Self-propelled inspection device and inspection method for metal plate, and method for manufacturing metal plate

Abstract

The present invention aims to provide a self-propelled inspection device and inspection method for metal plates, which can efficiently produce inspection results even when the amount of information of flaw detection data becomes huge, and a method for manufacturing metal plates using the inspection device. The self-propelled inspection device (300a, 300b) for metal plates comprises: a trolley (14) that travels on the surface of the metal plate; a navigation transmitter (12b) or a navigation receiver (12a); an inspection device (15) including a flaw detection head (35) having an inspection sensor that scans an inspection area of ​​the metal plate (10) and an inspection result production unit (71) that produces inspection results, and a control unit, which controls the trolley to autonomously travel to the target position and controls the flaw detection head to scan based on the position of the trolley measured by a position measurement system and a target position as the position of the trolley, and the inspection result production unit produces the inspection result based on the inspection information obtained by the inspection sensor and the position information of the flaw detection head.

Description

Technical Field

[0001] The present invention relates to a self-propelled inspection device and an inspection method for a metal plate using a position measurement system. Further, the present invention relates to a method for manufacturing a metal plate having a process of inspecting defects of a metal plate using the self-propelled inspection device for a metal plate. Background Art

[0002] Conventionally, in order to ensure the quality of metal plates such as steel plates, inspections are performed to detect injuries on the surface of the metal plate and defects (hereinafter also simply referred to as internal defects) inside the metal plate by ultrasonic flaw detection.

[0003] In recent years, self-propelled inspection devices have been developed as devices for inspecting injuries on the surface of a metal plate and internal defects. As the simplest self-propelled inspection device, there is an inspection device in which a flaw detector is mounted on a device capable of moving on a metal plate. In such an inspection device, in order to scan the entire surface of the plate to be inspected, it is necessary to install ribs or the like around the plate to be inspected.

[0004] Regarding the self-propelled inspection device disclosed in Patent Document 1, as Figure 22 shown, the crawler vehicle 8 travels by a chain-shaped crawler 8a, and when moving in the lateral direction, it travels by a lateral movement wheel 8b. Metal plate edge detection sensors 2b are provided at the front and rear of the crawler vehicle 8, and a probe 2a for inspecting injuries on the metal plate is provided on the guide rail. The crawler vehicle 8 is configured to be able to calculate the exploration position by a measurer A provided at the edge of the metal plate 1 and a telescopic measurer B provided at a reference point P of the metal plate 1.

[0005] As a method for measuring the position of a self-propelled inspection device, for example, a method of providing an induction line on the travel path is known. Further, as another method, a method of photographing the ground and the ceiling surface of the travel path with a camera and performing image processing on the image is known. Further, as another method, a method of mounting a gyro sensor on the self-propelled inspection device and calculating the current position by accumulating the travel speed and the angular velocity at high speed is known.

[0006] The flaw detection device disclosed in Patent Document 2 is a self-propelled inspection device for metal plates that uses a position measurement system based on the principle of triangulation to measure its own position in an indoor space and inspects metal plates. In the embodiment, as an ultrasonic flaw detection inspection method for steel plates for pressure vessels in JIS G0801, an example based on the vertical flaw detection method is introduced. The vertical flaw detection method is one of the pulse reflection methods. Each flaw detector has one ultrasonic transmitter (oscillator), and as inspection data, it is the reflected echo (A region) as primary information. According to the information contained in the A region, the information on "the degree of the defect" is extracted from the peak height of the defect echo, and the information on "the position in the depth direction of the defect" is extracted from the ultrasonic propagation time. The inspection data, together with the inspection position information calculated in real time, is transmitted from the on-board computer to the main computer. Then, the configuration of the defects inside the metal plate is mapped on the metal plate plane, and through display, the planar configuration of the defects is visualized.

[0007] In JIS G0801, the ultrasonic inspection method for carbon steel or alloy steel plates with a thickness of 6 mm or more and 300 mm or less used for atomic reactors, boilers, pressure vessels, etc. by automatic or manual means is specified. In the ultrasonic inspection of steel plates with a thickness exceeding 60 mm, the type of probe is specified as a vertical probe. Generally, the thicker the plate thickness, the more the S / N ratio decreases due to the scattering and attenuation of ultrasonic waves in the propagation path.

[0008] However, since the development of ultrasonic phased array technology has advanced since the 1980s, it has entered the mature stage as a new technical field at the beginning of the 21st century. In phased array technology, multiple ultrasonic transmitters (oscillators) are used in the flaw detector, and by electrically controlling the transmission timing, the direction of the beam and the focusing point can be freely changed. That is, by controlling the focusing point in the plate thickness direction to improve the S / N ratio, it is possible to detect minute defects in steel plates with a thickness exceeding 300 mm, which were difficult to detect in the past.

[0009] Patent Document 1: Japanese Patent Laid-Open No. 5-172798

[0010] Patent Document 2: Japanese Patent No. 5954241

[0011] In Patent Documents 1 and 2, when the phased array method is used as the inspection equipment, the amount of information in the flaw detection data becomes huge. Thus, when the amount of information in the flaw detection data becomes huge, there is a problem of hindering the data transfer to the main computer.

[0012] In addition, when a phased array method is used in an inspection device, the primary information of inspection data is reflected echo. Therefore, operations on the paths of beams oscillated from multiple oscillators and identification of flaw detection results considering such paths are complex. Thus, technically, it is also difficult to make the inspection data independent of the flaw detector and enable the host computer to have the function of depicting flaw detection results. For this reason, a dedicated machine is generally used as the inspection sensor, and the function of this dedicated machine is used to depict the flaw detection results. Summary of the Invention

[0013] The present invention has been completed in view of this situation, and its object is to provide a self-propelled inspection device and inspection method for a metal plate that can efficiently produce inspection results even when the amount of flaw detection data becomes huge, and a manufacturing method of a metal plate using the inspection device.

[0014] The inventor of the present invention has conducted in-depth research to solve the above problems. During the research process, the inventor configured a self-propelled inspection device for a metal plate in the following manner, that is, it includes a specified inspection unit, a specified control unit, etc., and produces inspection results based on inspection information obtained by an inspection sensor and position information of a flaw detector head. The inventor found that by using the self-propelled inspection device for a metal plate with this structure, even when the amount of flaw detection data becomes huge, inspection results can be efficiently produced, and thus the present invention was completed. The above problems are solved by the following units.

[0015] [1] A self-propelled inspection device for a metal plate, which uses a position measurement system that measures positions based on the principle of triangulation to inspect the metal plate, and is characterized by comprising:

[0016] A trolley that travels on the surface of the metal plate;

[0017] A navigation transmitter that sends position measurement system signals or a navigation receiver that receives position measurement system signals, mounted on the aforementioned trolley;

[0018] An inspection unit, including a flaw detector head mounted on the aforementioned trolley and having an inspection sensor that scans an inspection area of the metal plate, and an inspection result production unit that produces inspection results; and

[0019] A control unit that controls the aforementioned trolley to autonomously travel to the aforementioned target position and controls a scan actuator of the aforementioned flaw detector head to scan based on the position of the aforementioned trolley measured by the position measurement system and the aforementioned target position of the aforementioned trolley during inspection,

[0020] The aforementioned inspection result production unit produces the aforementioned inspection results based on inspection information obtained by the aforementioned inspection sensor and position information of the aforementioned flaw detector head.

[0021] [2]The self-propelled inspection device for metal plates according to [1], characterized in that the control unit performs control to autonomously drive the trolley to the target position and posture based on the position and posture of the trolley measured by the position measurement system and the target position and posture of the trolley during inspection.

[0022] [3]The self-propelled inspection device for metal plates according to [1] or [2], characterized in that the inspection sensor is a phased array probe in which a plurality of ultrasonic transducers are arranged.

[0023] [4]The self-propelled inspection device for metal plates according to [3], characterized in that a pulse signal is used as the position information of the flaw detector head,

[0024] and an output unit is provided to output a pulse signal corresponding to the change amount of the position of the flaw detector head updated in each control cycle to the inspection sensor.

[0025] [5]The self-propelled inspection device for metal plates according to [4], characterized in that the output frequency of the pulse signal generated by the output unit is set to be synchronized with the product of the flaw detection data acquisition frequency, the pulse resolution, and the display resolution of the inspection result set by the inspection unit,

[0026] and the speed of the mechanical scanning of the flaw detector head is below the upper limit speed obtained by multiplying the display resolution of the inspection result by the flaw detection data acquisition frequency.

[0027] [6]The self-propelled inspection device for metal plates according to any one of [1] to [5], characterized in that

[0028] the position measurement system is an IGPS,

[0029] the navigation receiver receives a rotating fan beam emitted from one or more navigation transmitters of the IGPS and identifies the rotating fan beam as an IGPS signal serving as the position measurement system signal.

[0030] [7]The self-propelled inspection device for metal plates according to any one of [1] to [5], characterized in that

[0031] the position measurement system uses laser triangulation technology,

[0032] the navigation transmitter is configured as a laser triangulation device having functions of emitting and receiving laser light, causing the emitted laser light to be reflected by one or more reflectors, and receiving the reflected light as the position measurement system signal.

[0033] [8]The self-propelled inspection device for metal plates according to any one of [1] to [7], characterized in that

[0034] The aforementioned carriage has at least two wheels capable of rotating, and a drive unit for driving the aforementioned wheels. The aforementioned drive unit is composed of a first drive system that is provided corresponding to each of the aforementioned wheels and rotationally drives each of the aforementioned wheels, and a second drive system that can rotate around an axis orthogonal to the metal plate surface on which the aforementioned carriage travels and offset toward the carriage center side relative to each of the aforementioned wheels, and can steer and drive the aforementioned wheels by more than 90°.

[0035] [9] The self-propelled inspection device for metal plates according to any one of [1] to [8], characterized in that

[0036] It further includes an edge detection sensor, which is provided on the aforementioned carriage and is used to detect the edge of the metal plate to be inspected.

[0037]

[10] A self-propelled inspection method for metal plates is a self-propelled inspection method for metal plates that uses a position measurement system based on the principle of triangulation to measure positions, characterized in that it uses the following self-propelled inspection device for metal plates, that is, it includes:

[0038] A carriage that travels on the metal plate surface;

[0039] A navigation transmitter that sends position measurement system signals or a navigation receiver that receives position measurement system signals, which is mounted on the aforementioned carriage;

[0040] An inspection unit, including a flaw detection head mounted on the aforementioned carriage and having an inspection sensor for scanning the inspection area of the metal plate, and an inspection result production unit for producing inspection results; and

[0041] A control unit, based on the position of the aforementioned carriage measured by the position measurement system and the target position of the aforementioned carriage during inspection, performs control to autonomously drive the aforementioned carriage to the aforementioned target position and control of the scanning actuator for scanning the aforementioned flaw detection head.

[0042] The aforementioned inspection result production unit produces the aforementioned inspection results based on the inspection information obtained by the aforementioned inspection sensor and the position information of the aforementioned flaw detection head.

[0043]

[11] The self-propelled inspection method for metal plates according to

[10] , characterized in that

[0044] The aforementioned control unit, based on the position and posture of the aforementioned carriage measured by the aforementioned position measurement system and the target position and posture of the aforementioned carriage during inspection, performs control to autonomously drive the aforementioned carriage to the aforementioned target position and posture.

[0045]

[12] A manufacturing method of a metal plate, characterized by having:

[0046] Manufacturing process for manufacturing a metal plate;

[0047] Inspection process, using the self-propelled inspection device for metal plates described in any one of [1] to [9], to inspect defects present in the aforementioned metal plate; and

[0048] Sorting process, based on the inspection results obtained in the aforementioned inspection process, to sort the aforementioned metal plates.

[0049] According to the present invention, it is possible to provide a self-propelled inspection device and inspection method for metal plates that can efficiently produce inspection results even when the amount of flaw detection data becomes large, and a manufacturing method for metal plates using the inspection device. In addition, the self-propelled inspection device for metal plates of the present invention can be preferably used particularly in cases where ultrasonic phased array technology is employed in inspection equipment. Brief Description of the Drawings

[0050] Figure 1 It is a perspective view showing the schematic structure of the overall system according to the first embodiment of the present invention.

[0051] Figure 2 It is a perspective view showing the schematic structure of the overall system according to the second embodiment of the present invention.

[0052] Figure 3A It is a block diagram of the overall system according to the first embodiment of the present invention.

[0053] Figure 3B It is a block diagram of the position measurement system according to the second embodiment of the present invention.

[0054] Figure 4A It is a chart showing an example of the relationship between pulses and time for explaining the amount of change in the flaw detector head position updated for each control cycle.

[0055] Figure 4B It is a chart showing another example of the relationship between pulses and time for explaining the amount of change in the flaw detector head position updated for each control cycle.

[0056] Figure 5 It is a side view of the carriage used in the self-propelled inspection device for metal plates according to the first embodiment of the present invention.

[0057] Figure 6 It is a horizontal cross-sectional view of the carriage used in the self-propelled inspection device for metal plates according to the first embodiment of the present invention, based on line A-A.

[0058] Figure 7 It is a front view of the carriage used in the self-propelled inspection device for metal plates according to the first embodiment of the present invention.

[0059] Figure 8 It is a cross-sectional view showing an enlarged view of a drive unit of a carriage used in a self-propelled inspection device for a metal plate according to a first embodiment of the present invention.

[0060] Figure 9A It is a schematic diagram showing a turning state when the self-propelled inspection device for a metal plate is moved left and right.

[0061] Figure 9B It is a schematic diagram showing a turning state when the self-propelled inspection device for a metal plate is moved obliquely.

[0062] Figure 9C It is a schematic diagram showing a turning state when the self-propelled inspection device for a metal plate is moved forward and backward.

[0063] Figure 9D It is a schematic diagram showing a turning state when the self-propelled inspection device for a metal plate makes a turn in place.

[0064] Figure 10 It is a diagram for explaining a method of obtaining position and posture information of a metal plate.

[0065] Figure 11 It is a diagram showing a system configuration when obtaining position and posture information of a metal plate.

[0066] Figure 12 It is a flowchart of a method for detecting the position and posture of a metal plate and setting a target position and an inspection path.

[0067] Figure 13 It is a diagram showing a coordinate system for setting measurement points based on the plate ends in the operation process of detecting the position and posture of a metal plate.

[0068] Figure 14A It is a diagram for explaining the scanning division and the inspection part specified in "7.6 Inspection Part (Scanning Part and Range)" of the ultrasonic flaw detection inspection method for steel plates for pressure vessels in JIS G0801.

[0069] Figure 14B It is a diagram for explaining the scanning division and the inspection part specified in "7.6 Inspection Part (Scanning Part and Range)" of the ultrasonic flaw detection inspection method for steel plates for pressure vessels in JIS G0801.

[0070] Figure 14C It is a diagram for explaining the scanning division and the inspection part specified in "7.6 Inspection Part (Scanning Part and Range)" of the ultrasonic flaw detection inspection method for steel plates for pressure vessels in JIS G0801.

[0071] Figure 15AIt is a conceptual diagram of area A, which is the primary information obtained during flaw detection.

[0072] Figure 15B It is a graph showing the relationship between the sound pressure received by the probe and the ultrasonic propagation time in area A.

[0073] Figure 15C It is a conceptual diagram of area B, which is associated with the information of area A and the scanning position and performs a mapping display related to the vertical section of the material to be flaw-detected.

[0074] Figure 15D It is a conceptual diagram showing the information obtained on the XZ plane of the material to be flaw-detected in area B.

[0075] Figure 15E It is a conceptual diagram of area C, which performs a mapping display related to the horizontal section of the material to be flaw-detected.

[0076] Figure 15F It is a conceptual diagram showing the information obtained on the XY plane of the material to be flaw-detected in area C.

[0077] Figure 16 It is a diagram showing an example of a flaw (defect) existing inside the metal plate.

[0078] Figure 17 It is a diagram showing Figure 16 an example of the mapping process and display of the configuration of the flaws (defects) inside the metal plate shown on the metal plate plane.

[0079] Figure 18 It is a diagram showing an example of adding the information of the depth direction position of the flaw (defect) and grasping the configuration of the flaws (defects) inside the metal plate in the thickness direction.

[0080] Figure 19 It is an explanatory diagram for explaining the movement of the trolley during the flaw detection of the four sides.

[0081] Figure 20A It is an explanatory diagram for explaining the movement of the trolley when it moves to the left during the flaw detection inside the metal plate.

[0082] Figure 20B It is an explanatory diagram for explaining the movement of the trolley when it moves to the right during the flaw detection inside the metal plate.

[0083] Figure 21A It is a diagram showing the inspection positions and paths when the four sides of the metal plate are flaw-detected twice.

[0084] Figure 21B It is a diagram showing the inspection positions and paths when inspecting along the rolling direction inside the metal plate.

[0085] Figure 21C This is a diagram showing the inspection position and path in the case of inspecting the inside of a metal plate along the rolling direction.

[0086] Figure 21D This is a diagram showing the inspection position and path in the case of inspecting the inside of a metal plate along the rolling direction.

[0087] Figure 21E This is a diagram showing the inspection position and path in the case of inspecting the inside of a metal plate along the rolling direction.

[0088] Figure 22 This is a diagram for explaining an existing self-propelled inspection device. Detailed implementation mode

[0089] Hereinafter, preferred implementation modes of the present invention will be described with reference to the accompanying drawings. However, the scope of the invention is not limited to the illustrated examples.

[0090] The self-propelled inspection device for a metal plate of the present invention is a self-propelled inspection device for a metal plate that uses a position measurement system that measures positions based on the principle of triangulation to inspect the metal plate. The self-propelled inspection device for a metal plate of the present invention includes: a carriage that travels on the surface of the metal plate; a navigation transmitter that transmits a position measurement system signal or a navigation receiver that receives a position measurement system signal, mounted on the carriage; an inspection unit including a flaw detector head mounted on the carriage and having an inspection sensor that scans the inspection area of the metal plate, and an inspection result production unit that produces an inspection result; and a control unit that controls the carriage to autonomously travel to a target position and controls a scan actuator of the flaw detector head based on the position of the carriage measured by the position measurement system and the target position of the carriage during inspection, and the inspection result production unit produces an inspection result based on the inspection information obtained by the inspection sensor and the position information of the flaw detector head. Hereinafter, preferred implementation modes of the present invention will be described.

[0091] In addition, in the present invention, the position of the carriage during inspection is also simply referred to as the target position. In addition, in the present invention, "defect" refers to internal defects such as foreign substances, cracks, and voids existing inside the metal plate. In addition, in the present invention, "the posture of the carriage" refers to the inclination of the carriage with respect to a reference when the orientation of the carriage during inspection is set as the reference in a three-dimensional space. In the following description, it is assumed that a steel plate is used as an example of the metal plate for explanation, but the self-propelled inspection device for a metal plate of the present invention can also be applied to the inspection of various metal plates such as aluminum plates and copper plates.

[0092] Figure 1 This is a perspective view showing the schematic structure of the overall system 100a according to the first embodiment of the present invention. Figure 2It is a perspective view showing the schematic structure of the overall system 100b according to the second embodiment of the present invention. Figure 3A It is a block diagram showing the overall system 100a according to the first embodiment of the present invention. Figure 3B It is a block diagram of the position measurement system 200b according to the second embodiment of the present invention.

[0093] The overall system 100a according to the first embodiment includes a position measurement system 200a and a self-propelled inspection device 300a for metal plates.

[0094] The position measurement system 200a includes a plurality of navigation transmitters 11a, a navigation receiver 12a, and a main computer 13 containing position calculation software 16. The position measurement system 200a measures its own position in the indoor space based on the principle of triangulation. The position measurement system 200a can adopt, for example, IGPS (Indoor Global Position System).

[0095] Generally, the Global Positioning System (GPS) is a device that uses three or more GPS artificial satellites to identify and determine the three-dimensional coordinate values (hereinafter referred to as "coordinate values") corresponding to the position of a GPS receiver. Applying such a concept to an indoor position measurement system is IGPS. IGPS is described in detail, for example, in U.S. Patent No. 6,501,543.

[0096] The self-propelled inspection device 300a for metal plates according to the first embodiment includes, for example: a carriage 14 that travels on the metal plate 10; a navigation receiver 12a mounted on the carriage 14; an inspection device (inspection unit) 15 including a flaw detector head 35 mounted on the carriage 14 and equipped with a probe (inspection sensor); and a main computer 13 containing software for autonomously driving the carriage 14 to a specified target position.

[0097] In the position measurement system 200a, each navigation transmitter 11a emits two rotating fan beams (sector beams). The rotating fan beam can be a laser fan beam or other light emission units. The navigation receiver 12a receives the rotating fan beams emitted from the transmitters and can thus determine the relative positions with respect to multiple transmitters. At this time, the rotating fan beams are offset by a specified angle, and the coordinate values of the receiver that receives them, that is, the position or height, can be measured. The received information in the navigation receiver 12a is wirelessly transmitted to the main computer 13, and the main computer 13 calculates the position of the navigation receiver 12a based on the principle of triangulation. Therefore, by calculating the position of the navigation receiver 12a in this way, the current position and pose information of the traveling carriage 14 equipped with the navigation receiver 12a can be obtained in real time.

[0098] In Figure 2 Fig. shows a schematic structure of an overall system 100b according to a second embodiment. The overall system 100b includes a position measurement system 200b and a self-propelled inspection device 300b for metal plates. Relative to the self-propelled inspection device 300a for metal plates according to the first embodiment, which includes a navigation receiver 12a that receives a position measurement system signal, the self-propelled inspection device 300b for metal plates according to the second embodiment includes a navigation transmitter 12b that transmits a position measurement system signal.

[0099] As Figure 3B shown, the position measurement system 200b according to the second embodiment includes: a navigation transmitter 12b disposed on the upper part of the carriage 14; a plurality of reflectors 11b; and a main computer 13 containing position calculation software 16. The position measurement system 200b according to the second embodiment performs self-position measurement in an indoor space based on the principle of triangulation. The position measurement system 200b according to the second embodiment can, for example, adopt a laser triangulation technique mounted on a cleaning robot that autonomously travels in an office building (for example, refer to http: / / robonable.typepad.jp / news / 2009 / 11 / 25subaru.html).

[0100] The self-propelled inspection device 300b for metal plates includes, for example: a carriage 14 that travels on the metal plate 10; a navigation transmitter 12b disposed on the upper part of the carriage 14; an inspection device 15 including a flaw detector head 35 having an inspection sensor, i.e., a probe; and the above-mentioned main computer 13 containing software for autonomously driving the carriage 14 to a specified target position.

[0101] In the second embodiment, the navigation transmitter 12b is configured using a laser triangulation technique. The autonomous travel of the carriage 14 is performed by the navigation transmitter 12b as a laser triangulation and, for example, reflectors 11b disposed on the wall surface. The navigation transmitter 12b is, for example, disposed on the upper part of the carriage 14 and has a function of emitting and receiving laser light. Laser light L is emitted 360° from the navigation transmitter 12b, and the reflected light from the reflector 11b is received as a position measurement system signal. The distance is identified based on the time until the reflected light returns, and the direction of each reflector 11b is identified based on the angle, and compared with the coordinate positions of the reflectors 11b pre-registered, whereby the position and direction of the navigation transmitter 12b can be calculated. Therefore, by calculating the position of the navigation transmitter 12b in such a manner, the current position and posture information of the traveling carriage 14 equipped with the navigation transmitter 12b can be obtained in real time.

[0102] In the structure described below, the case where the self-propelled inspection device 300a for metal plates according to the first embodiment and the position measurement system 200a are adopted is taken as an example for explanation. The structure described below can also be applied to the self-propelled inspection device 300b for metal plates according to the second embodiment. In addition, the structure described below is explained by taking an example of using the position information and posture information of the carriage. However, when the metal plate to be inspected is placed parallel to a plane that is not inclined with respect to the horizontal ground and the posture of the carriage is kept constant, the posture information is not required.

[0103] As Figure 3A shown, the host computer 13 has, for example: position calculation software 16 for calculating the position of the above-described navigation receiver 12a; and setting software 17 for setting the target position of the carriage 14 and the posture information of the carriage 14 during inspection.

[0104] As Figure 3A shown, the carriage 14 includes, for example: a navigation receiver 12a, which is a part of the above-described position measurement system 200a; an inspection device 15, including a flaw detector head 35 and an inspection result production unit 71; a mounted computer 21; an edge detection sensor 22 for detecting the edge of the metal plate 10; an IO board 23; a scanning actuator 24 for scanning the flaw detector head 35; a drive control unit 25, including a controller and a driver; wheels 26 for traveling; and wheel motors 27 for driving and steering the wheels. Here, the position calculation software 16 and the setting software 17 mounted on the host computer 13 may also be installed on the mounted computer 21.

[0105] The on-vehicle computer 21 has a control unit that controls the on-vehicle computer 21 to autonomously travel the carriage 14 to the target position and posture based on the position and posture of the carriage 14 measured by the position measurement system 200a and the target position and posture of the carriage 14 during inspection, and controls the scanning actuator 24 of the scanning flaw detector 35. The flaw detector 35 is scanned at the target position of the carriage 14. During this autonomous travel, for example, information related to the operation result in the main computer 13, that is, the current position and posture of the carriage 14, the target position and posture of the carriage 14 during inspection, and the target position of the scanning actuator 24 is wirelessly transmitted to the on-vehicle computer 21 mounted on the carriage 14. Next, in the on-vehicle computer 21, the deviation of the current position and posture from the target position and posture is calculated. Then, a control signal is output from the drive control unit 25 to the wheel motor 27 so that the deviation depending on the position and posture of the carriage body becomes 0, and feedback control of the speed and steering angle of the wheel 26 is performed, thereby performing autonomous travel of the carriage 14 to the target position and posture. In addition, when the above-mentioned posture information is not required, the on-vehicle computer 21 may be provided with a control unit that controls the carriage 14 to autonomously travel to the target position based on the position of the carriage 14 measured by the position measurement system 200a and the target position of the carriage 14 during inspection, and controls the scanning actuator 24 of the scanning flaw detector 35.

[0106] The control of the scanning in the inspection sensor (probe) equipped with the computer 21 will be described. When depicting a two-dimensional defect image in the X and Y directions, for example, when using the pulse echo method as the scanning method, the scanning of the probe is controlled by mechanically scanning the flaw detector head 35 in the X and Y directions in a rectangular pattern. Additionally, for example, when using the phased array method as the scanning method, the electronic beam scanning in the X direction and the mechanical scanning of the flaw detector head 35 in the Y direction are controlled. The control of the mechanical scanning of the flaw detector head 35 is performed by the scanning actuator 24. The phased array flaw detector head 35 has multiple ultrasonic transmission sources (vibrators), and the distance capable of performing electronic beam scanning depends on the width, arrangement pitch, and number of the vibrators. The internal structure of the flaw detector head 35 requires a high manufacturing precision, so it generally becomes more expensive compared to the existing flaw detector heads of vertical probes. Considering the maintainability such as replacement in the case of a failure of the flaw detector head 35, generally, the number of vibrators consists of about 10 to 128. For example, when the beam scanning distance in the X direction is 120 mm and the X direction dimension of the metal plate is 5000 mm, in order to inspect the entire surface of the metal plate, the insufficient part in the beam scanning is supplemented by the 100 mm pitch travel of the wheels of the carriage 14. Additionally, for example, when the Y direction dimension is 2000 mm and the stroke of the scanning actuator 24 for mechanically scanning the flaw detector head 35 in the Y direction is 600 mm, the insufficient part in the mechanical scanning of the scanning actuator 24 is supplemented by the 500 mm pitch travel of the wheels of the carriage 14.

[0107] In the self-propelled inspection device 300a for metal plates, the function of inspecting the metal plate 10 will be described. For this function, for example, it is borne by the inspection device 15 including the probe (inspection sensor) having the inspection area of the metal plate 10, the scanning actuator 24 for controlling the scanning of the flaw detector head 35, the computer 21 on board, and the drive control unit 25. In the computer 21 on board, based on the inspection position from the host computer 13 and the information on the current position and posture of the carriage, the necessary scanning amount of the scanning actuator 24 for scanning the flaw detector head 35 as a structural element of the inspection device 15 is calculated. The drive control unit 25 outputs an electrical signal to the scanning actuator 24 in such a way as to drive only the amount corresponding to the necessary scanning amount, and this electrical signal is converted into the scanning motion of the flaw detector head 35 by the scanning actuator 24. The position information of the flaw detector head 35 is fed back to the computer 21 on board and is calculated as the inspection position information together with the current position information of the carriage 14. The inspection data in the inspection device 15 is taken into the computer 21 on board via the IO board 23 and is wirelessly transmitted to the host computer 13 together with the inspection position information. At this time, the scanning actuator 24 can perform the position control of the flaw detector head 35 in conjunction with the control for the autonomous travel of the carriage 14, or can perform the position control of the flaw detector head 35 independently of the autonomous travel of the carriage 14.

[0108] The inspection device 15 has an inspection head 35 and an inspection result production unit 71 that produces inspection results. The inspection result production unit 71 produces inspection results based on the inspection information obtained by the probe (inspection sensor) and the position information of the inspection head 35. As inspection results, for example, an inspection map associating the position information of the metal plate and the flaw detection result information is produced. With the device structure of the present invention, the production of inspection results can be performed by the inspection device 15, and there is no need for the host computer 13 to produce the inspection map.

[0109] Even when the ultrasonic phased array technology is used as the inspection sensor (probe), for a large amount of flaw detection data, there is no need to transfer the data to the host computer 13, and inspection results can be efficiently produced and evaluated even when the amount of information of the flaw detection data becomes large.

[0110] When the ultrasonic phased array technology is used, what can be utilized is a well-known technology. A simple explanation is given below. When the ultrasonic phased array technology is used, the inspection sensor provided in the inspection head 35 is a phased array probe in which a plurality of ultrasonic oscillators are arranged. In the ultrasonic phased array method, when ultrasonic waves are transmitted from each ultrasonic oscillator, the timing (delay time) of the transmission is electronically controlled, whereby the ultrasonic beam can be focused on an arbitrary position or the ultrasonic waves can be propagated in an arbitrary direction.

[0111] In addition, when the ultrasonic phased array technology is used to depict a two-dimensional defect image in the X direction and the Y direction, since electronic scanning of the beam is performed in the X direction, the defect image can be depicted within the range of the number of channels only by the mechanical scanning of the inspection head 35 in the Y direction. As the beam scanning method, well-known scanning methods such as linear scanning, sector scanning, and DDF (Dynamic Depth Focusing) can be adopted.

[0112] A pulse signal can be adopted as the position information of the inspection head 35. In this case, for example, a pulse signal output board 72 as an output unit is mounted on the mounting computer 21, and this output unit outputs a pulse signal corresponding to the change amount of the position of the inspection head 35 updated in each control cycle performed by the mounting computer 21 to the probe (inspection sensor). As the pulse signal, for example, pulse signals (A phase and B phase) in the X-axis direction and the Y-axis direction indicating the position in the horizontal plane of the steel plate can be adopted.

[0113] Thus, it is not necessary to take out a large amount of flaw detection data from the inspection device 15. That is, the path calculation of the beams oscillated by the multiple oscillators in the phased array method, and the analysis of the flaw detection results considering the path, etc. can be performed by the inspection device 15, and it is not necessary to output a large amount of data such as flaw detection data to the host computer 13. Therefore, the inspection method of the present invention is a highly practical method.

[0114] The mounting computer 21 mounted on the carriage 14 has a pulse signal output board (output unit) 72, and the pulse signal output board (output unit) 72 outputs a pulse corresponding to the change amount of the position of the flaw detector 35 updated for each control cycle to the inspection device 15. When making a flaw detection map, for example, based on the actual position and posture information of the carriage 14 and the stroke position of the scanning actuator 24, the real-time flaw detection position (the position of the flaw detector 35) is calculated and output to the inspection device 15 as a pulse signal. In addition, the actual position and posture information of the carriage 14 is obtained in real time through IGPS. The output frequency of the pulse signal generated by the pulse signal output board 72 is preferably determined to be synchronized with the setting conditions of the inspection device 15 and the mechanical scanning speed of the flaw detector 35.

[0115] For example, when the flaw detection map display resolution (display resolution of the inspection result) is 2 mm and the flaw detection data acquisition frequency is 50 Hz, the maximum scanning speed at which no flaw detection data is missing between the display resolutions of 2 mm is their product, which is 100 mm / s. That is, if the mechanical scanning speed of the flaw detector 35 exceeds 100 mm / s, an omission will occur in the flaw detection data during the period when the display resolution advances by 2 mm. Therefore, in order to improve the accuracy of the flaw detection result, it is preferable to adjust the mechanical scanning speed of the flaw detector 35 so that the flaw detection data can be reliably acquired during the period when the display resolution advances by 2 mm.

[0116] In addition, for example, the flaw detection data acquisition frequency is 50 Hz, the pulse resolution in the inspection device 15 on the pulse signal receiving side is set to 10 pulses / mm, and the spatial resolution when displaying the flaw detection result, that is, the flaw detection map display resolution, is set to 1 mm. In this case, the pulse frequency to be input to the inspection sensor is represented by the product of these, which is 500 Hz. When the output frequency of the pulse signal generated by the pulse signal output board 72 is 500 Hz synchronized with the above, the temporal change in the position of the flaw detector 35 received by the inspection sensor (probe) is continuous and close to the actual movement. Figure 4A shows the relationship between the actual flaw detector position information (pulse signal) and the pulse signal output by the pulse signal output board 72 in this case.

[0117] On the other hand, when the frequency of the pulse signal generated by the pulse signal output board 72 is greater than 500 Hz, the change over time in the position of the flaw detector head 35 received by the inspection sensor (probe) becomes discontinuous (step-shaped). Moreover, due to accidental factors such as the timing of the stroke position depending on the specifications of the linear slider for probe scanning and the difference in the timing of the pulse output instruction depending on the control cycle of the mounted computer 21, there may be a situation where the position information is not updated within the display resolution of 2 mm. In Figure 4B shows the relationship between the position information (pulse signal) of the actual flaw detector head and the pulse signal output by the pulse signal output board 72 in this case.

[0118] From these results, it is known that it is preferable to synchronize the output frequency of the pulse signal generated by the pulse signal output board 72 with the product of the flaw detection data acquisition frequency set by the inspection device 15, that is, the number of flaw detection data acquisitions per unit time (times / sec), the pulse resolution (pulse / mm), and the flaw detection map display resolution (mm / times), and to set the speed of the mechanical scanning of the flaw detector head 35 to be below the upper limit speed obtained by multiplying the flaw detection map display resolution (display resolution of the inspection result) by the flaw detection data acquisition frequency.

[0119] Next, the physical structure of the carriage 14, which forms the main part of the self-propelled inspection device for metal plates according to the present invention, will be described. Figure 5 is a side view of the carriage 14, Figure 6 is a horizontal cross-sectional view taken along line A-A thereof, Figure 7 is a front view thereof. In addition, Figure 8 is a cross-sectional view showing an enlarged view of its drive unit.

[0120] The carriage 14 has a carriage main body 31, and the carriage main body 31 is divided into an upper layer portion 31a, a middle layer portion 31b, and a lower layer portion 31c.

[0121] In the upper layer portion 31a, in addition to the above-mentioned navigation receiver 12a, mounted computer 21, IO board 23, and pulse signal output board 72, an ultrasonic flaw detector 32 and a wireless communication unit 33, which form part of the inspection device 15, are provided.

[0122] In the middle layer portion 31b, a water tank 34 serving as a water supply unit is provided. When inspecting the metal plate 10 based on ultrasonic flaw detection, it is necessary to always fill the space between the probe and the metal plate 10 with water. Therefore, water is always supplied from the water tank 34 to the space between the probe and the metal plate via a water supply hose (not shown). In addition, since the volume of the water tank has a limit, the water source can also be provided outside and supplied by a hose.

[0123] In the lower part 31c, there are provided an edge detection sensor 22 disposed around it, a traveling wheel 26, a drive control unit 25, a wheel drive motor 27a as a wheel motor 27 and a steering motor 27b, a flaw detector head 35 forming part of the inspection device 15, an edge detection sensor controller 37, and a battery 38.

[0124] In the case where a water source is provided outside and supplied by a hose, it is preferable to use a supply method in which the hose does not get caught on the end of the material to be flaw-detected and impede the movement of the robot, and the water supply does not stop due to hose kinking. For example, pillars are provided around the flaw detection work area, and a guide rail having a plurality of cable hangers for hanging the hose is rotatably fixed to the pillar, whereby the hose can be supplied from above the robot through the cable hanger. Utilizing the tension acting on the hose due to the movement of the robot, the guide rail rotates and the cable hanger slides on the guide rail, so that water supply can be stably performed without impeding the movement of the robot.

[0125] In this case, together with the water supply based on the hose, power and signals can also be supplied by wire. For example, in this case, the computer 21 is not mounted on the robot, and is housed in an operation panel provided near the work area, and the two are connected by a communication cable, whereby the equipment structure of the robot main body can be simplified and lightened. In addition, the wireless communication unit 33 is not mounted and wired communication is used, whereby the instability of wireless communication caused by environmental interference and the like can be eliminated, and a highly reliable system structure can be achieved. In addition, the power supply for driving the robot main body and the power supply to the inspection sensor (probe) mounted on the robot are externally supplied based on wire, whereby it is not necessary to mount the battery 38, and failures such as abnormal stops caused by battery depletion can be prevented.

[0126] The flaw detector head 35 has a probe as an inspection sensor for scanning the inspection area of the metal plate 10, and is supported by a flaw detector head support mechanism 36. The flaw detector head 35 is mounted on the vertical axis 39 via the flaw detector head support mechanism 36, and the vertical axis 39 can move in the vertical direction along the vertical guide rail 40. In addition, the vertical axis 39 is mounted on the horizontal guide rail 42 through the mounting portion 41, and the horizontal guide rail 42 is scanned along the horizontal scan axis 43 by a scan actuator 24 (not shown in Figure 5 、 Figure 6 and Figure 7 ).

[0127] Typically, the edge detection sensor 22 is composed of an eddy current sensor. Thus, when the carriage 14 autonomously travels on the metal plate 10, the plate end is detected to prevent the carriage 14 from falling off the metal plate 10. At the same time, the edge detection sensor 22 is used as a sensor for traveling along the plate end during the flaw detection of the plate end during flaw detection of the four sides. For example, as Figure 6As shown, for the side where the flaw detector head 35 is provided, two edge detection sensors 22 are arranged on the same line as the flaw detector head 35. The two edge detection sensors 22 always control the traveling direction of the carriage 14 in a manner of detecting the plate end, so that inspection along the plate end can be performed. In addition, for the side where the flaw detector head 35 is not provided, two edge detection sensors 22 are also arranged on the left and right in the same way.

[0128] Four wheels 26 are provided at the bottom of the carriage 14 in a manner that they can be independently steered and driven by more than 90°, enabling omnidirectional control based on them. After detecting the operating state of the motors using the respective motor encoders (not shown) of the multiple wheel motors, omnidirectional control for the control of a normal robot is performed using the detected signals.

[0129] The drive unit 50 independently drives each wheel and is provided for each wheel. As Figure 8 shown, as the wheel motor 27, it respectively has a wheel drive motor 27a as the first drive system and a steering motor 27b as the second drive system for steering. A pinion 51 is mounted on the shaft of the steering motor 27b for steering, and this pinion 51 is engaged with the rack 53 on the outer periphery of the steering turntable 52.

[0130] The housing of the wheel drive motor 27a (not shown) is mounted on the upper part of the steering turntable 52, and the output rotating shaft 54 of the reduction gear of the wheel drive motor 27a extends downward through the steering turntable 52. A first cross-axis gear 55 is coupled to the lower end of the output rotating shaft 54. A second cross-axis gear 56 is engaged with the first cross-axis gear 55, and the second cross-axis gear 56 is coupled to the shaft member 57 of the wheel 26. The shaft member 57 is supported by a suspension structure 58 extending downward from the steering turntable 52 so as to be rotatable.

[0131] Therefore, each wheel 26 is rotated by the wheel drive motor 27a, and through the steering motor 27b, the wheel 26 is steered together with the steering turntable 52 and the suspension structure 58. The wheel drive motor 27a can rotate the wheel forward and backward, and the steering motor 27b can steer by more than 90° around an axis orthogonal to the metal plate surface on which the carriage 14 travels and offset toward the center side of the carriage relative to the wheel 26.

[0132] Next, the steering mode for determining the traveling direction of the self-propelled inspection device for metal plates will be described. Figures 9A to 9D This is an explanatory diagram for explaining this steering mode. Figure 9A is moving left and right, Figure 9B is moving diagonally, Figure 9C is moving forward and backward, Figure 9DIt is the steering state of in-place turning. In addition, in-place turning means that vehicles with crawlers (endless tracks), such as hydraulic excavators and battle tanks, rotate the left and right endless tracks in opposite directions at the same speed, thereby changing the orientation of the vehicle body without moving.

[0133] Next, the inspection operation in the self-propelled inspection device 300a for metal plates adopting the position measurement system 200a according to the first embodiment will be described. First, the acquisition of the position and posture information of the metal plate in the pre-process of setting the target inspection position and inspection path will be described. Figure 10 It is a diagram for explaining the method of obtaining the position and posture information of the metal plate. Figure 11 It is a diagram showing the system configuration at this time.

[0134] As shown in these diagrams, here, the contact probe 61 of the metal plate position and posture detection jig 60 equipped with the navigation receiver 12a of the position measurement system 200a is attached to the corner position of the metal plate 10 as the measurement target to perform this position measurement. In order to measure the contact point coordinates with high precision, the geometric positional relationship between the navigation receiver 12a and the contact probe 61 is usually determined with high precision within ±50 micrometers. In the position measurement system 200a, information on the position (X, Y, Z) and posture (θx, θy, θz) of the navigation receiver 12a is obtained. If the positional relationship between the navigation receiver 12a and the contact probe 61 is determined, an operation of converting the position information of the navigation receiver 12a into the position information at the position of the contact probe 61 can be performed.

[0135] Figure 12 Processes 1 to 5 are flowcharts for detecting the position and posture of the metal plate. Figure 13This is a diagram showing the coordinate system set based on the measurement points at the plate ends in the operation process for detecting the position and orientation of a metal plate. First, in the operation screen of the host computer 13 that constitutes the position measurement system 200a, select the edge position detection mode of the metal plate (step 1). Next, use the fixture for detecting the position and orientation of the metal plate to measure the position of measurement point A, which is the plate end corner (corner) serving as the origin (step 2). Then, measure the position of plate end measurement point B, which is the plate corner (corner) adjacent to measurement point A along the rolling direction (step 3). Next, measure the position of plate end measurement point C, which is the plate corner (corner) diagonal to measurement point A (step 4). In this way, based on detecting the edge positions at at least three of the four corners (corners) of the metal plate, calculate the rectangular shape including these three points at the corner, thereby enabling the detection of the position and orientation of the metal plate. The host computer 13 calculates the position and orientation of the metal plate in the case of assuming a rectangular shape including the measured position coordinate data of the above-mentioned measurement points A (origin), B, and C at three corners. Set a coordinate system with measurement point A as the origin, the vector direction from measurement point A to B as the X direction, and the direction orthogonal to it as the Y direction (step 5). In addition, hereinafter, this coordinate system is referred to as the metal plate coordinate system.

[0136] In addition, since the metal plate is not necessarily rectangular, it is also possible to assume such a situation and detect the position and orientation of the metal plate as a four-sided shape connecting the four corners of the metal plate on a line.

[0137] In addition, in the case of the second embodiment, set the above-mentioned contact probe 61 on the fixture for detecting the position and orientation of the metal plate where the navigation transmitter 12b of the position measurement system 200b is installed, and attach it to the corner position of the metal plate 10 to be measured to perform this position measurement.

[0138] Next, a method for setting the target inspection position and inspection path will be described. Figure 12 Steps 6 to 10 are the flowcharts of the method for setting the target inspection position and inspection path. After setting the metal plate coordinate system as described above, in the setting software 17 in the host computer 13, select the target inspection position setting mode of the metal plate (step 6), and select the inspection mode of the metal plate based on industrial standards and the contract with the customer (step 7). Continuing on the software, for the flaw detection of the four sides of the metal plate, specify the flaw detection parts, intervals, and times (step 8), and for the flaw detection inside the steel plate, specify the flaw detection parts, the scanning direction of the probe, and the interval (step 9). Based on this specification and the position and orientation information of the metal plate, the software determines the target inspection position and inspection path in the metal plate coordinate system (step 10).

[0139] As an example of the inspection mode, in Figures 14A to 14CThe figure shows the scan divisions and inspection areas specified in "7.6 Inspection Areas (Scanning Areas and Ranges)" of the ultrasonic flaw detection inspection method for steel plates for pressure vessels in JIS G0801. Figure 14A Shows the inspection areas when inspecting in the rolling direction and the direction perpendicular to it. Figure 14B Shows the case of inspecting in the rolling direction. Figure 14C Shows the inspection areas for the case of inspecting in the direction perpendicular to the rolling direction with respect to the rolling direction. In this standard, as the inspection areas, the four peripheries of the metal plate and the inspection of the interior of the steel plate are specified. For the four peripheries, the inspection pitch is specified, and for the interior of the steel plate, the inspection pitch and the scanning direction are specified. Regarding the inspection of such metal plates, it is not limited to JIS, including foreign standards, and there are various standards. Ultimately, inspections based on contracts with customers need to be carried out. Therefore, in the selection of the above inspection modes, software for setting inspection modes is prepared in advance as needed so as to be able to respond flexibly according to the requirements of customers.

[0140] Figure 15A Is a conceptual diagram of the A region, which is the primary information obtained during flaw detection. Figure 15B Is a graph showing the relationship between the sound pressure received by the probe and the ultrasonic propagation time in the A region. Figure 15C Is a conceptual diagram of the B region that performs mapping display related to the vertical cross-section of the material to be inspected in association with the information of the A region and the scanning position. Figure 15D Is a conceptual diagram showing the information obtained in the XZ plane of the material to be inspected in the B region. Figure 15E Is a conceptual diagram of the C region that performs mapping display related to the horizontal cross-section of the material to be inspected. Figure 15F Is a conceptual diagram showing the information obtained in the XY plane of the material to be inspected in the C region. The A region is obtained as the primary information during flaw detection. The "degree of flaw" can be extracted from the echo peak height, and the "depth direction position of the flaw" can be extracted from the ultrasonic propagation time. In Figure 15A 、 Figure 15C 、 Figure 15E The defective parts are indicated by dots.

[0141] In the case of using the phased array method, Figure 15A 、 Figure 15C 、 Figure 15E The X-axis direction is the array direction of the oscillators, i.e., the electronic scanning direction, and the Y-axis direction is the mechanical scanning. As described above, the focal length is controlled in the plate thickness direction, thereby enabling the provision of an S / N ratio with respect to the pulse echo method. In addition, the inspection results include information in the plate thickness direction in addition to the X-axis and Y-axis direction positions, so the above A to C regions can be obtained.

[0142] In "9. Classification and Evaluation of Defects" in the ultrasonic flaw detection inspection method for steel plates for pressure vessels in JIS G0801, a determination method for the "degree of defects" based on the peak height of echoes is specified, but there is currently no regulation regarding the display of the "position in the depth direction of defects". However, for quality assurance and flexible response to customer requirements, it is necessary to grasp the three-dimensional distribution of defects in the steel plate as a product, including the "position in the depth direction of defects".

[0143] When scanning the target inspection position and inspection path with the probe, while identifying the current position of the probe, inspection is carried out, and flaw detection information associated with the inspection position information on the metal plate plane is obtained, so that the position of the defect can be correctly grasped. For example, when there are defects such as those represented by dots inside the metal plate Figure 16 as shown in the figure, as Figure 17 shown, based on the flaw detection information associated with the inspection position information, the configuration of the defects inside the metal plate is mapped and displayed on the metal plate plane. Thus, the planar configuration of the defects can be visualized, and the defects can be easily grasped. In addition, as Figure 18 shown, the configuration of the defects inside the metal plate can also be grasped in the thickness direction, and mapping and display can be carried out three-dimensionally within the metal plate flat. Specifically, it is possible to obtain a B region that is mapped and displayed related to the vertical section of the material to be flaw detected in association with the information of the A region and the scanning position, and a C region that is mapped and displayed related to the horizontal section.

[0144] In obtaining the position and posture information of the metal plate using the jig for detecting the position and posture of the metal plate composed of the above-mentioned navigation receiver and contact probe, the metal plate shape is assumed to be a rectangular shape. Therefore, when the metal plate is bent or in other situations, there may be a difference between the identified plate end position of the metal plate obtained by the above method and the actual plate end position, and when traveling based on the target inspection position and inspection path determined assuming a rectangular shape, the trolley may fall off the metal plate. Therefore, as described above, when performing four-sided flaw detection, it is preferable to travel while correcting by the edge detection sensor provided around the device outside the target inspection position and inspection path.

[0145] Figure 19 is an explanatory diagram for explaining the movement of the self-propelled inspection device (trolley) during four-sided flaw detection. (1) During inspection Figure 19When at the lower side plate end, the control device travels in the traveling direction such that the two edge detection sensors 22 arranged on the side surface of the carriage 14 in line with the flaw detector head 35 always detect the plate end. (2) Based on the target inspection position and inspection path, if the plate end position ahead in the traveling direction approaches, the device starts to decelerate. (3) Finally, when the two edge detection sensors 22 provided on the front surface of the device detect the edge of the metal plate 10, it temporarily stops. (4) Next, by an actuator (not shown) for scanning the flaw detector head 35 in the horizontal direction, the flaw detector head 35 is moved until it reaches the plate end position. (5) With the device stopped, a steering motor (not shown) is driven to turn the wheels 26 to a direction orthogonal to the previous traveling direction. (6) The device is advanced to perform Figure 19 the inspection of the left side plate end. Hereinafter, it is repeatedly performed until the specified four - week flaw detection is completed.

[0146] Figure 20A 、 Figure 20B is an explanatory diagram for explaining the movement of a self - propelled inspection device (carriage) during the internal flaw detection of a metal plate. For the interior of the metal plate 10, the inspection is performed based on the aforementioned target inspection position and inspection path, regardless of the plate end. According to the target inspection position path, the target carriage position and the target scanning amount of the actuator (not shown) for scanning the flaw detector head 35 are determined, and the control related to the driving and steering of the wheels 26 and the scanning of the scanning actuator 24 is performed.

[0147] Figures 21A to 21E is a diagram showing the inspection position and path in the case of performing the flaw detection of the four sides and the interior of the metal plate. Here, it shows the following situation, that is, first, as Figure 21A shown, after performing two - week flaw detection of the plate end and the area 75 mm inside from the plate end, as Figures 21B to 21E shown, the inspection is performed at 50 - mm intervals along the rolling direction for the distance from the adjacent scanning lines.

[0148] As described above, according to the first embodiment, a navigation receiver 12a is provided on the carriage 14 equipped with a sensor (probe) for inspecting defects in a metal plate. The navigation receiver 12a receives the rotating fan beam emitted from the navigation transmitter 11a of the position determination system 200a and identifies the rotating fan beam as an IGPS signal, thereby identifying its own position. According to the second embodiment, a navigation transmitter 12b is provided on the carriage 14 equipped with a sensor (probe) for inspecting defects in a metal plate. Laser is emitted 360° through a laser triangulation device from the navigation transmitter 12b, and the reflected light from the reflector 11b is received to identify its own position. Thus, without using the marks on the metal plate and the marks for image processing, the position and angle of the carriage 14 on the metal plate can be accurately identified. In addition, the deviation between the thus identified own position and the target position is calculated, and based on this deviation, the forward rotation, reverse rotation, and stop of the wheels are instructed to make the carriage 14 autonomously travel to a specified target position. Therefore, the outer periphery of the metal plate can also be inspected. In addition, the progressiveness with respect to the target travel route can be ensured.

[0149] In addition, in any of the embodiments, based on the position and posture information of the metal plate measured in advance, the scanning mode of the probe that approaches and scans the metal plate and the inspection positions and paths corresponding to the determined mode are determined. The target positions of the actuator that determines the position of the probe relative to the carriage and the carriage position can be determined in a manner that realizes the scanning path, so various scanning modes can be handled. In particular, for the carriage position, it can be controlled such that the deviation between the target position and the current position based on the navigation receiver is within the allowable amount for flaw detection. Therefore, any scanning mode can be accurately handled.

[0150] Also, the carriage 14 traveling on the metal plate surface may be configured to have four wheels that can rotate forward and backward, and a drive unit 50 is provided corresponding to each wheel, having drive motors for rotating each wheel. In addition, the carriage 14 may be structured with a steering motor capable of steering the wheels by more than 90° around an axis that is orthogonal to the metal plate surface on which the carriage 14 travels and is offset toward the carriage center side relative to the wheels. By having these structures, in addition to normal forward and backward movement, the carriage 14 can perform diagonal movement and left - right movement while maintaining the orientation of the front of the carriage. And the carriage 14 can perform a turning action in place. In addition, for various disturbances that cause a deviation between the current position and the target position, extremely fine position adjustment of the carriage 14 can be performed, and the straight - running property with respect to the target travel route can be made extremely high.

[0151] In addition, the trolley 14 that travels on the metal plate surface is provided with an edge detection sensor for detecting the edge of the metal plate to be inspected. Therefore, it is possible to prevent the trolley 14 from protruding from the metal plate and falling, and during the inspection of the edge of the metal plate, it is possible to perform an inspection along the edge of the metal plate.

[0152] In addition, it is possible to automatically detect flaws and internal defects on the surface of the metal plate according to the product inspection specifications of the metal plate. There is no need for an inspector to operate a flaw detector to detect flaws on the surface of the metal plate, which has the advantage of avoiding accidents such as falling on a water-sprinkled metal plate.

[0153] Furthermore, the present invention is not limited to the above-described embodiments and can be variously modified. For example, in the above-described embodiment, an example in which 4 wheels are provided on the trolley 14 is illustrated, but the number of wheels is not limited to 4, and 2 or more is sufficient. In addition, as long as the number of navigation receivers 12a in the position measurement system 200a of the self-propelled inspection device 300a for metal plates according to the first embodiment is 1 or more. In addition, as long as the number of reflectors 11b in the position measurement system 200b of the self-propelled inspection device 300b for metal plates according to the second embodiment is 1 or more.

[0154] Next, a method for manufacturing a metal plate using the self-propelled inspection device for metal plates of the present invention will be described. The method for manufacturing a metal plate of the present invention includes: a manufacturing process for manufacturing a metal plate; an inspection process for inspecting defects present in the metal plate using the self-propelled inspection device for metal plates of the present invention; and a sorting process for sorting the metal plates based on the inspection results obtained in the inspection process.

[0155] Examples of the metal plate include a steel plate, an aluminum plate, and a copper plate. In the manufacturing process for manufacturing these metal plates, known methods for manufacturing these metal plates can be used.

[0156] In addition, in the method for manufacturing a metal plate of the present invention, defects present in the metal plate are inspected using the self-propelled inspection device for metal plates of the present invention, and the metal plates are sorted based on the inspection results. Specifically, for example, according to the type and use of the metal plate, the acceptance criteria for the size and number of defects are determined in advance, and the metal plates that meet the acceptance criteria are sorted based on the inspection results obtained in the inspection process.

[0157] The embodiments of the present invention described above should be understood as illustrative in all aspects and not restrictive. That is, the scope of the present invention is shown by the scope of the technical solution rather than the above description, and is intended to include meanings equivalent to the scope of the technical solution and all changes within the scope.

[0158] Description of Reference Numerals

[0159] 10... Metal plate; 11a... Transmitter for navigation; 11b... Reflector; 12a... Receiver for navigation; 12b... Transmitter for navigation; 13... Main computer; 14... Trolley; 15... Inspection equipment (inspection section); 16... Software for position calculation; 17... Setting software; 21... Onboard computer; 22... Sensor for edge detection; 23... IO board; 24... Scanning actuator; 25... Drive control section; 26... Wheels; 27... Motors for wheels; 27a... Motor for wheel drive (first drive system); 27b... Motor for steering (second drive system); 31... Trolley body; 31a... Upper layer section; 31b... Middle layer section; 31c... Lower layer section; 32... Ultrasonic flaw detector; 33... Wireless communication unit; 34... Water tank; 35... Flaw detection head; 36... Flaw detection head support mechanism; 37... Sensor controller for edge detection; 38... Battery; 39... Vertical axis; 40... Vertical guide rail; 41... Mounting section; 42... Horizontal guide rail; 43... Horizontal scanning axis; 50... Drive section; 51... Pinion; 52... Steering turntable; 53... Rack; 54... Output rotating shaft; 55... First cross-axis gear; 56... Second cross-axis gear; 57... Shaft component; 58... Suspension structure; 60... Fixture for posture detection; 61... Contact probe; 71... Inspection result production section; 72... Pulse signal output board (output section); 100a, 100b... Overall system; 200a, 200b... Position measurement system; 300a, 300b... Self-propelled inspection device for metal plates

Claims

1. A self-propelled inspection device for metal plates, which uses a position measurement system based on the principle of triangulation to measure the position to inspect the metal plates, characterized in that: have: A trolley that travels on the surface of the metal sheet; a navigation transmitter for transmitting a positioning system signal or a navigation receiver for receiving a positioning system signal, mounted on the vehicle; An inspection unit including a flaw detection head mounted on the carriage and having an inspection sensor for scanning an inspection area of ​​the metal plate, and an inspection result producing unit for producing an inspection result; as well as The control unit controls the autonomous driving of the trolley to the target position and controls the scanning actuator for scanning the flaw detection head based on the position of the trolley measured by the position measurement system and the target position of the trolley when performing the inspection. The inspection result generating unit generates the inspection result based on the inspection information obtained by the inspection sensor and the position information of the flaw detection head. The self-propelled inspection device for metal plates includes an output unit that outputs a pulse signal corresponding to the amount of change in the position of the flaw detection head updated in each control cycle to the inspection unit as position information of the flaw detection head. The output frequency of the pulse signal generated by the output unit is set to be synchronized with the product of the flaw detection data acquisition frequency set by the inspection unit, the pulse resolution, and the display resolution of the inspection result. The speed of the mechanical scanning of the flaw detection head is equal to or less than an upper limit speed obtained by the product of the display resolution of the inspection result and the flaw detection data acquisition frequency.

2. The self-propelled inspection device for metal plates according to claim 1, characterized in that: The control unit performs control to cause the vehicle to autonomously travel to the target position and posture based on the position and posture of the vehicle measured by the position measurement system and the target position and posture of the vehicle when performing an inspection.

3. The self-propelled inspection device for metal plates according to claim 1, characterized in that: The inspection sensor is a phased array probe in which a plurality of ultrasonic transducers are arranged.

4. The self-propelled inspection device for metal plates according to claim 2, characterized in that: The inspection sensor is a phased array probe in which a plurality of ultrasonic transducers are arranged.

5. The self-propelled inspection device for metal plates according to any one of claims 1 to 4, characterized in that: The positioning system is an IGPS, that is, an indoor global positioning system. The navigation receiver receives a rotating fan beam emitted from one or more navigation transmitters of the IGPS, and recognizes the rotating fan beam as an IGPS signal which is the positioning system signal.

6. The self-propelled inspection device for metal plates according to any one of claims 1 to 4, characterized in that: The position determination system is a system using laser triangulation technology. The navigation transmitter is a laser triangulation device having the function of transmitting and receiving laser light, and reflects the emitted laser light on one or more reflectors, and receives the reflected light as the position measurement system signal.

7. The self-propelled inspection device for metal plates according to any one of claims 1 to 4, characterized in that: The vehicle has at least two rotatable wheels and a driving unit for driving the wheels. The driving unit is constructed to include a first driving system that is arranged corresponding to each wheel and rotationally drives each wheel, and a second driving system that can drive the wheel to turn more than 90 degrees around an axis that is orthogonal to the metal plate surface on which the trolley travels and is offset toward the center side of the trolley relative to each wheel.

8. The self-propelled inspection device for metal plates according to any one of claims 1 to 4, characterized in that: The device further includes an edge detection sensor which is provided on the carriage and is used to detect an edge of the metal plate to be inspected.

9. A self-propelled inspection method for metal plates, which is a self-propelled inspection method for metal plates that uses a position measurement system that measures positions based on the principle of triangulation to inspect the metal plates, characterized in that: A self-propelled inspection device for metal plates is provided, comprising: A trolley that travels on the surface of the metal sheet; a navigation transmitter for transmitting a positioning system signal or a navigation receiver for receiving a positioning system signal, mounted on the vehicle; An inspection unit including a flaw detection head mounted on the carriage and having an inspection sensor for scanning an inspection area of ​​the metal plate, and an inspection result producing unit for producing an inspection result; as well as a control unit that controls the autonomous movement of the trolley to the target position and controls a scanning actuator that scans the flaw detection head based on the position of the trolley measured by the position measurement system and the target position of the trolley when performing the inspection; as well as an output unit, which outputs a pulse signal corresponding to the amount of change in the position of the flaw detection head updated in each control cycle as position information of the flaw detection head to the inspection unit, The output frequency of the pulse signal generated by the output unit is set to be synchronized with the product of the flaw detection data acquisition frequency set by the inspection unit, the pulse resolution, and the display resolution of the inspection result. The mechanical scanning speed of the flaw detection head is less than the upper limit speed obtained by the product of the display resolution of the inspection result and the frequency of obtaining the flaw detection data. The inspection result generating unit generates the inspection result based on the inspection information obtained by the inspection sensor and the position information of the flaw detection head.

10. The self-propelled inspection method for metal plates according to claim 9, characterized in that: The control unit controls the vehicle to autonomously travel to the target position and posture based on the position and posture of the vehicle measured by the position measurement system and the target position and posture of the vehicle when performing an inspection.

11. A method for manufacturing a metal plate, characterized in that: have: Manufacturing process, manufacturing metal sheets; An inspection step, using the self-propelled inspection device for metal plates according to any one of claims 1 to 8 to inspect defects existing in the metal plates; as well as The sorting step sorts the metal plates based on the inspection results obtained in the inspection step.

Images