JP2970415B2 - Ultrasonic flaw detection signal memory analyzer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for recording, analyzing and displaying ultrasonic flaw detection signals.

[0002]

2. Description of the Related Art Ultrasonic flaw detection is often used as a nondestructive inspection method for steel products. A widely used method is to transmit an ultrasonic pulse to a subject and determine the presence or absence of a defect from a received signal (hereinafter, referred to as a flaw detection signal), which is called a pulse reflection method. In ordinary ultrasonic flaw detection, in many cases, flaw detection is performed while moving an object or a probe. Therefore, transmission of a pulse in the pulse reflection method is usually performed at short time intervals of about 0.1 to 10 msec. It is repeated. And usually, when the range gate signal decided inspection range (there after transmission of the transmission pulse time t ₁ has elapsed to be detected of the inner defect of the testing signals will gate open, then a predetermined time t ₂ elapses when a signal gate is closed ), The maximum value of the detected flaw detection signals is peak-held, the peak-hold value is compared with a preset threshold value, and the presence or absence of a defect is determined based on whether the peak-hold value exceeds the threshold value. The flaw detection is performed by using the method described below.

[0003] In order to maintain and further improve the reliability of flaw detection, it is necessary to determine whether or not there is any signal in the flaw detection signal that causes noise, and to analyze the noise characteristics in a normal portion. is there. For this purpose, it is necessary to record and grasp the status of the flaw detection signal. As a conventional technique for this purpose, a method of recording the intensity of a flaw detection signal on a chart is well known. That is, of the flaw detection signals, a signal within a time range in which a defect should appear is picked up by a gate signal, the maximum value of the picked up signals is peak-held, and the peak hold value is recorded as a DC voltage on a recorder. It is. In the display of the recorder, the horizontal axis represents time, and the vertical axis represents signal intensity. This method is frequently used especially in an automatic flaw detector for steel products.

There is also a method of recording not the peak hold value of the flaw detection signal but the signal waveform itself. For example, FIG.
FIG. 21 is a configuration diagram of a conventional ultrasonic flaw detection signal storage / analysis device indicated by reference numeral 21314 (1990). In FIG.
Is an ultrasonic probe, 22 is an ultrasonic pulser / receiver, 2
3 is a scanner, 24 is an ultra-high-speed A / D converter, 25 is a motor control, 26 is a personal computer (IBM, PC / AT, AX type), 27 is a display, and 28 is a printer. Constitute a storage analysis device.

[0005] In the apparatus shown in FIG.
The flaw detection signal obtained through the ultrasonic pulsar / receiver 22 is sampled by a high-speed A / D converter 24 to obtain digital data, and the digital data is sequentially stored in a memory of a personal computer 26.
The stored data can be scroll-displayed on the display 27 one by one for the waveform of the flaw detection signal.

[0006]

However, the conventional ultrasonic flaw detection signal storage / analysis device has the following problems.
First, the method of recording the peak hold value of the flaw detection signal is as follows:
Although all flaw detection signals can be recorded, only the intensity of the signal information is known, so that even if a strong signal is recorded, it cannot be distinguished whether it is a defect echo or noise. With the method of recording the signal waveform of the flaw detection signal itself, it is difficult to record all flaw detection signals over the entire surface of a mass-produced subject such as a steel product because of the memory capacity for recording data. It is. For example, the number of pulses required to detect one 10-meter steel pipe is 3 million or more, and the memory capacity is required to be about 1.5 GB (gigabytes). If this memory is constituted by a semiconductor memory so that reading and writing can be performed at high speed, the cost becomes very high. Also, since defect echoes and noises are suddenly observed spontaneously, if the memory capacity is reduced, the defect echoes and noises that you want to observe may not be recorded properly. Since the signal waveforms are scrolled and displayed one by one, it is difficult to intuitively grasp how the flaw detection signal has changed over time.

The present invention has been made in order to solve such problems, and it is possible to grasp whether or not a signal which becomes a noise in a flaw detection signal of an ultrasonic flaw detection and to analyze a noise property. Another object of the present invention is to provide an ultrasonic flaw detection signal recording / analyzing apparatus capable of obtaining a highly reliable flaw detection result.

[0008]

According to a first aspect of the present invention, there is provided an ultrasonic flaw detection signal storage / analysis apparatus which converts a flaw detection signal obtained based on an ultrasonic pulse transmitted to a subject at a predetermined repetition cycle. A / D conversion means for quantizing at a predetermined sampling period and sequentially outputting digital data of a fixed number of samples, and comparing a value of digital data output from the A / D conversion means with a preset threshold value, Comparison determination means for determining whether the value of the data has exceeded a threshold,
A first storage capable of storing a predetermined number of samples of digital data output from the A / D conversion means in each transmission cycle of an ultrasonic pulse up to a predetermined number of continuous n cycles, and capable of reading out the stored data. Means for sequentially storing up to a predetermined plurality of k sets of digital data for a plurality of predetermined continuous n cycles read from the first storage means;
The second storage means capable of reading out the storage data and the new fixed sample are always stored in the first storage means during a period in which the comparison determination means determines that the threshold value is not exceeded. A plurality of continuous digital data of a predetermined number n
The digital data is continuously written while the old data is updated to the new data so that the old data is stored for the period, and when the comparison and determination means determines that the threshold value is exceeded, the first storage is performed until then. The digital data being continuously written is written into the means for a plurality of m cycles smaller than the plurality n, including the transmission cycle exceeding the threshold, and the writing operation is temporarily suspended. Digital data for (n−m) periods before the threshold value is exceeded and m periods subsequent thereto are read out from the storage means, and the read data is stored in the second
The writing is sequentially performed so that the predetermined plurality of k sets can be stored in the storage means. Thereafter, the continuous writing of the digital data to the temporarily stopped first storage means is resumed, and the digital data is stored in the second storage means. And data reading and reading control means for sequentially reading digital data for a plurality of n cycles up to a plurality of k sets.

According to a second aspect of the present invention, there is provided an ultrasonic flaw detection signal storage / analysis apparatus, wherein the ultrasonic flaw detection signal storage / analysis apparatus according to the first aspect includes a plurality of k sets read out from the second storage means. And display means for sequentially displaying digital data for a plurality of n cycles.

[0010]

In the invention according to the first aspect, the A / D conversion means quantizes the flaw detection signal obtained based on the ultrasonic pulse transmitted to the subject at a predetermined repetition cycle at a predetermined sampling cycle. , And sequentially outputs digital data of a fixed number of samples. The comparing and determining means compares the value of the digital data output from the A / D converting means with a preset threshold value, and determines whether or not the value of the digital data has exceeded the threshold value. The first storage means can store digital data of a fixed number of samples output from the A / D conversion means in each transmission cycle of the ultrasonic pulse up to a predetermined number of continuous n cycles and read out the stored data. Is also possible. The second storage means can sequentially store up to a predetermined plurality of k sets of digital data for a plurality of predetermined continuous n cycles read from the first storage means, and can also read the stored data. The data writing and reading means always stores the new digital data of the predetermined number of samples in the first storage means during a period in which the comparison and determination means determines that the threshold value is not exceeded. The old data is continuously written with the digital data while being updated with the new data so as to be stored for a plurality of n cycles. In this case, the digital data being continuously written is written into the storage means for a plurality of m cycles smaller than the plurality n, including the transmission cycle exceeding the threshold, and the writing operation is temporarily interrupted. The (nm) period before the threshold value is exceeded from the first storage means and the following m
The digital data of the cycle is read out, and the read data is sequentially written in the second storage means so that the predetermined plurality of k sets can be stored, and thereafter, the digital data is continuously stored in the temporarily interrupted first storage means. At the same time, the writing is restarted, and the digital data for a plurality of continuous n cycles up to a plurality of k sets stored in the second storage means are sequentially read.

According to the second aspect of the present invention, the display means added to the first aspect of the present invention comprises a plurality of k sets of up to k sets read from the second storage means.
The digital data for the cycle is sequentially displayed.

[0012]

FIG. 1 is a block diagram of an apparatus for storing and analyzing ultrasonic flaw detection signals according to the present invention. In FIG. 1, reference numeral 1 denotes an A / D converter, which has a predetermined repetition period (1 msec in this example).
c) A flaw detection signal within a predetermined flaw detection range obtained based on an ultrasonic pulse transmitted every time is converted into digital data at a predetermined sampling cycle (40 nsec in this example), and is determined by the sampling cycle and the flaw detection range. Digital data of a fixed number of samples s (s = 500 in this example) is output. Reference numeral 2 denotes a first storage unit capable of writing and reading data, which is a RAM having a storage capacity of, for example, about 64 KB (kilobytes). In this example, 500 samples obtained in each transmission cycle of the ultrasonic pulse Can be stored up to a plurality of continuous n (in this example, n = 128) cycles.

Reference numeral 3 denotes a second storage unit capable of writing and reading data, which is a RAM having a storage capacity of, for example, about 1 MB (megabyte). In this example, the RAM 1 is transferred from the first storage unit 2. 500 consecutive ones per cycle
Digital data for 28 cycles can be sequentially stored up to a predetermined plurality of k (k = 16 in this example) sets. Reference numeral 4 denotes a comparison / determination means, which can variably set a threshold value in advance.
A comparison is made with the value of the digital data sequentially output from the conversion means 1 to determine whether or not the value of the digital data has exceeded a threshold value, and this determination result signal is output.

Reference numeral 4 denotes a controller for controlling the entire apparatus, which internally has a central processing unit (hereinafter referred to as a CPU) 51, and a write and read control for controlling writing and reading of data to and from the first and second storage means. Means 52. The write / read control means 52 performs a continuous write operation to the first storage means 2 during the period in which the comparison / determination means 4 determines that the threshold value is not exceeded, based on an instruction from the CPU 51 (writing when data is not collected). Operation), a limited number of write operations (write operation at the time of data collection) to the first storage means 2 when the comparison determination means 4 determines that the threshold value is exceeded, and the first storage means 2
The control of the data transfer operation from the second storage means 3 to the second storage means 3 and the data read operation from the second storage means 3 are performed.

Reference numeral 6 denotes a display means (for example, a CRT display) which performs a parallel display of a plurality of cycles of flaw detection signals of the digital data read from the second storage means 3. Reference numeral 7 denotes a recording unit (for example, a printer or a disk) which prints and records the read data, or records and stores the data on a memory disk in order to store the information stored in the second storage unit 3. Numeral 8 denotes an analyzing means, which performs a frequency analysis for converting, for example, a time domain signal into a frequency domain signal on the flaw detection signal read out from the second storage means 3, and performs a correlation process on a signal between adjacent cycles to generate a defect echo. A correlation analysis or the like for identifying noise is performed. An ultrasonic flaw detector 9 incorporates an ultrasonic pulsar and a receiver, and transmits and receives an ultrasonic pulse (in general, a burst wave is used) at a predetermined repetition period (in this example, 1 msec). 1
0 is an ultrasonic probe.

FIGS. 2 and 3 are explanatory diagrams of write operation examples 1 and 2 for the first storage means in FIG. 1, respectively. The operation of FIG. 1 will be described with reference to FIGS. First, the ultrasonic flaw detector 9 is connected to a subject (not shown) via the ultrasonic probe 10.
At the same time, an ultrasonic pulse (for example, a burst wave) is repeatedly transmitted with a period of 1 msec, and the received flaw detection signal is sequentially supplied to the A / D converter 1. Each time an ultrasonic pulse is transmitted, the A / D converter 1 converts the flaw detection signal supplied from the ultrasonic flaw detector 9 to a predetermined point in time after the transmission of the transmission pulse (this corresponds to the thickness, material, and transport speed of the subject). Etc., for example, when 5 μsec has elapsed after transmission pulse transmission)
The data is converted into digital data for a period of 500 samplings, that is, for a period of 20 μsec at a sampling cycle of 40 to 40 nsec.

That is, the A / D conversion means 1 outputs 500 pieces of flaw detection digital data obtained by quantizing the flaw detection signal waveform in the flaw detection range by high-speed sampling in each transmission cycle of the ultrasonic pulse. These 500 pieces of flaw detection digital data are written into one storage means 2 as soon as possible, and are compared by a comparison / determination means 4 with a preset threshold to determine whether or not the flaw detection digital data exceeds the threshold. . The operation of writing the output data of the A / D conversion means 1 to the first storage means 2 depends on whether the determination result of the comparison determination means 4 is within a period in which the threshold value is not exceeded or not. The operation is divided into two cases: when data is not collected (transferred) into the storage means 3 and when data is collected.

FIG. 2 is an explanatory diagram of an example 1 of a write operation to the first storage means 2 during a period when the digital flaw detection data does not exceed the threshold value. In the example of FIG. 1, the first storage means has a capacity to store 500 data per cycle for 128 cycles. Now, the inside of the first storage means 2 is divided into 128 unit areas each capable of storing 500 data, and the respective areas are # 1 area, # 2 area,
.., # 128 area. After the flaw detection operation is started, while the flaw detection digital data sequentially output by the A / D conversion means 1 does not exceed the threshold value, first, as shown in FIG.
The write area is sequentially changed and data is written, for example, writing 500 digital data of the cycle in the # 1 area and writing digital data of the next # 2 cycle in the # 2 area.

The digital data of # 128 cycle is #
When the digital data is written in 128 areas and continuous digital data of 128 cycles is written in all the areas in the first storage means 2, the digital data of the next # 129 cycle is returned to the # 1 area again and written. Be included. By this writing operation, the digital data of the past # 1 cycle that is already 128 cycles old is erased and updated to the new # 129 cycle data. The same operation is repeated until digital data exceeding the threshold value is generated, such that digital data of the next # 130 cycle is written in the # 2 area. In this way, the first storage means 2 always stores new continuous flaw detection data for 128 cycles. During a period in which the threshold value is not exceeded, data transfer from the first storage unit 2 to the second storage unit 3 is not performed. In other words, no data is collected in the device.

FIG. 3 is an explanatory diagram of a second example of the writing operation to the first storage means 2 when the flaw detection digital data exceeds the threshold value. If the determination result of the comparing and determining means 4 exceeds the threshold value while the flaw detection digital data is being written in the area # 61, this determination result signal is immediately sent to the CPU 51 in the controller 5. Upon receiving the message exceeding the threshold value, the CPU 51 instructs the write / read control unit 52 to switch to an operation of collecting data in the second storage unit 3 immediately.

In response to the operation switching instruction, the write / read control means 52 stores the digital data which has been continuously written in the first storage means 2 until then, and thereafter, the plurality of cycles n including the cycle exceeding the threshold value. Writing is performed for a plurality of m cycles (m = 108 in this example) smaller than (n = 128 in this example), and the writing operation to the first storage unit 2 is temporarily suspended. In this example, since the data value exceeded the threshold value while data was being written into the # 61 area of the first storage means 2,
After that, in the memory area in which data for 108 cycles to be continued is written, the writing operation is performed from the # 61 area to the # 128 area and the # 1 area to the # 40 area, and is temporarily suspended. By doing so, # 4 in the first storage means 2
Areas 1 to 60 store flaw detection data for 20 cycles before the threshold is exceeded, and areas # 61 to 40 store flaw detection data for 108 cycles after the threshold is exceeded. Preparation for data transfer from the first storage unit 2 to the second storage unit 3 is completed.

When the data transfer preparation is completed, C
The PU 51 instructs the write / read control means 52 to immediately transfer all the data stored in the first storage means 2 to the second storage means 3. Second storage means 3
Has 16 times the storage capacity of the first storage means 2 in this example, the storage capacity of the second storage means 3 is divided into 16 areas, and the # 1 area, # 2 area,. I will call it. Write and read control means 52
However, the order in which the data is read from the first control means 2 for data transfer is as follows: the flaw detection data for 108 cycles is subsequently written because the data value being written exceeds the threshold value.
Therefore, flaw detection data for 128 cycles is read from the next address area where the writing operation has been temporarily suspended.

In the above example, first, flaw detection data for 20 cycles before the threshold value is exceeded from the area # 41 and then flaw detection data for 108 cycles after the threshold value is exceeded from the area # 61 are read out in the second area. Are written in order from the # 1 area in the storage means 3. When the transfer of data for 128 cycles before and after the period including the period exceeding the threshold from the first storage unit 2 to the second storage unit 3 is completed as described above, the write / read control unit 52 immediately The interrupted operation of continuously writing data to the first storage means 2 is restarted. That is, the flaw detection data output from the A / D conversion means 1 is written in the first storage means 2 sequentially from the # 1 area in each transmission cycle of the ultrasonic pulse. Then, flaw detection data exceeding the threshold value is generated again, writing of flaw detection data for the subsequent 108 cycles is completed, and when data is transferred from the first storage means 2 to the second storage means 3 for the second time, The write / read control means 52 writes the data in the next # 2 area so as not to erase the previous data already stored in the second storage means 3.

In this example, the storage capacity of the second storage means 3 is set to 16 times that of the first storage means 2, so that 16 sets of data transfer from the first storage means 2 becomes full. Therefore, the stored data is analyzed before the storage capacity becomes full. The CPU 51 uses the period during which data transfer to the second storage unit 3 is not performed and, based on a read instruction given automatically or manually, sends a second instruction to the write / read control unit 52. In addition to sequentially reading out the flaw detection data of 128 cycles before and after that including the cycle exceeding the threshold up to 16 sets stored in the storage means 3 and supplying the data to the display means 6 and the recording means 7, the data is further supplied to the analysis means 8. Let it.

The flaw detection data of 128 consecutive cycles read out from the second storage means 3 for each group are displayed in parallel with waveforms of a plurality of continuous cycles by the display means 6 and recorded and output by the recording means 7. Further analysis means 8
Thus, frequency analysis, correlation analysis, and the like are performed, and the properties of the defect echo and noise are clarified. FIG. 4 is a diagram showing a display example of flaw detection data of a plurality of continuous cycles according to the present invention.
In FIG. 1 to the cycle No. Since up to 50 are displayed in parallel in order, it is easy to grasp the temporal change of the signal amplitude. In addition, the frequency analysis, correlation analysis, and the like by the analysis means 8 can be used to determine the distinction between a defective echo and noise and the cause of noise generation.

In the above embodiment, the sampling period of the A / D converter 1 is 40 nsec, the number of fixed samples to be quantized for each transmission period is 500, and the plurality of periods n stored in the first storage unit 2 are: 128, the writing cycle m after exceeding the threshold is 108, and the capacity of the second storage means 3 is the first.
Although the example in which the storage means 2 is 16 times as large as the above is shown, these numerical values are shown as an example of the embodiment, and the present invention is not limited to these numerical values. That is, the transmission frequency of the ultrasonic wave, the repetition period, the flaw detection range, and the like are selected according to the shape, material, transport speed, and the like of the subject, and the numerical values are generally changed to optimal values accordingly. Further, it is also possible to use a memory disk, a magnetic tape, or the like as the recording means 7 and thereafter read out the data stored therein, and perform comparison with the current data.
Further, the first storage means and the second storage means are provided in one RAM.
, It is possible to avoid complicating the circuit by dividing the addresses to be stored.

[0027]

As described above, according to the present invention, from the large amount of flaw detection data sequentially obtained by quantizing the ultrasonic flaw detection signal at high speed, only the significant part is determined by judging the magnitude relation with the threshold value. All are stored as raw data (waveform data), and by analyzing the stored waveform data, it is possible to know the presence or absence of noise, the cause of the noise, etc., so that the reliability of the ultrasonic flaw detector is improved. Now you can do it.

Further, according to the present invention, since the waveform data from before the flaw detection data exceeds the threshold value and before the flaw detection data exceeds the threshold value is displayed in parallel over a plurality of continuous periods, the temporal change of the signal amplitude can be clearly understood. It is now possible to fully understand the state of occurrence of defect echo and noise.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a storage analysis device of an ultrasonic flaw detector according to the present invention.

FIG. 2 is an explanatory diagram of a first operation example of writing to a first storage unit in FIG. 1;

FIG. 3 is an explanatory diagram of a second example of a write operation to the first storage unit in FIG. 1;

FIG. 4 is a diagram showing a display example of flaw detection data of a plurality of continuous cycles according to the present invention.

FIG. 5 is a configuration diagram of a conventional ultrasonic flaw detection signal storage analyzer.

[Explanation of symbols]

 Reference Signs List 1 A / D conversion means 2 First storage means 3 Second storage means 4 Comparison / determination means 5 Controller 6 Display means 7 Storage means 8 Analysis means 9 Ultrasonic flaw detector 10 Ultrasonic probe 51 CPU 52 Writing / writing Read control means

Claims (2)

(57) [Claims] An A / D converter for quantizing a flaw detection signal obtained based on an ultrasonic pulse transmitted to a subject at a predetermined repetition cycle at a predetermined sampling cycle and sequentially outputting digital data of a predetermined number of samples. Means for comparing the value of the digital data output from the A / D conversion means with a preset threshold value to determine whether or not the value of the digital data has exceeded the threshold value;
A first storage unit capable of storing digital data of a fixed number of samples output from the D conversion unit in each transmission cycle of the ultrasonic pulse up to a predetermined number of continuous n cycles and reading out the stored data; A second storage unit capable of sequentially storing up to a predetermined plurality of k sets of digital data for a predetermined plurality of continuous n cycles read from the first storage unit, and capable of reading the storage data; During the period in which the determination means determines that the threshold value is not exceeded, new digital data of the predetermined number of samples is always stored in the first storage means for a predetermined number of continuous n cycles. As described above, the old data is continuously written with the digital data while being updated with the new data, and when the comparing and judging means judges that the threshold value has been exceeded, the first data is kept until then. The digital data being continuously written is then written into the storage means for a plurality of m cycles smaller than the plurality n, including the transmission cycle exceeding the threshold, and the writing operation is temporarily suspended. The digital data for the (n−m) period before the threshold value is exceeded and the m periods following the (n−m) period are read out from the storage means, and the read data can be stored in the second storage means up to the predetermined plurality of k sets. Sequential writing, after which the continuous writing of the digital data into the first storage means, which has been temporarily interrupted, is resumed, and the digital data for a plurality of n consecutive cycles up to a plurality of k sets stored in the second storage means And a data writing and reading control means for sequentially reading data. 2. The storage analysis of an ultrasonic flaw detection signal according to claim 1, further comprising display means for sequentially displaying digital data of a plurality of n cycles up to a plurality of k sets read out from said second storage means. apparatus.