ray measurement even when the measurement unit 40 is not provided on the rail unit 30 and the shape of the object to be measured 2 varies.

[0048] Furthermore, in this embodiment, the X-ray measurement system 1 performs X-ray measurement on the object to be measured 2 that is formed in a spring shape, but this is not limited to this. The X-ray measurement system 1 may be any metal member that is flexible or elastic enough to allow the object to be measured 2 to bend under its own weight. With this configuration, the X-ray measurement system 1 can easily perform X-ray measurement even when the object to be measured 2 is not formed in a spring shape and the shape of the object to be measured 2 varies. [Explanation of symbols]

[0049] REFERENCE SIGNS LIST 1...X-ray measurement system, 2...object to be measured, 11...gripping section (first gripping section), 13...arm section (first arm), 23...arm section (second arm), 21...gripping section (second gripping section), 30...rail section, 40...measuring section, 41...distance sensor, 42...detecting section, 50...control device

Claims

1. a rail portion extending along a first direction; a measuring unit including a distance sensor connected to the rail portion so as to be movable in the first direction and configured to measure a distance to a spring-shaped object to be measured in a second direction perpendicular to the first direction, and a detecting unit that irradiates X-rays in the second direction and detects X-rays diffracted by the object to be measured; a first gripping portion whose position and inclination are variable and which grips one end of the object to be measured; a second gripping portion whose position and inclination are variable and which grips the other end of the object to be measured; a control device that acquires the inclination of the first gripping unit and the second gripping unit with respect to the second direction and the measurement results of the distance sensor, determines a position and inclination from the acquired inclination and measurement results, controls the operation of the first gripping unit and the second gripping unit so that the determined position and inclination are achieved, and controls the operation of the detection unit so that X-rays are irradiated and detected; An X-ray measurement system comprising:

2. The X-ray measurement system according to claim 1 , wherein the control device calculates a curvature indicating the degree of bending of the object to be measured from the acquired inclination and measurement results, and determines the position and inclination from the calculated curvature.

3. 3. The X-ray measurement system according to claim 2, wherein the control device controls the operations of the first gripping unit, the second gripping unit, and the measurement unit so as to perform a measurement process including obtaining the tilt and the measurement results, determining the position and tilt, and irradiating and detecting X-rays for a plurality of measurement points defined from one end to the other end of the object to be measured.

4. 4. The X-ray measurement system according to claim 3, wherein the control device controls the operation of the first gripping unit and the second gripping unit in the measurement process so that the measurement point of the object to be measured faces the measurement unit, and controls the movement of the measurement unit so that the measurement point faces the measurement unit, with the normal direction of the gripping surface as the rotation axis.

5. the first gripping portion is provided at a tip of a first arm of an articulated type, 5. The X-ray measurement system according to claim 1, wherein the second gripping portion is provided at the tip of a second arm of an articulated type that is different from the first arm.

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