Inner surface shape estimation method, device and program

Abstract

To provide an inner surface shape estimation method, device and program, enabling an appropriate estimation of an inner surface shape of an inspection object.SOLUTION: An inner surface shape estimation method includes: a step of obtaining a surface shape of an inspection object; a step of setting a measurement reference point to an oscillator on a surface of the inspection object to transmit an ultrasonic signal from the oscillator to the inspection object; a step of receiving the ultrasonic signal reflected from the inspection object to acquire inner surface position data of the inspection object to the measurement reference point; a step of changing the measurement reference point to the oscillator on the surface of the inspection object to acquire plural pieces of inner surface position data to plural measurement reference points; and a step of connecting the plural pieces of inner surface position data to estimate an inner surface shape of the inspection object.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to an inner surface shape estimation method, an apparatus, and a program. [Background technology]

[0002] The ultrasonic inspection method is a method of scanning an inspection object with ultrasonic signals to detect internal defects of the inspection object. An example of the ultrasonic inspection method is a technique described in Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-46212 Summary of the Invention [Problem to be solved by the invention]

[0004] When performing a flaw detection inspection of an object by an ultrasonic inspection method, it is desirable to grasp the overall shape of the object in advance. When the object is, for example, a pipe, it is possible to measure the surface shape, but it is difficult to measure the inner surface shape.

[0005] The present disclosure is devised to solve the above-mentioned problems, and aims to provide an inner surface shape estimation method, an apparatus, and a program that enable appropriate estimation of the inner surface shape of an object to be inspected. [Means for solving the problem]

[0006] To achieve the above-mentioned object, the inner surface shape estimation method disclosed herein includes the steps of acquiring the surface shape of an object to be inspected, setting a measurement reference point for a transducer on the surface of the object to be inspected and transmitting an ultrasonic signal from the transducer toward the object to be inspected, receiving an ultrasonic signal reflected from the object to be inspected and acquiring inner surface position data of the object to be inspected relative to the measurement reference point, changing the measurement reference point for the transducer on the surface of the object to be inspected to acquire multiple pieces of inner surface position data for multiple measurement reference points, and connecting the multiple pieces of inner surface position data to estimate the inner surface shape of the object to be inspected.

[0007] The inner surface shape estimation device of the present disclosure further comprises a plurality of transducers that transmit ultrasonic signals to an object to be inspected and receive ultrasonic signals reflected from the object to be inspected, and a control unit that acquires data obtained by scanning the object to be inspected with ultrasonic signals using the plurality of transducers and processes and synthesizes the acquired ultrasonic signal data, wherein the control unit acquires the surface shape of the object to be inspected, sets measurement reference points for the transducers on the surface of the object to be inspected and transmits ultrasonic signals from the transducers toward the object to be inspected, receives ultrasonic signals reflected from the object to be inspected and acquires inner surface position data of the object to be inspected relative to the measurement reference points, changes the measurement reference points for the transducers on the surface of the object to be inspected to acquire a plurality of pieces of inner surface position data for the plurality of measurement reference points, and connects together the plurality of inner surface position data to estimate the inner surface shape of the object to be inspected.

[0008] In addition, the program disclosed herein causes a computer to execute the steps of acquiring the surface shape of the object to be inspected, setting a measurement reference point for a transducer on the surface of the object to be inspected and transmitting an ultrasonic signal from the transducer toward the object to be inspected, receiving an ultrasonic signal reflected from the object to be inspected and acquiring inner surface position data of the object to be inspected relative to the measurement reference point, changing the measurement reference point for the transducer on the surface of the object to be inspected to acquire multiple pieces of inner surface position data for multiple measurement reference points, and connecting the multiple pieces of inner surface position data to estimate the inner surface shape of the object to be inspected. Effect of the Invention

[0009] According to the inner surface shape estimation method, apparatus, and program disclosed herein, it is possible to appropriately estimate the inner surface shape of an object to be inspected. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a block diagram showing a schematic configuration of an inner surface shape estimation device according to the present embodiment. [Diagram 2] FIG. 2 is a schematic diagram showing a jig used when estimating the inner surface shape. [Diagram 3] FIG. 3 is a schematic diagram for explaining the arrangement of the jigs. [Figure 4] FIG. 4 is a schematic diagram for explaining the process of overlaying the acquired images. [Diagram 5] FIG. 5 is a flowchart showing the inner surface shape estimation method of the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Preferred embodiments of the present disclosure will be described in detail below with reference to the drawings. Note that the present disclosure is not limited to these embodiments, and when there are multiple embodiments, the present disclosure also includes a configuration in which each embodiment is combined. In addition, the components in the embodiments include those that a person skilled in the art can easily imagine, those that are substantially the same, and those that are within the so-called equivalent range.

[0012] <Inner surface shape estimation device> FIG. 1 is a block diagram showing a schematic configuration of an inner surface shape estimation device according to the present embodiment.

[0013] As shown in FIG. 1, the object to be inspected is a pipe 1. However, the object to be inspected is not limited to the pipe 1. The pipe 1 as the object to be inspected has a front surface 1a and an inner surface (rear surface) 1b. The inner surface shape estimation device 10 is a device that estimates the inner surface shape of the pipe 1 as the object to be inspected. However, the inner surface shape estimation device 10 may also use an inspection device (flaw detection device) for detecting (flaw detection) internal defects such as cracks in the pipe 1 as the object to be inspected.

[0014] The inner surface shape estimation device 10 includes a flaw detector 11, a control unit 12, an operation unit 13, a display unit 14, and a memory unit 15.

[0015] <Flaw detector> The flaw detector 11 has a linear array probe 21. The flaw detector 11 also has a pulser, a receiver, a data storage unit, and a control element switching unit, not shown. The linear array probe 21 has a plurality (N pieces) of transducers (elements) 22. The plurality of transducers 22 are arranged in a linear array. A medium 2 capable of propagating an ultrasonic signal S is filled between the transducer 22 and the pipe 1. The transducer 22 transmits the ultrasonic signal S to the pipe 1 via the medium 2. The transducer 22 also receives the ultrasonic signal S reflected from the pipe 1 via the medium 2. The flaw detector 11 switches between the transducer 22 that transmits the ultrasonic signal S among the plurality of transducers 22 in accordance with an instruction from the control unit 12.

[0016] The medium 2 filling the gap between the transducer 22 and the pipe 1 may be any material that can propagate ultrasonic waves. For example, ultrasonic transmission gel, water, etc. can be used as the medium 2. When ultrasonic transmission gel is used as the medium 2, by pressing a pocket of the ultrasonic transmission gel against the surface of the pipe 1 with an appropriate force, the ultrasonic transmission gel deforms according to the shape of the pipe 1 even if the surface of the pipe 1 has a complex shape. Therefore, the medium 2 can fill the gap between the pipe 1 and the linear array probe 21 without leaving any gaps. This allows the ultrasonic signal S to propagate between the linear array probe 21 and the pipe 1 via the medium 2.

[0017] <Control Unit> The control unit 12 is a processor provided separately from the flaw detector 11 and connected to the flaw detector 11. The control unit 12 is, for example, an externally connected personal computer. The control unit 12 may be provided integrally with the flaw detector 11.

[0018] The control unit 12 is an arithmetic processing device constituted by, for example, a CPU (Central Processing Unit) and the like. The control unit 12 is connected to the flaw detector 11. The control unit 12 loads a program stored in the storage unit 15 into memory and executes instructions included in the program. In more detail, the control unit 12 acquires information on the inspection conditions set by the user from the operation unit 13. Based on the acquired information on the inspection conditions, the control unit 12 controls the flaw detector 11 to sequentially transmit ultrasonic signals S from each transducer 22 of the linear array probe 21 to the pipe 1, and collects data of the ultrasonic signals S reflected from the pipe 1.

[0019] <Data collection method> The data collection of the ultrasonic signals S is performed by a so-called full matrix capture (hereinafter referred to as "FMC"). FMC is a data collection method in which the procedure of receiving the ultrasonic signals S emitted from one transducer 22 and reflected from the pipe 1 by all transducers 22 is performed by all transducers 22. More specifically, the control unit 12 causes one of the multiple transducers 22 of the linear array probe 21 to transmit the ultrasonic signal S to the pipe 1. Then, the ultrasonic signal S reflected from the pipe 1 is received by all transducers 22 and stored in the memory unit 15 via the control unit 12. At this time, if the number of the multiple transducers 22 of the linear array probe 21 is N, the memory unit 15 stores N pieces of data on the ultrasonic signals S reflected from the pipe 1.

[0020] Next, the control unit 12 causes an ultrasonic signal S to be transmitted from a transducer 22 different from the transducer 22 that generated the ultrasonic signal S at the previous timing. As a result, the memory unit 15 stores N new data items for the ultrasonic signals S reflected from the piping 1. This process is repeated until ultrasonic signals S are transmitted from all of the N transducers 22. As a result, the memory unit 15 stores N×N matrix data items for the ultrasonic signals S reflected from the piping 1. The N×N matrix data items for the ultrasonic signals S are data obtained by scanning the piping 1 with the ultrasonic signals S.

[0021] Furthermore, the control unit 12 receives data of N×N ultrasonic signals S collected by FMC from the storage unit 15. The control unit 12 processes and synthesizes the data of the N×N ultrasonic signals S, i.e., data obtained by scanning the piping 1, by a total focusing method (hereinafter referred to as "TFM"), and creates a calculation result depicting the inside of the piping 1 based on the synthesis result. The TFM is a method of analyzing the data of the ultrasonic signals S collected by FMC and synthesizing the ultrasonic signals S.

[0022] (Operation unit) The operation unit 13 is a device having an input operation function as a user interface. For example, a keyboard or a touch panel display can be used as the operation unit 13. The operation unit 13 is provided separately from the flaw detector 11 and is connected to the control unit 12. The operation unit 13 is a user interface through which the user sets the inspection conditions. The inspection conditions include, for example, information such as the arrangement of the multiple transducers 22 of the linear array probe 21 and the type of medium 2. The inspection conditions also include, for example, information such as the fact that the object to be inspected is a pipe 1, the size (wall thickness) of the pipe 1, and the type of material constituting the pipe 1. The operation unit 13 sets calculation conditions based on the inspection conditions input by the user and transmits them to the control unit 12.

[0023] (Display) The display unit 14 is a device equipped with a display function for displaying the inspection results. For example, a display or a touch panel display can be used as the display unit 14. The display unit 14 is provided separately from the flaw detector 11 and connected to the control unit 12. The operation unit 13 and the display unit 14 may be provided integrally with the flaw detector 11. The operation unit 13 and the display unit 14 may also be used as a touch panel display.

[0024] The display unit 14 is connected to the control unit 12. The display unit 14 displays the inspection results received from the control unit 12, that is, the image results of the inside of the pipe 1, to the user.

[0025] <Storage section> The storage unit 15 stores data (programs) required for various processes in the inner surface shape estimation device 10. The storage unit 15 is, for example, a semiconductor memory element such as a random access memory (RAM), a read only memory (ROM), or a flash memory, or a storage device such as a hard disk or an optical disk. The storage unit 15 is connected to the flaw detector 11 via the control unit 12. The storage unit 15 receives and stores data of N×N ultrasonic signals S collected by the FMC. The storage unit 15 transmits the stored data of ultrasonic signals S in response to a command from the control unit 12.

[0026] <Inner surface shape estimation method> FIG. 2 is a schematic diagram showing a jig used when estimating the inner surface shape, FIG. 3 is a schematic diagram for explaining the arrangement of the jig, and FIG. 4 is a schematic diagram for explaining the superimposition process of acquired images.

[0027] 2, the inner surface shape estimation method of the present embodiment estimates the inner surface shape of a pipe 1 by the above-mentioned inner surface shape estimation device 10. Here, the processing for implementing the inner surface shape estimation method by the inner surface shape estimation device 10 is performed by the control unit 12 executing a program stored in the storage unit 15. That is, the control unit 12 executes the program stored in the storage unit 15 based on a command from the operation unit 13, and controls the flaw detector 11.

[0028] The process for implementing the inner surface shape estimation method by the inner surface shape estimation device 10 is performed using a measuring jig 30. The measuring jig 30 has a jig body 31 and a plurality of (three in this embodiment) legs 32. The jig body 31 has a box shape, and the linear array probe 21 is fixed to the lower part. The linear array probe 21 has a plurality of transducers 22 arranged along the X direction, which is the scanning direction (axial direction of the pipe 1). The linear array probe 21 transmits ultrasonic signals from the transducers 22 in the Y direction, which is the transmission direction (radial direction of the pipe 1). One end of the leg 32 is connected to the lower part of the jig body 31, and the other end can be grounded to the surface 1a of the pipe 1. A plurality of legs 32 are provided. That is, the number of legs 32 may be two or more, but it is preferable to provide three or more. A medium 2 is filled between the plurality of transducers 22 of the linear array probe 21 and the pipe 1.

[0029] A measurement reference point P for the linear array probe 21 (transducers 22) is set on the surface 1a of the pipe 1. That is, the measurement reference point P is set at a grounding point on the surface 1a of the pipe 1 where one leg 32 of the measuring jig 30 is grounded. Since the linear array probe 21 formed by the transducers 22 is fixed to the measuring jig 30, the positional relationship between the linear array probe 21 and the other end of the leg 32 of the measuring jig 30 does not change. The measurement reference point P may be any leg 32 of the measuring jig 30. That is, the measuring jig 30 maintains a constant distance between the linear array probe 21 and the surface 1a of the pipe 1. Therefore, when an ultrasonic signal S is transmitted from the linear array probe 21 with each leg 32 of the measuring jig 30 grounded on the surface 1a of the pipe 1, the ultrasonic signal S is reflected by the inner surface 1b (see FIG. 1) of the pipe 1, and the reflected ultrasonic signal S is received by the linear array probe 21. Then, it is possible to obtain the position (inner surface position data) of the inner surface 1b of the pipe 1 relative to the surface 1a where the measurement reference point P is located. Here, the inner surface position data is data of one or more points (coordinates) on the inner surface 1b of the pipe 1 relative to the measurement reference point P.

[0030] In this case, the surface shape of the surface 1a of the pipe 1 is acquired in advance. A preferable method for acquiring the surface shape of the surface 1a of the pipe 1 is, for example, a method of taking a mold of the shape of the surface 1a of the pipe 1 and generating it as design drawing data by CAD. However, the method for acquiring the surface shape of the surface 1a of the pipe 1 is not limited to this method, and may be acquisition from initial manufacturing drawing data or a method using image recognition by a camera.

[0031] As shown in FIG. 3, the measuring jig 30 to which the linear array probe 21 is attached is moved at a predetermined interval along the surface 1a of the pipe 1 in the X direction. That is, the position of the measurement reference point P is changed by moving the measuring jig 30 in the X direction. For example, a plurality of measurement reference points P0, P1, P2, P3, P4, P5, P6, P7, and P8 are set by positioning the measuring jig 30 at different positions in the X direction. Then, every time the measuring jig 30 is positioned at each of the measurement reference points P0, P1, P2, P3, P4, P5, P6, P7, and P8, an ultrasonic signal S is transmitted from the linear array probe 21, and the ultrasonic signal S reflected by the inner surface 1b (see FIG. 1) of the pipe 1 is received by the linear array probe 21. Then, inner surface position data at each of the measurement reference points P0, P1, P2, P3, P4, P5, P6, P7, and P8 is obtained.

[0032] When a plurality of pieces of inner surface position data are acquired at each of the measurement reference points P0, P1, P2, P3, P4, P5, P6, P7, and P8, the inner surface shape of a predetermined length of the inner surface 1b of the pipe 1 is estimated by connecting the plurality of pieces of inner surface position data as shown in Fig. 4. That is, the inner surface position data Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7, and Q8 for each of the measurement reference points P0, P1, P2, P3, P4, P5, P6, P7, and P8 are connected. In this case, the plurality of pieces of inner surface position data are two-dimensional image data with some areas overlapping, and the inner surface shape of the pipe 1 is estimated by overlapping the plurality of pieces of inner surface position data.

[0033] <Procedure for estimating inner surface shape> FIG. 5 is a flowchart showing the inner surface shape estimation method of the present embodiment.

[0034] The inner surface shape estimation method of this embodiment includes the steps of acquiring the surface shape of a pipe (object to be inspected) 1, setting a measurement reference point P for a linear array probe 21 (transducer 22) on the surface 1a of the pipe 1 and transmitting an ultrasonic signal from the linear array probe 21 toward the pipe 1, receiving an ultrasonic signal reflected from the pipe 1 and acquiring inner surface position data of the pipe 1 relative to the measurement reference point P, changing the measurement reference point P for the linear array probe 21 on the surface 1a of the pipe 1 to acquire multiple inner surface position data for the multiple measurement reference points P, and connecting the multiple inner surface position data to estimate the inner surface shape of the pipe 1.

[0035] Specifically, as shown in FIG. 5, in step S11, the surface shape of the pipe (inspection object) 1 is acquired. For example, the shape of the surface 1a of the pipe 1 is molded and generated as design drawing data by CAD. In step S12, a plurality of measurement reference points P are set on the surface 1a of the pipe 1 for the surface shape (design drawing data) on the surface 1a of the pipe 1. That is, the measurement reference points P0, P1, P2, P3, P4, P5, P6, P7, and P8 shown in FIG. 3 are set. In this case, the number of measurement reference points, that is, the length for acquiring the inner surface shape of the pipe 1, may be set appropriately. In step S13, the measurement jig 30 to which the linear array probe 21 is attached is placed at the measurement reference point P (measurement reference point P0 in FIG. 3).

[0036] In step S14, the inner surface of the pipe 1 is measured using the linear array probe 21. That is, an ultrasonic signal S is transmitted from the linear array probe 21 toward the surface 1a of the pipe 1, and the ultrasonic signal S reflected by the inner surface 1b of the pipe 1 is received by the linear array probe 21. In step S15, the ultrasonic signals S transmitted from the multiple transducers 22 and reflected by the inner surface 1b of the pipe 1 are received, thereby acquiring the position of the inner surface 1b with respect to the surface 1a of the pipe 1 (inner surface position data).

[0037] In step S16, it is determined whether or not the inner surface position data of the pipe 1 in the predetermined range has been acquired. The inner surface position data of the pipe 1 in the predetermined range is the inner surface position data obtained by all the transducers 22 when the measurement jig 30 is positioned at the measurement reference point P (measurement reference point P0 in FIG. 3). If it is determined that the inner surface position data of the pipe 1 in the predetermined range has not been acquired (No), the process returns to step S14 and continues.

[0038] On the other hand, if it is determined that the inner surface position data of the pipe 1 in the predetermined range has been acquired (Yes), then in step S17, it is determined whether the inner surface position data of the pipe 1 in the entire range has been acquired. The inner surface position data of the pipe 1 in the entire range is the inner surface position data of the predetermined length of the pipe 1, for example, the inner surface position data Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7, and Q8 shown in FIG. 4. Here, if it is determined that the inner surface position data of the pipe 1 in the entire range has not been acquired (No), then in step S20, the measurement jig 30 to which the linear array probe 21 is attached is moved from the measurement reference point P (measurement reference point P0 in FIG. 3) to the next measurement reference point P (measurement reference point P1 in FIG. 3). Then, in steps S14 and after, the above-mentioned process is executed at the next measurement reference point P (measurement reference point P1 in FIG. 3).

[0039] If it is determined in step S17 that the inner surface position data of the pipe 1 in the entire range has been acquired (Yes), in step S18, the multiple inner surface position data are connected together to estimate the inner surface shape of a predetermined length of the inner surface 1b of the pipe 1. That is, the inner surface position data Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7, and Q8 for each of the measurement reference points P0, P1, P2, P3, P4, P5, P6, P7, and P8 are superimposed. Then, in step S19, the inner surface shape of the inner surface 1b of the pipe 1 can be estimated.

[0040] [Effects of this embodiment] The inner surface shape estimation method of the first aspect includes the steps of acquiring the surface shape of a pipe (object to be inspected) 1, setting a measurement reference point P for a linear array probe 21 (transducer 22) on the surface 1a of the pipe 1 and transmitting an ultrasonic signal from the linear array probe 21 toward the pipe 1, receiving an ultrasonic signal reflected from the pipe 1 and acquiring inner surface position data of the pipe 1 relative to the measurement reference point P, changing the measurement reference point P for the linear array probe 21 on the surface 1a of the pipe 1 to acquire multiple inner surface position data for the multiple measurement reference points P, and connecting the multiple inner surface position data to estimate the inner surface shape of the pipe 1.

[0041] According to the first aspect of the inner surface shape estimation method, inner surface position data of the pipe 1 is obtained relative to a measurement reference point P, and the inner surface shape of the pipe 1 is estimated by connecting together multiple inner surface position data relative to multiple measurement reference points P, thereby making it possible to appropriately estimate the inner surface shape of the pipe (object to be inspected) 1.

[0042] The inner surface shape estimation method according to the second aspect is the inner surface shape estimation method according to the first aspect, further comprising the step of: the plurality of inner surface position data being image data with some overlapping regions; and the inner surface shape of the pipe 1 is estimated by superimposing the plurality of inner surface position data. This allows the inner surface shape of the pipe 1 to be estimated with high accuracy.

[0043] The inner surface shape estimation method according to the third aspect is the inner surface shape estimation method according to the first or second aspect, further comprising: attaching the linear array probe 21 to a measuring jig 30 grounded to the surface 1a of the pipe 1; and setting the measurement reference point P at the ground point between the measuring jig 30 and the surface 1a of the pipe 1. As a result, by attaching the linear array probe 21 to the measuring jig 30, the distance between the linear array probe 21 and the measuring jig 30 is constant, and therefore the distance between the linear array probe 21 and the surface 1a of the pipe 1 can be maintained constant.

[0044] The inner surface shape estimation method according to the fourth aspect is the inner surface shape estimation method according to the third aspect, and further includes a measurement jig 30 having a jig body 31 to which the linear array probe 21 is fixed, and a plurality of legs 32 having one end connected to the jig body 31 and the other end capable of being grounded on the surface 1a of the pipe 1. This makes it possible to stabilize the posture of the measurement jig 30 in which the linear array probe 21 is supported with respect to the surface 1a of the pipe 1.

[0045] The inner surface shape estimation method according to the fifth aspect is the inner surface shape estimation method according to the third or fourth aspect, and further comprises moving the measuring jig 30 a predetermined distance along the surface 1a of the pipe 1 to change the measurement reference point P on the surface 1a of the pipe 1, and acquiring a plurality of inner surface position data for the changed plurality of measurement reference points P. This makes it possible to estimate with high accuracy the inner surface shape of a predetermined range of the region in the axial direction of the pipe 1.

[0046] The inner surface shape estimation device of the sixth aspect includes a plurality of transducers 22 that transmit ultrasonic signals to a pipe (object to be inspected) 1 and receive ultrasonic signals reflected from the pipe 1, and a control unit 12 that acquires data obtained by scanning the pipe 1 with ultrasonic signals using the plurality of transducers 22 and processes and synthesizes the acquired ultrasonic signal data, and the control unit 12 acquires the surface shape of the pipe 1, sets a measurement reference point P for the linear array probe 21 (transducers 22) on the surface 1a of the pipe 1, transmits ultrasonic signals from the linear array probe 21 toward the pipe 1, receives ultrasonic signals reflected from the pipe 1, acquires inner surface position data of the pipe 1 relative to the measurement reference point P, changes the measurement reference point P for the linear array probe 21 on the surface 1a of the pipe 1 to acquire multiple inner surface position data for the multiple measurement reference points P, and connects the multiple inner surface position data to estimate the inner surface shape of the pipe 1.

[0047] According to the inner surface shape estimation device of the sixth aspect, the inner surface shape of the pipe (inspection object) 1 can be appropriately estimated. [Explanation of symbols]

[0048] 1 Piping (inspection object) 1a surface 1b Inner surface 2. Medium 10. Inner surface shape estimation device 11 Flaw detector 12 Control section 13 Control section 14 Display section 15 Storage section 21 Linear array probe 22 Transducer 30 Measuring fixture 31 Jig body 32 Legs P Measurement reference point

Claims

1. acquiring a surface shape of an object to be inspected; setting a measurement reference point for a transducer on a surface of the test object and transmitting an ultrasonic signal from the transducer toward the test object; receiving an ultrasonic signal reflected from the test object to obtain inner surface position data of the test object relative to the measurement reference point; a step of changing the measurement reference point for the transducer on the surface of the inspection object to obtain a plurality of pieces of the inner surface position data for a plurality of the measurement reference points; A step of estimating an inner surface shape of the inspection object by connecting a plurality of pieces of inner surface position data; The inner surface shape estimation method includes the steps of:

2. the plurality of inner surface position data are image data having overlapping regions, and the inner surface shape of the inspection object is estimated by superimposing the plurality of inner surface position data; The method for estimating an inner surface shape according to claim 1 .

3. the transducer is attached to a measuring jig that is grounded on a surface of the object to be inspected, and the measurement reference point is set at a ground point between the measuring jig and the surface of the object to be inspected; The method for estimating an inner surface shape according to claim 1 .

4. The measurement jig has a jig body to which the transducer is fixed, and a plurality of legs each having one end connected to the jig body and the other end capable of being grounded to a surface of the object to be inspected. The method for estimating an inner surface shape according to claim 3 .

5. by moving the measuring tool a predetermined distance along the surface of the object to be inspected, changing the measurement reference point on the surface of the object to be inspected, and acquiring a plurality of pieces of inner surface position data for the changed plurality of measurement reference points; The method for estimating an inner surface shape according to claim 3 or 4.

6. a plurality of transducers for transmitting ultrasonic signals to an object to be inspected and receiving ultrasonic signals reflected from the object to be inspected; a control unit that acquires data obtained by scanning the inspection object with ultrasonic signals using the plurality of transducers, and processes and synthesizes the acquired ultrasonic signal data; The control unit is Acquire a surface shape of the inspection object; A measurement reference point for the transducer is set on the surface of the test object, and an ultrasonic signal is transmitted from the transducer to the test object; receiving an ultrasonic signal reflected from the test object to obtain inner surface position data of the test object relative to the measurement reference point; changing the measurement reference point for the transducer on the surface of the inspection object to obtain a plurality of pieces of inner surface position data for a plurality of the measurement reference points; A plurality of pieces of the inner surface position data are stitched together to estimate an inner surface shape of the inspection object. Inner surface shape estimation device.

7. acquiring a surface shape of an object to be inspected; setting a measurement reference point for a transducer on a surface of the test object and transmitting an ultrasonic signal from the transducer toward the test object; receiving an ultrasonic signal reflected from the test object to obtain inner surface position data of the test object relative to the measurement reference point; a step of changing the measurement reference point for the transducer on the surface of the inspection object to obtain a plurality of pieces of the inner surface position data for a plurality of the measurement reference points; A step of estimating an inner surface shape of the inspection object by connecting a plurality of pieces of inner surface position data; A program that causes a computer to execute the following.

Images