JP6959598B2 - Ultrasound visualization method - Google Patents

Description

Embodiments of the present invention relates to an ultrasonic imaging method.

Ultrasonic testing (UT) is a technology that can confirm the soundness of the surface and inside of structural materials as a non-destructive test, and is an indispensable inspection technology in various fields.

In addition to the contact type UT that sends and receives ultrasonic waves by contacting the piezoelectric element with the inspection target, a laser that excites ultrasonic waves by irradiation with a pulse laser and measures minute vibrations on the surface to be inspected by another laser and a laser interferometer. Methods such as ultrasonic methods (LUT: Laser Ultrasonic Testing) are also used. Since the LUT can be inspected without contacting the inspection target, it can be applied to a high temperature target, a moving target, a narrow portion, and the like, and is also applied to an inspection during welding work.

Various forms have been proposed for ultrasonic signal processing methods and devices and methods for visualizing the inside of an inspection target, depending on the application. For example, when the inside of a living body is visualized by ultrasonic waves, the speed of sound differs depending on the tissue in the living body. A method for evaluating the sound velocity distribution based on the difference between the result and the expected result has been proposed.

Japanese Patent No. 5651533 Japanese Patent No. 4632517 Japanese Patent No. 5528083 Japanese Unexamined Patent Publication No. 2016-114570

New edition "Non-destructive inspection engineering" edited by Yugoro Ishii (Sanpo Publishing)

When visualizing an object to be visualized using a signal obtained by ultrasonic inspection, if the object to be visualized is composed of materials with different physical properties, the crystal grains become coarse even in the same material, for example, at a welded part. If there is a temperature distribution inside the object to be visualized, or if there is a temperature distribution inside the object, the sound velocity of the ultrasonic waves inside the object will not be uniform. Therefore, there is a problem that the measurement accuracy of the imaged defect position and plate thickness is lowered due to the influence of the sound velocity anisotropy or the sound velocity distribution inside the imaged object.

An object of the present invention is to visualize the shape of an object to be visualized in a medium with high accuracy.

Further, in the ultrasonic imaging method according to the embodiment of the present invention, the ultrasonic receiver receives as a reception signal the reflected wave obtained by the ultrasonic wave transmitted from the ultrasonic transmitter into the medium and reflected by the ultrasonic reflection source. The ultrasonic reception step to be performed, the visualization area setting step in which the visualization area setting unit sets the visualization area in the medium and divides the inside of the visualization area into meshes, and the propagation speed addition unit is the medium. A propagation velocity setting step for determining the mesh propagation velocity, which is the propagation velocity of the ultrasonic waves for each of the meshes based on the temperature distribution inside, and a propagation time calculation unit are described from the ultrasonic transmitter via the target mesh. a propagation path to the ultrasonic receiver is divided into a plurality of divided paths having a predetermined path division width, determines the mesh that corresponds to each of the plurality of divided paths of said mesh, said corresponding determined the mesh on the basis of the propagation velocity the through the target mesh from the ultrasonic transmitter the lead to ultrasonic receiver the ultrasonic total propagation time of the position of the ultrasonic transmitter and the ultrasonic receiver for each mesh The reception signal is used for each combination of the position of the ultrasonic transmitter and the position of the ultrasonic receiver by the step of creating the propagation time table for creating the propagation time table determined for each combination of the positions of the instruments and the intensity assigning unit. each received strength, and before Symbol intensity data table creation to create the intensity data table assigned to each step of the mesh in correspondence with the total propagation time determined the propagation time table included in the intensity synthesis section A strength data synthesis step of synthesizing the strength data of the strength data table to calculate the composite strength for a plurality of combinations of the position of the ultrasonic transmitter and the position of the ultrasonic receiver, and the display unit perform the synthesis. From the intensity, a display step for displaying an image of the shape of the ultrasonic reflection source and the ultrasonic reception step to the display step are performed at a plurality of installation locations of the ultrasonic transmitter and the ultrasonic receiver. It is characterized by having a step of superimposing each of the above images.

According to the embodiment of the present invention, the shape of the object to be visualized in the medium can be visualized with high accuracy.

It is a block diagram which shows the structure of the ultrasonic wave detection device and the ultrasonic wave imaging device which concerns on 1st Embodiment. It is a perspective view for demonstrating the mesh division of the imaging region by the ultrasonic imaging apparatus which concerns on 1st Embodiment. It is a graph which shows the temperature-dependent characteristic data of the propagation velocity in the medium of the ultrasonic wave which the propagation velocity addition part of the ultrasonic imaging apparatus which concerns on 1st Embodiment has. It is a block diagram which shows the structure when a single probe is used for the ultrasonic transmitter and the ultrasonic receiver of the ultrasonic detection apparatus which concerns on 1st Embodiment. It is a block diagram which shows the structure when the ultrasonic array probe is used for the ultrasonic transmitter and the ultrasonic receiver of the ultrasonic detection apparatus which concerns on 1st Embodiment. It is a block diagram which shows the structure when the laser system is used for the ultrasonic wave transmitter and the ultrasonic wave receiver of the ultrasonic wave detection device which concerns on 1st Embodiment. It is a flow chart which shows the whole procedure of the ultrasonic imaging method which concerns on 1st Embodiment. It is a flow chart which shows the detail of the step of making a propagation time table in the procedure of the ultrasonic imaging method which concerns on 1st Embodiment. It is a flow chart which shows the detail of the step of calculating the total propagation time of a path among the steps of creating the propagation time table of the procedure of the ultrasonic imaging method which concerns on 1st Embodiment. It is a mesh diagram explaining the content of the division step to the division path among the steps of creating the propagation time table of the procedure of the ultrasonic visualization method according to the first embodiment. It is a figure which shows the example of the propagation time table created by the step of creating a propagation time table in the procedure of the ultrasonic imaging method which concerns on 1st Embodiment. It is a figure which shows the example of the total propagation time curve which explains the intensity data table creation step in the procedure of the ultrasonic imaging method which concerns on 1st Embodiment. It is a graph which shows the example of the received waveform explaining the content of the intensity data table creation step in the procedure of the ultrasonic imaging method which concerns on 1st Embodiment. It is a figure which shows the example of the intensity data table created by the step of allocating the signal intensity to each mesh based on the received waveform in the procedure of the ultrasonic imaging method which concerns on 1st Embodiment. It is a figure explaining the content of the signal strength synthesis step for all combinations of the positions of an ultrasonic transmitter and a receiver in the procedure of the ultrasonic imaging method which concerns on 1st Embodiment. The figure which shows the example of the received waveform of each case explaining the content of the signal strength synthesis step for all combinations of the positions of an ultrasonic transmitter and a receiver in the procedure of the ultrasonic imaging method which concerns on 1st Embodiment. Is. It is a figure which shows the example of the result calculated in the synthesis step of the signal strength for all combinations of the positions of an ultrasonic transmitter and a receiver in the procedure of the ultrasonic imaging method which concerns on 1st Embodiment. It is a graph explaining the content of the shape extraction step in the procedure of the ultrasonic imaging method which concerns on 1st Embodiment. It is a figure explaining the example of the measurement which moved the ultrasonic wave transmitter and the ultrasonic wave receiver to a plurality of places in the ultrasonic wave imaging method which concerns on 1st Embodiment. It is a conceptual diagram which shows the example which applied the ultrasonic imaging method which concerns on 1st Embodiment to the detection of the molten metal pond. It is a conceptual diagram which shows the example which applied the ultrasonic imaging method which concerns on 1st Embodiment to the detection of the object in the liquid. It is a conceptual diagram which shows the example which applied the ultrasonic imaging method which concerns on 1st Embodiment to the detection of the object which exists in a layer. It is a block diagram which shows the structure of the ultrasonic wave detection device and the ultrasonic wave imaging device which concerns on 2nd Embodiment. It is a flow chart which shows the whole procedure of the ultrasonic imaging method which concerns on 2nd Embodiment.

Hereinafter, with reference to the accompanying drawings, a description will be given engagement Ru ultrasound imaging method in an embodiment of the present invention. Here, parts that are the same as or similar to each other are designated by a common reference numeral, and duplicate description will be omitted.

[First Embodiment]
FIG. 1 is a block diagram showing a configuration of an ultrasonic detection device and an ultrasonic visualization device according to the first embodiment.

The ultrasonic wave detection device 200 transmits ultrasonic waves to the medium 2 and visualizes the shape inside the medium 2 including the boundary between the ultrasonic reflection source 3 and the medium 2 in the medium 2 from the received signal.

The ultrasonic detection device 200 includes a transmission / reception unit 210 and an ultrasonic visualization device 100. The transmission / reception unit 200 includes an ultrasonic transmitter 211 that emits ultrasonic waves in the medium 2 and an ultrasonic receiver 212 that receives the reflected wave from the medium 2.

The ultrasonic imaging device 100 uses a computer system and includes a memory 110, a calculation unit 120, an input unit 130, a display unit 140, and a control unit 150. Here, the control unit 150 monitors and controls the memory 110, the calculation unit 120, the input unit 130, and the display unit 140 so that they operate in harmony with each other as a computer system.

The memory 110 includes a signal recording unit 111 and a calculation result storage unit 112. The signal recording unit 111 stores the received signal received by the ultrasonic receiver 212. Specifically, for each combination of the position of the ultrasonic transmitter 211 and the position of the ultrasonic receiver 212, the received signal data received by the ultrasonic receiver 212 from the medium 2 is stored as a temporal intensity change. The calculation result storage unit 112 stores the calculation result in the calculation unit 120 and the input received from the outside by the input unit 130.

The arithmetic unit 120 generates a visualization signal based on the received signal stored in the signal recording unit 111 of the memory 110. The calculation unit 120 includes a visualization area setting unit 121, a mesh division unit 122, a propagation speed addition unit 123, a propagation time calculation unit 124, an intensity allocation unit 125, an intensity synthesis unit 126, and a shape extraction unit 127.

The visualization region setting unit 121 sets the visualization region 10 from the region including the visualization target 1 and the ultrasonic reflection source 3 existing inside or adjacent to the visualization target 1. Specifically, if the visualization region 10 has a rectangular parallelepiped shape, for example, when end point conditions such as coordinate axes and the positions of the respective corners are specified from the outside, the calculation result storage unit 112 first stores the end point conditions. The visualization area setting unit 121 reads out the end point conditions stored in the calculation result storage unit 112, and makes it possible to calculate the coordinates of each point on the boundary surface based on the set coordinate axes.

The mesh dividing unit 122 divides the medium 2 in the visualization region 10 into meshes. FIG. 2 is a perspective view for explaining the mesh division of the imaging region by the ultrasonic imaging apparatus 100. The visualization region 10 is divided by a width of ΔX in the X-axis direction, ΔY in the Y-axis direction, and ΔZ in the Z-axis direction. The division widths ΔX, ΔY and ΔZ may be specified externally to the input unit 130 or may be determined values. The respective values of ΔX, ΔY and ΔZ may be similar to each other or may be the same value. Further, for example, when the change width of the temperature distribution in the X-axis direction is larger than the width of the temperature distribution in the Y-axis and Z-axis directions, the value of ΔX is made smaller than the values of ΔY and ΔZ. The value may be set according to the change width of the temperature distribution.

The propagation velocity addition unit 123 has temperature-dependent characteristic data of the propagation velocity of ultrasonic waves according to the type of the medium 2. The propagation speed addition unit 123 assigns a mesh propagation speed, which is a propagation speed corresponding to the temperature of each mesh designated by the external input, to each mesh.

FIG. 3 is a graph showing temperature-dependent characteristic data of the propagation velocity of ultrasonic waves in the medium of the propagation velocity addition unit. The horizontal axis represents the temperature of the medium (° C.), and the vertical axis represents the propagation velocity (m / sec) of ultrasonic waves in the medium at that temperature. The propagation velocity addition unit 123 may have the temperature-dependent characteristic data of the propagation velocity as data in the form of a function or as data in the form of a table. Alternatively, the memory 110 may store these data, and the propagation speed addition unit 123 may read the data from the memory 110 as needed.

The propagation velocity addition unit 123 derives the mesh propagation velocity, which is the propagation velocity in each mesh according to the temperature of each mesh in the medium, based on the temperature-dependent characteristic data of the propagation velocity, and obtains the propagation velocity table 123a (FIG. 7). create.

The propagation time calculation unit 124 determines the propagation time outward path from the ultrasonic transmitter 211 to the mesh and the mesh for each mesh for each combination of the position of the ultrasonic transmitter 211 and the position of the ultrasonic receiver 212. The total propagation time, which is the sum of the propagation times from the to the ultrasonic receiver 212 to the ultrasonic receiver 212, is calculated and associated with the mesh for all the meshes in the visualization region 10, and the propagation time table 124a (FIG. 7) is created. .. The propagation time table 124a created by the propagation time calculation unit 124 is stored in the calculation result storage unit 112 and displayed by the display unit 140.

The intensity allocation unit 125 creates an intensity data table 125a (FIG. 7) for each combination of the position of the ultrasonic transmitter 211 and the position of the ultrasonic receiver 212.

That is, first, for each combination of the position of the ultrasonic transmitter 211 and the position of the ultrasonic receiver 212, the received waveform transmitted from the ultrasonic transmitter 212 and received by the ultrasonic receiver 212 is transmitted from the signal recording unit 111. read out. Next, the propagation time table 124a is read out from the calculation result etc. storage unit 112, and the intensity data at the time corresponding to the total propagation time is extracted from the received waveform based on the value of the total propagation time corresponding to each mesh, and each Assign to mesh. In this way, the intensity data table 125a for each combination of the position of the ultrasonic transmitter 211 and the position of the ultrasonic receiver 212 is created. The intensity data table 125a is stored in the calculation result storage unit 112 and displayed by the display unit 140.

The intensity synthesis unit 126 uses the intensity data of the intensity data table 125a for each combination of the position of the ultrasonic transmitter 211 and the position of the ultrasonic receiver 212 created by the intensity allocation unit 125, and the positions of all the ultrasonic transmitters 211. And the combined strength is calculated by superimposing the combination of the positions of the ultrasonic receiver 212. It is not necessary to limit the combination to all combinations. That is, it may be a plurality of combinations within the required range. Hereinafter, even when the combination of the positions of all the ultrasonic transmitters 211 and the positions of the ultrasonic receivers 212 is described, the positions of the ultrasonic transmitter 211 and the positions of the ultrasonic receiver 212 are within the required range. It means that it may be a plurality of combinations.

That is, for the combination of the m-th position (m = 1 to M) of the ultrasonic transmitter 211 and the n-th position (n = 1 to N) of the ultrasonic receiver 212, the intensity of the mesh ij is set to A _ij ^mn . Then, the synthetic strength AA _ij of the superposed mesh ij is given by the following equation (1).
AA _ij = ΣΣA _ij ^mn ... (1)
However, ΣΣ represents the sum for m = 1 to M and n = 1 to N.

The composite strength data calculated by the strength synthesis unit 126 is stored in the calculation result storage unit 112 and displayed by the display unit 140.

The shape extraction unit 127 reads the composite intensity data calculated by the intensity synthesis unit 126 from the calculation result etc. storage unit 112, and based on this, derives the boundary between the ultrasonic reflection source 3 and the medium 2 in more detail, and superimposes it. Clarify the shape of the sound wave reflection source 3.

FIG. 4 is a block diagram showing a configuration when a single probe is used for each of the ultrasonic transmitter and the ultrasonic receiver of the ultrasonic detection device according to the present embodiment. In FIG. 4, for convenience of explanation, the visualization region 10 is shown as a two-dimensional plane extending in the X-axis direction and the Z-axis direction. This point is the same below.

An ultrasonic wave is transmitted from an ultrasonic transmitter 211 having a single ultrasonic probe, and an ultrasonic wave including a reflected wave reflected at a boundary between the ultrasonic reflection source 3 and the medium 2 is used as a single ultrasonic probe. The ultrasonic receiver 212 having the receiver receives the signal.

Here, the ultrasonic probe is composed of a combination of an ultrasonic wave generating mechanism, a damping material for damping the ultrasonic waves, and / or a front plate attached to the front surface of the ultrasonic wave generating mechanism, and is generally used. It is called an ultrasonic probe. The ultrasonic generation mechanism refers to a piezoelectric element made of ceramics, a composite material, or other piezoelectric element capable of generating ultrasonic waves by a piezoelectric effect, or a piezoelectric element made of a polymer film or a mechanism capable of generating ultrasonic waves other than that. ..

FIG. 5 is a block diagram showing a configuration when an ultrasonic array probe is used for the ultrasonic transmitter and the ultrasonic receiver in the ultrasonic detection device according to the present embodiment. Here, the ultrasonic array probe 220 includes an ultrasonic probe 221 in which a plurality of ultrasonic waves are arranged to transmit and receive ultrasonic waves, and a housing 222 that holds them. Sequentially, some ultrasonic probes 221 are used to transmit ultrasonic waves, and other ultrasonic probes 221 are used to receive signals from the medium.

FIG. 5 shows a case where the piezoelectric elements are arranged one-dimensionally and what is generally called a linear array probe is used as the ultrasonic array probe 220. In addition to this, a matrix array probe in which piezoelectric elements are arranged two-dimensionally, a ring array probe in which ring-shaped piezoelectric elements are arranged concentrically, and a split ring in which the piezoelectric elements of the ring array probe are divided in the circumferential direction. Ultrasonic arrays include array probes, non-uniform array probes in which piezoelectric elements are non-uniformly arranged, arc-shaped array probes in which piezoelectric elements are arranged in the circumferential position of an arc, and spherical array probes in which elements are arranged on the surface of a spherical surface. It may be used as a probe.

Further, a so-called tandem flaw detection method may be used in which a plurality of these ultrasonic array probes are used in combination regardless of the type. The ultrasonic array probes described above include those that can be used in air or in water by caulking or packing.

When installing the ultrasonic array probe 220, a wedge (not shown) is provided between the ultrasonic array probe 220 and the imaging target 1 in order to inject ultrasonic waves into the imaging target 1 in a highly directional angular direction. May be provided and used. For the wedge, an isotropic material capable of propagating ultrasonic waves and whose acoustic impedance can be grasped, for example, acrylic, polyimide, gel, or other polymer is used. Alternatively, a material having an acoustic impedance close to that of the front plate or a material having the same acoustic impedance as the front plate may be used.

Further, a composite material whose acoustic impedance is changed stepwise or gradually may be used as a wedge. Further, a damping material may be arranged inside or outside the wedge, a chevron-shaped wave-eliminating shape may be provided, or a multiple reflection reduction mechanism may be provided so that the multiple reflection waves inside the wedge do not affect the flaw detection result. ..

FIG. 6 is a block diagram showing a configuration when a laser transmission / reception device is used for the ultrasonic transmitter and the ultrasonic receiver of the ultrasonic detection device according to the present embodiment. The laser transmission / reception device 230 is a laser scanning device 232 that irradiates an arbitrary position of the imaging target 1 with the transmitted laser light emitted from the ultrasonic excitation laser device 231 for exciting ultrasonic waves and the ultrasonic excitation laser device 231. It has a receiving probe 233 that emits a receiving laser beam, a scanning mechanism 234 that scans the receiving probe 233 around a target position, an optical transmission unit 235, and a laser ultrasonic receiver 236.

Since the spot irradiated with the laser irradiation light corresponds to the ultrasonic transmitter 211, this portion is also referred to as the ultrasonic transmitter 211 below. In the example shown in FIG. 6, the laser scanning device 232 is used for irradiating the imaging target 1 with the transmitted laser beam, but the present invention is not limited to this. Direct irradiation from the ultrasonic excitation laser device 231, irradiation by spatial transmission using reflection of an optical mirror, or irradiation by transmission using a combination of an optical fiber and an optical lens may be used.

The ultrasonic Ut generated at the spot irradiated with the laser irradiation light and incident on the inside of the imaging target 1 is the surface of the ultrasonic reflection source 3, that is, ultrasonic reflection, as in the case of FIGS. 4 and 5. It is reflected at the boundary between the source 3 and the medium 2, and the reflected ultrasonic wave Ur reaches the surface of the imaging target 1.

In the case of laser ultrasonic method, the ultrasonic receiver 212 is irradiated with the received laser light. The laser ultrasonic receiver 236 includes a receiving laser transmitter 236a and a laser interference meter 236b.

The received laser light generated by the receiving laser oscillator 236a is sent to the receiving probe 233 composed of optical components through an optical transmission unit 235 such as an optical fiber. The receiving laser beam is irradiated from the receiving probe 233 to the imaging target 1. Since this irradiated spot corresponds to the ultrasonic receiver 212, this portion is also referred to as the ultrasonic receiver 212 below. The reflected / scattered light of the received laser light reflected on the surface of the image target 1 is collected by the receiving probe 233 and incident on the laser interferometer 236b of the laser ultrasonic receiver 236 through the optical transmission unit 235.

At this time, the position of the ultrasonic receiver 212 can be changed by moving the receiving probe 233 using the laser scanning mechanism 234. The ultrasonic signal converted into an electric signal by the interference measurement by the laser interference meter 236b is sent to the signal recording unit 111 (FIG. 1).

Ultrasonic excitation lasers and lasers The light sources of the receiving lasers of the ultrasonic receivers are, for example, neodymium: YAG laser, carbon dioxide gas laser, erythium: YAG laser, titanium sapphire laser, Alexandrite laser, ruby laser, dye (die) laser and Exima laser etc. can be used. Further, the light source of the ultrasonic excitation laser and the reception laser of the laser ultrasonic receiver is a continuous wave or a pulse wave, and may be configured not only by one unit but also by a plurality of units. When configuring from multiple units, use multiple units as necessary for other functional parts required for measuring ultrasonic waves.

As the laser interferometer, for example, Michelson interferometer, homodyne interferometer, heterodyne interferometer, fizo interferometer, Mach zender interferometer, Fabry-Perot interferometer, photorefractive interferometer and the like can be used. A knife edge method can also be considered as a method other than the interference measurement. In some cases, a plurality of interferometers may be used.

As described above, a laser ultrasonic method using a laser for transmitting and receiving ultrasonic waves can also be applied.

FIG. 7 is a flow chart showing the entire procedure of the ultrasonic imaging method according to the first embodiment.

First, as described above, when the specified contents of the basic conditions related to the visualization area 10 are input from the input unit 130, the visualization area setting unit 121 sets the visualization area 10 in detail, and the mesh division unit 122 sets the visualization area 10. The mesh of the visualization region 10 is divided (step S100).

Next, the input unit 130 reads the temperature of each mesh in the visualization region 10 based on the temperature distribution condition of the medium 2 (step S200). The temperature of each mesh read by the input unit 130 is stored in the calculation result storage unit 112.

Next, the propagation velocity addition unit 123 sequentially reads out the temperature of each mesh stored in the calculation result storage unit 112, and uses the propagation velocity addition unit 123 as the temperature-dependent characteristic data of the propagation velocity of the ultrasonic waves in the medium. Based on this, the mesh propagation velocity, which is the propagation velocity in each mesh, is derived and the propagation velocity table 123a is created (step S300). The created propagation speed table 123a is stored in the calculation result storage unit 112.

Next, the propagation time calculation unit 124 creates a propagation time table 124a for each combination of the position of the ultrasonic transmitter 211 and the position of the ultrasonic receiver 212 (step S400). The created propagation time table 124a is stored in the calculation result storage unit 112.

Next, the intensity allocation unit 125 creates an intensity data table 125a for each combination of the position of the ultrasonic transmitter 211 and the position of the ultrasonic receiver 212 (step S500). The created intensity data table 125a is stored in the calculation result storage unit 112.

Next, the intensity synthesizing unit 126 synthesizes the signal intensities assigned to each mesh for all combinations of the positions of the ultrasonic transmitter 211 and the positions of the ultrasonic receiver 212 (step S600). That is, the assigned values of the respective strength data tables 125a to each mesh are integrated to calculate the combined strength data.

Next, the shape extraction unit 127 performs shape extraction (step S700). That is, based on the distribution of the synthetic intensity data for each mesh calculated in step S600, the shape of the ultrasonic reflection source 3, that is, the shape of the boundary between the ultrasonic reflection source 3 and the medium 2 is further clarified. This result is stored in the calculation result storage unit 112 and displayed by the display unit 140 (step S800).

FIG. 8 is a flow chart showing details of the steps for creating the propagation time table. The detailed procedure of the propagation time table creation step S400 shown in FIG. 8 will be described below.

First, for each received signal data stored in the signal recording unit 111, a combination of the position of the ultrasonic transmitter 211 and the position of the ultrasonic receiver 212 is selected (step S410). Next, the target mesh for which the total propagation time is calculated is selected from the mesh divided meshes in the visualization region 10 (step S420).

Next, with respect to the target mesh 2a (FIG. 10) selected in step S420, the path from the set position of the ultrasonic transmitter 211 to the position of the ultrasonic receiver 212 via the position of the target mesh 2a. The total propagation time is calculated (step S430). The calculated total propagation time is sequentially stored in the calculation result storage unit 112 as propagation time data corresponding to the target mesh 2a. The calculation of this total propagation time will be described in detail in the description of FIG.

Next, the propagation time calculation unit 124 determines whether or not the calculation of the total propagation time data is completed with all the meshes divided into meshes in the visualization region 10 as the target mesh 2a (step S440).

If it is not determined that all the meshes have been completed (step S440 NO), the next target mesh 2a is selected (step S420), and steps up to step S440 are repeated.

When it is determined that all the meshes have been completed (step S440 YES), the total propagation time data corresponding to each mesh stored in the calculation result storage unit 112 is the ultrasonic transmitter selected in step S410. It is completed as a propagation time table 124a for one combination of the position of 211 and the position of the ultrasonic receiver 212. The propagation time table 124a is stored in the calculation result storage unit 112.

Next, the propagation time calculation unit 124 sets the propagation time table 124a for all combinations of the position of the ultrasonic transmitter 211 and the position of the ultrasonic receiver 212 in the received signal data stored in the signal recording unit 111. It is determined whether or not the creation of is completed (step S450). If it is not determined that the propagation time table 124a has been created for all combinations (step S450 NO), the process returns to step S410, which is next to the position of the ultrasonic transmitter 211 and the position of the ultrasonic receiver 212. After selecting the combination, the process up to step S450 is repeated.

When it is determined that the creation of the propagation time table 124a is completed for all the combinations (step S450 YES), the propagation time table creation step S400 ends, and the process proceeds to the next step S500.

FIG. 9 is a flow chart showing the details of the calculation step S430 of the total propagation time of the route in the propagation time table creation step S400 of the procedure of the ultrasonic visualization method according to the first embodiment. Hereinafter, the details of the calculation step S430 of the total propagation time of the route will be described.

Calculation of the total propagation time of the route In step S430, first, the route from the ultrasonic transmitter 211 to the target mesh 2a and the route from the target mesh 2a to the ultrasonic receiver 212 are each divided into a plurality of divided routes (step). S431).

FIG. 10 is a mesh diagram illustrating the content of the division step S431 to the division path in the propagation time table creation step S400 of the procedure of the ultrasonic visualization method according to the first embodiment.

Strictly speaking, when there is a temperature distribution inside the imaging region 10, ultrasonic waves are refracted between regions having different temperatures. However, if the refraction angle is not extremely large, from the viewpoint of calculating the total propagation time, for example, the path from the ultrasonic transmitter 211 to the target mesh 2a and the path from the target mesh 2a to the ultrasonic receiver 212. The error is practically small enough, even assuming that is linear. Therefore, it is assumed that the path from the ultrasonic transmitter 211 to the target mesh 2a and the path from the target mesh 2a to the ultrasonic receiver 212 are linear below. If necessary, the following may be carried out in a refracted state.

First, the propagation time calculation unit 124 divides the propagation route into a plurality of division routes for each predetermined route division width ΔL. The path division width ΔL may be set according to the degree of temperature distribution in the medium 2. For example, when the temperature distribution is relatively large, the path division width ΔL is set to be substantially the same length as the mesh division widths ΔX, ΔY, and ΔZ. On the contrary, when there is almost no temperature distribution, the path division width ΔL may be relatively long. For example, when the transmission surface of the ultrasonic transmitter 211 is sequentially divided by the path division width ΔL on the outward path, the length of the final division path is smaller than the normal path division width ΔL, but there is a particular problem. However, it may be treated in the same manner as the division route having the route division width ΔL. The width of the divided route may be different for each divided route.

Next, the propagation time calculation unit 124 determines the mesh corresponding to each division path (step S432). Specifically, the mesh to which the center of each division path belongs is defined as the mesh corresponding to the division path. It is not limited to the center. For example, it may be an end.

Within the visualization region 10 on the two-dimensional plane as shown in FIG. 10, X1, X2, X3, etc. are sequentially set in the X-axis direction when viewed from the end point 10a of the visualization region, and Z1, Z2, Z3, etc. are sequentially set in the Z-axis direction. Then, the position of each mesh is represented as a position (Xi, Zj). Now, for example, the target mesh 2a is a mesh at positions (X7, Z7) as shown in FIG.

The outward path of the ultrasonic wave transmitted from the ultrasonic transmitter 211 first enters the mesh at the position (X6, Z1), and is a path from the mesh at the position (X6, Z1) to the mesh at the position (X7, Z7). .. Further, since the ultrasonic wave received by the ultrasonic receiver 212 finally reaches the mesh at the position (X13, Z1), the return path is from the target mesh 2a at the position (X7, Z7) to the position (X13, Z1). The route to the mesh of.

Here, as shown in FIG. 10, the mesh to which the midpoint of each division width belongs is specified. For example, the mesh to which the midpoint M1 of the first division path belongs is the mesh of the position (X6, Z1), and the mesh to which the midpoint M2 of the second division path belongs is the mesh of the position (X6, Z3).

Next, the propagation time calculation unit 124 determines the propagation speed for each division route and calculates the division route propagation time (step S433).

For example, the position of the target mesh 2a is (Xi, Zj), and the division path length of the kth division path k is ΔLk. The propagation time calculation unit 124 reads out the propagation speed table 123a created by the propagation speed addition unit 123 and stored in the calculation result storage unit 112. From the propagation velocity table 123a, the mesh propagation velocity Vk of the mesh to which the midpoint of the division width of the division path k belongs is obtained, and the division path propagation time Δtijk of each division path is calculated from the mesh propagation velocity Vk. The division path propagation time Δtijk of the division path k is given by the following equation (2).
Δtijk = ΔLk / Vk ・ ・ ・ (2)

Next, the propagation time calculation unit 124 integrates the division route propagation time and allocates the integrated total propagation time to the target mesh (step S434).

Specifically, first, the division route propagation time Δijk for all of the outward division route and the return division route is integrated by the following equation (3), and the total propagation time tij for the target mesh 2a (Xi, Zj). Is calculated.
tij = ΣΔtijk ・ ・ ・ (3)
However, Σ in the equation (3) indicates that it is the sum of all of the outward division path and the return division path k.

The total propagation time tij calculated in this way is transmitted from the ultrasonic transmitter 211 and reflected by the target mesh 2a when the reflection position of the ultrasonic wave transmitted from the ultrasonic transmitter 211 is the target mesh 2a. It means the time until reception by the ultrasonic receiver 212.

The calculated total propagation time tij for the target mesh 2a at the position (Xi, Zj) is stored in the calculation result storage unit 112. The total propagation time tij is data that constitutes the propagation time table 124a stored in the calculation result storage unit 112.

FIG. 11 is a diagram showing an example of a propagation time table created in step S500 of creating a propagation time table in the procedure of the ultrasonic imaging method according to the first embodiment. Regarding the combination of the position of the ultrasonic transmitter 211 and the position of the ultrasonic receiver 212, the position of the mesh through which the ultrasonic wave transmitted from the ultrasonic transmitter 211 first passes (X6, Z1) and the position of the ultrasonic receiver 212 The combination of the positions (X13, Z1) of the mesh through which the ultrasonic waves received last pass is shown. That is, the title of the propagation time table 124a is described as [transmission mesh (X6, Z1), reception mesh (X13, Z1)]. The title may be in another format as long as the combination of the position where the ultrasonic wave is transmitted and the position where the ultrasonic wave is received can be specified.

The propagation time table 124a is a matrix corresponding to the mesh of the visualization region 10, and the value of the data of the ij element of the matrix is the total propagation time tij for the target mesh 2a at the mesh position (Xi, Zj). ing.

Next, as step S500, as the next step of the above-mentioned propagation time table creation step, as described above, the intensity allocation unit 125 is a combination of the position of the ultrasonic transmitter 211 and the position of the ultrasonic receiver 212. Create a strength data table for each. The propagation time table is read from the calculation result storage unit 112, and based on the value of the total propagation time corresponding to each mesh, the intensity data at the time corresponding to the total propagation time is extracted from the received waveform and assigned to each mesh. In this way, the intensity data table 125a for each combination of the position of the ultrasonic transmitter 211 and the position of the ultrasonic receiver 212 is created.

FIG. 12 is a diagram showing an example of an equal propagation time curve for explaining the intensity data table creation step. The display of the mesh for the visualization area 10 is omitted.

The ultrasonic transmitter 211 is the m-th transmission position, and the ultrasonic receiver 212 is the n-th reception position. Now, consider an ultrasonic wave that reaches the point P1 from the m-th position and reaches the n-th position from the point P1. In this case, the length of the outward path is Ut1 and the length of the return path is Ur1. Further, the sum of the length Ut1 of the outward route and the length Ur1 of the return route, that is, the length of the route passing through the point P1 is defined as U1. Further, considering the ultrasonic wave reaching the point P2 from the m-th position and reaching the n-th position from the point P2, the length of the outward route in this case is Ut2, the length of the return route is Ur2, and the total of these is U2. do.

Now, if U2 is equal to U1, the points P1 and P2 will be on the same ellipse E3 with the m-th and n-th positions as focal points. In the case of three dimensions, they exist on the same ellipsoid whose focal point is the m-th position and the n-th position, but for convenience of explanation, they will be described below as two dimensions.

In this way, the ellipse at the m-th position and the n-th position is an equal propagation distance curve that keeps the length of the ultrasonic path transmitted from the m-th position and received at the n-th position constant. .. In the case of three dimensions, it is an equal propagation distance curved surface.

Now, if the temperature distribution in the visualization region 10 is constant, the equal propagation time curve becomes an ellipse focusing on the m-th position and the n-th position, similarly to the equal propagation distance curve. On the other hand, when there is a temperature distribution in the visualization region 10, the equal total propagation time curve is created based on the propagation time table 124a created in the propagation time table creation step of step S400, not the elliptic curve itself. It becomes a thing.

FIG. 12 shows each of the equal total propagation time curve E1, the equal total propagation time curve E2, the equal total propagation time curve E3, and the equal total propagation time curve E4 focusing on the m-th position and the n-th position. There is. Assuming that the total propagation time is t1, t2, t3 and t4, the total propagation time becomes longer as the total propagation time curve moves away from the points m and n, as shown in the following equation (4).
t1 <t2 <t3 <t4 ... (4)

FIG. 13 is a graph showing an example of a received waveform for explaining the content of the intensity data table creation step in the procedure of the ultrasonic imaging method according to the first embodiment. An example of the reception waveform of the ultrasonic wave transmitted from the m-th position and received at the n-th position shown in FIG. 12 is shown. The horizontal axis represents the time t, and the vertical axis represents the signal intensity A of the ultrasonic waves received by the ultrasonic receiver 212. The signal strengths A at time t1, t2, t3 and t4 are A1, A2, A3 and A4, respectively.

The time when the value of time t on the horizontal axis is 0 is the time when ultrasonic waves are transmitted from the ultrasonic transmitter 211. Therefore, the times t1, t2, t3 and t4 correspond to the cases where the total propagation time is t1, t2, t3 and t4, respectively. For example, ultrasonic waves transmitted from the m-th position in FIG. 12 and reach the n-th position after changing the direction at a point on the total propagation time curve E3 including the points P1 and P2. The receiver 212 receives the signal at time t3. That is, it is the signal strength A3 that corresponds to the case where the total propagation time is t3. Similarly, the signal strengths A1, A2, and A4 correspond to the cases where the total propagation times are t1, t2, and t4, respectively.

The intensity allocation unit 125 reads the propagation time table 124a obtained in step S400 from the calculation result etc. storage unit 112, and also signals the received waveform of the ultrasonic wave transmitted from the m-th position and received at the n-th position. Read from the recording unit 111. The intensity allocation unit 125 reads the total propagation time ti of the target mesh from the propagation time table 124a, obtains the signal intensity Ai of the time ti corresponding to the total propagation time ti from the received waveform, and sets the target mesh on the signal intensity Ai. Allocate the signal strength Ai. This is done for all meshes in the visualization region 10. As a result, the intensity data table 125a is completed.

If the approximate location of the target ultrasonic reflection source is known in advance, the intensity data table may be used not for all meshes but for only the meshes in the required range including the location.

In this way, the intensity allocation unit 125 creates one intensity data table 125a for each combination of the m-th position which is the transmission point and the n-th position which is the reception point.

FIG. 14 is a diagram showing an example of an intensity data table created by the step of creating data for allocating signal intensity to each mesh based on the received waveform.

Also in the intensity data table 125a, the combination of the m-th position which is the transmission point and the n-th position which is the reception point is the title. Here, similarly to the propagation time table 124a shown in FIG. 11, the position (Xm, Z1) of the mesh through which the ultrasonic wave transmitted from the ultrasonic wave transmitter 211 first passes and the position (Xm, Z1) of the mesh and the ultrasonic wave are received by the ultrasonic wave receiver 212. The combination of the positions (Xn, Z3) of the mesh through which the ultrasonic waves last pass is described as [transmitting mesh (Xm, Z1), receiving mesh (Xn, Z1)].

A signal strength is assigned to each mesh by the strength allocation unit 125. In FIG. 14, the value of _Aij ^mn is assigned to the mesh of (Xi, Zj). Here, i and j indicate the coordinates of the mesh, and m and n indicate the position numbers of the transmission point and the reception point.

_{The result of allocating the signal strength Aij} ^mn to each mesh is stored in the calculation result storage unit 112 as the strength data table 125a.

FIG. 15 is a diagram illustrating the content of the signal strength synthesis step S600 for all combinations of the positions of the ultrasonic transmitter and the receiver in the procedure of the ultrasonic imaging method according to the first embodiment. As a combination of the position of the ultrasonic transmitter 211 and the position of the ultrasonic receiver 212, the position of the ultrasonic transmitter 211 and the position of the ultrasonic receiver 212 are the m-th position, the n1st position, and the m-th position. An example is shown in the case of passing through the point B corresponding to the target mesh 2a at each of the three combinations of the n2nd position and the mth position and the n3rd position.

Now, paying attention to the point B, the position of the ultrasonic transmitter 211 and the position of the ultrasonic receiver 212 are the first case of the mth position and the n1st position, the mth position and the n2nd position. The equal total propagation time curves including the point B in the second case of the above and the third case of the mth position and the n3rd position are set to E1, E2, and E3, respectively, and the sum of the ultrasonic waves in each case. Let the propagation times be t1, t2, and t3.

FIG. 16 is a diagram showing an example of the received waveform in each case. The horizontal axis represents time t. The time t is 0, which indicates the time when the ultrasonic wave is transmitted from the ultrasonic transmitter 211. Therefore, for example, the time t1 corresponds to the total propagation time t1. The vertical axis indicates the magnitude of the received signal, that is, the signal strength A.

From the top of FIG. 16, the received signal data D1 of the first case where the ultrasonic wave transmission position is the m-th position and the reception position is the n1st position, and the ultrasonic wave transmission position is the m-th position and the reception position is n2. The reception signal data D2 of the second case at the second position and the reception signal data D3 of the third case where the ultrasonic wave transmission position is the m-th position and the reception position is the n3rd position are shown. The total propagation times of these three cases are t1, t2, and t3, respectively, as described in the description of FIG.

As shown in FIG. 16, the signal strength of the received signal data D1 in the first case at time t1 is A1, the signal strength of the received signal data D2 in the second case at time t2 is A2, and the third case. The signal strength of the received signal data D3 at time t3 is A3. Each of these values is a value assigned to the same target mesh 2a in the strength data table 125a of each case. As described above, the strength data table 125a of each case is calculated by the strength allocation unit 125 and stored in the calculation result storage unit 112.

Note that, in FIGS. 15 and 16, the case where the ultrasonic wave transmission position is one and the ultrasonic wave reception position is three is shown as an example, but the present invention is not limited to this. For example, there may be a case where there are a plurality of ultrasonic wave transmission positions and one ultrasonic wave reception position. Alternatively, both the ultrasonic wave transmitting position and the ultrasonic wave receiving position may be a combination of a plurality of each.

FIG. 17 is a diagram showing an example of the result calculated in the signal strength synthesis step for all combinations of the positions of the ultrasonic transmitter and the receiver. The shades in the visualization region 10 indicate the combined intensity, and the higher the density, the larger the value of the combined signal intensity.

When the signal intensities of each case are combined by the intensity synthesizing unit 126, the original signal is integrated, but the noise components close to white noise cancel each other out and are integrated as compared with the original signal. Low. Therefore, the SN ratio for the original signal is increased by integrating the numerical values of each mesh in the intensity data table 125a of each case. As a result, an image in which the shape inside the medium 2 such as the boundary between the ultrasonic reflection source 3 and the medium 2 is clearer can be obtained as compared with the case of each case alone. The calculation result by the strength synthesis unit 126 is stored in the calculation result storage unit 112.

At this stage, the display unit 140 may use the calculation result by the intensity synthesizing unit 126 as data for visualizing the shape of the ultrasonic reflection source 3 and display it as an image of the shape of the ultrasonic reflection source 3. ..

FIG. 18 is a graph illustrating the contents of the shape extraction step. The horizontal axis is the position in the Z-axis direction, and the vertical axis is the combined strength A. The vertical axis may be the value of the index indicating the concentration shown in FIG. In FIG. 18, the vicinity where the peak of the combined intensity A is generated is enlarged in the Z-axis direction.

The shape extraction unit 127 reads the synthesis result of the intensity data calculated by the intensity synthesis unit 126 from the calculation result etc. storage unit 112, and based on this, derives the boundary between the ultrasonic reflection source 3 and the medium 2 in more detail. , Clarify the shape of the ultrasonic reflection source 3.

Specifically, for example, as shown in FIG. 17, when the composite intensity in the visualization region 10 is cut out at the position of X = x, the composite when Z changes from 0 to Z0 as shown in FIG. A change in intensity A is obtained. Based on FIG. 18, the value of Z to be regarded as the boundary between the ultrasonic reflection source 3 and the medium 2 is determined. The following is an example of a method for determining the value of Z that should be regarded as a boundary, but is not limited thereto. Which method is appropriate can be confirmed by using a known ultrasonic reflection source 3. Further, it may be changed to a more appropriate method based on the confirmation result.

The first method for determining the value of Z is a method in which Zm giving the peak value Am is obtained and this Zm is regarded as a boundary.

The second method for determining the value of Z is to obtain Z1 and Z2, which are two Zs giving a value Am / 2, which is half of the peak value Am, and regard the average value of Z1 and Z2 as a boundary.

The third method of determining the value of Z is to set a certain threshold value Ath and regard Zth at the time when the threshold value Ath is first crossed as a boundary.

By obtaining Z that is considered to give a boundary at each x while changing x by the above method, a curve that is considered to be the boundary between the ultrasonic reflection source 3 and the medium 2 can be obtained. Even in the case of three dimensions, one boundary surface can be obtained by extending this method.

The shape of the boundary between the ultrasonic reflection source 3 and the medium 2 derived in more detail by the shape extraction unit 127 is stored in the calculation result storage unit 112. Further, the display unit 140 uses the calculation result by the shape extraction unit 127 as data for visualizing the shape of the ultrasonic reflection source 3, and displays it as an image of the shape of the ultrasonic reflection source 3.

FIG. 19 is a diagram illustrating an example of measurement in which the ultrasonic transmitter and the ultrasonic receiver are moved to a plurality of locations in the ultrasonic imaging method according to the present embodiment. In the example of the system shown in FIG. 19, a liquid ultrasonic reflection source 3 exists in the solid medium 2. The numerical value on the X-axis represents the position in mm units, and the center of the ultrasonic reflection source 3 is the origin.

In this example, the interface between the medium 2 and the ultrasonic reflection source 3 has a shape convex downward, that is, toward the solid medium 2. In such a case, depending on the angle of the ultrasonic wave incident on the interface, it may not be reflected well and the entire shape of the interface may not be grasped well.

Therefore, in order to efficiently capture the entire shape of the interface, measurements are taken from multiple directions. That is, while fixing the position of the ultrasonic receiver 212, the ultrasonic transmitter 211 is moved in a certain region at a pitch of 1 mm in the X-axis direction. The ultrasonic receiver 212 positions are n1 (X = -7.5 mm) shown in (a), n2 (X = 0 mm) shown in (b), and n3 (X = +7.5 mm) shown in (c). ) Is done.

Specifically, for the first reception point n1, there are 27 transmission points in the range of X = -20 mm to -10 mm and -5 mm to +10 mm, and for the second reception point n2. The transmission points are in the range of X = -10 mm to +5 mm and +10 mm to +20 mm with respect to 10 locations in the range of X = -10 mm to -5 mm and +5 mm to +10 mm, and the third reception point n3. Measurements were taken at 27 locations.

As a result, when the ultrasonic receiver 212 position is n1, as shown in (a), the shape of the left side (negative direction of the X-axis) and the central portion of the interface between the medium 2 and the ultrasonic reflection source 3. Has been detected. When the position of the ultrasonic receiver 212 is n2, as shown in (b), the shapes of the portions on both sides near the center of the interface are detected. When the ultrasonic receiver 212 position is n3, as shown in (c), the shape of the right side (positive direction of the X-axis) and the central part of the interface between the medium 2 and the ultrasonic reflection source 3 is It has been detected.

As described above, the range in which the interface is detected differs depending on the position of the receiving point, but the entire interface can be detected by superimposing the three images.

For example, when the number of measurement results of the cases shown in (a) is overwhelmingly larger than the number of measurement results of the cases shown in (b) and (c), the strength data table for all cases is used. When they are overlapped, the synthetic strength of the portion detected in the case shown in (a) becomes overwhelmingly large, and there is a problem that the shape of the other portion may not be sufficiently grasped. In such a case, it is appropriate to use a plurality of intensity data tables selected as necessary from all the intensity data tables.

FIG. 20 is a conceptual diagram showing an example in which the ultrasonic imaging method according to the present embodiment is applied to the detection of a metal molten pool. Specifically, the welding torch is brought close to the upper surface of the metal 4, and as a result of applying heat Q from the metal surface, a state when a molten pool 4a is formed on a part of the upper surface of the metal 4 is detected.

In this case, the molten pool 4a has the highest temperature, and inside the solid portion of the metal 4, the temperature of the metal 4 decreases as the distance from the molten pool 4a increases, as shown in T1 to T6. It becomes a system with. In this way, the shape of the interface between the molten pool 4a and the solid portion of the metal 4 when two types of the same substance but different phases exist can be visualized with high accuracy.

FIG. 21 is a conceptual diagram showing an example in which the ultrasonic imaging method according to the present embodiment is applied to the detection of an object in a liquid. This is the case where the solid detection target 7 is present in the liquid 5. For example, when the shape of a foreign substance in an opaque liquid is confirmed, the shape of the interface between the liquid 5 and the detection target 7 when the liquid and a solid of a substance different from the liquid are present can be visualized with high accuracy. ..

FIG. 22 is a conceptual diagram showing an example in which the ultrasonic imaging method according to the present embodiment is applied to the detection of objects existing in layers. That is, in the basic substance 6, for example, a plurality of detection targets 7a, 7b, and 7c are present in layers. Even if the basic substance 6 and the detection targets 7a, 7b, and 7c are all solids or liquids, for example, ultrasonic waves are emitted at the interface between the detection targets 7a, 7b, and 7c and the basic substance 6. It is possible to visualize the shape of each interface in the case of reflection with high accuracy.

As described above, according to the present embodiment, for various combinations of the medium and the visualization target in the medium, the shape of the visualization target in the medium including the boundary between the medium and the visualization target in the medium is determined. It can be visualized with high accuracy.

[Second Embodiment]
FIG. 23 is a block diagram showing the configurations of the ultrasonic wave detection device and the ultrasonic wave visualization device according to the second embodiment.

This embodiment is a modification of the first embodiment. In the second embodiment, in the ultrasonic imaging device 100, the calculation unit 120 has a temperature distribution setting unit 128. Further, the ultrasonic detection device 200 has a temperature sensor 240. Other than this, it is the same as that of the first embodiment.

The temperature sensor 240 measures the temperatures of a plurality of representative locations of the visualization target 1 and the temperature of the atmosphere in which the visualization target 1 is placed. The temperature sensor 240 is, for example, a thermocouple or a resistance temperature detector. The output of the temperature sensor 240 is input to and stored in the signal recorder 111 of the memory 110. When the temperature of the image target 1 changes with time, the output of the temperature sensor 240 is input to the signal recorder 111 at each sampling interval.

The temperature distribution setting unit 128 has a temperature distribution analysis tool and calculates the temperature distribution in the visualization target 1. The temperature distribution analysis tool may be stored in the memory 110 or the like, and the temperature distribution setting unit 128 may read out the necessary portion of the temperature distribution analysis tool from the memory 110 and use it.

Information on temperature distribution analysis conditions, that is, information on conditions necessary for performing temperature distribution analysis, such as physical property values, shapes, and dimensions of the imaged object 1, is input to the input unit 130 from the outside. The temperature distribution setting unit 128 accepts this temperature distribution analysis condition, models the visualization target 1, and uses it as the analysis condition.

Further, the temperature distribution setting unit 128 reads the output from the temperature sensor 240 from the signal recorder 111 and uses it as a boundary condition. Alternatively, the output from the temperature sensor 240 may be used to modify the analysis content, specifically, the analysis model.

FIG. 24 is a flow chart showing the entire procedure of the ultrasonic imaging method according to the second embodiment. In the ultrasonic imaging method of the present embodiment, step S210 is used instead of step S200 in the first embodiment.

In step S210, the temperature distribution setting unit 128 calculates and sets the temperature of each mesh in the medium 2. Based on this result, the propagation velocity addition unit 123 sets the sound velocity of each mesh (step S300).

In this embodiment, the temperature distribution of the visualization target 1 can be simulated. For this reason, in particular, in the imaged object 1 of a system in which the temperature distribution changes, the temperature distribution is accurately grasped, and the boundary between the medium 2 and the imaged object 1 in the medium is considered in consideration of the temperature distribution. The shape of the visualization target 1 in the medium 2 can be visualized with high accuracy.

Further, in the first embodiment, the temperature of each mesh is specified by an external input, whereas the temperature distribution setting unit 128 calculates and sets the temperature of each mesh, so that the possibility of an input error or the like can be eliminated. In addition, it is possible to reduce the burden on the members who perform ultrasonic flaw detection.

[Other Embodiments]
Although the embodiments of the present invention have been described above, the embodiments are presented as examples and are not intended to limit the scope of the invention.

Furthermore, these embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, as well as in the scope of the invention described in the claims and the equivalent scope thereof.

1 ... Imaging target, 2 ... Medium, 2a ... Target mesh, 3 ... Ultrasonic reflection source, 4 ... Metal, 4a ... Molten pond, 5 ... Liquid, 6 ... Basic substance, 7, 7a, 7b, 7c ... Detection target 10, ... Visualization area, 10a ... End point, 100 ... Ultrasonic visualization device, 110 ... Memory, 111 ... Signal recording unit, 112 ... Calculation result storage unit, 120 ... Calculation unit, 121 ... Visualization area setting unit, 122 ... Mesh division part, 123 ... Propagation speed addition part, 123a ... Propagation speed table, 124 ... Propagation time calculation part, 124a ... Propagation time table, 125 ... Strength allocation part, 125a ... Strength data table, 126 ... Strength synthesis part, 127 ... Shape extraction unit, 128 ... Temperature distribution setting unit, 130 ... Input unit, 140 ... Display unit, 150 ... Control unit, 200 ... Ultrasonic detection device, 210 ... Transmission / reception unit, 211 ... Ultrasonic transmitter, 212 ... Super Sound receiver, 220 ... ultrasonic array probe, 221 ... ultrasonic probe, 222 ... housing, 230 ... laser transmission / reception device, 231 ... ultrasonic excitation laser device, 232 ... laser scanning device, 233 ... reception probe, 234 ... Scan mechanism, 235 ... Optical transmission unit, 236 ... Laser ultrasonic receiver, 236a ... Received laser transmitter, 236b ... Laser interferometer, 240 ... Temperature sensor

Claims (4)

Ultrasonic receiver, and ultrasonic receiving step of ultrasonic wave transmitted into the medium from the ultrasonic transmitter to receive a reflected wave reflected by the ultrasonic reflection source as a reception signal,
The visualization area setting unit sets the visualization area in the medium and divides the inside of the visualization area into meshes, and the visualization area setting step.
Propagation velocity adding unit, the propagation speed setting step of determine the mesh propagation velocity is an ultrasonic propagation speed of each of the mesh based on the temperature distribution in the medium,
Propagation time calculating unit, wherein said through target mesh from the ultrasonic transmitter propagation path to the ultrasonic receiver is divided into a plurality of divided paths having a predetermined path division width, the plurality of divided paths of the mesh wherein determining the mesh that corresponds to each, extending from said ultrasonic transmitter on the basis of the mesh propagation speed for each of the determined said corresponding to Rume mesh to the ultrasonic receiver via the target mesh A propagation time table creation step for creating a propagation time table in which the total propagation time of ultrasonic waves is determined for each combination of the position of the ultrasonic transmitter and the position of the ultrasonic receiver, and
Intensity allocation unit, said each combination of the position and the position of the ultrasonic receiver of the ultrasonic transmitter, the respective reception intensity included in the received signal, before SL propagates the total propagation time determined in the time table Intensity data table creation step to create an intensity data table by assigning to each of the meshes corresponding to
Strength synthesis section, said plurality of combinations of position and the position of the ultrasonic receiver of the ultrasonic transmitter, the intensity data synthesizing step of synthesizing the intensity data of the intensity data table for calculating the weighting coefficients,
A display step in which the display unit displays an image of the shape of the ultrasonic reflection source from the combined intensity, and
A step of performing the ultrasonic wave receiving step to the display step at a plurality of installation locations of the ultrasonic wave transmitter and the ultrasonic wave receiver and superimposing the respective images.
An ultrasonic imaging method characterized by having. The ultrasonic wave according to claim 1 , wherein the shape extraction unit further includes a shape extraction step for deriving the position of the ultrasonic reflection source after the intensity data synthesis step and before the display step. Visualization method . The propagation time table creation step is performed for each of the target meshes of the mesh.
The propagation time calculation unit divides the path from the ultrasonic transmitter to the target mesh and the path from the target mesh to the ultrasonic receiver into the plurality of divided paths with the predetermined path division width. Steps and
A corresponding mesh determination step in which the propagation time calculation unit determines the corresponding mesh for each of the plurality of divided paths.
The propagation time calculation unit calculates the division route propagation time, which is the propagation time of each of the plurality of division paths, from each of the plurality of division paths and the mesh propagation speed housed in the corresponding mesh. Divided route propagation time calculation step and
A propagation time calculation allocation step in which the propagation time calculation unit integrates the division route propagation time and allocates the integrated division route propagation time to the target mesh as the total propagation time.
The ultrasonic imaging method according to claim 1 or 2, wherein the method is characterized by having. The ultrasonic imaging method according to claim 3, wherein in the corresponding mesh determination step, the mesh to which the midpoint of each of the plurality of division paths belongs is determined as the mesh corresponding to the division path.

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