JPH01180450A - Synthetic aperture processor - Google Patents

Abstract

PURPOSE:To vary access time according to variation in the thickness of a material to be inspected and sampling period by setting a maximum address value to be accessed corresponding to variation in discrete digital value. CONSTITUTION:When the value of an address counter 19 for memories provided to an A/D line memory part and a waveform memory part 6 reaches a set address value 16, the processor stops access to addresses preceding the set address value 16 by an address control part 14 and uses the memories of one A/D line memory and the waveform memory part 6 as variable address length memories. Namely, when the thickness of the material to be inspected is different, i.e. when the number of discrete digital values is smaller than the address length, address length meeting requirements is set previously and control 14 is so performed that access is not performed beyond the set address. Consequently, the one-address-length memory can be used for the proper purpose, the flexibility of the processor is not lost, and the processing time is shortened.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is a non-destructive technology that can detect defects in metal materials using, for example, ultrasonic waves and display images of the defects in high resolution and in real time. This invention relates to a synthetic aperture processing device using a synthetic aperture radar that can be used for inspection or visualize the ground surface situation from above using electromagnetic waves.

[Conventional technology]

One of the methods used in ultrasonic non-destructive testing, etc., narrows down the ultrasonic beam and measures the spatial information of a single point on the object to be reproduced based on the propagation time from transmission to reception of the reflected signal.
Sequentially scan the ultrasonic transmitter/receiver electronically or mechanically,
In contrast to the method of visualizing and displaying the object image to be reproduced as a collection of point information, this method irradiates the object with a spread ultrasonic beam.

The reflected wave or transmitted wave is received by a receiving element, and the amplitude and phase information of the wave is recorded (hologram creation).

There is a so-called synthetic aperture method that reproduces an object image from this hologram.

In principle, this synthetic aperture method has a feature that the resolution is constant regardless of the distance to the object.

FIG. 3 shows a conventional example of a synthetic Sekiguchi processing apparatus that performs regeneration processing of an object using an ultrasonic synthetic aperture method.

In the same figure, (1) is an ultrasonic transceiver (hereinafter referred to as a transceiver), +21 is a transmitter, (3) is a receiver, and (4) is an A
/D converter.

(51t! A/D line memory section, +6)t! Waveform memory section, (7) is latch gate circuit, (8) is arithmetic unit, (9) is image display section (hereinafter referred to as 1 display section), αα is reproduction calculation control section (hereinafter referred to as reproduction control section), Qlt focus table , Q2a is a measurement control unit, α31 is a scanning drive mechanism, and (Is is a material to be inspected).

The waveform memory section (6) has M waveform memories (hereinafter simply referred to as memories) with an address length of N, that is, 1M□ to Mvt', while the A/D line memory section (5) has an address length of N. N A/D line memory (hereinafter simply referred to as A/D
(Mesori) Equipped with one MD.

Note that FIGS. 4(,) and (b) respectively show the memories M,
-A conceptual diagram of MM and A/D memory MD is shown.

Furthermore, FIG. 5 is a diagram for explaining the principle of reproduction processing using the one-synthesis method.

In the figure, the horizontal axis represents the scanning direction of the transmitter/receiver, the vertical axis represents the time fee, and T represents the time fee for transmission.

The received signal at each scanning point, which includes the information of point a that is about to be reproduced, has a phase delay corresponding to the distance between each scanning point and point a, and the locus of the phase delay is as shown in the figure. It becomes a hyperbola with at-vertex. In addition, the range in the scanning direction in which a received signal containing the information of one point a can be obtained is determined by the spread of the ultrasound beam, and the range in the scanning direction in which the information at the maximum distance in the depth direction to be reproduced can be received is determined by the spread of the ultrasonic beam. The range is called the synthetic aperture length and is shown in Figure 9. In order to reproduce the point at in Fig. 1, the received signals at each scanning point regarding the two points a in the range of the sweet acid aperture length are added along the phase locus (hereinafter referred to as 1 phase history line). Become.

Furthermore, FIG. 6 shows the memory M of the waveform memory section (6).

It is a diagram for explaining the configuration of ~MM.

In the figure, the horizontal axis corresponds to the scanning direction, and the vertical axis corresponds to the depth direction. L and L2 are defined by the synthetic aperture range based on the synthetic aperture length, and I! , and t are reproduction target lines (hereinafter referred to as target lines) reproduced by the synthetic aperture range, and
, also 1, 2.3. ...-, (M-1), M,
(M+1), each of the nine scanning points a and a' are points in the same depth direction, and the object line l! 1 and l, which are also the points above.

The received signal obtained corresponding to each scanning point is A/D converted at a predetermined sampling period by the A/D converter (4), and one synthetic aperture range is scanned from scanning point l to scanning point M. When finished, 9M discrete digital planting arrays are obtained for the number of scanning points.

Therefore, the number M of memories M8 to MM in the waveform memory section (6) corresponds to the number of scanning points within the synthetic aperture range, and the address length NtlX corresponds to the number of discrete digital values. .

The procedure for one-point AF reproduction is as follows: (1) The discrete digital planting array obtained at the scanning points l to M in the synthetic aperture range L M, (required data determined from the phase history line in the discrete digital array at each scanning point resulting in 21 points ath is extracted and added.

The necessary data determined from the phase history line in the discrete digital array at each scanning point for 9-point at-reproduction can be retrieved from the waveform memory section (6) using a first-order method. That is, address values in the memories M, to MM of the waveform memory unit (6) in which necessary discrete digital values are stored are determined in advance according to the phase history line uniquely defined corresponding to the point to be reproduced. is made into a table corresponding to each scanning point, that is, each mesori, and based on the address information from this table, that is, the focus table (11), a plurality of data corresponding to the point to be reproduced are stored from the waveform memory section (6). The discrete digital values of are read out and transferred to the arithmetic unit (8).

Next, to reproduce point a', the synthetic aperture range L! Read out from the waveform memory section (6) based on the address information of the focus table I based on the phase history line regarding one point a' of the discrete digital array of each received signal obtained at each scanning point 2 to (M+l) in All of the resulting plurality of discrete digital values are added in the same manner.

As described above, the fact that the target line is sequentially shifted in the scanning direction means that the data in the waveform memory section (6) operates as follows. That is, the above (M+1
) After obtaining the received signal for one line at the scanning point (M+1), the discrete digital values for one line at the scanning point (M+1) are stored in the A/D memory section (5). I.J.
When storing data from MD into the memory MM of the waveform memory section (6), the discrete digital planting array stored in the memories M1 to MM is line-shifted by 12 inches, and the data for one line at the scanning point l is shifted by 12 inches. The data is discarded, and the 1 at
Data for each line is stored. In addition, the transmitter/receiver (ll
The latch gate circuit (7) performs the above-mentioned 2-in shift operation every time t-scan is performed.

By the way, if the depths of point a and point a' are the same, the nine phase history lines will also be the same, and therefore.

The addresses in the waveform memory section (6) of data necessary to reproduce points having the same depth are also the same. That is, the focus table Q11t based on a phase history line uniquely determined corresponding to a certain depth can be commonly used for points at the same depth in different synthetic aperture ranges.

Each of the above operations t-To summarize, the operations for one scanning question are as follows.

(2) A transmission pulse is applied from the transmitter (2) to the transmitter/receiver tl+. ■The received signal is the A/D converter (4)
The discrete digital array is converted into a discrete digital value in the A/D: A/D memo IJ of the fine memory section (5).
Stored in MD. (2) Line shifting in the memories M8 to MM of the waveform memory section (6) and data transfer and storage from the A/D memory MD of the A/D line memory section (5) are performed. (2) Necessary data is read from each of the memories M1 to MM based on the address information of the focus table circle and transferred to the arithmetic unit (8).

(2) The arithmetic unit (8) performs addition processing for each point to be reproduced. ■The result of addition in the arithmetic unit (8), that is, the data for 1247 in the depth direction is transferred to the display unit (9).
The image is displayed for 47 minutes.

That is, each time the transmitter/receiver is scanned, the above
0 operations are performed.

The reproduction control unit (11) controls the timing until one line is reproduced from the received signal A/D converted by the A/D converter (4) according to instructions from the measurement control unit a. Also, the measurement control section.

Controls the timing of transmission, reception, playback, and image display.

[Problem to be solved by the invention]

As explained in the prior art section, the waveform memory section (
Data structure in 6) t! , M' is the number of scanning points within the synthetic aperture range, and the number of discrete digital values resulting from digitizing the received signal obtained by Nt-1 scans at a predetermined sampling period. It has a configuration in which columns are lined up for the number of scanning points, that is, a two-dimensional matrix configuration of MXN.

Further, the address length of the A/D memory MD is also equal to the address length N of the memories M□ to MD.

By the way, during the line shift, the addresses of the discrete digital values to be line shifted are sent one by one from l to N from the reproduction control unit to the waveform memory unit (6) and the A/D.
The line memory section (5) is accessed and line shifting of the discrete digital values is repeated N times in total twice for all scanning points at the same time as shown below.

That is, the waveform memory section (6) has a predetermined number of bits.

And a memory of address length N, M pieces for the number of scanning points, that is, 9
Since M1 to MM are provided, line shifting can be performed simultaneously and repeatedly N times for all scanning points.

■A/D memory M in A/D line memory section (5) → latch gate circuit (7) → memory M in waveform memory section (6)
M-1 time ■ Pigeon of waveform memory section (6) -> Latch gate circuit (7)
→Memory M(J+1) (N
l) times again. The operation of storing the discrete digital values A/D-converted by the A/D converter (4) in the A/D converter (4) is similarly repeated N times.

By the way, since Nt'j is the number of discrete digital values obtained in one scan, if the thickness of the specimen a9 in the depth direction is different or the sampling period is different, the number of discrete digital values will be different. The values will also be different.

Therefore, for the address length N of the memories M8 to M1,
Let 'iK be the number of discrete digital values obtained under the condition of , all addresses must be accessed iN times regardless of the thickness of the material to be inspected, and the access time required for this is fixed.

Also, if you want to avoid unnecessary access time when N<K or N)K.

It becomes necessary to prepare a memo IJ't with an address length corresponding to the number of discrete digital values under predetermined conditions, and the versatility of the device is lost.

This invention was made to solve the above-mentioned problems, and it is possible to convert fixed address length memory into waveform memory and A/
I) Prepare for y-in-memory, and also adjust the address length by setting the maximum address value to be accessed in response to changes in the number of scattered digital values, such as changes in the thickness of the test material and changes in the sampling period. It is made variable so that the access time can be changed in response to changes in the shore depth of the material to be inspected or changes in the sampling period.

[Means to solve the problem]

The synthetic aperture processing device IL related to this invention is conventional.

9 If the number of discrete digital values obtained at a scanning point is smaller than the address length provided, for example when the thickness of the material to be inspected is different, all addresses can be stored. However, while memory with a fixed address length is provided in the A/D line memory section and the waveform memory section, it is possible to An address control unit is provided to set the address length to be accessed and to prevent addresses beyond the set address value from being accessed. The access time is made variable.

In other words, in the synthesis Sekiguchi processing device according to the present invention, when the value of the address counter for the memory provided in the A/D line memory section and the waveform memory section matches the set address value.

Accesses to addresses beyond the set address value are stopped, and the memory in one A/D 2-in memory section and the waveform memory section is used as variable address length memory, so the versatility of the device is maintained and the processing speed is reduced. The purpose of the present invention is to provide an apparatus that does not consume unnecessary access time, that is, has a processing time that is appropriate for the purpose.

[Effect]

In the synthetic aperture processing device according to the present invention, when a memory having a certain address length is used as a memory in the waveform memory section and the A/D fin memory section, the number of discrete digital values is limited to the address length, such as when the thickness of the test material is different. Even if the address length is smaller, the address length can be set in advance according to the nine conditions, and in order to control the address beyond the set address by not accessing it, a memory with one address length can be used according to the purpose. Memory can be used selectively, and unnecessary processing time can be saved without losing the versatility of the device.

〔Example〕

FIG. 1 shows an embodiment of a synthetic aperture processing apparatus according to the present invention.

In the same figure, (1) is an ultrasonic transceiver (hereinafter referred to as a transceiver), 121 is a transmitter, (3) is a receiver, +41t
ljA/D converter.

(51 is the A/D line memory section, +611; is the waveform memory section, (7) is the Labuchi gate circuit, (8111 arithmetic unit, (9) is the image display section (hereinafter referred to as 1 display section), (IG is the reproduction calculation control section) (hereinafter referred to as a reproduction control section), (Ill is a focus table, (12 is a measurement control section, Q3H scanning drive mechanism, Q41tff address control section, and a9 is a material to be inspected.

Further, the waveform memory section (6) is composed of M waveform memories (hereinafter simply referred to as memories) with an address length N, that is, 1M1 to MM, and the A/D line memory section (5) is configured with an A/D line memory section (5) having an address length N. D line memory (hereinafter simply referred to as A/D memory) 1
ie 9MDt-.

The configurations of the memories M to MM and the A/D memo IJM are as shown in the fourth prisoner.

The overall operation of the synthetic aperture processing apparatus according to the present invention is the same as that of the conventional synthetic aperture processing apparatus.

That is, the matrix structure of the data in the memories M, to MM is as follows.

The row direction corresponds to the number of scanning points in the scan direction synthetic aperture range, and the one row direction corresponds to the number of discrete digital values of the fc reception signal obtained in one scan.

Then, in one scanning period, (1) a transmission pulse is applied from the transmitter (2) to the transmitter/receiver (1).

Ultrasonic waves are irradiated from the transmitter/receiver (1) to the test material a9. ■The ultrasonic wave reflected in the test material α9 is received by the transmitter/receiver (1), converted into an electrical signal, and then passed through the receiver (3) to the A/D converter (4).
) is output to. (2) As a result of discretization by the A/D converter (4), a string of discrete digital values corresponding to l scanning points is stored in the A/D memory MD. ■The memory M1
~MM, data is shifted by 12 inches, and the sequence of discrete digital values is transferred from the A/D memory MD to the memory MM. ■Focus table a
Based on the address information from the sword, data necessary to reproduce the reproduction target point on the reproduction target line is accessed and sent to the arithmetic unit (8). ■The arithmetic unit (8
), the addition process is performed for each reproduction target point, and in the end, the total number is 124.
Seven minutes of data is transferred to the display section (9).

Note that the reproduction control section aQ performs various timing controls for processing the received signal to the reproduction calculation and display section according to instructions from the measurement control section 02. Also.

Under the control of the measurement control unit α, the scanning mechanism (to)
scans the transmitter/receiver (1).

Next, the operation of the address control section α4, which is a feature of the synthetic aperture processing apparatus of the present invention, will be described below with reference to FIG. FIG. 2 is a diagram showing an embodiment of the address control section I. In the same figure.

Qeij address setting value (hereinafter referred to as setting value), a'n is a comparison circuit.

141! is a control circuit, and the address control section (141!
The structure includes the comparison circuit a1 and the control circuit. Further, (PI is an address counter, and an is a buffer, which is provided in the playback control section.

For example, during the line shift, the address of the discrete digital value is transferred from the address counter αI to the memory M in the waveform memory section (6) via the buffer mt-.
Accessed from 8 to MM. and.

As described above, after the discrete digital values of the accessed memories M□ to MM are once latched by the edge gate section (7), at a certain timing when the playback control section α [is sent out], the discrete digital values of the accessed memories M□ to MM are It is shifted by ~MM- times (equivalent to Mayoha-scanned seafood) and stored again in the memories M1 to M. By the way, the address counter α! J counts the addresses one by one, so while counting the addresses, the carry CO generated by the address counter αl is transferred to the address control unit (1).
41, that is, it is sent to the comparison circuit α9. And the carry c.

When becomes equal to the set value αe, the control circuit 0& operates, closes the gate of the buffer (2), and clears the address counter number. Also.

The signal output from the control circuit (181) is also transmitted to a circuit having a timing generation function (not shown) in the playback control unit aO.Thus, for addresses beyond the set value αθ, the playback control unit The song will not be accessed.

In this embodiment, the memory address control operation of the address control section a4 was shown only for the waveform memory section (6), but the operation of the memory address control of the A/D line memory section (5) was
It goes without saying that the same operation as in this embodiment is performed for the /D memo IJMD, and the same effect is obtained.

In addition, in this embodiment, the second address control section I is
Although the configuration shown in the figure is used, when the set value αe and the address value in the address counter αl in the playback control unit song match, the waveform memo, part 9 (6) and A/D line memory An address control section having another configuration may be used as long as the circuit has a control function to stop access to the section (5).

Similar effects can be achieved.

〔Effect of the invention〕

As described above, according to the synthetic aperture processing device according to the present invention, when the number of discrete digital values is different, such as when the thickness of the test material is different, the waveform is This is because the address control section has a function of controlling the memories of the memory section and the A/D line memory section so that addresses t beyond the set address are not accessed.

Depending on the application, processing requires only the minimum necessary access time while maintaining memory versatility.

This has the effect of saving processing time.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a synthetic aperture processing apparatus according to the present invention, and FIG. 2 is a diagram for explaining an address control section that is a feature of the synthetic aperture processing apparatus according to the present invention. FIG. 3 is a diagram showing a conventional synthetic aperture processing device, FIG. 4 is a diagram showing the A/D line memory and waveform memory of the present invention and a conventional synthetic aperture processing device, and FIG. 5 is a reproduction process using the synthetic aperture method. Figure 6 is a diagram for explaining the configuration of the waveform memory, where the mountain is a transmitter/receiver, +21 is a transmitter, (3) is a receiver, and (4) is an A/ D
Converter, (51t;! A/D fin memory section,
(611! Waveform memory section, (7) is the latch gate circuit. (8) is the arithmetic unit, [1G is the reproduction arithmetic control section, tin
is the focus table, α~ is the address control section, α61
9 is an address setting value, MDT'S A/D line memory, and 9M1 to MM are the waveform memories. In FIG. 9, the same or corresponding parts are designated by the same reference numerals.

Claims (1)

[Claims] A transceiver that generates and detects ultrasonic waves or electromagnetic waves,
a transmitter that applies an electrical signal to the transceiver; and a transmitter that mechanically or electronically scans the transceiver to transmit a spatially spread ultrasonic or electromagnetic wave beam into the interior of the target object at each scanning point in the scanning direction. A receiver receives the reflected wave of the ultrasonic wave or electromagnetic beam detected by the transceiver from inside the target object as a result of the transmission, and converts the received signal corresponding to one scanning point from the receiver from analog to digital. an A/D line memory section comprising an A/D converter and an A/D line memory storing a plurality of discrete digital values corresponding to one scanning point obtained by the A/D converter; A two-dimensional memory is used to sequentially receive a plurality of discrete digital values corresponding to one scanning point from the A/D line memory for each scanning and store them as a discrete digital value string corresponding to the scanning point for the plurality of scanning points. A waveform memory unit including a waveform memory configured as a frame memory, and all discrete digital value strings in the memory of the waveform memory unit in which the discrete digital value strings up to the latest scanning point are stored. The line shift is performed by each scanning point, and the A/D value is also transferred to the area in the waveform memory where the discrete digital value sequence was stored corresponding to the latest previous scanning point before the line shifting.
a latch gate circuit for storing a sequence of discrete digital values corresponding to the latest scanning point from a D-line memory section, and temporarily storing the discrete digital values in the waveform memory section for line shifting within the waveform memory section; In order to read out the discrete digital values of the waveform memory section for each scanning point, which are necessary when reproducing each point on the center line that is an arbitrary reproduction target within the synthetic aperture range, the discrete digital value for each scanning point is read out. a focus table in which addresses of digital values are tabulated in correspondence with playback target points; an address control unit that controls access to the A/D line memory section and the waveform memory section based on predetermined address setting values; When performing calculations, the necessary data in the focus table is sent to the waveform memory unit, and the address of the discrete digital value in the waveform memory unit is line shifted and the A/A is latched by the latch gate circuit.
a reproduction calculation control unit that instructs the address of the discrete digital value in the D line memory unit and controls the timing of the line shift and reproduction calculation; and a reproduction calculation control unit that adds the plurality of discrete digital values read from the waveform memory unit. A synthetic aperture processing device characterized by comprising a computing unit.