Detection system, control method and detection device

Abstract

A detection system of an embodiment has a multi-joint arm mechanism and an end effector (200). The end effector (200) is provided at a front end of the arm mechanism. The end effector (200) includes a rotary stage (210) and a detector (220). The detector (220) is provided at the front end via the rotary stage (210) and performs transmission of ultrasonic waves and detection of reflected waves. A front end of the detector (220) is located at a rotation center (C1, C2) of the rotary stage (210).

Description

Technical Field

[0001] The embodiments of the present invention relate to a detection system, a control method, and a detection device. Background Technology

[0002] There exists a system and apparatus for inspecting arbitrary objects. These systems and apparatuses require improved ease of use.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2019-90727 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] The problem to be solved by the present invention is to provide a detection system, control method and detection device that can improve the ease of use.

[0008] Methods for solving problems

[0009] The detection system of this embodiment includes a multi-jointed arm mechanism and an end effector. The end effector is disposed at the front end of the arm mechanism. The end effector includes a rotary table and a detector. The detector is disposed at the front end via the rotary table and performs ultrasonic wave transmission and reflected wave detection. The front end of the detector is located at the rotation center of the rotary table. Attached Figure Description

[0010] Figure 1 This is a perspective view of the detection system according to the implementation method.

[0011] Figure 2 This is a perspective view of the end effector in the embodiment.

[0012] Figure 3 This is a perspective view of the end effector in the embodiment.

[0013] Figure 4 This is a top view showing the end effector of the implementation method.

[0014] Figure 5 This is a flowchart illustrating the operation of the detection system in the implementation method.

[0015] Figure 6 It is a flowchart showing the details of the first action.

[0016] Figure 7 It is a schematic diagram used to illustrate singularities.

[0017] Figure 8It is a three-dimensional diagram showing the internal structure of the detector front end.

[0018] Figure 9 This is a diagram used to illustrate the calculation method for tilt during inspection.

[0019] Figure 10 This is an example of an image obtained during an inspection.

[0020] Figure 11 This is an example of an image obtained during an inspection.

[0021] Figure 12 This is a schematic diagram used to illustrate an inspection method that uses a detector.

[0022] Figure 13 This is a three-dimensional view showing the end effector of a modified example.

[0023] Figure 14 This is a flowchart showing the details of the first action of the end effector using a variant example.

[0024] Figure 15 This is a schematic diagram illustrating a modified detection system. Detailed Implementation

[0025] Hereinafter, various embodiments of the present invention will be described with reference to the accompanying drawings.

[0026] The accompanying drawings are schematic or conceptual, and the relationships between the thicknesses and widths of the parts, as well as the ratios between the sizes of the parts, may not be the same as in reality. Even when representing the same parts, there are cases where the dimensions and ratios of the parts may be represented differently depending on the accompanying drawings.

[0027] In the specification and figures of this application, elements that are the same as those already described are labeled with the same reference numerals, and detailed descriptions are omitted where appropriate.

[0028] Figure 1 This is a perspective view of the detection system according to the implementation method.

[0029] like Figure 1 As shown, the detection system 1 of the embodiment includes an arm mechanism 100, an end effector 200, a control device 300, a processing device 400, and a storage device 410.

[0030] The arm mechanism 100 includes multiple links 110 and multiple rotating shafts 120. One end of each link 110 is connected to the other via a rotating shaft 120. When the rotating shaft 120 is driven by a motor, one link 110 rotates relative to another link 110.

[0031] The arm mechanism 100 preferably has 4 or more degrees of freedom. For example, the arm mechanism 100 is a vertical multi-joint robot with 6 degrees of freedom. That is, the arm mechanism 100 can control the position of its front end in three directions and the angle of its front end around the three directions.

[0032] The end effector 200 is located at the front end of the arm mechanism 100. Figure 1 In the detection system 1 shown, the end effector 200 is configured to have 6 degrees of freedom.

[0033] Wiring and conduit for supplying power and coupling agent to the end effector 200 are installed on the arm mechanism 100. The wiring and conduit are bundled, for example, by a bundling member 140. The bundling member 140 may be, for example, a spiral tube, clamp, pliers, or strapping. Alternatively, the wiring and conduit may also be installed through the inside of each link 110.

[0034] The control device 300 sends drive signals to each motor of the arm mechanism 100. Each motor is driven according to the drive signals, controlling the rotation angle of each rotation axis 120. This controls the attitude of the front end of the arm mechanism 100. For example, the control device 300 calculates the rotation angle of each rotation axis 120 through inverse kinematics calculations to make the attitude of the control point the desired attitude. The control point is the point whose position and orientation are controlled by the control device 300. The control point may be set, for example, at any point on the front end of the arm mechanism 100. Alternatively, the control point may also be set at any point on the end effector 200.

[0035] The processing unit 400 calculates the tilt angle of the detector 220 mounted on the end effector 200. Based on the detection results of the detector 220, the processing unit 400 inspects any object. The storage unit 410 stores the detection results, data obtained through processing by the processing unit 400, etc.

[0036] The control device 300 and the processing device 400 respectively include, for example, a central processing unit (CPU), a read-only memory (ROM), a random access memory (RAM), a storage device, an input interface, an output interface, a communication interface, and a bus connecting them. The storage device 410 includes, for example, at least one selected from hard disk drives (HDDs), solid-state drives (SSDs), and network-attached hard drives (NAS).

[0037] Input device 420 and output device 430 may also be connected to processing device 400. Input device 420 is used for a user to input data to processing device 400. Input device 420 includes, for example, at least one selected from keyboard, mouse, touchpad, and microphone (voice input). Output device 430 outputs data sent from processing device 400 to the user. Output device 430 includes, for example, at least one selected from monitor, speaker, printer, and projector.

[0038] Figure 2 and Figure 3 This is a perspective view of the end effector in the embodiment.

[0039] like Figure 2 and Figure 3 As shown, the end effector 200 includes a rotary table 210, a detector 220, an ejector 230, a first drive unit 241, a second drive unit 242, a third drive unit 243, an outer cylinder 251, a rotary joint 252, and a sensor 260.

[0040] The rotary table 210 has two degrees of freedom relative to the front end of the arm mechanism 100. The detector 220 is mounted to the front end of the arm mechanism 100 via the rotary table 210. That is, the detector 220 is configured to have two degrees of freedom relative to the front end of the arm mechanism 100. The front end of the detector 220 is located at the rotation center of the rotary table 210. The orientation of the detector 220 is determined by the orientation of the front end of the arm mechanism 100 and the state of the rotary table 210.

[0041] Here, attitude refers to position and orientation. Attitude is determined by the position in three mutually orthogonal directions and the angles around each direction (lateral roll, yaw, and roll).

[0042] Detector 220 performs a probe (detection) on the object being inspected. During the probe, ultrasonic waves are transmitted and reflected waves are detected. The direction of ultrasonic wave transmission changes according to the orientation of detector 220.

[0043] Rotary stage 210 includes a first stage 211 and a second stage 212. One of the first stage 211 and the second stage 212 is mounted on the rotary stage of the other. In the illustrated example, the second stage 212 is mounted on the rotary stage of the first stage 211.

[0044] The first actuator 211 rotates about the X direction (first direction). The second actuator 212 rotates about the Y direction (second direction). The X and Y directions are orthogonal to each other. The X and Y directions intersect the Z direction from the front end of the arm mechanism 100 toward the end effector 200. For example, when the first actuator 211 and the second actuator 212 are not tilted, the Z direction is perpendicular to the X and Y directions.

[0045] The ultrasonic wave transmission direction (third direction) of detector 220 intersects a plane parallel to the X and Y directions. For example, the ultrasonic wave is transmitted along a direction perpendicular to the X and Y directions. When the first detector 211 and the second detector 212 are not tilted, the ultrasonic wave transmission direction is parallel to the Z direction.

[0046] For example, the first unit 211 includes a base 211a and a rotating part 211b. The base 211a is fixed relative to the front end of the arm mechanism 100. The base 211a has an arc-shaped curved surface parallel to the X direction and centered on the rotation center C1. The rotating part 211b rotates about the X direction along the curved surface of the base 211a.

[0047] The rotating part 211b of the first unit 211 is rotated by the first drive unit 241. The first drive unit 241 includes an electric motor and is powered via wiring 241a. When the first drive unit 241 is activated, power is transmitted to the first unit 211 via the transmission part 241b. By rotating the first unit 211 about the X direction, the angle of the detector 220 about the X direction changes.

[0048] For example, the second unit 212 includes a base 212a and a rotating part 212b. The base 212a is fixed relative to the rotating part 211b. The base 212a has an arc-shaped curved surface parallel to the Y direction and centered on the rotation center C2. The rotating part 212b rotates about the Y direction along the curved surface of the base 212a.

[0049] The rotating part 212b of the second unit 212 is rotated by the second drive unit 242. The second drive unit 242 includes an electric motor and is powered via wiring 242a. When the second drive unit 242 is activated, power is transmitted to the second unit 212 via the transmission part 242b. By rotating the second unit 212 about the Y direction, the angle of the detector 220 about the Y direction changes.

[0050] The lengths of the first drive unit 241 and the second drive unit 242 in the Z direction are longer than their lengths in the X or Y direction. The rotation axis directions of the motors of the first drive unit 241 and the second drive unit 242 intersect the X and Y directions. For example, the rotation axis directions of the motors are parallel to the Z direction. The rotation direction of the motors is converted to the X and Y directions by the transmission units 241b and 242b, respectively, and transmitted to the first unit 211 and the second unit 212.

[0051] Ejector 230 ejects a liquid or gel. The ejected liquid or gel is used as a coupling agent. The coupling agent is a medium used to achieve acoustic matching of ultrasound between detector 220 and the object being inspected. Ejector 230 ejects the coupling agent along the Z-direction.

[0052] The ejector 230 and the rotary table 210 are mounted independently at the front end of the arm mechanism 100. The orientation of the ejector 230 corresponds to the orientation of the front end of the arm mechanism 100. Alternatively, the ejector 230 can also be mounted at the front end of the arm mechanism 100 via the rotary table 210. In this case, the rotary table 210 is enlarged. The output of the first drive unit 241 and the second drive unit 242 required to rotate the rotary table 210 is also increased. In order to minimize the size of the end effector 200, the ejector 230 is preferably mounted independently at the front end of the arm mechanism 100 from the rotary table 210.

[0053] The third drive unit 243 is mounted independently of the rotary table 210 at the front end of the arm mechanism 100. The third drive unit 243 moves the ejector 230 relative to the front end of the arm mechanism 100 in the Z direction. For example, the third drive unit 243 includes a cylinder. The third drive unit 243 may also include an actuator.

[0054] The piston of the third drive unit 243 is positioned along the Z-direction. The piston slides along the Z-direction on a plate member 243a fixed to the outer cylinder 251 (described later). When viewed from the Z-direction, the ejector 230 and the third drive unit 243 are located on opposite sides of each other across the outer cylinder 251. A connecting portion 243b is connected to the piston of the third drive unit 243. A connecting portion 243c is connected to the connecting portion 243b. The ejector 230 is fixed relative to the connecting portion 243c. The connecting portion 243b is a curved plate-shaped member configured to avoid interference with other members during sliding. The connecting portion 243c is a concave member extending in the Z-direction. The upper part of the ejector 230 is fixed to the inner side of the concave portion 243c. The ejector 230 and the third drive unit 243, located on opposite sides of each other across the outer cylinder 251, are connected by the connecting portion 243b. When the third drive unit 243 slides in the Z direction, the ejector 230 moves in the Z direction via the connecting parts 243b and 243c. A speed controller 243d is provided in the third drive unit 243. The speed controller 243d controls the flow rate of the gas flowing through the cylinder.

[0055] The rotary table 210, ejector 230, and first drive unit 241 to third drive unit 243 are mounted on the front end of the arm mechanism 100 via the outer cylinder 251. The outer cylinder 251 is a hollow cylindrical component extending in the Z direction and is fixed relative to the front end of the arm mechanism 100. A rotary joint 252 is provided on the inner side of the outer cylinder 251. The rotary joint 252 is rotatable relative to the outer cylinder 251 in the Z direction.

[0056] Inside the outer cylinder 251, wiring for supplying power to the rotary table 210, detector 220, and ejector 230, and piping for supplying coupling agent to the ejector 230 (second piping) pass through. The piping for supplying coupling agent is connected via a rotary joint 252 to piping secured by the binding member 140 (first piping). That is, the piping mounted on the end effector 200 is rotatably mounted relative to the piping mounted on the arm mechanism 100. For example, when the outer cylinder 251 rotates about the Z direction via the rotation axis 120, the piping mounted on the arm mechanism 100 does not rotate substantially due to the rotary joint 252. Furthermore, the wiring mounted on the end effector 200 can also be connected to the wiring mounted on the arm mechanism 100 via the rotary joint 252.

[0057] The wiring inside the outer cylinder 251 for supplying power to the rotary table 210 is connected to wirings 241a and 242a (not shown). The coupling agent piping inside the outer cylinder 251 is connected to the ejector 230 via connector 231, piping (not shown), and connector 232. The gas piping inside the outer cylinder 251 is connected to the speed controller 243d (not shown).

[0058] Sensor 260 detects the contact between detector 220 and the object being inspected, either directly or indirectly. Sensor 260 may be, for example, a force sensor, an acceleration sensor, an angular velocity sensor, a light sensor, or a distance sensor.

[0059] The control device 300 controls the various components of the end effector 200. For example, the control device 300 sends drive signals to the first drive unit 241 and the second drive unit 242. The first drive unit 241 and the second drive unit 242 are driven according to the drive signals. The control device 300 is connected to the arm mechanism 100 and the end effector 200 via wired communication, wireless communication, or a network. The arm mechanism 100 and the end effector 200 can be controlled by one control device 300. Alternatively, the arm mechanism 100 and the end effector 200 can be controlled by multiple control devices 300. For example, the motor of the rotating shaft 120, the first drive unit 241, and the second drive unit 242 are controlled by one control device 300. The ejector 230 is controlled by other control devices 300. The processing device 400 is connected to the detector 220 via wired communication, wireless communication, or a network. The processing of the detection results of the detector 220, the calculation of tilt, and the inspection can also be performed by multiple processing devices 400. Alternatively, a portion of the processing may be performed by a dedicated processing device 400, while other portions of the processing may be performed by other general-purpose processing devices 400.

[0060] Figure 4 This is a top view showing the end effector of the implementation method.

[0061] Figure 4This shows the view of the end effector 200 when viewed from the Z direction. Figure 4 In the diagram, dashed lines represent the first unit 211 and the second unit 212.

[0062] like Figures 2-4 As shown, the front end of detector 220 is located at the rotation center C1 of the first unit 211. Figure 4 As shown, the position of the rotation center C1 of the first unit 211 in the Y direction is the same as the position of the front end of the detector 220 in the Y direction. When the first unit 211 rotates, the front end of the detector 220 rotates around the rotation center C1. Therefore, when the first unit 211 rotates, changes in the position of the front end of the detector 220 in the Y direction can be suppressed. For example, the position of the front end of the detector 220 in the Y direction remains unchanged, only the tilt angle of the front end of the detector 220 around the X direction changes.

[0063] The front end of detector 220 is located at the rotation center C2 of the second unit 212. The position of the rotation center C2 of the second unit 212 in the X direction is the same as the position of the front end of detector 220 in the X direction. When the second unit 212 rotates, the front end of detector 220 rotates at the rotation center C2. Therefore, when the second unit 212 rotates, changes in the position of the front end of detector 220 in the X direction can be suppressed. For example, the position of the front end of detector 220 in the X direction remains unchanged, and only the tilt angle of the front end of detector 220 around the Y direction changes.

[0064] The processing unit 400 receives the detection result of the reflected ultrasonic wave from the detector 220. Based on the detection result, the processing unit 400 calculates the tilt angle of the detector 220 relative to the object. Based on the calculated tilt angle, the control unit 300 rotates the rotary table 210. That is, feedback control based on the detection result of the reflected wave is performed for the tilt angle of the detector 220. If the calculated tilt angle is within a preset allowable range (first range), the processing unit 400 inspects the object based on the detection result.

[0065] Figure 5 This is a flowchart illustrating the operation of the detection system in the implementation method.

[0066] The control device 300 executes a first action (step S1). In the first action, the control device 300 moves the arm mechanism 100, causing the detector 220 to move. For example, the control device 300 sets the attitude of the front end of the arm mechanism 100 to a pre-taught attitude, setting the attitude in such a way that the front end of the detector 220 contacts the object.

[0067] For example, sensor 260 is a light-blocking sensor or a distance-measuring sensor. Detector 220 is movable a small distance in the Z-direction relative to the rotary table 210. When the tip of detector 220 contacts the object during the first action, the detector 220 moves in the Z-direction relative to the rotary table 210 due to the reaction force of the object on detector 220. Sensor 260 detects the movement of detector 220. When sensor 260 detects the movement of detector 220, control device 300 determines that the tip of detector 220 is in contact with the object. Control device 300 stops arm mechanism 100.

[0068] When detector 220 comes into contact with the object, detector 220 performs a probe (step S2). Detector 220 detects the reflected wave and sends its detection result to processing device 400. Processing device 400 calculates the tilt angle of detector 220 relative to the object (step S3). Processing device 400 determines whether the tilt angle is within a preset allowable range (step S4).

[0069] If the tilt angle is not within the allowable range, the processing device 400 sends the calculated tilt angle to the control device 300. The control device 300 performs a second action (step S5). In the second action, the control device 300 moves the rotary table 210, causing a change in the tilt angle of the front end of the detector 220. As a result, the difference between the tilt angle and the allowable range decreases. Then, the detection is performed again. If the tilt angle is within the allowable range, the processing device 400 inspects the object based on the detection result (step S6). The processing device 400 outputs the inspection result (step S7).

[0070] Figure 6 It is a flowchart showing the details of the first action.

[0071] The first action includes, for example, the following actions: The control device 300 actuates the arm mechanism 100 (step S11), thereby positioning the nozzle 230 at a position for spraying coupling agent onto the object. The control device 300 slides the third drive unit 243 along the Z direction to bring the nozzle 230 closer to the object (step S12). The nozzle 230 sprays coupling agent toward the object (step S13). The control device 300 slides the third drive unit 243 along the Z direction to move the nozzle 230 away from the object (step S14). The control device 300 actuates the arm mechanism 100 (step S15). As a result, the tip of the detector 220 comes into contact with the object. Contact with the object is determined based on the detection result of the sensor 260. Then, a detection is performed.

[0072] The effects of the implementation method are explained.

[0073] The detection system 1 of this embodiment includes an arm mechanism 100 and an end effector 200. The arm mechanism 100 is multi-jointed, allowing for easy adjustment of the attitude of the end effector 200. The end effector 200 includes a detector 220. The detector 220 performs a detection. The tilt angle of the detector 220 relative to the object being detected has a preferred range. By setting the tilt angle of the detector 220 within the preferred range for detection, the accuracy of the inspection using the detection results is improved.

[0074] On the other hand, there are control singularities in the multi-joint arm mechanism 100. A control singularity refers to an orientation (position and orientation) where the rotation angle of each rotation axis 120 cannot be determined by inverse kinematics calculations. At a singularity, the rotation angle of each rotation axis 120 cannot be uniquely determined. Therefore, the orientation of the arm mechanism 100 cannot be set to such an orientation. Near a singularity, the movement of the arm mechanism 100 may become unstable. Hereinafter, the singularity and the orientation near the singularity will be collectively referred to as "near the singularity."

[0075] Figure 7 (a) and Figure 7 (b) is a schematic diagram used to illustrate the singularity.

[0076] Figure 7 (a) indicates the situation when viewing arm mechanism 100 from the side. Figure 7 (b) shows the view of the arm mechanism 100 from above. Multiple rotation axes 120 extend from the base 130 to the end effector 200, including rotation axes 121-126. (e.g.) Figure 7 As shown in (a), when the rotation centers of rotation shaft 124 and rotation centers of rotation shaft 126 are aligned on the same straight line, the rotation of the end effector 200 can be achieved by rotating either rotation shaft 124 or 126. Figure 7 As shown in (b), when the rotation centers of rotation shaft 121 and rotation shaft 126 are aligned on the same straight line, the rotation of the end effector 200 can also be achieved by rotating either rotation shaft 124 or 126. Figure 7 (a) and Figure 7 The postures represented in (b) cannot be uniquely determined by inverse kinematics calculations to determine the rotation angles of the rotation axes 121 to 126. Therefore, if the posture of the control point is near a singularity, there is a possibility that the arm mechanism 100 cannot be controlled, or that the movement of the arm mechanism 100 becomes unstable.

[0077] For example, when the arm mechanism 100 repeatedly performs the exact same action through a teach-and-play method, the arm mechanism 100 can be taught the action so that the orientation of the control point is not near the singularity. However, when the orientation of the control point is adjusted based on the calculation results of the tilt angle of the processing device 400, the control point may become an untaught orientation. Therefore, during the adjustment of the orientation of the control point, the orientation of the control point may be near the singularity.

[0078] In the detection system 1 of this embodiment, the end effector 200 includes a rotary table 210. The rotary table 210 rotates the detector 220 relative to the front end of the arm mechanism 100. The front end of the detector 220 is located at the rotation center of the rotary table 210. Therefore, the rotary table 210 can suppress changes in the position of the front end of the detector 220 while allowing changes in the tilt angle of the detector 220. By using the rotary table 210, it is possible to prevent the attitude of the control point of the arm mechanism 100 from becoming an attitude other than the pre-taught attitude. Therefore, it is possible to reduce the possibility that the attitude of the control point is near an outlier and to suppress the occurrence of unstable movements. According to this embodiment, a detection system with more stable movements and good ease of use can be provided.

[0079] Compared to the arm mechanism 100, the rotary table 210 is easier to control and has fewer mechanical elements. By using the rotary table 210 to adjust the tilt angle of the front end of the detector 220, the tilt angle can be adjusted with higher precision compared to using the arm mechanism 100. Compared to using units with more than 3 degrees of freedom, the rotary table 210 can easily achieve a large output. Therefore, by using the rotary table 210, the large size of the end effector 200 can be suppressed. For example, when the detector 220 contacts the object, interference between the end effector 200 and other components can be suppressed.

[0080] The end effector 200 includes a first drive unit 241 and a second drive unit 242 for driving the first stage 211 and the second stage 212 of the rotary table 210, respectively. The rotation direction of the motors of the first drive unit 241 and the second drive unit 242 is converted to the X-direction and the Y-direction, respectively, by transmission units 241b and 242b, and transmitted to the first stage 211 and the second stage 212. According to this structure, compared with the case where the rotation axis of the motor is parallel to the XY plane, the size of the end effector 200 in the X and Y directions can be reduced. For example, even when the object being inspected is located deep within the machine, the end effector 200 is less likely to come into contact with other components. This improves the ease of use of the end effector 200.

[0081] like Figure 4As shown, the first detector 211 and the second detector 212 do not overlap with the front end of the detector 220 when viewed from the Z direction. That is, the position of the first detector 211 in the X direction is different from the position of the front end of the detector 220 in the X direction. The position of the second detector 212 in the Y direction is different from the position of the front end of the detector 220 in the Y direction. According to this structure, when the wiring of the detector 220 is led out to the front end of the arm mechanism 100, interference between the wiring and the first detector 211 and the second detector 212 can be suppressed. For example, it is not necessary to lengthen the wiring and wind it to avoid interference with the first detector 211 and the second detector 212. When the arm mechanism 100 and the end effector 200 are in operation, interference between the wiring and other components can be suppressed.

[0082] like Figure 4 As shown, when viewed from the Z direction, a portion of the first unit 211 overlaps with a portion of the second unit 212. For example, a portion of the rotating part 211b of the first unit 211 overlaps with the base 212a and the rotating part 212b of the second unit 212. According to this structure, compared to the case where the first unit 211 and the second unit 212 do not overlap, the dimensions of the end effector 200 in both the X and Y directions can be reduced. For example, the ease of use of the end effector 200 can be improved.

[0083] When adjusting the tilt of detector 220 relative to the object, if the change in tilt exceeds the rotatable range of the rotary table 210, the tilt of detector 220 can also be adjusted via the arm mechanism 100. For example, after adjusting the tilt of detector 220 via the arm mechanism 100, the detector 220 is probed again. Then, the tilt of detector 220 is adjusted via the rotary table 210. In this case, by using the rotary table 210 to adjust the tilt, the amount of tilt change caused by the arm mechanism 100 can be reduced, thus suppressing the attitude of the control point from becoming near a singularity.

[0084] The detection system 1 can be widely used in non-destructive inspections using ultrasound. By using the detection system 1 for inspection, the tilt angle of the detector 220 can be automatically adjusted. This improves the accuracy of the inspection compared to when a person holds the detector 220 for probing. Since the inspection results do not depend on human experience or intuition, the reliability of the inspection results is improved.

[0085] For example, inspection system 1 is suitable for inspecting welded joints. Here, the inspection of a joint formed by resistance spot welding of multiple components will be described. In resistance spot welding, multiple components are joined at points. Parts of the multiple components melt and mix with each other and then solidify to form a weld. For example, in the inspection, it is investigated whether the diameter of the weld is large enough.

[0086] When using detector 220 for probing, a coupling agent is preferably used. Using a coupling agent facilitates the propagation of ultrasound between detector 220 and the object. A rotary joint 252 is preferably provided to supply the coupling agent to ejector 230. Specifically, a first conduit for supplying the coupling agent is provided on arm mechanism 100. This first conduit is, for example, provided in binding member 140. A second conduit is provided on end effector 200. One end of the second conduit is connected to the first conduit via rotary joint 252. The other end of the second conduit is connected to ejector 230.

[0087] When dispensing the coupling agent, the end effector 200 is sometimes rotated around the Z-direction to adjust the position of the nozzle 230. Without the rotary joint 252, twisting occurs in the piping used to supply the coupling agent when the end effector 200 rotates. The length of the piping needs to accommodate this twisting. With the rotary joint 252, the twisting of the piping during the rotation of the end effector 200 can be suppressed. This allows for a shorter piping length and reduces the possibility of interference between the piping and other components.

[0088] Similarly, wiring other than that provided by conduit is preferably installed via rotary joint 252. This shortens the wiring length and reduces the possibility of interference between the wiring and other components.

[0089] Figure 8 It is a three-dimensional diagram showing the internal structure of the detector front end.

[0090] Inside the front end of detector 220, such as Figure 8 The element array 221 is arranged as shown. The element array 221 includes a plurality of detection elements 222. The detection elements 222 are, for example, transducers. The plurality of detection elements 222 are arranged along a first arrangement direction D1 and a second arrangement direction D2. The first arrangement direction D1 and the second arrangement direction D2 intersect each other. In the illustrated example, the first arrangement direction D1 and the second arrangement direction D2 are orthogonal to each other.

[0091] A propagation section 223 is also provided at the front end of the detector 220. Ultrasonic waves transmitted from the element array 221 propagate to the object through the propagation section 223. Reflected waves from the object propagate back to the element array 221 through the propagation section 223. The propagation section 223 is made of a resin material or the like that easily propagates ultrasonic waves. By providing a propagation section 223 that corresponds to the surface shape of the object, ultrasonic waves can easily propagate into the interior of the object. Through the propagation section 223, deformation and damage to the detector 220 when it comes into contact with the object can be suppressed. The propagation section 223 has sufficient hardness to suppress deformation and damage when in contact with the object.

[0092] Figure 8This indicates the condition of the joint 5 being inspected. The joint 5 is manufactured by spot welding metal plate 51 (first component) and metal plate 52 (second component) at a welding section 53. At the welding section 53, a solidified section 54 is formed where a portion of metal plate 51 and a portion of metal plate 52 are melted, mixed, and solidified. Each detection element 222 sends an ultrasonic wave US toward the joint 5 coated with coupling agent 55 and receives the reflected wave RW from the joint 5.

[0093] As a more specific example, such as Figure 8 As shown, a detection element 222 transmits an ultrasonic wave US toward the weld 53. A portion of the ultrasonic wave US is reflected by the upper or lower surface of the joint 5. Multiple detection elements 222 respectively receive (detect) the reflected wave RW. Each detection element 222 transmits the ultrasonic wave US sequentially, and each reflected wave RW is received by the multiple detection elements 222. Thus, the detection result of the reflected wave indicating the state near the weld 53 is obtained.

[0094] Based on the detection results, the processing device 400 calculates the tilt angle of the detector 220 relative to the object about the first arrangement direction D1 and the tilt angle about the second arrangement direction D2. The following explanation addresses the cases where the first arrangement direction D1 and the second arrangement direction D2 are parallel to the X and Y directions, respectively.

[0095] Figure 9 This diagram illustrates the method for calculating the tilt during inspection.

[0096] Figure 10 and Figure 11 This is an example of an image obtained during the inspection.

[0097] Figure 10 It is a three-dimensional volume data depicted based on the detection results of reflected waves. Figure 11 (a) indicates Figure 10 The surface of the welded part 53 in the body data shown. Figure 11 (b) indicates Figure 10 The YZ section near weld 53 in the volume data shown. Figure 11 (c) represents Figure 10 The XZ section near weld 53 in the volume data shown. Figure 11 (b) and Figure 11 In (c), the upper part represents the surface of the welded part 53, and the lower part represents the data in the depth direction. The brighter areas are those with high ultrasonic wave reflection intensity. Ultrasonic waves are strongly reflected by the bottom surface of the welded part 53, the surfaces between unjoined parts, etc.

[0098] The tilt of detector 220 corresponds to Figure 9The angle shown is between direction 53a, which is perpendicular to the welded part 53, and direction 220a of detector 220. Direction 220a of detector 220 is perpendicular to the arrangement direction of detection element 222. This angle is represented by the angle around the first arrangement direction D1 and the angle around the second arrangement direction D2. When the first arrangement direction D1 and the second arrangement direction D2 are parallel to the X direction and the Y direction, respectively, the angle between direction 53a and direction 220a is represented by the angle θx around the X direction and the angle θy around the Y direction.

[0099] like Figure 11 As shown in (b), the angle θx is calculated based on the detection results on the YZ profile. Figure 11 As shown in (c), the angle θy is calculated based on the detection results on the XZ profile. The processing device 400 calculates the mean of the three-dimensional brightness gradient for each profile as angles θx and θy. The processing device 400 stores the calculated angles θx and θy as the tilt of the detector 220 in the storage device 410.

[0100] The closer the angles θx and θy are to zero, the higher the inspection accuracy. Control device 300 moves the rotary table 210 to bring the calculated angles θx and θy close to zero. For example, control device 300 moves the first stage 211 to change the angle of detector 220 around the X direction, thus reducing angle θx. Control device 300 moves the second stage 212 to change the angle of detector 220 around the Y direction, thus reducing angle θy.

[0101] The first arrangement direction D1 and the second arrangement direction D2 are preferably parallel to the X and Y directions, respectively. As described above, the tilt of the detector 220 relative to the object is calculated as the angle around the first arrangement direction D1 and the angle around the second arrangement direction D2. When the first arrangement direction D1 and the second arrangement direction D2 are tilted relative to the X and Y directions, respectively, it is necessary to calculate the angle around the X and Y directions based on the calculated angles. If the first arrangement direction D1 and the second arrangement direction D2 are parallel to the X and Y directions, respectively, it is not necessary to calculate the angle around the X and Y directions. When the tilt of the detector 220, the tilt of the rotary table 210, etc., are output to the user, the user can easily understand each tilt.

[0102] Figure 12 This is a schematic diagram used to illustrate an inspection method that uses a detector.

[0103] like Figure 12As shown in (a), a portion of the ultrasonic wave US is reflected by the upper surface 5a of the metal plate 51 or the upper surface 5b of the weld 53. Another portion of the ultrasonic wave US is incident on the joint 5 and reflected by the lower surface 5c of the metal plate 51 or the lower surface 5d of the weld 53.

[0104] The upper surface 5a, upper surface 5b, lower surface 5c, and lower surface 5d are all at different positions in the Z direction. That is, the distances in the Z direction between these surfaces and the detection element 222 are all different. When the detection element 222 receives reflected waves from these surfaces, it detects the peak value of the reflected wave intensity. After transmitting the ultrasonic wave US, by calculating the time until each peak value is detected, it is possible to investigate on which surface the ultrasonic wave US was reflected.

[0105] Figure 12 (b) and Figure 12 (c) is a graph illustrating the relationship between the time after the transmission of the ultrasonic wave US and the intensity of the reflected wave RW. Here, the intensity of the reflected wave RW is expressed in absolute value. Figure 12 The graph in (b) illustrates the reception results of the reflected wave RW from the upper surface 5a and lower surface 5c of the metal plate 51. Figure 12 The graph in (c) illustrates the reception results of the reflected wave RW from the upper surface 5b and lower surface 5d of the welded part 53.

[0106] exist Figure 12 (b) and Figure 12 In the curve (c), peak Pe10 is based on the reflected wave RW from the surface of the propagation section 223. Peak Pe11 is based on the reflected wave RW from the upper surface 5a. Peak Pe12 is based on the reflected wave RW from the lower surface 5c. The time from the transmission of the ultrasonic wave US to the detection of peaks Pe11 and Pe12 corresponds to the positions of the upper surface 5a and lower surface 5c of the metal plate 51 in the Z direction, respectively.

[0107] Similarly, peak Pe13 is based on the reflected wave RW from the upper surface 5b. Peak Pe14 is based on the reflected wave RW from the lower surface 5d. The time from the transmission of the ultrasonic wave US to the detection of peak Pe13 and peak Pe14 corresponds to the Z-direction positions of the upper surface 5b and lower surface 5d of the welded part 53, respectively.

[0108] The processing device 400 determines whether a peak value Pe12 exists in the intensity distribution of reflected waves in the Z direction at each point in the XY plane. Specifically, the processing device 400 detects peak values ​​within a specified range in the Z direction where a peak value Pe12 might be detected. The processing device 400 compares the intensity of this peak value with a specified threshold. If the peak value exceeds the threshold, the processing device 400 determines that the peak value is a peak value Pe12. The presence of a peak value Pe12 indicates that the lower surface 5c, metal plates 51 and 52 are not bonded at that point. The processing device 400 determines the point where a peak value Pe12 is detected as not bonded. The processing device 400 sequentially determines whether each point in the XY plane is bonded. The set of points determined to be bonded corresponds to the welded portion 53.

[0109] The intensity of the reflected wave can be represented in any way. For example, the intensity of the reflected wave output from the detection element 222 may contain both positive and negative values ​​depending on the phase. Various processing methods can be performed based on the reflected wave intensity containing both positive and negative values. The reflected wave intensity containing both positive and negative values ​​can also be converted to an absolute value. The average value of the reflected wave intensity at each time step can also be subtracted from the reflected wave intensity at each time step. Alternatively, a weighted average value, a weighted moving average value, or the like can be subtracted from the reflected wave intensity at each time step. Even when using the results obtained by applying these processing methods to the reflected wave intensity, the various processing methods described in this application can be performed.

[0110] <Variation Example>

[0111] Figure 13 This is a three-dimensional view showing the end effector of a modified example.

[0112] Figure 13 The end effector 200a shown also includes an imaging device 270 compared to the end effector 200. The imaging device 270 captures images of the object. The imaging device 270 or the processing device 400 determines the location to be inspected based on the captured images. Based on the determination result, the control device 300 actuates the arm mechanism 100, causing the detector 220 and the ejector 230 to move.

[0113] Figure 14 This is a detailed flowchart showing the first action of the end effector using a variant example.

[0114] Figure 14 The flowchart shown is Figure 6 The flowchart shown also includes steps S21 and S22. In step S21, the imaging device 270 captures an image of the object. In step S22, the control device 300 actuates the arm mechanism 100 to correct for deviations calculated based on the image.

[0115] According to the modified end effector 200a, even if the position of the object to be inspected deviates from the pre-taught position relative to the detection system 1, the deviation can be corrected by the imaging device 270. As a result, the accuracy of the inspection can be improved.

[0116] The above description illustrates an example of a detection system 1 comprising a vertically articulated arm mechanism 100 with 6 degrees of freedom. The arm mechanism 100 may also have 4 or 5 degrees of freedom. Alternatively, a horizontally articulated arm mechanism 100 with more than 4 degrees of freedom may also be provided. In either case, the likelihood of the control point being near a singularity can be reduced by using a rotary table 210 to adjust the tilt of the detector 220.

[0117] Figure 15 This is a schematic diagram of a detection system representing a modified example of the implementation method.

[0118] like Figure 15 As shown, the detection system 1a in the modified example does not include the arm mechanism 100. The detection system 1a includes a detection device 200b. The structure of the detection device 200b is the same as that of the end effector 200 or 200a.

[0119] The detection device 200b can be mounted on any object. The detection device 200b can be mounted on other devices, equipment, walls, etc. The orientation of the detection device 200b is arbitrary. The detection device 200b can be mounted with the detector 220 facing horizontally or vertically. The detector 220 can rotate relative to the mounted object in both the X and Y directions via the rotary table 210.

[0120] For example, the conveying device T conveys the coupling body 5. The conveying device T transports the coupling body 5 to the position where the detector 220 contacts the coupling body 5. After the detector 220 contacts the coupling body 5, the following steps are performed: Figure 5 The flowchart shown contains steps S2 to S7.

[0121] By applying the structure of the end effector 200 or 200a described above, the ease of use of the detection device 200b can be improved. Specifically, the front end of the detector 220 is located at the rotation center of the rotary table 210. Therefore, the rotary table 210 can adjust the tilt angle of the detector 220 while suppressing changes in the position of the front end of the detector 220. By using the rotary table 210 to adjust the tilt angle of the detector 220, a larger output can be easily obtained compared to using units with 3 or more degrees of freedom. For example, the detection device 200b can be miniaturized, and interference between the detection device 200b and other components can be suppressed.

[0122] The implementation methods include the following technical solutions.

[0123] <Technical Solution 1>

[0124] A detection system, comprising:

[0125] Multi-joint arm mechanisms; and

[0126] An end effector is disposed at the front end of the arm mechanism;

[0127] The end effector includes:

[0128] Rotary stage; and

[0129] The detector, which is mounted on the front end via the rotating stage, transmits ultrasonic waves and detects reflected waves.

[0130] The front end of the detector is located at the center of rotation of the rotary table.

[0131] <Technical Solution 2>

[0132] According to the detection system described in technical solution 1, wherein,

[0133] The rotary table is capable of rotating about a first direction and about a second direction perpendicular to the first direction.

[0134] The detector transmits the ultrasonic waves in a direction that intersects a surface parallel to the first direction and the second direction.

[0135] <Technical Solution 3>

[0136] According to the detection system described in technical solution 2, wherein,

[0137] The rotary table includes a first stage that rotates about the first direction and a second stage that rotates about the second direction.

[0138] The position of the first unit in the first direction is different from the position of the front end of the detector in the first direction.

[0139] The position of the second unit in the second direction is different from the position of the front end of the detector in the second direction.

[0140] <Technical Solution 4>

[0141] According to the detection system described in technical solution 3, wherein...

[0142] When viewed from a third direction perpendicular to the first and second directions, at least a portion of the first platform does not overlap with at least a portion of the second platform.

[0143] <Technical Solution 5>

[0144] The detection system according to any one of technical solutions 2 to 4, wherein,

[0145] The detector comprises multiple detection elements that respectively transmit the ultrasonic waves and receive the reflected waves.

[0146] The plurality of detection elements are arranged along intersecting first and second arrangement directions.

[0147] The direction in which the ultrasonic wave is transmitted intersects a plane parallel to both the first and second arrangement directions.

[0148] <Technical Solution 6>

[0149] According to the detection system described in technical solution 5, wherein,

[0150] The first arrangement direction is parallel to the first direction.

[0151] The second arrangement direction is parallel to the second direction.

[0152] <Technical Solution 7>

[0153] The detection system according to any one of technical solutions 1 to 6, wherein,

[0154] The detection system also includes a control device for controlling the arm mechanism and the rotary table.

[0155] The control device performs:

[0156] The first action involves actuating the arm mechanism to bring the detector into contact with the object; and

[0157] The second action involves moving the rotating platform based on the detection result of the detector on the reflected wave, thereby changing the tilt angle of the front end of the detector.

[0158] <Technical Solution 8>

[0159] According to the detection system described in technical solution 7, wherein,

[0160] The object in question is the welded portion of the joint.

[0161] <Technical Solution 9>

[0162] According to the detection system described in technical solution 7 or 8, wherein,

[0163] The detection system also includes a processing device for calculating the tilt angle of the front end of the detector based on the detection results.

[0164] If the calculated tilt angle is not included in a pre-set first range, the control device causes the rotary table to move based on the calculated tilt angle.

[0165] <Technical Solution 10>

[0166] According to the detection system described in technical solution 9, wherein,

[0167] If the calculated tilt is within the first range, the processing device examines the object based on the detection result of the reflected wave.

[0168] <Technical Solution 11>

[0169] The detection system according to any one of technical solutions 1 to 10, wherein,

[0170] The end effector includes an ejector that ejects liquids or gels.

[0171] <Technical Solution 12>

[0172] According to the detection system described in technical solution 11, wherein,

[0173] The arm mechanism includes a first conduit for supplying the liquid or gel to the ejector.

[0174] The end effector includes:

[0175] Rotary joints; and

[0176] The second piping has one end connected to the first piping via the rotary joint, and the other end connected to the ejector.

[0177] <Technical Solution 13>

[0178] A control method is a control method for a system having a multi-jointed arm mechanism and an end effector, the end effector being disposed at the front end of the arm mechanism, comprising:

[0179] Rotary stage; and

[0180] The detector, which is mounted on the front end via the rotating stage, transmits ultrasonic waves and detects reflected waves.

[0181] The control method causes the front end of the detector to rotate around the rotation center of the rotary table by the movement of the rotary table, thereby changing the tilt angle of the front end of the detector.

[0182] <Technical Solution 14>

[0183] According to the control method described in technical solution 13, wherein,

[0184] The tilt angle of the detector is changed by rotating the rotary table about a first direction and about a second direction perpendicular to the first direction.

[0185] The ultrasonic wave is transmitted from the detector in a direction that intersects a surface parallel to the first direction and the second direction.

[0186] <Technical Solution 15>

[0187] According to the control method described in technical solution 13 or 14, wherein,

[0188] The rotating platform is moved based on the detection result of the detector on the reflected wave, causing the tilt angle of the detector to change.

[0189] <Technical Solution 16>

[0190] According to the control method described in technical solution 15, wherein,

[0191] If the calculated tilt angle is not included in a pre-set first range, the rotary table is moved based on the calculated tilt angle.

[0192] <Technical Solution 17>

[0193] According to the control method described in technical solution 16, wherein,

[0194] If the calculated tilt is within the first range, the object is inspected based on the detection result of the reflected wave.

[0195] <Technical Solution 18>

[0196] A detection device, comprising:

[0197] Rotary stage; and

[0198] A detector, mounted on the rotating stage, is used to transmit and detect ultrasonic waves.

[0199] The front end of the detector is located at the center of rotation of the rotary table.

[0200] The above examples illustrate several embodiments of the present invention, but these embodiments are provided as examples and are not intended to limit the scope of the invention. These new embodiments can be implemented in various other ways, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included within the scope and spirit of the invention, and are included within the scope of the invention as described in the claims and its equivalents. The foregoing embodiments can be combined with each other.

Claims

1. A detection system, characterized in that, have: Multi-joint arm mechanisms; and An end effector is disposed at the front end of the arm mechanism; The end effector includes: Rotary stage; and The detector, which is mounted on the front end via the rotating stage, transmits ultrasonic waves and detects reflected waves. The front end of the detector is located at the center of rotation of the rotary table. The rotary table includes a first stage that rotates about a first direction and a second stage that rotates about a second direction perpendicular to the first direction. The detector transmits the ultrasonic waves in a direction that intersects a plane parallel to the first direction and the second direction. Regarding the detector, As the first unit rotates around the first direction, the tilt angle of the detector's front end around the first direction changes. As the second unit rotates around the second direction, the tilt of the front end of the detector around the second direction changes.

2. The detection system according to claim 1, characterized in that, The position of the first unit in the first direction is different from the position of the front end of the detector in the first direction. The position of the second unit in the second direction is different from the position of the front end of the detector in the second direction.

3. The detection system according to claim 2, characterized in that, When viewed from a third direction perpendicular to the first and second directions, at least a portion of the first platform does not overlap with at least a portion of the second platform.

4. The detection system according to any one of claims 1 to 3, characterized in that, The detector comprises multiple detection elements that respectively transmit the ultrasonic waves and receive the reflected waves. The plurality of detection elements are arranged along intersecting first and second arrangement directions. The direction in which the ultrasonic wave is transmitted intersects a plane parallel to both the first and second arrangement directions.

5. The detection system according to claim 4, characterized in that, The first arrangement direction is parallel to the first direction. The second arrangement direction is parallel to the second direction.

6. The detection system according to any one of claims 1 to 3, characterized in that, The detection system also includes a control device for controlling the arm mechanism and the rotary table. The control device performs: The first action is to activate the arm mechanism, bringing the detector into contact with the object; as well as The second action involves moving the rotating platform based on the detection result of the detector on the reflected wave, thereby changing the tilt angle of the front end of the detector.

7. The detection system according to claim 6, characterized in that, The object in question is the welded portion of the joint.

8. The detection system according to claim 6, characterized in that, The detection system also includes a processing device for calculating the tilt angle of the front end of the detector based on the detection results. If the calculated tilt angle is not included in a pre-set first range, the control device causes the rotary table to move based on the calculated tilt angle.

9. The detection system according to claim 8, characterized in that, If the calculated tilt is within the first range, the processing device examines the object based on the detection result of the reflected wave.

10. The detection system according to any one of claims 1 to 3, characterized in that, The end effector includes an ejector that ejects liquids or gels.

11. The detection system according to claim 10, characterized in that, The arm mechanism includes a first piping for supplying the liquid or gel to the ejector. The end effector includes: Rotary joints; and The second piping has one end connected to the first piping via the rotary joint, and the other end connected to the ejector.

12. A control method for a system having a multi-jointed arm mechanism and an end effector, the end effector being disposed at the front end of the arm mechanism, comprising: Rotary stage; and The detector, which is mounted on the front end via the rotating stage, transmits ultrasonic waves and detects reflected waves. The control method is characterized in that... The movement of the rotating platform causes the front end of the detector to rotate around the center of rotation of the platform, thereby changing the tilt angle of the front end of the detector. The rotary table includes a first stage that rotates about a first direction and a second stage that rotates about a second direction perpendicular to the first direction. The detector transmits the ultrasonic waves in a direction that intersects a plane parallel to the first direction and the second direction. Regarding the detector, When the first unit is rotated about the first direction, the tilt angle of the front end of the detector about the first direction changes. When the second unit is rotated about the second direction, the tilt of the front end of the detector about the second direction changes.

13. The control method according to claim 12, characterized in that, The rotating platform is moved based on the detection result of the detector on the reflected wave, causing the tilt angle of the detector to change.

14. The control method according to claim 13, characterized in that, If the calculated tilt angle is not included in a pre-set first range, the rotary table is moved based on the calculated tilt angle.

15. The control method according to claim 14, characterized in that, If the calculated tilt is within the first range, the object is inspected based on the detection result of the reflected wave.

16. A detection device, characterized in that, have: Rotary stage; and A detector, mounted on the rotating stage, is used to transmit and detect ultrasonic waves. The front end of the detector is located at the center of rotation of the rotary table. The rotary table includes a first stage that rotates about a first direction and a second stage that rotates about a second direction perpendicular to the first direction. The detector transmits the ultrasonic waves in a direction that intersects a plane parallel to the first direction and the second direction. Regarding the detector, As the first unit rotates around the first direction, the tilt angle of the detector's front end around the first direction changes. As the second unit rotates around the second direction, the tilt of the front end of the detector around the second direction changes.

Images