KR102141051B1 - Method for detecting target and equipment for detecting target - Google Patents

Abstract

A target detecting method according to an embodiment of the present invention comprises: a step of moving a plurality of detectors in other direction different from one direction while radiating transmission signals from each of the plurality of detectors arranged in the one direction; a step of sampling reception signals, which are received by each of the plurality of detectors after the transmission signals are reflected, multiple times at a set period to acquire multiple sampled signals; a correction step of removing clutter from the plurality of sampled signals sampled from the reception signals of each of the plurality of detectors to transform each of the plurality of sampled signals into process signals; a step of generating detection signals by using the process signals for each of the plurality of detectors; and a step of detecting a position of a target in the one direction by using the detection signals. Therefore, according to embodiments of the present invention, an arrangement type target detecting facility including the plurality of detectors arranged in one direction can process the signals of each of the plurality of detectors in real time and can process the reception signals with a low calculation amount. In addition, a correction or a clutter removing method according to an embodiment of the present invention can reduce errors in which things besides detection targets are detected as targets. Therefore, accuracy in detecting the targets can be improved.

Description

METHOD FOR DETECTING TARGET AND EQUIPMENT FOR DETECTING TARGET

The present invention relates to a target detection method and a target detection facility, and relates to a target detection method and a target detection facility capable of improving target detection accuracy.

Underground buried detection is required in various fields such as the private sector, industrial sector, and military sector, targeting the detection of minerals, cultural assets, land mines, and unexploded dangerous substances buried underground. In general, a metal detector (MD) is used as equipment for detecting underground burial. Metal detectors have the advantage of simple implementation and good detection performance by electromagnetic induction, but have limitations in detecting non-metallic objects. Accordingly, an electromagnetic wave-based detection radar capable of detecting non-metallic objects has recently been spotlighted.

The detection radar is called a ground penetration radar (GPR) because it detects objects buried underground, for example land mines, through the ground. Examples of the detection device using the ground transmission radar are presented in Korean Patent Registration No. 10-0365141, Korean Patent Registration No. 10-1241313, Korean Patent Registration No. 10-1267016, and Korean Patent Registration No. 10-1267017. The ground transmission radar uses an ultrawide band (UWB) frequency of approximately 100 MHz to 1 kHz because it must detect land mines using signals reflected through the ground at a certain depth. In this way, the ground transmission radar using the ultra-wide band is called an ultra-wideband ground penetration radar.

The ultra-wide-band transmission radar can estimate the shape, buried depth, and the like by radiating an ultra-wideband transmission wave to the ground and analyzing signals reflected from the mine.

On the other hand, a land mine is detected using a ground transmission radar having a transmitter for transmitting electromagnetic waves and a receiver for receiving reflected signals. In other words, when a soldier is on the ground, he picks up a mine detector equipped with a radar to detect land mines. Such a detection method takes a considerable amount of time to detect a large amount of landmines, and is inefficient.

Korean Registered Patent 1783776

The present invention relates to a target detection method and a target detection facility capable of improving detection accuracy.

Target detection method according to an embodiment of the present invention, while radiating a transmission signal from each of a plurality of detectors arranged in one direction, while moving the plurality of detectors in the other direction different from the one direction; Obtaining a plurality of sampling signals by sampling the received signals received by each of the plurality of detectors by a predetermined period by reflecting the transmitted signals; A correction process of removing a clutter from a plurality of sampling signals sampled from each of the plurality of detectors and converting each of the plurality of sampling signals into processing signals; Generating a detection signal by using the processing signals for each of the plurality of detection objects; And detecting the position of the target in the one direction using the detection signal.

The one direction is an X-axis direction, and the other direction is a Y-axis direction horizontally orthogonal to the X-axis direction.

In the correction process, a process signal is generated by maintaining or discarding the n-th sampling signals as they are according to the entropy of the n-th sampling signals sampled n-th from the received signal of each of the plurality of detectors. Includes.

The target detection method according to an embodiment of the present invention includes the steps of moving the plurality of detectors while emitting a transmission signal from each of the plurality of detectors; Obtaining a plurality of sampling signals from received signals received by each of the plurality of detectors; A correction process of removing a clutter from the plurality of sampling signals and converting each of the plurality of sampling signals into processing signals; Generating a detection signal by using the processing signals for each of the plurality of detection objects; And detecting a position of a target using the detection signal; and the correction process includes, according to entropy of the n-th sampling signals sampled n-th from the received signals of each of the plurality of detectors, And generating or processing the n-th sampling signals as they are or discarding them.

The correction process may include calculating n-th entropy for n-th sampling signals sampled n-th from each of the plurality of received signals; Comparing the calculated n-th entropy with a reference entropy; When the calculated n-th entropy is less than a reference entropy, maintaining the n-th sampling signals as they are; And discarding the n-th sampling signals when the calculated n-th entropy is greater than or equal to a reference entropy.

The process of detecting the position of the target may include generating a top view video image by binarizing the detection signal into a detection value and a background value according to signal strength for each detection signal; And moving the window having an area on the video image, comparing an area occupied by a pixel having a detection value in the window with a preset reference area, and targeting the target in one direction, which is a direction in which the plurality of detectors are arranged The process of detecting the location of; includes.

In moving the window on the video image, the image is alternately moved multiple times in a first direction corresponding to the one direction and a second direction corresponding to another direction different from the one direction.

In moving the window on the video image in the first and second directions, the window is moved to partially overlap with an area occupied by the window at a previous viewpoint.

In generating a detection signal using the processing signals for each of the plurality of detection objects, a plurality of processing signals are averaged by each of the plurality of detection objects.

The step of detecting the position of the target in the one direction includes detecting a detector that has received a signal reflected from the target among the plurality of detectors using the electromagnetic wave intensity included in the detection signal, And detecting the position of the target in the other direction and the buried depth direction using the detection signal in the other direction generated from the detection object detected as receiving the signal reflected from the target.

The process of detecting the position of the target in the other direction and the buried depth direction is performed by hough transforming the detection signal in the other direction generated from the detection object detected as receiving the signal reflected from the target in the other direction. Generating a visual image in which a parabola having a width is visible; And detecting the position of the target in the other direction and the depth direction by detecting the vertex position of the parabola generated by the Huff transform.

A target detection facility according to an embodiment of the present invention includes a transmitter for emitting a transmission signal and a receiver for receiving a reception signal from which the transmission signal emitted from the transmitter is reflected, and a plurality of detectors arranged in one direction. ; A moving device equipped with the plurality of detectors and movable in another direction different from the one direction; A signal converter configured to sample the received signal received by each of the plurality of detectors multiple times at regular cycles to obtain a plurality of sampling signals; A first signal processor for removing clutter from the plurality of sampling signals; It includes; a detection unit for detecting the position of the target through a detection signal generated by using the sampling signal from which the clutter is removed by the first signal processing unit.

The first signal processing unit generates a processing signal by maintaining or discarding the n-th sampling signals as they are according to entropy of n-th sampling signals sampled n-th from each of the plurality of detectors. .

Each target detection facility according to an embodiment of the present invention includes a transmitter and a receiver for receiving the reflected received signal, arranged in one direction, a plurality of detectors movable in another direction different from the one direction; A signal converter configured to acquire a plurality of sampling signals from received signals received by each of the plurality of detectors; A first signal processor for removing clutter from the plurality of sampling signals; The first signal processing unit detects a detector that has received a signal reflected from a target through a detection signal generated using a clutter-removed sampling signal, and detects a target position in one direction. part; A second detection unit for detecting the position of the other direction and the buried depth direction by using the detection signal of the other direction generated by the detection body detected as having received the signal reflected from the target by the first detection unit; Includes.

The first detection unit generates a top view image image by binarizing the detection signal into a detection value and a background value according to the electromagnetic wave intensity for each detection signal of each of the plurality of detection objects, and reflects the target from the first detection unit In detecting a detector that has received a signal, the first detector moves a window having an area on the video image and detects a position in the window where an area occupied by pixels having a detection value is greater than a preset reference area. Thus, among the plurality of detectors, a detector that receives a signal reflected from a target is detected.

The second detector hough transforms the detection signal of the other direction generated by the detector detected by the first detector to generate a video image in which a parabola having a width in the other direction is visible, The second detection unit detects the position of the vertex of the parabola generated by the Huff transformation, and detects the position of the target in the other direction and the depth direction.

According to an embodiment of the present invention, according to an array type target detection facility including a plurality of detectors arranged in one direction, it is possible to process signals of each of the plurality of detectors in real time and to process a received signal with a low computation amount. have.

In addition, by the correction or clutter removal method according to an embodiment of the present invention, it is possible to reduce the error of detecting targets other than the detection target. Accordingly, it is possible to improve target detection accuracy.

And, by detecting the position of the target by analyzing the top view (image) image, it is possible to analyze the signal of the overall size of the target and the direction of movement of the object. Thus, it is possible to detect the exact position of the target.

1 is a view conceptually showing a target detection facility based on an ultra-wideband ground transmission radar according to an embodiment of the present invention.
2 is a diagram conceptually illustrating operations of a transmitter and a receiver of one detector in a target detection facility according to an embodiment of the present invention.
3 is a block diagram illustrating a detector and a detection device according to an embodiment of the present invention.
4 is a diagram illustrating an example in which a plurality of sampling signals sampled from each of the plurality of received signals are arranged and arranged.
5 and 6 are views for explaining the correction method according to the first embodiment of the present invention.
7 is a diagram conceptually schematically illustrating a correction method according to a first embodiment of the present invention using a data cube.
8 to 10 are views for explaining a correction method according to a second embodiment of the present invention.
11 is a diagram conceptually illustrating a correction method according to a second embodiment of the present invention using a data cube.
12 is a diagram for conceptually explaining calculating a root mean square for an input signal for each received signal in a second signal processing unit according to an embodiment of the present invention.
13 is a diagram conceptually showing a detection signal obtained by calculating a root mean square for an input signal for each received signal in a second signal processing unit according to an embodiment of the present invention.
14 is a view showing an example of a top view image generated by using a detection signal generated by the second signal processing unit.
15 is a diagram conceptually showing a method of detecting a position of a target in an X-axis direction in a first detection unit according to an embodiment of the present invention.
16 is a photograph showing an example of a method for detecting a position of a target in the X-axis direction in a first detection unit according to an embodiment of the present invention.
17 is a view for explaining a detection signal in the Y-axis direction (detector movement direction) of the detection object detected by the first detection unit.
18 is a diagram conceptually showing a parabolic signal having a predetermined width in a direction in which the detector moves (Y-axis direction).
19 and 20 are diagrams showing a video image in which a parabola having a predetermined width is visible in a direction in which the detector moves (Y-axis direction).
21 is a view sequentially showing a target detection method according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various different forms, and only these embodiments allow the disclosure of the present invention to be complete, and the scope of the invention to those skilled in the art. It is provided to inform you completely.

The target detection facility according to an embodiment of the present invention is a target detection facility that detects the presence of metal and non-metal targets. As a more specific example, the target detection facility according to the embodiment may be a device for detecting a target, for example, a landmine, which is buried under the ground or underground.

Hereinafter, a target detection facility according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3.

1 is a view conceptually showing a target detection facility based on an ultra-wideband ground transmission radar according to an embodiment of the present invention. 2 is a diagram conceptually illustrating operations of a transmitter and a receiver of one detector in a target detection facility according to an embodiment of the present invention. 3 is a block diagram illustrating a detector and a detection device according to an embodiment of the present invention. 4 is a diagram illustrating an example in which a plurality of sampling signals sampled from each of the plurality of received signals are arranged and arranged.

1 to 3, the target detection facility according to an embodiment of the present invention includes a transmitter 1100 for radiating a signal and a receiver 1200 for receiving a reflected signal, and arranged in one direction. It includes a plurality of detectors (1000), a detection device (2000) for detecting a target (T) buried underground based on the signals received and collected by the detector (1000).

In addition, the target detection facility includes a plurality of detectors 1000 mounted thereon, and includes a mobile device (not shown) movable in a direction crossing the direction in which the detectors 1000 are arranged.

The transmitter 1100 generates a transmission signal of a predetermined frequency and radiates the transmission signal to a predetermined depth underground through the ground. The transmitter 1100 generates an electromagnetic wave transmission signal having an ultrawide band frequency of 100 MHz to 1 GHz and a predetermined intensity, for example. At this time, the transmitter 1100 may generate transmission signals of various frequencies by adjusting the frequency within the above range. In addition, the transmitter 1100 may be generated by variously adjusting the strength of a transmission signal. In this way, the transmission signals of various frequencies and intensities are generated from the transmitter 1100 so that the depth of arrival of the transmission signals can be variously adjusted. For example, the lower the frequency of the transmission signal and the higher the intensity, the deeper the arrival depth of the transmission signal may be, and, conversely, the higher the frequency of the transmission signal and the lower the intensity, the lower the arrival depth of the transmission signal.

The receiver 1200 receives an electromagnetic wave signal (hereinafter, a reception signal) reflected by an underground medium, such as a mine, in which the radiation signal by the transmitter 1100 is buried underground. The electric field signal and the magnetic field signal may be formed by the signal emitted from the transmitter 1100, and the receiver 1200 may include at least one pair of antennas for measuring the electric field signal and the magnetic field signal, respectively. That is, the receiver 1200 may include an electric field signal receiving antenna and a magnetic field signal receiving antenna. The electric field signal receiving antenna may be configured in the form of a dipole antenna in which two conductive radiators are arranged side by side based on the feed point, and the impedance of some or all of the antenna arms is increased to increase the resolution of the received signal. It may be configured in the form. In addition, the magnetic field signal receiving antenna may be configured in the form of a loop antenna in which a single conductive radiator is wound, and is configured in a form loaded with impedance having a certain value or a constant value for a plurality of sections at a single point of the antenna. It may be.

As described above, the transmitted signal radiated from the transmitter 1100 is reflected underground, and the reflected signal is received by the receiver 1200 of the detector 1000. At this time, the received signal received by the receiver 1200, that is, the electromagnetic wave intensity is changed according to the distance between the point where the transmitted signal is reflected and the receiver 1200. That is, the closer the distance between the detector 1000 and the reflected point, the greater the received signal strength, and the farther the distance, the smaller the received signal strength.

The detectors are provided in plural and arranged in one direction. Hereinafter, the direction in which the plurality of detectors 1000 are arranged is defined as the “X-axis direction”, which may be described in other words as “detector direction” or “one direction” (see FIG. 1 ). Then, a target detection facility including a plurality of detectors arranged or arranged in one direction may be referred to as an'array-type target detection facility'.

The plurality of detectors 1000 may be mounted on a movable device (hereinafter, a mobile device), for example, a vehicle. That is, a plurality of detectors are installed on the mobile device to be arranged in the X-axis direction. The moving device moves in a direction that crosses, for example, an orthogonal direction to the array direction of the plurality of detector bodies 1000. Hereinafter, the moving direction of the mobile device is defined as'Y-axis direction' (see FIG. 1 ). At this time, since the plurality of detectors 1000 are moved in the Y-axis direction by the mobile device, the Y-axis direction may be described in other words as a'movement direction of the detector' or a'other direction' different from'one direction'. have.

In addition, in the detection zone to detect the target T, the depth direction of the detection zone is defined as the Z-axis direction (see FIG. 1 ). Here, the Z-axis direction may be described as a transmission direction of a transmission signal emitted from the transmitter 1100.

In the embodiment, it will be described, for example, that 48 detectors 1000 are provided. In addition, for convenience of explanation, the sequence numbers are sequentially assigned to the 48 detectors 1000 and are referred to as the first to 48th detectors 1000.

Of course, the number of detectors 1000 is not limited to the above 48, and may be provided in various numbers of two or more.

The plurality of detectors 1000 may be operated individually, and the plurality of detectors 1000 emit a transmission signal with a short pulse width and receive the reflected reception signal. In addition, while one of the detectors 1000 of the plurality of detectors 1000 is operating, the remaining detectors 1000 may not operate, and the plurality of detectors 1000 may be sequentially operated.

In addition, a plurality of detectors 1000 arranged in the X-axis direction are installed on the mobile device, and the mobile device moves in a direction intersecting the array direction of the plurality of detectors 1000, that is, in the Y-axis direction. At this time, as the plurality of detectors sequentially move while the plurality of detectors move in the Y-axis direction, each of the plurality of detectors operates intermittently or periodically.

Accordingly, a plurality of signals are generated in the X-axis direction of the detection zone according to the arrangement type of the detector, and a plurality of signals are generated in the Y-axis direction of the detection provision by the movement direction of the detector, in the X-axis and Y-axis directions Each signal has depth direction information.

Accordingly, according to the array type detector 1000 according to an embodiment of the present invention, a signal including three-dimensional (X-axis, Y-axis, and Z-axis) data may be generated.

In the field of detecting targets buried underground, such as land mines, the one-dimensional signal obtained by transmitting and receiving electromagnetic waves by one detector 1000 is called A-scan, two-dimensional signal B-scan, and three-dimensional signal C-scan. .

Referring to FIG. 3, the detection apparatus 2000 according to an embodiment of the present invention includes a first processing unit 2200 that corrects by removing a clutter from a received signal received by a plurality of detectors 1000 and It includes a first detection unit 2300 for detecting the position of the target (T) in the X-axis direction using the received signal processed by the first processing unit 2200.

In addition, the detection device 2000 controls the operating conditions or set values of each of the detection object 1000 and the detection device 2000 before the target detection starts according to the states of the detection object 1000 and the detection device 2000, respectively. It may include a pre-processing unit 2100.

In addition, the detection apparatus 2000 corrects by removing a clutter from a signal in the Y-axis direction for a position in the X-axis direction in which the target is detected as being present in the first detection unit 2300, and corrected. The position of the target T in the Y-axis and Z-axis direction is detected by using the signals processed by the second processing unit 2400 and the second processing unit 2400 processing the signal as a signal for easy detection of the target T The X-direction position of the target T is received from the second detection unit 2500 and the first detection unit 2300, and the Y- and Z-axis direction positions are transmitted from the second detection unit 2500, and the X of the target T is transmitted. , A target positioning unit 2600 for determining the position in the Y and Z axis directions.

In addition, the detection apparatus 2000 includes a detection image display unit 2700 that displays a position in the X-axis direction provided from the first detection unit 2300 and a second and third direction location provided from the second detection unit 2500 on the screen. It includes.

Meanwhile, as described above, when a signal is radiated from the transmitter 1100 of the detector 1000, the transmitted signal is reflected and then received by the receiver 1200. At this time, the time until the transmission signal is reflected and received by the receiver 1200 varies according to the reflected position as described above, but may vary according to the state of the detector 1000 itself. In more detail, when a transmission signal is radiated from each of the plurality of transmitters 1100 and the transmission signal is reflected at the same location, the time required to receive a signal to each of the plurality of receivers 1200 should be the same. will be. However, depending on the current state or set value of the detector 1000, the time at which the signal is received may be different.

Then, the received signal received by the detector 1000 is sampled by the first processing unit 2200 at regular intervals. That is, the entire received signal received while the detector 1000 is operating is not transmitted to the first processing unit 2200, and a part is sampled and transmitted. To this end, the first processing unit 2200, which will be described later, is configured to include a signal conversion unit 2210 that samples the received signal of the detector 1000 and converts it into a digital signal.

It is necessary that the period or sampling rate at which the received signals of each of the plurality of detectors 1000 are sampled by the first processing unit 2200 is the same or uniform. However, when the temperature of the chip constituting the signal converter 2210 is different or the size of the applied power is different due to an environment or an internal problem, the received signal of each of the plurality of detectors 1000 The sampling rate may be different. This is a factor that lowers its reliability in target detection.

Therefore, in the exemplary embodiment of the present invention, the pre-processing unit 2100 is provided to adjust or correct operating conditions or set values of the detector 1000 and the signal converter 2210 before the target T detection starts.

The pre-processing unit 2100 has a delay compensation unit 2110 for adjusting the time at which the signals are received by each of the plurality of detectors 1000 and the receivers 1200, and the rate at which the received signals of each of the plurality of detectors 1000 are sampled. It includes a sampling rate control unit 2120 for adjusting the set value of the signal conversion unit 2210 to be adjusted.

The delay compensator 2110 compensates for signal reception unevenness or time delay due to the state of the detector 1000 itself, not the distance from the target T when signals are received by the plurality of detectors 1000. . To this end, first, a transmission signal is emitted from each of the plurality of detectors 1000. At this time, the transmission signal is emitted from each of the plurality of detectors 1000 under the condition that the type of the object emitting the transmission signal and the height of the object are the same. Thereafter, the delay compensation unit 2110 detects a time at which a signal is received by the receiver 1200 of each of the plurality of detectors 1000. That is, the time (hereinafter, the signal reception time) from the time when the signal is emitted from the transmitter 1100 to the time when the signal is received by the receiver 1200 is detected.

In addition, the delay compensation unit 2110 organizes signal reception times for each of the plurality of detectors 1000 to create a look up table. That is, a look up table is created so that a signal reception time is indicated for each of the plurality of detectors 1000.

Next, the delay compensation unit 2110 analyzes the difference in signal reception times of the plurality of detectors 1000 and sets compensation values so that the signal reception times of the plurality of detectors 1000 are uniform. At this time, a compensation value is set for each of the plurality of detectors 1000, and the compensation values may be different or some may be the same. In addition, in setting the compensation value, the signal reception time of any one of the plurality of detectors 1000 is used as a reference, for example, the first detector.

Before the target detection is performed, the delay compensator 2110 controls the detector 1000 so that a delay in signal reception time due to a problem inside the detector 1000 does not occur. Therefore, it is possible to prevent a target detection error from occurring due to a delay in receiving a signal according to an internal problem of the detector 1000, thereby improving detection reliability.

The sampling rate adjusting unit 2120 adjusts the set value of the signal converting unit 2210 of the first processing unit 2200 so that the sampling rate or period of the received signal for each of the plurality of detectors 1000 is uniform. To this end, first, each received signal of each of the plurality of detectors 1000 is sampled by a signal converter. Then, the sampling rate control unit 2120 detects the sampling rate for each received signal. Subsequently, the interpolation method adjusts the sampling rate for each received signal to be the target sampling rate of the operator.

As described above, the signal converter 2210 controls the sampling rate of the received signals of each of the plurality of detectors 1000 through the sampling rate adjusting unit 2120 before the target detection is performed. Therefore, it is possible to prevent the occurrence of a target detection error due to a difference in the sampling rate, thereby improving detection reliability.

The first processing unit 2200 samples the received signal, which is an analog signal received by the plurality of detectors 1000, and converts the converted signal into a digital signal, and removes clutter from the sampled and digitized received signal. The second signal is processed so that the target signal in the X-axis direction, which is the alignment direction of the detector 1000, is emphasized by using the received signal corrected by the first signal processing unit 2220 and the first signal processing unit 2220. It includes a processing unit 2230.

The signal converter 2210 samples the received signal received by the detector 1000 at regular intervals, and converts the sampled received signal into a digital signal.

Here, sampling the received signal may mean that a part of the received signal is sampled and received without receiving the entire received signal while the detector 1000 is operating. In addition, the signal converter may sample the received signal at a predetermined period, which may mean that the sample has a predetermined rate at a predetermined Hz. In addition, when sampling the received signal generated from the detector 1000 at regular intervals, a plurality of signals are extracted from the received signal.

Since the transmission signal emitted from the transmitter 1100 is received by the receiver 1200, the time received by the receiver 1200 varies according to a position where the transmission signal is reflected. That is, the deeper the reflected position, the longer the time received by the receiver 1200. Accordingly, the received signal received by the receiver 1200 may be described as data over time or depth.

The signal converter 2210 samples a received signal at regular intervals according to a time sequence. Accordingly, signals sequentially sampled from one received signal may be named by giving a sequence number according to the sampled order. For example, according to the order of sampling,'the first sampling signal, the second sampling signal, and the third sampling signal... You can name it.

In addition, as described above, received signals are generated from a plurality of detectors 1000, and each of them is sampled, and the number of samples from each detector 1000 is the same. That is, each of the first to forty-eighth received signals, which are received by each of the first to forty-eight detectors, is sampled, so that the number of these samples is the same. This can be achieved by equalizing the operating times of the first to 48th detectors 1000 and adjusting the sampling period, that is, the same speed, through the sampling rate adjusting unit 2120.

Since the first to forty-eighth received signals received by each of the first to forty-eight detectors are sampled at the same period, the sampling signals sampled at the same time may be arranged, for example, as shown in FIG. 4.

Hereinafter, for convenience of description, the sampling signal is'S', the received signal sequence number according to the sequence number of the detector is'a', the sampling sequence number is'b', and the total number of samples is sn.

Here, the total number of sampling may mean a total number of samples of a received signal received during an operation time when a plurality of detectors are alternately operated in sequence, and when they are operated once. That is, it may be the total number of samples of the received signal that the detector operates at one position in the Y-axis direction. Accordingly, the b-th sampling signal of the a-th received signal due to the a-detector may be represented as'S _a,b '.

Therefore, FIG. 4 can be described as showing a sampling signal for each of a plurality of received signals.

For a more specific example, the first sampling signals (S _{1, 1} , S _{2, 1} , S _{3, 1} ,…, S _{48, 1} ) sampled first from each of the first to 48th received signals, respectively. Is arranged in the arrangement direction of the first to forty-eighth received signals, and the second sampling signals (S _{1, 2} , S _{2, 2} , S _{3, 2} , ...) sampled a second time from each of the first to forty-eight received signals. , S _{48, 2} ) are arranged in the direction in which the first to 48th received signals are arranged, and the remaining sampling signals are also arranged in the same manner as in FIG. 4.

Hereinafter, for convenience of description, _a set of sampling signals S _{a and b} sampled at the same time is referred to as an'extraction signal'.

Accordingly, a set of first sampling signals S _{1, 1} , S _{2, 1} , S _{3, 1} ,…, S _{48, 1 of} each of the first to 48 received signals is first extracted signals, and first to A set of second sampling signals (S _{1, 2} , S _{2, 2} , S _{3, 2} ,..., S _{48, 2} ) of each of the 48th received signals is a second extracted signal, and each of the first to 48th received signals The set of third sampling signals S _{1, 3} , S _{2, 3} , S _{3, 3} ,…, S _{48, 3} of may be described as a third extraction signal.

In other words, the first extraction signal includes the first sampling signals S _{1, 1} , S _{2, 1} , S _{3, 1} ,…, S _{48, 1 of} each of the first to 48th reception signals. And, the second extraction signal is a second sampling signal (S _{1, 2} , S _{2, 2} , S _{3, 2} , ..., S _{48, 2} ) of each of the first to 48 received signals, the third extraction signal May be described as including the third sampling signals S _{1, 3} , S _{2, 3} , S _{3, 3} , ..., S _{48, 3 of} each of the first to 48th received signals.

In addition, the first extraction signal is a collection of the first sampling signals (S _{1, 1} , S _{2, 1} , S _{3, 1} ,…, S _{48, 1} ), and the second extraction signal is the second sampling signals (S _{A collection of 1, 2} , S _{2, 2} , S _{3, 2} ,…, S _{48, 2} ), the third extraction signal is the third sampling signals (S _{1, 3} , S _{2, 3} , S _{3, 3} , …, S _{48, 3} ), it can be explained that the direction in which the plurality of extraction signals are sequentially arranged is a depth signal underground.

Although not illustrated in FIG. 4, a plurality of sampling signals for each received signal are continuously generated in the moving direction of the detector.

Meanwhile, the detector 1000 is a means for detecting metal and non-metal targets. However, in the detection zone, there are surface reflection signals other than the target signal, reflection signals due to a difference in dielectric constant in the soil, and reflection signals in the medium. This signal received by the receiver 1200 is called a clutter, and a problem in target detection may be caused by the clutter. That is, the detection signal may be buried by the clutter component, non-detection objects that are not targets, or reliability of detecting the target location may be deteriorated.

Accordingly, as a receiver of the detector 1000, not only the reflected signal by the target to be detected, but also a clutter signal that is not the target of detection may be received.

Therefore, it is necessary to detect the target using the signal from which the clutter has been removed.

The first signal processor 2220 corrects the clutter by removing the clutter from the plurality of extracted signals. In other words, the first signal processing unit 2220 corrects the clutter to be removed from the plurality of sampling signals constituting each of the plurality of extraction signals.

In the first signal processing unit 2220, the method according to the first embodiment (the first method) and the entropy of the extracted signal using the average of the plurality of sampling signals for the extracted signal in correcting the plurality of extracted signals It is corrected by the method (second method) according to the second embodiment using (entropy).

5 and 6 are views for explaining the correction method according to the first embodiment of the present invention. 7 is a diagram conceptually schematically illustrating a correction method according to a first embodiment of the present invention using a data cube.

First, the correction method according to the first embodiment will be described with reference to FIGS. 5 to 7.

The correction method according to the first embodiment is a method of subtracting each of a plurality of sampling signals constituting the extraction signal by the average of the previously sampled extraction signals.

When the extraction signal to be corrected is referred to as an n-th extraction signal, the first signal processing unit averages each of a plurality of sampling signals constituting the n-th extraction signal (A _{n -1} ) ((a), (b) in FIG. 7) to correct the absolute value ((c) in FIG. 7).

For a specific example, each of the second sampling signals (S _1,2 , S _{2, 2} , S _{3, 2} ,…, S _{48, 2} ) constituting the second extraction signal constitutes a first extraction signal. Is subtracted by the average value A ₁ of the first sampling signals S _{1, 1} , S _{2, 1} , S _{3, 1} ,…, S _{48, 1} . Accordingly, the second sampling signals S _1,2 , S _{2, 2} , S _{3, 2} ,..., S _{48, 2} of the second extraction signal are subtracted by the average value A ₁ to be converted or corrected.

As another example, each of the third sampling signals (S ₁ , ₃ , S _{2, 3} , S _{3, 3} ,…, S _{48, 3} ) constituting the third extraction signal may be second sampling constituting the second extraction signal. It is subtracted by the average value A ₂ of the signals S _1,2 , S _{2, 2} ,S _{3, 2} ,…,S _{48, 2} . Accordingly, the third sampling signals S ₁ , ₃ , S _{2, 3} , S _{3, 3} , ..., S _{48, 3} of the third extraction signal are subtracted by the average value A ₂ to be converted or corrected.

Hereinafter, for convenience of explanation, each of the plurality of sampling signals constituting the nth extraction signal converted or corrected by being subtracted by the average (A _n-1 ) of the plurality of sampling signals constituting the n-1th extraction signal is converted. Name it a signal.

Hereinafter, for convenience of description, the sampling signal is'C', the received signal sequence number according to the sequence number of the detector is'a', the converted signal sequence number is'b', and the total number of converted signals is cn. Here, since the converted signal is a converted sampling signal, the total number of converted signals may be equal to the total number of sampling (sn). Accordingly, the b-th converted signal obtained by converting the b-th sampling signal of the a-th received signal may be expressed as'Ca,b'.

In addition, hereinafter, for convenience of description, a set of transformed signals obtained by converting (that is, correcting) sampling signals sampled at the same time is referred to as a'correction signal'.

Therefore, the second converted signals (C) for correcting each of the second sampling signals (S _{1, 2} , S _{2, 2} , S _{3, 2} ,…, S _{48, 2} ) of each of the first to 48 received signals _{A set of 1, 2} , C _{2, 2} , C _{3, 2} ,..., C _{48, 2} ) is a second correction signal, and the third sampling signals S _{1, 3} , S of each of the first to 48th received signals. _{2, 3} , S _{3, 3} ,…, S _{48, 3} ) A set of third transformed signals (C _{1, 3} , C _{2, 3} , C _{3, 3} ,…, C _{48, 3} ) corrected for each May be referred to as a third correction signal.

Accordingly, the second correction signal includes second converted signals (C _{1, 2} , C _{2, 2} , C _{3, 2} ,..., C _{48, 2} ) for each of the first to 48 received signals, and The third correction signal may be described as including third transformed signals C _{1, 3} , C _{2, 3} , C _{3, 3} ,..., C _{48, 3} for each of the first to 48th received signals. .

The rest of the extracted signals are corrected in the same way as described above, and if they are summarized, they are shown in FIG. 5, for example. In addition, the correction signals obtained by correcting each of the plurality of extraction signals in FIG. 5 may be summarized as shown in FIG. 6, and when they are schematically illustrated in the form of a data cube, as shown in FIG. 7(c).

The correction signal converted in this way is transmitted to the second signal processing unit 2230 and used as data for detecting the target T.

However, the first sampling signals (S ₁ , ₁ , S ₂ , ₁ , sampled first after the operation of the detector) S _3,1 ,… , S _47,1 , S _48,1 ) Since the previous sampling signal does not exist, the first sampled signal is not converted or corrected, and is transmitted to the second signal processing unit 2230 as it is for target detection data. Can be utilized.

Accordingly, the first sampled first sampling signals (S _1,1 , S _2,1 , S _3,1 ,… , S _47,1 , S _48,1 ) are not subtracted by the average of the previous sampling signals, but pass through the first signal processing unit 2220, so for convenience of explanation, the first signal processing unit 2220 First sampling signals S ₁ , ₁ , S ₂ , ₁ , S _3,1 ,… , S _47,1 , S _48,1 ) Each of _{them is} referred to as a first transform signal, and the reference numerals are _{also'C 1,1} , C _2,1 , C _3,1 ,… , C _47,1 , C _48,1 '(see FIG. 6 ). And, the first conversion signals (C _1,1 , C _2,1 , C _3,1 ,… ,C _47,1 , C _48,1 ) is _{referred to as a'first} correction signal'.

On the other hand, when the signal emitted from the transmitter is reflected by the target, a ringing phenomenon due to multiple reflections may occur, and the propagation may be weakened by the dielectric constant of the soil, moisture, or the like. Accordingly, the first signal processor 2220 compensates for the gain by using a gain curve and then transmits it to the second signal processor 2230.

As described above, in the first embodiment, the clutter is removed by subtracting each of the plurality of sampling signals constituting the extracted signal to be corrected by the average of the previously sampled sampling signals, thereby detecting targets other than detection targets. Can be reduced. Accordingly, it is possible to improve target detection accuracy.

8 to 10 are views for explaining a correction method according to a second embodiment of the present invention. 11 is a diagram conceptually illustrating a correction method according to a second embodiment of the present invention using a data cube.

12 is a diagram for conceptually explaining calculating a root mean square for an input signal for each received signal in a second signal processing unit according to an embodiment of the present invention. 13 is a diagram conceptually showing a detection signal obtained by calculating a root mean square for an input signal for each received signal in a second signal processing unit according to an embodiment of the present invention. 14 is a view showing an example of a top view image generated by using a detection signal generated by the second signal processing unit.

Hereinafter, a correction method according to the second embodiment will be described with reference to FIGS. 8 to 11.

The correction method according to the second embodiment is a method of calculating entropy for each of a plurality of extraction signals, and processing the extracted signal not to be used for target detection when the calculated entropy is greater than or equal to a reference entropy.

To calculate entropy for each extracted signal, the first signal processor 2220 first converts sampling signals of each of the plurality of extracted signals using Equation (1).

[Equation 1]

Here, R is the converted signal obtained by converting the sampling signal, a is the received signal sequence number according to the sequence number of the detector, b is the converted signal sequence number, and Rn is the total number of converted signals. Here, since the converted signal is a converted sampling signal, the total number of converted signals may be equal to the total number of sampling (sn).

Accordingly, the b-th converted signal obtained by converting the b-th sampling signal of the a-th received signal may be expressed as'R _a,b '.

Since each of the plurality of extraction signals includes a plurality of sampling signals, _a set of transform signals R _{a and b} that convert the sampling signals constituting one extraction signal is referred to as a correction signal. Thus, one correction signal may be described as including a plurality of conversion signals (R _{a, b} ).

A method of converting the sampling signal of each extracted signal using Equation 1 will be described below with specific examples.

The first sampling signal (S _{1, 1} , S _{2, 1} ) of each of the first and second received signals constituting the first extraction signal is the first transform signal (R _{1, 1} , R _{2, 1} ) through Equation ₁ ) (For example, see equations 1 and 2).

[Example Equation 1]

[Example Equation 2]

In addition, similarly, if the first sampling signals S _{3, 1} , ..., S _{48, 1} of each of the third to 48 received signals constituting the first extracted signal are converted through Equation 1, the first converted signal (R _{3, 1} ,... .R _{48, 1} ) is produced. Accordingly, the first correction signal includes a first converted signal for each of the first to 48th received signals, that is, R _{1, 1} to R _{48, 1}

As another example, the first sampling signal (S _{1, 2} , S _{2, 2} ) of each of the first and second received signals constituting the second extraction signal is the second transform signal (R _{1, 2} , R) through Equation 1 _{2, 2} ) (see Equations 3 and 4 for example).

[Example Equation 3]

[Example 4]

Also, similarly, if the first sampling signals S _{3, 2} , ..., S _{48, 2} of each of the third to 48 received signals constituting the second extracted signal are converted through Equation 1, the second converted signal (R _{3, 2} ,…,R _{48, 2} ) is produced. Accordingly, the second correction signal includes a second converted signal for each of the first to 48th received signals, that is, R _{1, 2} to R _{48, 2}

In this way, the sampling signals of each of the remaining extracted signals are converted using Equation 1, which is shown in Fig. 8 in summary.

Next, the first signal processing unit 2220 calculates entropy E _b for each of the calculated plurality of correction signals (see FIGS. 11A and 11B ). At this time, it can be calculated using Equation 2 below.

[Equation 2]

That is, when the converted signals R _{a and b} of each correction signal calculated in Equation 1 are applied to R _{a and b} in Equation 2, entropy E _b for each correction signal is calculated.

For example, when the first transform signals R _{1, 1} to R _{48, 1} constituting the first correction signal are applied to Equation 2, the first entropy E ₁ for the first correction signal is calculated. As another example, when the second transform signals R _{1, 2} to R _{48, 2} constituting the second correction signal are applied to Equation 2, the second entropy E ₂ for the second correction signal is calculated.

In addition, when using Equation 2 for each of the other correction signals, the entropy for each is calculated.

When the entropy of the correction signal is calculated in this way, the first signal processing unit 2220 compares the preset reference entropy (E _st ) with the calculated entropy (E _b ) (see FIGS. 9 and 11(c) ).

At this time, if the calculated entropy (E _b ) is less than the reference entropy (E _st ) (Yes in FIG. 11(c)), the second signal processing unit extracts the extracted signal, which is a signal before correction of the correction signal that calculated the entropy ( 2230). That is, even if the calculated entropy (E _b ) is less than the reference entropy (E _st ), (Yes in FIG. 11(c)), a plurality of sampling signals constituting the extracted signal, which is a signal before correction of the correction signal, is the second signal. It is transmitted to the processing unit 2230 and used for target detection.

For example, when the calculated second entropy (E ₂ ) is less than the reference entropy (E _st ), the second extraction signal, which is the pre-correction signal of the second correction signal that calculates the second entropy (E ₂ ), is the second signal. It is transmitted to the processing unit 2230 and used for target detection. That is, when the second entropy (E ₂ ) is less than the reference entropy (E _st ), a plurality of sampling signals (S _{1, 2} , S _{2, 2} , constituting the second extraction signal, which is a signal before the correction of the second correction signal), , S _{48, 2} ) is transmitted to the second signal processing unit 2230 and used for target detection.

However, if the calculated entropy (E _b ) is greater than or equal to the reference entropy (E _st ) ('No' in FIG. 11(c)), the extracted signal, which is a signal before correction of the correction signal that calculated the entropy, is not used for target detection Process it.

Here, processing not to be used for target detection means that in transmitting the extraction signal to the second signal processing unit 2230, the sampling signal constituting the extraction signal that calculates the entropy equal to or greater than the reference entropy (E _st ) is '0 (Zero )'. And, processing the sampling signal constituting the extracted signal as '0 (Zero)' may mean that the sampling signals of the extracted signal are discarded.

For example, even if the third entropy (E ₃ ) is greater than or equal to the reference entropy (E _st ),'No' in 11(c)), and targets a third extraction signal that is a signal before correction of the correction signal that calculated the third entropy. It is processed so that it is not used for detection. That is, a plurality of sampling signals (S _{1, 3} , S _{2, 3 ,,} S _{48, 3} ) constituting the third extraction signal, which is a signal before the correction of the third correction signal, are processed as '0 (Zero)' ( See Figure 10).

In this way, in the second embodiment, the entropy for each extraction signal is calculated, and when the calculated entropy is greater than or equal to the reference entropy, clutter is removed by discarding the extracted signal so that it is not used for target detection. Accordingly, errors in target detection of things other than the detection target can be reduced, thereby improving target detection accuracy.

As described above, in the first embodiment, the correction signal corrected for the extraction signal is transmitted to the second signal processing unit 2230 and used to detect the target.

In addition, in the second embodiment, the target signal can be detected using only the extraction signal having a reference entropy or higher. In the second embodiment, the extraction signal whose entropy is less than the reference entropy is transmitted to the second signal processing unit 2230, and entropy The clutter is removed and transmitted to the second signal processing unit 2230 by processing the sampling signals constituting the extracted signal having a reference entropy or higher as '0'.

Therefore, hereinafter, for convenience of description, after processing with the signal processing method according to the first embodiment, after processing with the correction signal transmitted to the second signal processing unit 2230 and the signal processing method according to the second embodiment, 2 All the extracted signals transmitted to the signal processing unit 2230 are referred to as input signals.

Meanwhile, the correction signal input or transmitted to the second signal processing unit 2230 includes a plurality of conversion signals, and the extraction signal includes a plurality of sampling signals. Accordingly, the input signal input or transmitted to the second signal processing unit 2230 includes a plurality of converted signals or a plurality of sampling signals. Therefore, for convenience of description below, a conversion signal or a sampling signal constituting the input signal transmitted to the second signal processing unit 2230 is referred to as a'process signal (P _{a, b} )'.

In the processing signals'P _{a, b} ', a is the received signal sequence number'a' according to the sequence number of the detector, and b is the processing signal sequence number. In addition, the total number of processed signals per received signal is surfaced as'pn', where the total number of processed signals (pn) may be equal to the total number of converted signals per received signal (cn or Rn).

One input signal can be described as including a plurality of processing signals. Further, the plurality of processing signals constituting the input signal may be described as a conversion signal processed by the method according to the first embodiment or a sampling signal processed and transmitted by the method according to the second embodiment.

For a specific example, the first input signal includes a plurality of first processing signals (P _{1, 1} , P _{2, 1} ,..., P _{48, 1} ), and the second input signal includes a plurality of second processing signals. Signal (P _{1, 2} , P _{2, 2} ,…, P _{48, 2} ), and the third input signal is a plurality of third processing signals (P _{1, 3} , P _{2, 3} ,…, P _{48, 3} ). In addition, the remaining input signals also include a plurality of processing signals, which are collectively shown in FIG. 12.

Here, the first input signal is a collection of the first processing signals (P _{1, 1} , P _{2, 1} , ..., P _{48, 1} ), the second input signal is the second processing signals (P _{1, 2} , P _{2, 2} ,..., P _{48, 2} ), the third input signal is a collection of third processing signals (P _{1, 3} , P _{2, 3} ,..., P _{48, 3} ), so a plurality of input signals It can be explained that the ordering direction according to the sequence number is the depth direction of the underground.

The second signal processing unit 2230 processes the target signal in the X-axis direction, which is an array direction of the detector 1000, to be emphasized by using the input signal processed and transmitted by the first signal processing unit 2220. Then, the second signal processor 2230 creates a top view image image using the transmitted input signal. To this end, the second signal processing unit 2230 may obtain a root mean square for an input signal for each received signal of each detector 1000 (see FIG. 12), and use this to create a top view image image .

Since the input signal includes a processing signal for each received signal, the'input signal for each received signal of each detector' may mean'a plurality of processed signals for each received signal of each detector'. Accordingly, obtaining an average square root of an input signal for each detector received signal may mean that an average square root is performed for a plurality of processing signals for each received signal of each detector.

Hereinafter, a specific example of obtaining a root mean square of an input signal for each received signal of each detector will be described.

The mean square root (D ₁ ) of the plurality of processing signals (P _{1, 1} , P _{1, 2} ,…, P _{1, pn-1} , P _{1, pn} ) generated from the first received signal is shown in Equation 5 below. The mean square root (D) for a plurality of processing signals (P _{2, 1} , P _{2, 2} ,…, P _{2, pn-1} , P _{2, pn} ) generated from the second received signal ₂ ) can be calculated as in Example 6 below.

[Example 5]

[Example 6]

Further, although not specifically illustrated, the average square roots D ₃ , ..., D ₄₈ are obtained in the same manner for the plurality of processing signals generated from each of the third to 48th received signals. As a result, an average square root signal D1, ..., D _{48 in} the X-axis direction in which the first to 48th detectors are arranged is generated.

And, as described above, the plurality of detectors arranged in the X-axis direction moves in the Y-axis direction by the moving device. An average square root (D1,...,D ₄₈ ) signal in the X-axis direction is generated in the Y-axis direction. Accordingly, the mean square roots (D ₁ ,...,D ₄₈ ) of the plurality of processed signals for each received signal of each detector are arranged in a plurality of detectors (in the X-axis direction), and the movement direction of the plurality of detectors (Y 13), for example, as shown in FIG.

Here, a plurality of input signals for each received signal of each detector 1000 and a plurality of processed signals for each received signal of each detector 1000 are signals in a depth direction underground. Accordingly, the meaning of obtaining an average square root for an input signal for each received signal of each detector 1000 or obtaining an average square root for a plurality of processed signals for each received signal of the detector 1000 is an average square root in a depth direction. It can be explained in the sense of seeking.

The average square root (D ₁ ,...,D ₄₈ ) of the plurality of processing signals for each received signal of each detector calculated by the method described above in the second signal processing unit 2230 is the first detection unit 2300. It is used to detect targets through transmission or input. Accordingly, hereinafter, a signal having an average square root (D ₁ ,..., D ₄₈ ) for a plurality of processing signals for each received signal of each detector 1000 is referred to as a'detection signal'.

When the detection signals D ₁ , ..., D ₄₈ are derived by averaging the square of the average of the plurality of processing signals for each received signal of each detector 1000 calculated by the second signal processing unit 2230, these signals are used. Create a top view video image.

The detection signals (D ₁ , ..., D ₄₈ ) for each received signal of each detector 1000 generated by the second signal processing unit 2230 are coordinates (X-axis coordinates) and detection in the direction in which the detectors 1000 are arranged. It may be a signal having electromagnetic wave intensity information according to coordinates (Y-axis direction coordinates and depth-direction coordinates (Z-axis coordinates)) in the direction of movement of the sieve 1000.

Accordingly, the top view image image generated using the detection signals in the second signal processing unit 2230 may be an image image showing electromagnetic wave intensity according to X-axis, Y-axis, and Z-axis coordinates. The second signal processing unit may classify the image so that at least one of saturation, business card, and brightness differs according to the intensity of electromagnetic waves, for example, as shown in FIG. 14.

15 is a diagram conceptually showing a method of detecting a position of a target in an X-axis direction in a first detection unit according to an embodiment of the present invention. 16 is a photograph showing an example of a method for detecting a position of a target in the X-axis direction in a first detection unit according to an embodiment of the present invention. 17 is a view for explaining a detection signal in the Y-axis direction (detector movement direction) of the detection object detected by the first detection unit.

The first detection unit 2300 detects a target using a detection signal and a video image generated and processed by the second signal processing unit 2230. To this end, the first detection unit 2300 first filters the transmitted or input detection signals by comparing them with a preset reference value.

The detection signal includes electromagnetic wave intensity according to the position of the detector body 1000 in the alignment direction (X-axis direction) and the position of the detector body 1000 in the movement direction (Y-axis direction), the first detection unit 2300 Filters the detection signal according to the electromagnetic wave strength. Accordingly, the reference value preset in the first detection unit 2300 may be a reference electromagnetic wave intensity, which may be referred to as a mask filter.

The reference value may be set by reflecting electromagnetic waves reflected from a target to be detected, such as a mine.

According to the first detection unit 2300, the electromagnetic wave intensity of the detection signals inputted through the second signal processing unit 2230 is compared with a reference value, and the electromagnetic wave intensity is classified into two types based on the reference value, that is, binarized. .

For example, the detection signal having an electromagnetic wave above the reference value is '1', and the detection signal having an electromagnetic wave below the reference value is binarized to be '0'. Accordingly, as shown in FIG. 15, a value of '1' or '0' may be assigned to each pixel of a video image.

Then, the first detection unit 2300 images the binary detection signal. In this case, the first detection unit 2300 may image an image so as to display different colors, for example, so that a detection signal processed as '1' and a detection signal processed as '0' are distinguished. As a more specific example, a detection signal processed with an electromagnetic wave value of '1' may be imaged such that the detection signal processed with red (red) and an electromagnetic wave value of '0' is represented by blue (blue). Same as 16. Hereinafter, for convenience of description, '1' is referred to as a detection value '0' as a background value.

15 and 16, the vertical direction (hereinafter, the first direction) is a direction in which the detector is arranged, and the horizontal direction (hereinafter, a second direction) is a direction corresponding to the movement direction of the detector, and may be.

The first detection unit 2300 detects or detects a target signal using the binarized image image as shown in FIG. 15 or FIG. 16. To this end, the first detection unit generates a window of a predetermined size and detects the target position while moving the window on the video image as shown in FIG. 16.

The window W may have a rectangular shape, for example, and more preferably a square. Then, the window W is moved in each of the first direction and the second direction on the video image, and a portion of the area of the window W is moved to overlap. That is, the position of the area occupied by the window W when in the first position and the position of the area occupied by the window W when moving from the first position to the second position are partially overlapped. At this time, the overlapping area is, for example, 50% or more and 90% or less, and more preferably 75% to 85%.

In addition, since a value of'background value (0)' or'detection value (1)' is assigned to each pixel of a video image,'background value' and'detection value' within a window according to the position of the window W, respectively The areas of the given pixels are different.

The first detector 2300 compares the area occupied by the pixels to which the “detection value” is assigned in the window W with the preset reference area while moving the window W on the video image. Then, the position in the first direction of the window W in which the area to which the detection value is applied becomes greater than or equal to the reference area is detected or detected. At this time, the first detection unit 2300 determines the position of the first direction corresponding to the center position of the first direction in the window W as the first direction position of the target.

In addition, the first direction of the video image corresponds to the direction in which the detectors 1000 are arranged, and the scale in the first direction is set to correspond to the sequence numbers of the detectors 1000. Accordingly, when the center position of the first direction of the window W in which the area to which the detection value is applied becomes the reference area or more is detected, the target position in the X-axis direction in which the plurality of detectors 1000 are arranged is detected or detected. do. That is, since any one of the plurality of detectors 1000 is detected from the position in the first direction of the target T detected on the video image, if the position in the first direction of the target detected on the video image is detected, through this It is possible to know the detector 1000 that has received the signal reflected from the target T.

Accordingly, the first detector 2300 detects or selects the detector 1000 that has received the signal reflected from the target T by using the position of the first direction detected on the video image. Then, the X-axis position of the detected or selected detector 1000 is the X-axis position of the target T.

For example, when the center of the first direction of the window W is on the scale '27' of the first direction on the image image, the area to which the detection value is applied in the window W may be greater than or equal to the reference area.

Accordingly, the first detection unit 2300 detects a position corresponding to the scale '27' in the first direction on the video image as the first direction position of the target T. In addition, the scale '27' in the first direction on the video image refers to the 27th detector among the plurality of detectors 1000. Accordingly, the first detection unit 2300 determines that the target T exists at the position in the X-axis direction of the 27th detection body.

The X-axis position of the target T thus detected is transmitted to the target positioning unit 2600 and the detection image detection image display unit 2700.

The signal in the Y-axis direction at the X-axis direction detected by the first detector 2300, that is, in the direction of movement of the detector is transmitted to the second processing unit 2400 (see FIG. 17).

Here, the detection signals generated from one detector 1000 are signals according to the position of the movement direction (ie, the Y-axis direction) of the detector 1000 as described with reference to FIG. 13. Therefore, transmitting detection signals of the selected detector 1000 from the first detector 2300 to the second processing unit 2400 may be described as transmitting scan data in a moving direction of the selected detector 1000. have.

The second processing unit 2400 uses the detection signal transmitted from the first detection unit 2300 to process the signal to facilitate target detection in the Y-axis direction. To this end, the second processing unit 2400 removes clutter from the detection signals transmitted from the first detection unit 2300.

At this time, the detection signal transmitted to the second processing unit 2400 is a signal in the Y-axis direction of the detection object 1000 detected or selected by the first detection unit 2300. Accordingly, the second processing unit 2400 removes clutter from the signal in the Y-axis direction generated by the detector 1000, which is determined to have received the signal reflected from the target T by the first detection unit 2300. At this time, the clutter is removed using either the correction method according to the first embodiment or the method according to the second embodiment described above. Then, the second processing unit 2400 gain-compensates the detection signal from which the clutter is removed, and then transmits it to the second detection unit 2500.

18 is a diagram conceptually showing a parabolic signal having a predetermined width in a direction in which the detector moves (Y-axis direction). 19 and 20 are diagrams showing a video image in which a parabola having a predetermined width is visible in a direction in which the detector moves (Y-axis direction).

The second detection unit 2500 visualizes a parabolic target signal, and detects a position of the target T in the Y-axis direction and a position in the Z-axis direction (ie, buried depth).

On the other hand, the closer the distance between the detector 1000 and the target T is, the shorter the time it is reflected from the target and received by the detector 1000. Conversely, the farther the distance between the detector 1000 and the target T is, the longer it is reflected from the target T and received by the detector 1000. Accordingly, when a target exists in the basement, a parabolic signal having a predetermined width is obtained in a direction in which the detector 1000 moves (Y-axis direction) as shown in FIG. 18.

If the equation for the parabola is expressed by the equation, it may be equation 3 below. Where Xc is the X-axis position of the parabola vertex, Yc is the Y-axis position of the parabola vertex, and p is the width of the parabola.

[Equation 3]

The second detection unit 2500 uses the detection signal input through the second processing unit 2400 to image the image. To this end, the second detection unit 2500 transforms the detection signal into a hough transform method.

When the image is imaged using the Huff-converted signal, for example, as shown in FIG. 19, an image image in which a parabola is formed in a moving direction of the detector 1000 is obtained.

Referring to FIG. 19, a strong signal appears at the apex of the parabola, which is due to the electromagnetic wave intensity according to the distance from the target T. That is, the closer the distance between the detector 1000 and the target T is, the greater the received signal, that is, the electromagnetic wave intensity. Conversely, the farther the detector 1000 is from the target T, the smaller the received signal, that is, the electromagnetic wave intensity.

The second detection unit 2500 detects a position indicating an electromagnetic wave intensity higher than a preset reference value. That is, the Huff transformed detection signal is analyzed to detect positions in the Y-axis direction and the Z-axis direction that show electromagnetic wave strengths higher than a reference value, and display them in an image image so that they can be identified.

Then, the second detection unit 2500 locates the apex of the parabola and displays it so that it can be identified. In other words, it is possible to find the location where the electromagnetic wave intensity is greatest, and mark this location with a red dot so that it can be identified as shown in FIG. 20.

Also, the second detection unit 2500 detects the depth of the parabolic vertex position. It is possible to calculate the depth by using the movement speed of electromagnetic waves in the soil being detected, and the interval between the time the signal was transmitted from the transmitter of the detector and the time the signal was received by the receiver.

Accordingly, the second detection unit 2500 may detect a parabolic Y-axis position and a parabolic vertex depth. Then, the position of the target detected by the second detection unit 2500, that is, the Y-axis and Z-axis direction (buried depth) position information is transmitted to the target positioning unit 2600 and the detection image detection image display unit 2700. .

21 is a view sequentially showing a target detection method according to an embodiment of the present invention. Hereinafter, a target detection method according to an embodiment of the present invention will be described with reference to FIGS. 1 to 21.

First, before performing detection of the target T, the detector 1000 is controlled by using the delay compensation unit 2110 of the preprocessing unit so that a delay in signal reception time due to a problem inside the detector 1000 does not occur. do. That is, the difference in signal reception time of the plurality of detectors 1000 is analyzed, and a compensation value is set so that the signal reception time of the plurality of detectors 1000 is uniform.

In addition, the set value of the signal conversion unit 2210 of the first processing unit 2200 is adjusted by using the sampling rate adjustment unit 2120 so that the sampling rate or period of the received signal for each of the plurality of detectors 1000 is uniform. . That is, the sampling rate adjusting unit 2120 adjusts the sampling rate for each received signal to be the sampling rate targeted by the operator by interpolation.

When the pre-processing is completed by controlling the detector 1000 through the delay compensation unit 2110 and the signal conversion unit 2210 through the sampling rate controller 2120, the target detection facility is moved to the detection zone. Target detection is performed.

To this end, while sequentially moving the plurality of detectors 1000 arranged in the X-axis direction, the moving device is moved in the Y-axis direction. That is, while moving the mobile device in the Y-axis direction, the plurality of detectors 1000 are sequentially operated to emit a transmission signal (S100). Thus, while the plurality of detectors 1000 move in the Y-axis direction, a plurality of The detectors 1000 are sequentially operated, and each of the plurality of detectors 1000 is operated intermittently or periodically.

When each of the plurality of detectors 1000 is operated, the transmission signal radiated from the transmitter 1100 moves in the depth direction of the underground, is reflected, and is received by the receiver 1200. At this time, the received signal is generated in the X-axis direction of the detection zone by the arrangement type of the detector 1000, the received signal is generated in the Y-axis direction of the detection zone by the movement direction of the detector 1000, the X axis And each received signal in the Y-axis direction has depth direction information. Accordingly, a received signal including three-dimensional (X-axis, Y-axis, and Z-axis) data can be generated.

The signal converter 2210 of the first processor 2200 samples the received signal received by the receiver 1200 of the detector 1000 at regular intervals and digitally converts the received signal.

Next, the first signal processing unit 2220 performs correction to remove clutter from the sampling signal (S200) to generate a processing signal.

At this time, the first signal processing unit 2220 is a plurality of sampling signals for the n-1 th extraction signal (S _{1, sn-1} , S _{2, sn-1} , S _{3, sn-1} ,…, S _{48, sn} using the average (a _{sn-1) -1)} may be carried out a correction to remove the clutter in a manner according to the first embodiment.

In addition, the first signal processing unit 2220 may perform correction by removing the clutter by detecting the clutter according to entropy of each extracted signal and discarding the clutter.

In this way, when a processing signal is generated by removing the clutter from the sampling signal, the second signal processing unit uses the processing signal to process the target signal in the X-axis direction, which is an array direction of the detector 1000, to be emphasized. Create a top view video image using them (S300). To this end, the second signal processor 2230 calculates the root mean square of the processed signal for each received signal of each detector 1000 to detect the detected signals D ₁ , D ₂ ,..., D ₄₈ . Create (see FIGS. 12 and 13), and use this to create a top view video image.

The top view image image created using the detection signals in the second signal processing unit 2230 may be an image image showing electromagnetic wave intensity according to X-axis, Y-axis, and Z-axis coordinates. The second signal processing unit may classify the image so that at least one of saturation, business card, and brightness differs according to the intensity of electromagnetic waves, for example, as shown in FIG. 14.

Next, the first detection unit 2300 filters the detection signals by comparing them with a preset reference value. That is, the electromagnetic wave intensity of the detection signals is compared with the reference value, and the electromagnetic wave intensity is classified into two types based on the reference value, that is, binarized. For example, the detection signal having an electromagnetic wave above the reference value is '1', and the detection signal having an electromagnetic wave below the reference value is binarized to be '0'. Accordingly, as shown in FIG. 15, a value of '1' or '0' may be assigned to each pixel of a video image.

Then, the first detection unit 2300 images the binary detection signal. At this time, the first detection unit 2300 images the detection signal with the electromagnetic wave value '1' in red, and the detection signal with the electromagnetic wave value '0' in blue. (See Figure 15).

Thereafter, the first detection unit 2300 detects the target location by the clustering method (S400). That is, while moving the window W having a predetermined area on the video image, the area occupied by the pixels to which the'detection value' is assigned in the window W is compared with a preset reference area (S500). Then, the position in the first direction of the window W in which the area to which the detection value is applied becomes greater than or equal to the reference area is detected or detected.

Then, when the area to which the detection value is assigned in the window W becomes equal to or greater than the reference area, the center position of the current window W in the first direction is detected. Through this, the detector 1000 corresponding to the scale corresponding to the central position in the first direction may be detected on the video image. The detected detector 1000 is regarded as a detector that has received a signal reflected from the target T, and thus the position of the target in the X-axis direction is detected (S600).

When the X-axis position of the target T is detected in the first detection unit 2300, the second processing unit 2400 removes clutter from detection signals transmitted from the first detection unit 2300. That is, the second processing unit 2400 corrects for removing clutter from the signal in the Y-axis direction generated by the detector 1000, which is determined to have received the signal reflected from the target T by the first detection unit 2300. It is carried out (S700). Then, the second processing unit 2400 gain-compensates the detection signal from which the clutter is removed, and then transmits it to the second detection unit 2500.

The second detection unit 2500 detects the position of the target T in the Y-axis direction and the position of the Z-axis direction by using the detection signal transmitted from the second processing unit 2400 (S800). To this end, the second detection unit 2500 converts the detection signal transmitted from the second processing unit 2400 to a hough transform method.

Then, when the visualization is performed using the Huff-converted detection signal, a parabolic target signal having a predetermined width is visualized in a direction in which the detector 1000 moves (Y-axis direction) as shown in FIG. 19.

Next, the second detection unit 2500 analyzes the Huff-converted detection signal, detects positions in the Y-axis direction and the Z-axis direction showing electromagnetic wave strengths higher than a reference value, and displays them in an image image to be identifiable.

Then, the second detection unit 2500 finds the apex position of the parabola and detects the depth of the apex position. The peak position of the parabola can be detected using the intensity of the electromagnetic wave, and the depth of the peak position is determined by using the movement speed of the electromagnetic wave and the interval between the time the signal is transmitted from the transmitter of the detector and the time the signal is received by the receiver. Can be calculated. In addition, the apex position of the parabola and the depth of the apex position may be displayed on the detection image display unit to be identifiable by the operator as shown in FIG. 20.

Target position determining unit (X) in the X-axis direction of the target (T) detected by the first detection unit 2300, the position of the Y-axis and Z-axis direction of the target (T) detected by the second detection unit (2500) 2600) and the detected image display unit 2700 (S910, S920). From this, the operator can grasp the position of the target in the X-axis, Y-axis, and Z-axis directions, and remove the detected target.

As described above, in the embodiment of the present invention, a target is detected using an array type target detection facility including a plurality of detectors 1000 arranged in one direction. In addition, according to the detection apparatus 2000 according to an embodiment of the present invention, it is possible to process signals of each of the plurality of detectors 1000 in real time and to process a received signal with a low computation amount.

In addition, in the embodiment of the present invention, clutter is removed by the method according to the first embodiment using the average of a plurality of sampling signals for the n-1 th extraction signal, or the clutter is obtained according to the entropy of the extraction signal. Is detected, and the clutter is removed by the method according to the second embodiment for discarding the clutter. Accordingly, errors in target detection of things other than the detection target can be reduced. Accordingly, it is possible to improve target detection accuracy.

Then, using the detection signal generated by the second signal processing unit 2230 to create a top view (top view) image image, the second detection unit 2500 analyzes the top view (top view) image image target (T) It detects the coordinates of Y-axis direction and Z-axis direction. At this time, the second detection unit 2500 may analyze the overall size of the target T and the signal of the moving direction of the detector 1000 using a top view image image. Thus, it is possible to detect the exact position of the target.

1000: detector 1100: transmitter
1200: receiver

Claims (16)

delete delete delete A process of moving the plurality of detectors while emitting a transmission signal from each of the plurality of detectors;
Obtaining a plurality of sampling signals from received signals received by each of the plurality of detectors;
A correction process of removing a clutter from the plurality of sampling signals and converting each of the plurality of sampling signals into processing signals;
Generating a detection signal by using the processing signals for each of the plurality of detection objects; And
Detecting a position of a target using the detection signal;
Including,
The correction process,
Calculating an n-th entropy by using a plurality of n-th sampling signals sampled at the same time from each of the plurality of received signals;
Comparing the calculated n-th entropy with a reference entropy;
When the calculated n-th entropy is less than a reference entropy, maintaining the n-th sampling signals as they are; And
Discarding the n-th sampling signals when the calculated n-th entropy is greater than or equal to a reference entropy;
Target detection method comprising a. The method according to claim 4,
The plurality of detectors are arranged in one direction, the plurality of detectors target detection method for moving in the other direction different from the one direction. The method according to claim 5,
The process of detecting the position of the target,
Generating a top view image image by binarizing the detection signal into a detection value and a background value according to the signal strength for each detection signal; And
While moving a window having an area on the video image, the area occupied by a pixel having a detection value in the window is compared with a preset reference area, and the target of the target in the one direction is a direction in which the plurality of detectors are arranged and arranged. The process of detecting the location;
Target detection method comprising a. The method according to claim 6,
In moving the window on the video image,
A target detection method of shifting a plurality of times alternately in a first direction corresponding to the one direction and a second direction corresponding to another direction different from the one direction on the video image. The method according to claim 7,
In moving the window on the video image in the first and second directions,
Target detection method to move the window occupied by a portion of the area occupied by the previous position. In claim 4,
In generating a detection signal using the processing signals for each of the plurality of detectors,
For each of the plurality of detectors, a target detection method of performing a plurality of processing signals on a root mean square. The method according to claim 6,
The process of detecting the position of the target in the one direction,
And detecting a detector receiving the signal reflected from the target among the plurality of detectors by using the electromagnetic wave intensity included in the detection signal,
A target detection method comprising detecting a position of a target in the other direction and the buried depth direction by using the detection signal in the other direction generated from the detection object detected as receiving the signal reflected from the target. The method according to claim 10,
The process of detecting the position of the target in the other direction and the buried depth direction,
Generating a video image in which a parabola having a width in the other direction is visible by hough transforming a detection signal in the other direction generated from the detector detected as receiving the signal reflected from the target;
Detecting a position of a vertex of a parabola generated by Huff transform and detecting a position of a target in the other direction and the depth direction;
Target detection method comprising a. A plurality of detectors each having a transmitter for emitting a transmission signal and a receiver for receiving a received signal from which the transmitted signal emitted from the transmitter is reflected, and arranged in one direction;
A moving device equipped with the plurality of detectors and movable in another direction different from the one direction;
A signal converter configured to sample the received signal received by each of the plurality of detectors multiple times at regular cycles to obtain a plurality of sampling signals;
A first signal processor for removing clutter from the plurality of sampling signals;
A detection unit detecting a position of a target through a detection signal generated using a sampling signal from which the clutter is removed by the first signal processing unit;
Including,
The first signal processing unit,
From the received signal of each of the plurality of detectors, the n-th entropy is calculated using a plurality of n-th sampling signals sampled at the same time, and according to the calculated n-th entropy, the n-th sampling signals are intact. Target detection facility that generates or disposes to generate a processing signal. delete The method according to claim 12,
The detection unit,
The first signal processing unit detects a detector that has received a signal reflected from a target through a detection signal generated using a clutter-removed sampling signal, and detects a target position in one direction. part; And
A second detection unit for detecting the position of the other direction and the buried depth direction by using the detection signal of the other direction generated by the detection body detected as receiving the signal reflected from the target by the first detection unit;
Target detection facility comprising a. The method according to claim 14,
The first detection unit generates a top view image image by binarizing the detection signal into a detection value and a background value according to the electromagnetic wave intensity for each detection signal of each of the plurality of detection objects,
In the first detection unit for detecting a detection object that receives the signal reflected from the target,
The first detector moves a window having an area on the video image, detects a position in the window where an area occupied by a pixel having a detection value is greater than a preset reference area, and reflects from a target among the plurality of detectors Target detection facility that detects the object that has received the signal. The method according to claim 15,
The second detector hough transforms the detection signal of the other direction generated by the detector detected by the first detector to generate a video image in which a parabola having a width in the other direction is visible,
The second detection unit is a target detection facility for detecting the position of the target in the other direction and the depth direction by detecting the vertex position of the parabola generated by the Huff transform.

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