JP7342469B2 - Buried object detection device and buried object detection method - Google Patents

Description

The present invention relates to a buried object detection device and a buried object detection method.

For example, as a device for detecting the location data of a location-specific object below the detection surface, such as a gas pipe or pipe buried in a wall or underground, it emits electromagnetic waves toward the detection surface and receives the reflected waves. BACKGROUND ART A position specifying system (buried object detection device) that detects a position specifying object using a hand-held position specifying device, in particular, a hand-held position specifying device is used (see, for example, Patent Document 1).

Special table 2017-532528 publication

However, the conventional position specifying system (buried object detection device) described above has the following problems.
In other words, in the conventional device described above, in order to prevent electromagnetic waves from being emitted to the outside except when detecting a locating object (buried object), for example, the placement recognition device detects when the locating device has been lifted from the detection surface. Detected.

However, if an infrared sensor is used as this mounted recognition device, for example, it will affect the received waveform of the reflected wave received to detect the location specific object (buried object), and the detection of the location specific object There is a risk that accuracy will decrease.
Furthermore, as a method other than using an infrared sensor to detect lifting of the device, a method of detecting a change in the received intensity of reflected waves when the device is lifted from the detection surface may also be considered.

However, with this method, there is a risk that lifting of the device may be incorrectly recognized due to the influence of external noise such as Wi-Fi (registered trademark) radio waves.
Furthermore, if there is a metal plate near the surface of the target object, including the buried object whose position is to be detected, or if there is a metal buried object directly under a dielectric material such as gypsum board, the waveform of the reflected wave will simply change. There is a possibility that lifting of the device cannot be accurately detected by simply checking the change.

An object of the present invention is, for example, to provide a buried object detection device and a buried object detection method that can suppress the influence of external noise or accurately detect lifting of the device regardless of the detection status of the buried object. There is a particular thing.

A buried object detection device according to a first aspect of the present invention is a buried object detection device that detects a buried object in an object using data regarding reflected waves of electromagnetic waves emitted toward the object, and includes a main body portion, a radiation , a receiving section, a variable delay section, and a control section. The radiation section is provided in the main body and emits electromagnetic waves. The receiver is provided in the main body and receives reflected waves of electromagnetic waves. The variable delay section sets a delay time of a sampling pulse for sampling the reflected wave in the receiving section. The control unit acquires the first data for one line of the reflected wave received by the receiving unit, and the control unit acquires the first data for one line of the reflected wave, and selects a predetermined step before and after a sampling step position that is the midpoint of the maximum amplitude value of the waveform for one line of the reflected wave. It is determined whether or not the waveform contains noise based on a graph showing the calculation results obtained by differentiating data in a numerical range.

Here, in a buried object detection device that detects buried objects inside an object using data regarding reflected waves of electromagnetic waves emitted toward the object, we will explain the amplitude of one line of the waveform of the reflected wave received at the receiver. It is determined whether or not the waveform contains noise based on a graph showing a calculation result obtained by differentiating data in a range of ±a predetermined number of steps centered on the sampling step position that is the midpoint of the maximum value.

As a result, when the receiving section receives the reflected wave, even if it also receives noise from wireless LAN, etc., the sampling step position that is the midpoint of the maximum amplitude of the waveform for one line of the reflected wave can be Using a graph showing calculation results obtained by differentiating data within a predetermined number of steps, it is possible to easily determine whether or not a received reflected wave contains noise.
As a result, if it is determined that noise is included, for example, by excluding this result from the device lifting determination process, it is possible to suppress the influence of noise and accurately detect device lifting.

A buried object detection device according to a second invention is the buried object detection device according to the first invention, in which the control unit is configured to set a predetermined position before and after a sampling step position that is a midpoint of the maximum amplitude value of the waveform of the reflected wave. In a graph showing a calculation result obtained by differentiating data in the range of the number of steps, if there are a predetermined number or more of plus or minus changing points, it is determined that the waveform contains noise.
Here, the plus or minus change point refers to the slope of the graph that shows the calculation result of differentiating data in a range of a predetermined number of steps before and after the sampling step position that is the midpoint of the maximum amplitude of the waveform of the reflected wave. It means the point where the value changes from positive to negative, or from negative to positive.
Thereby, by detecting the influence of noise as the number of plus/minus change points in the graph, it is possible to easily determine whether or not noise is included.

A buried object detection device according to a third invention is the buried object detection device according to the first or second invention, in which the control unit detects that the main body detects a target object when it is determined that the waveform does not contain noise. Lifting determination processing is performed to detect that the device has been lifted from the surface of the device and to stop emitting electromagnetic waves from the radiation section.

As a result, only when it is determined that there is no noise in the noise determination process described above, the buried object detection device (main body) detects that it has been lifted from the surface of the object and stops emitting electromagnetic waves. processing can be carried out.
That is, in the noise determination process described above, if it is determined that noise is included, this measurement result can be excluded from the lifting determination process. Therefore, by performing the lifting determination process using only results that are less affected by noise, the lifting determination process can be performed with high accuracy.

A buried object detection device according to a fourth invention is the buried object detection device according to the third invention, in which the control section determines whether the maximum amplitude value of the reflected wave is larger than a predetermined first threshold value. , if it is determined that it is larger than the first threshold value, it is determined that a metal plate is being scanned.
As a result, in the lifting determination process, by detecting the presence or absence of an amplitude maximum value (peak) larger than the first threshold value that appears when a metal plate (sheet metal) placed directly below the object is scanned, Lifting determination processing can be performed on the assumption that a metal plate (sheet metal) is being scanned.

The buried object detection device according to the fifth invention is the buried object detection device according to the fourth invention, which includes a wheel that is attached to the main body and rotates while being in contact with the surface of the object, and a main body. The vehicle further includes a rotation detecting section, which is connected to the wheel and detects information regarding rotation of the wheel. The control unit acquires the second data for one line again after a predetermined period of time has passed since the rotation of the wheel detected by the rotation detection unit has stopped, and determines whether or not the waveform includes noise. .

Here, when determining whether or not the above-mentioned scan is on a metal plate (sheet metal), a rotation detecting section such as an encoder stops the rotation of the wheel and after a predetermined period of time has elapsed, one line is scanned again. The second data for the second period is acquired and the presence or absence of noise is determined.
As a result, if the first data for one line is acquired, and it is determined that the second data acquired after a predetermined period of time has passed since the rotation of the wheels stopped includes noise, the second data is It can be excluded from the determination of lifting determination processing on a metal plate (sheet metal).
As a result, more accurate lifting determination processing can be performed.

A buried object detection device according to a sixth invention is the buried object detection device according to the fifth invention, in which the control unit generates a waveform of the second data at a step position where the maximum amplitude value in the waveform of the first data is sampled. and the maximum amplitude value of the waveform of the first data, and if there is a difference of more than a predetermined value, it is detected that the main body has been lifted from the surface of the object on the metal plate. and performs lifting determination processing to stop the emission of electromagnetic waves from the radiator.

This allows the maximum amplitude value (peak) in the waveform of the first data and the waveform of the first data to When it is determined that there is a difference of more than a predetermined value by comparing the maximum amplitude value at the sampled step position with the amplitude value of the waveform of the second data at the sampled step position, the buried object detection device lifts the buried object on the metal plate (sheet metal). It is possible to determine that an electromagnetic wave has been detected and stop emitting electromagnetic waves.

A buried object detection device according to a seventh aspect of the present invention is the buried object detection device according to any one of the first to third inventions, wherein the control unit is configured such that the maximum amplitude value of the reflected wave is larger than the first threshold value. If it is determined that it is smaller than the first threshold value, it is determined that the dielectric material is being scanned.
As a result, in the lifting determination process, by detecting the presence or absence of a difference in the maximum amplitude value (peak) that is smaller than the first threshold that appears when scanning a dielectric placed directly under the object, the dielectric Lifting determination processing can be performed on the premise that scanning on the body is in progress.

A buried object detection device according to an eighth invention is a buried object detection device according to the seventh invention, which includes a wheel that is attached to a main body and rotates while being in contact with the surface of the object, and a main body. The vehicle further includes a rotation detecting section, which is connected to the wheel and detects information regarding rotation of the wheel. The control unit acquires the second data for one line again after a predetermined period of time has passed since the rotation of the wheel detected by the rotation detection unit has stopped, and determines whether or not the waveform includes noise. .
As a result, if the first data for one line is acquired, and it is determined that the second data acquired after a predetermined period of time has passed since the rotation of the wheels stopped includes noise, the second data is It can be excluded from the judgment in the lifting judgment process on the dielectric.
As a result, more accurate lifting determination processing can be performed.

A buried object detection device according to a ninth invention is the buried object detection device according to the eighth invention, in which the control unit detects an amplitude value at a midpoint having an amplitude half the maximum amplitude value in the waveform of the first data. Compare the amplitude value of the waveform of the second data and the amplitude value of the midpoint of the waveform of the first data in the step of sampling, and if there is a difference of more than a predetermined value, the main body part is Lifting determination processing is performed to detect that the object has been lifted from the surface and to stop emitting electromagnetic waves from the radiation section.

Here, it is known that when the buried object detection device is lifted on the dielectric, the amplitude at the midpoint having an amplitude that is half the maximum amplitude value in the data waveform changes by more than a predetermined value.
As a result, in the step of sampling the amplitude value at the midpoint having an amplitude half the maximum amplitude value in the waveform of the first data, and the amplitude value at the midpoint having an amplitude half the maximum amplitude value in the waveform of the first data, By comparing the amplitude value of the waveform of the second data, it is possible to determine whether or not to perform lifting determination processing on the dielectric depending on whether the difference is greater than or equal to a predetermined value. .

A buried object detection device according to a tenth invention is the buried object detection device according to the ninth invention, in which the control section is configured to detect a buried object at a step position where the amplitude value of the midpoint between the first data and the second data is sampled. If there is no difference of more than a predetermined value in the comparison of amplitude values, the maximum amplitude value in the waveform of the first data and the amplitude value of the waveform of the second data at the step position where the maximum amplitude value in the waveform of the first data was sampled. If there is a difference of more than a predetermined value, it is detected that the main body has been lifted from the surface of the object when there is a buried metal object directly under the dielectric, and the radiation is emitted. Lifting determination processing is performed to stop the emission of electromagnetic waves from the part.

Here, when the buried object detection device is lifted when there is metal directly under the dielectric, unlike when lifting on the dielectric mentioned above, a midpoint with an amplitude that is half the maximum amplitude value of the data waveform is detected. It is known that the amplitude does not change by more than a predetermined value.
As a result, the amplitude value at the midpoint of the maximum amplitude of the waveform of the first data is compared with the amplitude value of the second data at the step position where the amplitude value of the midpoint of the maximum amplitude of the waveform of the first data is sampled. If there is no difference of more than a predetermined value, the maximum amplitude value of the waveform of the first data is compared with the amplitude value of the waveform of the second data at the step position where the maximum amplitude value of the waveform of the first data is sampled. If the difference is greater than a predetermined value, it is detected that the main body has been lifted from the surface of the object while a metal buried object is present directly below the dielectric.
As a result, even if there is metal directly under the dielectric, it can be accurately determined that the buried object detection device has been lifted.

A buried object detection device according to an eleventh invention is a buried object detection device that detects a buried object within an object using data regarding reflected waves of electromagnetic waves radiated toward the object, and includes a main body portion, a radiation A receiver, a variable delay section, a wheel, a rotation detection section, and a control section. The radiation section is provided in the main body and emits electromagnetic waves. The receiver is provided in the main body and receives reflected waves of electromagnetic waves. The variable delay section sets a delay time of a sampling pulse for sampling the reflected wave in the receiving section. The wheels are attached to the main body and rotate while in contact with the surface of the object. The rotation detection section is provided in the main body, connected to the wheel, and detects information regarding the rotation of the wheel. The control unit acquires the first data for one line of the reflected wave received by the reception unit, and also acquires the first data for one line again after a predetermined period of time has passed since the rotation of the wheel detected by the rotation detection unit has stopped. A predetermined value is obtained by comparing the maximum amplitude value of the waveform of the first data with the amplitude value of the waveform of the second data at the step position where the maximum amplitude value of the waveform of the first data is sampled. If there is the above difference, a lifting determination process is performed to detect that the main body has been lifted from the surface of the object on the metal plate and to stop the radiation of electromagnetic waves from the radiation part.

Here, in a buried object detection device that detects a buried object within an object using data regarding reflected waves of electromagnetic waves radiated toward the object, first data for one line of reflected waves received by the receiving section will be described. At the same time, after a predetermined period of time has passed since the rotation of the wheel detected by the rotation detection unit has stopped, one line of second data is acquired again, and the maximum amplitude value in the waveform of the first data and the second data are acquired. The maximum amplitude value of the waveform of the first data is compared with the amplitude value of the waveform of the second data at the sampled step position to determine whether the main body has been lifted from the surface of the object on the metal plate.
As a result, the maximum amplitude value (peak) in the waveform of the first data is compared with the amplitude value of the waveform of the second data at the step position where the maximum amplitude value in the waveform of the first data is sampled, and the difference is greater than or equal to a predetermined value. If it is determined that there is a buried object detection device, it can be determined that the buried object detection device has been lifted on the metal plate (sheet metal), and the emission of electromagnetic waves can be stopped.

A buried object detection device according to a twelfth invention is a buried object detection device that detects a buried object in an object using data regarding reflected waves of electromagnetic waves radiated toward the object, and includes a main body and a radiation source. A receiver, a variable delay section, a wheel, a rotation detection section, and a control section. The radiation section is provided in the main body and emits electromagnetic waves. The receiver is provided in the main body and receives reflected waves of electromagnetic waves. The variable delay section sets a delay time of a sampling pulse for sampling the reflected wave in the receiving section. The wheels are attached to the main body and rotate while in contact with the surface of the object. The rotation detection section is provided in the main body, connected to the wheel, and detects information regarding the rotation of the wheel. The control unit acquires the first data for one line of the reflected wave received by the reception unit, and also acquires the first data for one line again after a predetermined period of time has passed since the rotation of the wheel detected by the rotation detection unit has stopped. , and the second data at the step position where the amplitude value at the midpoint having half the amplitude of the maximum amplitude value in the waveform of the first data and the amplitude value at the midpoint in the waveform of the first data are sampled. If there is no difference of more than a predetermined value, the maximum amplitude value in the waveform of the first data and the second data at the step position where the maximum amplitude value in the waveform of the first data was sampled are compared. Compare the amplitude value of the waveform with , and if there is a difference of more than a predetermined value, it is determined that the main body has been lifted from the surface of the object when there is a buried metal object directly under the dielectric. A lifting determination process is carried out to detect this and stop the emission of electromagnetic waves from the radiator.

Here, in a buried object detection device that detects a buried object within an object using data regarding reflected waves of electromagnetic waves radiated toward the object, first data for one line of reflected waves received by the receiving section will be described. At the same time, after a predetermined period of time has passed since the rotation of the wheel detected by the rotation detection unit has stopped, one line of second data is acquired again, and the second data is half of the maximum amplitude value in the waveform of the first data. Compare the amplitude value of the midpoint with amplitude and the amplitude value of the waveform of the second data at the step position where the amplitude value of the midpoint in the waveform of the first data was sampled, and if there is no difference of more than a predetermined value, , based on the result of comparing the maximum amplitude value of the waveform of the first data with the amplitude value of the waveform of the second data at the step position where the maximum amplitude value of the waveform of the first data was sampled, metal is placed directly under the dielectric. It is determined whether or not the main body has been lifted from the surface of the object in a state where a buried object made of metal is present.

Here, when the buried object detection device is lifted when there is metal directly under the dielectric, unlike when lifting on the dielectric mentioned above, a midpoint with an amplitude that is half the maximum amplitude value of the data waveform is detected. It is known that the amplitude does not change by more than a predetermined value.
As a result, there is no difference of more than a predetermined value in the comparison between the amplitude value at the midpoint of the first data and the amplitude value of the waveform of the second data at the step position where the amplitude value of the midpoint in the waveform of the first data is sampled. In this case, the maximum amplitude value of the waveform of the first data is compared with the amplitude value of the waveform of the second data at the step position where the maximum amplitude value of the waveform of the first data is sampled, and the difference is greater than a predetermined value. In some cases, it is detected that the main body has been lifted from the surface of the object in a state where there is a buried metal object directly under the dielectric.
As a result, even if there is metal directly under the dielectric, it is possible to accurately determine that the buried object detection device has been lifted, and to stop emitting electromagnetic waves.

A buried object detection method according to a thirteenth invention is a buried object detection method using a buried object detection device that detects a buried object within an object using data regarding reflected waves of electromagnetic waves radiated toward the object. , a radiation step, a delay time setting step, a reception step, and a determination step. The radiation step radiates electromagnetic waves from the radiation section. The delay time setting step sets a delay time of a sampling pulse for sampling the reflected wave. In the receiving step, the receiving section receives the reflected electromagnetic wave based on the delay time set in the delay time setting step. The determination step acquires the first data for one line of the reflected wave received in the receiving step, and also acquires the first data for one line of the reflected wave at a predetermined step before and after the sampling step position that is the midpoint of the maximum amplitude value of the waveform for one line of the reflected wave. It is determined whether or not the waveform contains noise based on a graph showing the calculation results obtained by differentiating data in a numerical range.

Here, in a buried object detection method using a buried object detection device that detects a buried object within an object using data on reflected waves of electromagnetic waves emitted toward the object, we will discuss the reflected waves received at the receiver. Based on a graph showing the calculation results of differentiating data within a range of ± a predetermined number of steps around the sampling step position that is the midpoint of the maximum amplitude of the waveform for one line, determine whether the waveform contains noise or not. Determine whether

As a result, when the receiving section receives the reflected wave, even if it also receives noise from wireless LAN, etc., the sampling step position that is the midpoint of the maximum amplitude of the waveform for one line of the reflected wave can be Using a graph showing calculation results obtained by differentiating data within a predetermined number of steps, it is possible to easily determine whether or not a received reflected wave contains noise.
As a result, if it is determined that noise is included, for example, by excluding this result from the device lifting determination process, it is possible to suppress the influence of noise and accurately detect device lifting.

The buried object detection method according to the fourteenth invention is the buried object detection method according to the thirteenth invention, in which, in the determination step, a predetermined value is selected before and after the sampling step position that is the midpoint of the maximum amplitude value of the waveform of the reflected wave. In a graph showing a calculation result obtained by differentiating data in the range of the number of steps, if there are a predetermined number or more of plus or minus changing points, it is determined that the waveform contains noise.
Here, the plus or minus change point refers to the slope of the graph that shows the calculation result of differentiating data in a range of a predetermined number of steps before and after the sampling step position that is the midpoint of the maximum amplitude of the waveform of the reflected wave. It means the point where the value changes from positive to negative, or from negative to positive.
Thereby, by detecting the influence of noise as the number of plus/minus change points in the graph, it is possible to easily determine whether or not noise is included.

A buried object detection method according to a fifteenth invention is a buried object detection method according to the thirteenth or fourteenth invention, wherein when it is determined in the determination step that the waveform does not contain noise, the buried object detection device The apparatus further includes a lifting determination step of detecting that the object has been lifted from the surface and performing a lifting determination process of stopping emission of electromagnetic waves from the radiation section.

As a result, only when it is determined that there is no noise in the noise determination process described above, the buried object detection device (main body) detects that it has been lifted from the surface of the object and stops emitting electromagnetic waves. processing can be carried out.
That is, in the noise determination process described above, if it is determined that noise is included, this measurement result can be excluded from the lifting determination process. Therefore, by performing the lifting determination process using only results that are less affected by noise, the lifting determination process can be performed with high accuracy.

A buried object detection method according to a sixteenth invention is a buried object detection method using a buried object detection device that detects a buried object within an object using data regarding reflected waves of electromagnetic waves radiated toward the object. The method includes a radiation step, a delay time setting step, a reception step, and a determination step. The radiation step radiates electromagnetic waves from the radiation section. The delay time setting step sets a delay time of a sampling pulse for sampling the reflected wave. In the receiving step, the receiving section receives the reflected electromagnetic wave based on the delay time set in the delay time setting step. The rotation detection step is connected to a wheel that is attached to the main body of the buried object detection device and rotates while in contact with the surface of the object, and detects information regarding the rotation of the wheel. The determination step acquires the first data for one line of the reflected wave received in the reception step, and also acquires the first data for one line again after a predetermined period of time has passed since the rotation of the wheel detected in the rotation detection step has stopped. A predetermined value is obtained by comparing the maximum amplitude value of the waveform of the first data with the amplitude value of the waveform of the second data at the step position where the maximum amplitude value of the waveform of the first data is sampled. If there is the above difference, a lifting determination process is performed to detect that the main body has been lifted from the surface of the object on the metal plate and to stop the radiation of electromagnetic waves from the radiation part.

Here, in a buried object detection device that detects a buried object within an object using data regarding reflected waves of electromagnetic waves radiated toward the object, first data for one line of reflected waves received by the receiving section will be described. At the same time, after a predetermined period of time has passed since the rotation of the wheel detected by the rotation detection unit has stopped, one line of second data is acquired again, and the maximum amplitude value in the waveform of the first data and the second data are acquired. The maximum amplitude value of the waveform of the first data is compared with the amplitude value of the waveform of the second data at the sampled step position to determine whether the main body has been lifted from the surface of the object on the metal plate.
As a result, the maximum amplitude value (peak) in the waveform of the first data is compared with the amplitude value of the waveform of the second data at the step position where the maximum amplitude value in the waveform of the first data is sampled, and the difference is greater than or equal to a predetermined value. If it is determined that there is a buried object detection device, it can be determined that the buried object detection device has been lifted on the metal plate (sheet metal), and the emission of electromagnetic waves can be stopped.

A buried object detection method according to a seventeenth invention is a buried object detection method using a buried object detection device that detects a buried object within an object using data regarding reflected waves of electromagnetic waves radiated toward the object. The method includes a radiation step, a delay time setting step, a reception step, and a determination step. The radiation step radiates electromagnetic waves from the radiation section. The delay time setting step sets a delay time of a sampling pulse for sampling the reflected wave. In the receiving step, the receiving section receives the reflected electromagnetic wave based on the delay time set in the delay time setting step. The rotation detection step is connected to a wheel that is attached to the main body of the buried object detection device and rotates while in contact with the surface of the object, and detects information regarding the rotation of the wheel. The determination step acquires the first data for one line of the reflected wave received in the reception step, and also acquires the first data for one line again after a predetermined period of time has passed since the rotation of the wheel detected in the rotation detection step has stopped. , and the second data at the step position where the amplitude value at the midpoint having half the amplitude of the maximum amplitude value in the waveform of the first data and the amplitude value at the midpoint in the waveform of the first data are sampled. If there is no difference of more than a predetermined value, the maximum amplitude value in the waveform of the first data and the second data at the step position where the maximum amplitude value in the waveform of the first data was sampled are compared. Compare the amplitude value of the waveform with , and if there is a difference of more than a predetermined value, it is determined that the main body has been lifted from the surface of the object when there is a buried metal object directly under the dielectric. A lifting determination process is carried out to detect this and stop the emission of electromagnetic waves from the radiator.

Here, in a buried object detection device that detects a buried object within an object using data regarding reflected waves of electromagnetic waves radiated toward the object, first data for one line of reflected waves received by the receiving section will be described. At the same time, after a predetermined period of time has passed since the rotation of the wheel detected by the rotation detection unit has stopped, one line of second data is acquired again, and the second data is half of the maximum amplitude value in the waveform of the first data. Compare the amplitude value of the midpoint with amplitude and the amplitude value of the waveform of the second data at the step position where the amplitude value of the midpoint in the waveform of the first data was sampled, and if there is no difference of more than a predetermined value, , based on the result of comparing the maximum amplitude value of the waveform of the first data with the amplitude value of the waveform of the second data at the step position where the maximum amplitude value of the waveform of the first data was sampled, metal is placed directly under the dielectric. It is determined whether or not the main body has been lifted from the surface of the object in a state where a buried object made of metal is present.

Here, when the buried object detection device is lifted when there is metal directly under the dielectric, unlike when lifting on the dielectric mentioned above, a midpoint with an amplitude that is half the maximum amplitude value of the data waveform is detected. It is known that the amplitude does not change by more than a predetermined value.
As a result, there is no difference of more than a predetermined value in the comparison between the amplitude value at the midpoint of the first data and the amplitude value of the waveform of the second data at the step position where the amplitude value of the midpoint in the waveform of the first data is sampled. In this case, the maximum amplitude value of the waveform of the first data is compared with the amplitude value of the waveform of the second data at the step position where the maximum amplitude value of the waveform of the first data is sampled, and the difference is greater than a predetermined value. In some cases, it is detected that the main body has been lifted from the surface of the object in a state where there is a buried metal object directly under the dielectric.

As a result, even if there is metal directly under the dielectric, it is possible to accurately determine that the buried object detection device has been lifted, and to stop emitting electromagnetic waves.

According to the buried object detection device according to the present invention, for example, it is possible to suppress the influence of external noise or to accurately detect lifting of the device regardless of the buried object detection status.

FIG. 1 is a perspective view showing the configuration of a buried object detection device according to an embodiment of the present invention. FIG. 2 is a block diagram showing the configuration of the buried object detection device shown in FIG. 1. FIG. FIG. 3 is a block diagram showing the configuration of the impulse control module of FIG. 2. FIG. 4 is a diagram showing reflected wave data acquired by the MPU in FIG. 3. FIG. FIG. 3 is a block diagram showing the configuration of the main control module in FIG. 2; 2 is a flowchart showing the process flow of a buried object detection method carried out by the buried object detection device of FIG. 1; 7 is a flowchart showing the process flow of electromagnetic wave emission start control included in the buried object detection method of FIG. 6. FIG. (a) is a schematic diagram showing a state in which the buried object detection device of FIG. 1 is in contact with an exploration surface (concrete surface). (b) is a schematic diagram showing a state in which the buried object detection device of FIG. 1 is lifted (separated) from the exploration surface (concrete surface). 8A and 8B are graphs showing the relationship between the number of steps of the delay IC and reflected wave data (digital values) obtained in the states of FIGS. 8(a) and 8(b). 2 is a graph showing a relationship between the number of steps with a delay IC and data (digital value) of reflected waves, in order to show changes when noise is included in data received by the receiving antenna of the buried object detection device shown in FIG. 1; (a) is a schematic diagram showing a state in which the buried object detection device of FIG. 1 receives reflected waves from buried objects existing in concrete. (b) is a schematic diagram showing a state in which a sheet metal is present on the surface of concrete in the buried object detection device of FIG. 1; (a) is a graph showing data of reflected waves acquired in the state of FIG. 11(a). (b) is a graph showing data of reflected waves acquired in the state of FIG. 11(b). (a) is a schematic diagram showing a state in which a metal buried object exists directly under a dielectric scanned by the buried object detection device of FIG. 1; (b) is a schematic diagram showing a state in which the buried object detection device of FIG. 1 is lifted up in a state where a metal buried object exists directly below the dielectric scanned by the buried object detection device. 13A and 13B are graphs showing the relationship between the number of steps of the delay IC and reflected wave data (digital values) obtained in the states of FIGS. 13A and 13B. FIG. 7 is a sequence diagram showing the flow of the electromagnetic wave radiation stop control process shown in FIG. 6; 7 is a flowchart showing a process flow of electromagnetic wave radiation stop control included in the buried object detection method of FIG. 6; 5 is a flowchart showing the flow of lifting determination processing in a buried object detection method according to an embodiment of the present invention. 5 is a flowchart showing the flow of lifting determination processing on a sheet metal in a buried object detection method according to an embodiment of the present invention. 5 is a flowchart showing the flow of lifting determination processing on a dielectric in a buried object detection method according to an embodiment of the present invention. 5 is a flowchart showing the flow of a lifting determination process on a metal buried object directly under a dielectric body in a buried object detection method according to an embodiment of the present invention.

A buried object detection device 1 and a buried object detection method according to an embodiment of the present invention will be described below using FIGS. 1 to 20.
FIG. 1 is a perspective view showing a state in which a buried object detection device 1 of this embodiment is placed on concrete (object) 100. FIG. 2 is a block diagram showing a schematic configuration of the buried object detection device 1 of this embodiment.

(1-1. Configuration of buried object detection device 1)
The buried object detection device 1 of this embodiment emits an impulse wave (electromagnetic wave) toward the concrete 100 while moving on the surface 100a of an object such as the concrete 100, and receives and analyzes the reflected wave. The positions of buried objects 101a, 101b, 101c, and 101d in concrete 100 are detected. In FIG. 1, the moving direction of the buried object detection device 1 is indicated by an arrow A.

In the example shown in FIG. 1, the buried objects 101a, 101b, 101c, and 101d are reinforcing bars, and are buried, for example, at depths of 20 cm, 15 cm, 10 cm, and 5 cm from the surface 100a of the concrete 100, respectively. . In FIG. 1, the depth direction of the concrete 100 is indicated by an arrow B, and the opposite direction (surface direction) is indicated by an arrow C.
The four reinforcing bars (buried objects 101a to 101d) buried in the concrete 100 are arranged in a direction that is substantially parallel to the surface 100a of the concrete 100 and intersects with the moving direction of the buried object detection device 1. has been done.

As shown in FIG. 2, the buried object detection device 1 includes a main body 2, a handle 3, four wheels 4, an impulse control module 5, a main control module 6, an encoder (rotation detection section) 7, A display section 8 is provided.
The handle 3 is a handle portion that is held by an operator (user), and is provided on the upper surface of the main body portion 2 . The four wheels are rotatably attached to the lower part of the main body 2. When detecting the buried object 101 inside the concrete 100, the operator moves the buried object detection device 1 on the surface 100a of the concrete 100 while holding the handle 3 and rotating the wheels 4.

The impulse control module 5 controls the timing of emitting impulse waves toward the surface 100a of the concrete 100, the timing of receiving reflected waves of the emitted impulse waves, and the like.
The encoder 7 is connected to the wheel 4, detects information regarding the rotation of the wheel 4, and, based on the detected information, tells the impulse control module 5 the emission timing of the impulse wave and the reception timing of the reflected wave. Send signals to control.
The main control module 6 receives data regarding the reflected waves received by the impulse control module 5 and detects the buried object 101.
The display section 8 is provided on the upper surface of the main body section 2, and displays images showing the positions of the buried objects 101a, 101b, 101c, and 101d.

(1-2. Impulse control module 5)
FIG. 3 is a block diagram showing the configuration of the impulse control module 5. As shown in FIG.

As shown in FIG. 3, the impulse control module 5 includes a control section 10, a transmission antenna (transmission section) 11, a reception antenna (reception section) 12, an impulse generation circuit 13, a delay IC 14, and a sampling pulse generation circuit. 15, a high-speed sample and hold circuit 16, an A/D converter 17, and a storage section 18.
The control section 10 is constituted by an MPU (Micro Processing Unit), etc., and uses an encoder input as a trigger to instruct the impulse generation circuit 13 to generate an impulse wave.

The control unit 10 also controls a delay IC 14 that adjusts a sampling pulse that sets the timing and period for receiving reflected waves at the receiving antenna 12.
Further, the control unit 10 determines whether external noise is included in the data of the reflected waves received by the receiving antenna 12, and also determines whether the buried object detection device 1 is lifted from the exploration surface (surface 100a of concrete 100). Determine whether or not. Note that the noise determination process and the lifting determination process will be described in detail later.

The transmitting antenna 11 is provided on the bottom side of the main body 2, and emits impulse waves at a constant period based on the pulse period.
The receiving antenna 12 is provided on the bottom side of the main body 2 and mainly receives reflected waves of impulse waves radiated from the transmitting antenna 11. Specifically, for example, if the time required for the impulse wave radiated from the transmitting antenna 11 to travel back and forth within the concrete 100 is 5 ns (=5000 ps), the receiving antenna 12 will receive the impulse wave 5 ns after the impulse wave is radiated from the transmitting antenna 11. (5000 ps), a received waveform as shown in FIG. 4 can be obtained.

The impulse generation circuit 13 is controlled by the control unit 10, and is triggered by the input of the encoder 7 inputted via the control unit 10, and generates an impulse wave a predetermined number of times at a predetermined time interval based on a command from the MPU. (for example, 500 times at 10 ps intervals) and output to the transmitting antenna 11.
The delay IC 14 is controlled by the control unit 10, and sets the delay time and sampling period of a sampling pulse for sampling the reflected wave at the reception antenna 12 using a digital signal.

Based on the delay time set by the delay IC 14, the sampling pulse generation circuit 15 transmits a sampling pulse to the high speed sample and hold circuit 16 so as to capture the reflected wave received by the receiving antenna 12.
The high-speed sample-and-hold circuit 16 receives the sampling pulse from the sampling pulse generation circuit 15 , captures the reflected wave received at the receiving antenna 12 , and transmits it to the A/D converter 17 .

The A/D converter 17 A/D (Analog/Digital) converts the reflected wave signal received from the high-speed sample and hold circuit 16 and transmits it to the control unit 10 .
The storage unit 18 is connected to the control unit 10 and stores sampling data corresponding to one line received by the reception antenna 12, for example, from steps 0 to 511.
In the buried object detection device 1 of this embodiment, with the above configuration, the impulse control module 5 outputs an impulse wave from the transmitting antenna 11 multiple times using the input from the encoder 7 as a trigger. Then, the impulse control module 5 uses the delay IC 14 to set a delay time after the impulse wave is emitted, and by delaying the acquisition timing of the reflected waves, the reflected waves are reflected at each distance from the surface 100a of the concrete 100. data can be obtained.

Here, FIG. 4 is a diagram showing reflected wave data acquired by the MPU. The vertical axis shows the digital data of 0 to 4095 gradations obtained by A/D converting the received reflected wave with a resolution of 2 to the 12th power, with the median value of 2048 gradations as axis O, and the direction of the arrow is negative. Show the side. The horizontal axis indicates the distance to the receiving antenna 12, and the direction of the arrow (corresponding to the depth direction B) indicates that the distance from the receiving antenna 12 is long. Further, a long distance corresponds to a large depth.

Note that the waveform W1 shown in FIG. 4 also includes reflected waves reflected by the antenna without being radiated into the concrete 100 (p1, etc.), so by calculating the difference from the reference waveform, The changes in the reflected wave data are extracted.
Further, the data shown in FIG. 4 is data indicating the strength of the received signal after the input from the encoder 7 until the next input from the encoder 7. By gradually delaying the acquisition timing of the reflected waves based on the delay time set by the delay IC 14, the reflected waves from a position far from the receiving antenna 12 are received. However, when there is input from the encoder 7, , the delay in the reception timing is restored, and the reception timing is gradually delayed again. That is, the reflected wave in the depth direction B at a predetermined measurement position in the movement direction A (the position where the input from the encoder 7 is received) is received. The data of the reflected waves received after the input of the encoder 7 shown in FIG. 4 until the input of the next encoder is referred to as data for one line. The control unit 10 transmits one line of RF (Radio Frequency) data to the main control module 6 every time one line of data is accumulated.

Note that since the buried object detection device 1 is moved by the worker (user) on the surface 100a of the concrete 100, the measurement position is not exactly the same position, and the depth direction B is also different from the surface 100a of the concrete 100. The direction is not strictly vertical.
(1-3. Main control module 6)
FIG. 5 is a block diagram showing the configuration of the main control module 6. As shown in FIG.

As shown in FIG. 5, the main control module 6 includes a reception section 21, an RF data management section 22, a buried object determination section 24, a determination result registration section 25, and a display control section 26. .
The receiving unit 21 receives one line of RF data each time it is transmitted from the control unit 10 of the impulse control module 5.
The RF data management unit 22 stores one line of RF data received by the reception unit 21.

The buried object determination section 24 uses one line of RF data stored in the RF data management section 22 to determine the presence or absence of the buried object 101 and detects the position of the buried object 101.
Note that the process of detecting the buried object 101 in the buried object determination unit 24 may be performed using a known method based on a plurality of one line of RF data received by the receiving antenna 12. Specifically, for example, when the buried object 101 is made of metal such as a reinforcing bar, the impulse wave radiated from the transmitting antenna 11 is reflected on its surface. Therefore, by detecting the velocity (intensity) of the reflected wave reflected from the surface of the buried object 101 and the time until the reflected wave is received by the receiving antenna 12, the buried object in the concrete 100 can be detected. The presence or absence of 101 and its position can be detected.

The determination result registration unit 25 registers the position of the buried object 101 detected by the buried object determination unit 24 in the RF data management unit 22.
The display control unit 26 controls the display unit 8 so as to display an image obtained by color-gradation processing of the signal intensity in the plane of the movement direction A and the depth direction B, and the position of the buried object 101.
<Flow of buried object detection processing>
In the buried object detection method of this embodiment, for example, a buried object 101 in concrete 100 is detected using the above-described buried object detection device 1 according to the flowchart shown in FIG.

That is, in step S1, initialization processing is performed, and inputs from the encoder 7 and a timer (not shown) are used as triggers to control the transmitting antenna 11 and the receiving antenna 12 to receive one line of RF data. do.
Next, in step S2, the control unit 10 performs electromagnetic wave radiation start control to determine whether or not to radiate impulse waves (electromagnetic waves) from the transmitting antenna 11 based on the information regarding the rotation of the wheels 4 received from the encoder 7. implement.

The electromagnetic wave radiation start control will be described in detail later using FIG. 7.
Next, in step S3, after the impulse wave emission start condition is satisfied and impulse wave emission is started in step S2, the impulse wave is Implement radiation stop control.
Next, in step S4, after determining whether to stop the emission of impulse waves in step S3, it is determined whether to end the search for buried object 101 in concrete 100.

Here, if the search is to be continued, the process returns to step S2, and if the search is to be terminated, the process is to proceed to step S5.
Next, in step S5, the presence or absence of the buried object 101 in the concrete 100 and its position are detected using one line of RF data of the reflected wave received by the receiving antenna 12, and the process ends.

<Flow of electromagnetic wave emission start control>
In the buried object detection method of this embodiment, the electromagnetic wave emission start control in step S2 of FIG. 6 described above is carried out according to the flowchart shown in FIG.
That is, in the buried object detection device 1 of this embodiment, as described above, the control unit 10 included in the impulse control module 5 starts emitting impulse waves from the transmitting antenna 11 based on the input status from the encoder 7. Decide whether or not to do so.

More specifically, in step S11, the control unit 10 first determines whether there is an input from the encoder 7. Here, if there is an input from the encoder 7, the process advances to step S12, and step S11 is repeated until there is an input.
Next, in step S12, the control unit 10 detects whether or not the encoder 7 has inputted N times or more in the same direction continuously, thereby stabilizing the rotation of the wheels 4 on the surface 100a of the concrete 100. Determine whether or not there is.

Next, in step S13, the control unit 10 determines in step S12 that the input from the encoder 7 is stable, that is, that the rotation of the wheels 4 is stable, so it emits a temporary impulse wave for a predetermined period of time. The transmitting antenna 11 is controlled via the impulse generating circuit 13 so as to do so.
Next, in step S14, data for one line, which is the reflected wave of the impulse wave radiated from the transmitting antenna 11 in step S13, is received from the receiving antenna 12.

Next, in step S15, the control unit 10 uses the waveform of the reflected wave of the temporary impulse wave received from the reception antenna 12 to obtain data indicating the air (with the buried object detection device 1 lifted up). Yes).
If it is determined in step S15 that the buried object detection device 1 has not been lifted from the surface 100a of the concrete 100 based on the waveform of the reflected wave, the process proceeds to step S16. On the other hand, if it is determined that the buried object detection device 1 is in the lifted state, the process advances to step S17.

Here, the data indicating in the air means a state in which the buried object detection device 1 is lifted up by a worker and is separated from the surface 100a of the concrete 100.
Furthermore, the principle for detecting that the buried object detection device 1 is separated from the surface 100a of the concrete 100 will be explained.
For example, when the wheels 4 of the buried object detection device 1 are in contact with the surface 100a of the concrete 100, the radiated impulse wave passes through the inside of the concrete 100 from the surface 100a as shown in FIG. Then, the reflected wave is received by the receiving antenna 12.

At this time, if the dielectric constant of air is 1, the dielectric constant of concrete 100 is 7, so the impulse wave moving in concrete 100 is attenuated and has a slower speed than moving in air.
On the other hand, when the wheels 4 of the buried object detection device 1 are separated from the surface 100a of the concrete 100, the radiated impulse waves move in the air and are received by the receiving antenna 12, as shown in FIG. 8(b). be done.

Similarly, if the dielectric constant of air is 1, then the dielectric constant of concrete 100 is 7, so the impulse wave that travels through the air is hardly attenuated and becomes faster than the impulse wave that passes through the concrete 100. .
FIG. 9 shows reflected wave data (digital values) (vertical axis) with respect to depth (horizontal axis) from the surface 100a of concrete 100 in the states shown in FIGS. 8(a) and 8(b). .

Here, the difference between the reflected wave data (solid line) in the state shown in FIG. 8(a) and the reflected wave data (dotted chain line) in the state shown in FIG. 8(b) is shown in the graph shown in FIG. It will be done. That is, when the buried object detection device 1 is lifted from the surface 100a of the concrete 100, the phase of the received waveform at the receiving antenna 12 is shifted between before and after the lift due to the dielectric constant of the dielectric material.

In the buried object detection device 1 of this embodiment, by utilizing the fact that the phase of the received waveform shifts during lifting, for example, the midpoint that takes half the maximum amplitude value (peak value) of the received waveform is detected. At the step position, it is determined that there is lifting based on whether or not the change in amplitude is a digital value greater than or equal to a predetermined value (for example, 35).
Here, in such a lift determination process, if the waveform received by the receiving antenna 12 includes external noise such as Wi-fi (registered trademark), the noise is not included as shown in FIG. Compared to a waveform without noise (solid line), a waveform containing noise (dotted line) causes the reception strength to fluctuate up and down.

For this reason, if the lifting determination process is performed using a waveform containing noise, there is a risk that it will be erroneously determined that the buried object detection device 1 has been lifted even though it has not actually been lifted. In this case, while the operator (user) is using the buried object detection device 1, it is incorrectly determined that there is lifting, and as a result, the emission of impulse waves from the transmitting antenna 11 is stopped, and the display on the display unit 8 also disappears. This will cause problems.

Therefore, in the buried object detection device 1 and buried object detection method of the present embodiment, in the lifting determination process in step S15, a noise determination process is performed to determine whether or not the waveform received by the receiving antenna 12 contains noise. .
Note that the details of the noise determination process will be described in detail later.
In addition, as shown in FIGS. 11(a) and 11(b), another factor that causes erroneous determination in the lifting determination process is that when scanning the buried object detection device 1 along the surface 100a of the concrete 100, A configuration in which a sheet metal (metal plate) is arranged near the surface 100a is considered.

Specifically, as shown in FIG. 11(b), the impulse wave radiated from the transmitting antenna 11 is reflected by the sheet metal near the surface 100a of the concrete 100, and the buried object 101 underneath is detected. things become difficult.
In the lifting determination process as well, the received waveform received in the state shown in FIG. 11(a) (see FIG. 12(a)) indicates that the buried object detection device 1 is Compared to the received waveform generated when lifted from the surface 100a, there is a possibility that the waveform (see FIG. 12(b)) has a similar first peak. Therefore, it is difficult to perform lifting determination processing with high accuracy.

Therefore, in the buried object detection device 1 and the buried object detection method of the present embodiment, in the lifting determination process in step S15, a process is performed to determine whether or not the lifting determination process is on a sheet metal.
Note that the details of the lifting determination process on the sheet metal will be described in detail later.
Furthermore, as shown in FIGS. 13(a) and 13(b), there is another factor that causes erroneous determination in the lifting determination process. A configuration in which a metal buried object 101 exists is considered.

Specifically, as shown in FIG. 13(a), if a metal buried object 101 exists directly under the dielectric, the buried object detection device 1 is lifted up as shown in FIG. 13(b). Even in this case, as shown in FIG. 14, no phase shift occurs in the received waveform.
For this reason, it is difficult to detect that the buried object detection device 1 has been lifted using the normal lifting determination method shown in FIG. 9 that utilizes a phase shift.

Therefore, in the buried object detection device 1 and the buried object detection method of the present embodiment, in the lifting determination process in step S15, it is determined whether or not the lifting determination process is performed on the metal buried object 101 provided directly below the dielectric. Execute processing to determine.
Note that the details of the lifting determination process on the metal buried object 101 directly under the dielectric will be described in detail later.

Next, in step S16, since it was determined in step S15 that the buried object detection device 1 is near the surface 100a of the concrete 100, the control unit 10 determines that the buried object detection device 1 is moving stably and It is determined that it is near the surface 100a of the concrete 100, and control is performed so that the impulse wave is radiated from the transmitting antenna 11.
Thereby, when starting detection of buried object 101 in concrete 100, impulse waves can be automatically emitted without operator's operation.

Note that the impulse wave emitted here and the temporary impulse wave emitted in step S13 may have the same intensity, or may have different intensities, for example, by weakening the intensity of the temporary impulse wave. Good too.
Next, in step S17, since it was determined in step S15 that the buried object detection device 1 is in the air, away from the surface 100a of the concrete 100, the control unit 10 controls the transmitting antenna 11 to transmit an impulse wave. stop the radiation.

Thereby, when starting detection of the buried object 101 in the concrete 100, it is determined that the buried object detection device 1 is in a state separated from the surface 100a of the concrete 100, that is, the buried object detection device 1 is in a lifted state. Then, the emission of impulse waves can be automatically stopped without any operation by the operator.
<Flow of electromagnetic radiation stop control>
In the buried object detection method of this embodiment, the above-described buried object detection device 1 is used to perform control to stop the emission of impulse waves from the transmitting antenna 11 according to the sequence diagram shown in FIG. 15 and the flowchart shown in FIG. 16.

That is, in step S21, it is detected whether an impulse wave is being emitted. Here, if the emission of the impulse wave is confirmed, the process proceeds to step S22, and if the emission of the impulse wave has already been stopped, the process ends.
Here, as shown in FIG. 15, the impulse wave radiation is inputted from the encoder 7 to the control unit 10 by the operator operating the buried object detection device 1 on the surface 100a of the concrete 100, and is controlled by the encoder 7. This is performed by the unit 10 transmitting an impulse wave radiation instruction to the transmitting antenna 11.

On the surface 100a of the concrete 100, each time the worker operates the buried object detection device 1, an input is received from the encoder 7 to the control unit 10, and each time there is an input from the encoder 7, the receiving antenna 12 Data of reflected waves is transmitted to the control unit 10.
Next, in step S22, since it is detected that an impulse wave is being radiated, it is detected whether the input from the encoder 7 has stopped. Here, if the input from the encoder 7 has stopped, the process advances to step S23, and if the input from the encoder 7 is continuing, the process waits until the input from the encoder 7 stops.

Next, in step S23, it is determined whether the exploration surface separation comparison data used to detect that the buried object detection device 1 is separated from the surface 100a of the concrete 100 has been initialized. Here, if it has been initialized, the process advances to step S24. On the other hand, if the comparison data has not been initialized, the process advances to step S25 and the comparison data is initialized using one line data.

Note that as the exploration surface separation comparison data, for example, a graph (see FIG. 9) showing data of reflected waves when the buried object detection device 1 mentioned above is in contact with the surface 100a of the concrete 100 can be used.
Next, in step S24, data for one line of reflected waves received by the receiving antenna 12 (solid line in FIG. 9) is compared with pre-stored exploration surface separation comparison data (dotted chain line in FIG. 9). Then, it is determined whether there is a difference (change) greater than or equal to a predetermined threshold. Here, if there is a difference (change) greater than or equal to the predetermined threshold, the process advances to step S26.

More specifically, as shown in FIG. 15, among the data transmissions (1) to (3) from the receiving antenna 12 that are performed every 100 ms after the input from the encoder 7 to the control unit 10 stops, If it is determined that there is a difference (change) between the data (1) and the data (3) by a predetermined threshold value or more, the process proceeds to step S26.
In addition, based on the state in which the buried object detection device 1 is in contact with the surface 100a of the concrete 100 (see FIG. 8(a)), it is determined whether the buried object detection device 1 is in a state separated from the surface 100a (see FIG. 8(b)). The process of determining whether or not the difference is true can be similarly carried out using the graph shown in FIG. 9 described above.

Next, in step S26, the control unit 10 confirms the emission of the impulse wave in step S21, confirms that the input from the encoder 7 has stopped in step S22, and confirms that the data of the reflected wave is the comparison data in step S24. By confirming that the difference is greater than or equal to a predetermined threshold, it is determined that the buried object detection device 1 has moved away from the surface 100a of the concrete 100, and a signal is sent via the impulse generation circuit 13 to stop the emission of impulse waves. Controls the transmitting antenna 11.

Thereby, when the work of detecting the buried object 101 in the concrete 100 is finished, the emission of impulse waves can be automatically stopped without any operation by the operator. Further, by preventing impulse waves from being radiated outside of work, wasteful power consumption can be suppressed, and life deterioration of parts such as circuit elements of the transmitting antenna 11 can be prevented.
<Flow of lifting determination processing of buried object detection device 1>
In the buried object detection device 1 and the buried object detection method of this embodiment, in addition to the lifting determination process by detecting the phase shift of the waveform of the reflected wave shown in FIG. To accurately determine whether an object has been lifted from the surface.

That is, in the electromagnetic wave radiation stop control shown in FIG. 16, if the data of reflected waves received by the receiving antenna 12 includes external noise etc. (see FIG. 11(b)), when scanning over a metal buried object 101 placed directly under a dielectric material such as concrete 100 (see FIG. 13(b)), etc. There is a possibility that the lifting determination of the buried object detection device 1 cannot be performed accurately.

Therefore, in the buried object detection device 1 and buried object detection method of this embodiment, the lifting determination process is performed according to the flowcharts of FIGS. 17 to 20.
Note that the flowcharts shown in FIGS. 17 to 20 describe in detail the contents of step S15 in FIG.
Specifically, as shown in FIG. 17, in step S31, the control unit 10 receives the signal from the receiving antenna 12, acquires it from the high-speed sample-and-hold circuit 16, and A/D-converts it from the A/D converter 17. One line data (digital value) is stored in the storage unit 18.

Next, in step S32, the control unit 10 acquires digital values for 0 to 511 steps from the one line data stored in the storage unit 18.
Next, in step S33, the control unit 10 acquires the maximum amplitude value from 0 to 511 steps and the step position from the acquired digital value data.
Next, in step S34, the control unit 10 determines whether the maximum amplitude value from steps 0 to 511 is greater than 3500 (digital value) (first threshold).

Note that the determination in step S34 is a process of determining whether any of the situations that may reduce the accuracy of lifting determination is applicable.
Specifically, if it is determined in step S34 that the maximum amplitude value from 0 to 511 steps is larger than 3500 (digital value), the control unit 10 controls the During scanning, as shown in FIG. 12(b), the maximum amplitude value of the received waveform is larger than the received waveform in the scanning state on the dielectric shown in FIG. 11(a) (see FIG. 12(a)). It is determined that this is the case, and the process proceeds to the lifting determination process on the sheet metal.

On the other hand, if it is determined in step S34 that the maximum amplitude value from 0 to 511 steps is less than or equal to 3500 (digital value), the control unit 10 determines that the sheet metal is not being scanned, and the dielectric Proceed to the lifting determination process above (on the dielectric or on the metal directly below the dielectric).
Then, in step S34, when the process proceeds to the lifting determination process on the sheet metal, the control unit 10 executes the lifting detection process on the sheet metal according to the flowchart shown in FIG.

That is, in step S41, in order to determine whether or not the received waveform contains noise, the control unit 10 first determines whether or not the received waveform contains noise, in order to determine whether the received waveform contains noise or not. With respect to the calculation result obtained by differentiating the data, it is determined whether the number of ± changing points is 10 or less (10 steps).
Note that the ± change point means the point where the slope of the graph of the differentiated calculation result changes from positive to negative, and the point where the slope changes from negative to positive.

Here, in step S41, if it is determined that the number of ± changing points is 10 or less, the control unit 10 determines that there is no noise mixed in that would reduce the accuracy of the lifting determination, and proceeds to step S42. .
On the other hand, as shown in FIG. 10, if it is determined that there are more than 10 points of change in ±, the control unit 10 proceeds to step S16, since it is recognized that there is noise that reduces the accuracy of the lifting determination. The data is excluded from the target of the lift determination process, and the emission of impulse waves (electromagnetic waves) is started without performing the lift determination process.

Next, in step S42, the control unit 10 determines whether 200 msec has elapsed since the encoder 7 stopped (the wheels 4 stopped rotating).
Here, if the elapsed time has elapsed, the process advances to step S43; if the elapsed time has not elapsed, the control unit 10 determines that the buried object detection device 1 is in contact with the surface 100a of the concrete 100 and is in use. Then, the process proceeds to step S16, where emission of electromagnetic waves is started.

Next, in step S43, the control unit 10 acquires the next one line data (second data) at the step position of the maximum amplitude value in step S33 on one scan.
Next, in step S44, in order to determine whether or not the received waveform contains noise regarding the 1-line data as the second data, the control unit 10 selects a Regarding the calculation result obtained by differentiating the data within the range of ±30 steps from the point, it is determined whether the ± change points are 10 or less (10 steps).

Here, if it is determined in step S44 that the number of ± changing points is 10 or less, the control unit 10 determines that there is no noise mixed in that would reduce the accuracy of the lifting determination, and proceeds to step S45. .
On the other hand, as shown in FIG. 10, if it is determined that there are more than 10 points of change in ±, the control unit 10 proceeds to step S16, since it is recognized that there is noise that reduces the accuracy of the lifting determination. The data is excluded from the target of the lift determination process, and the emission of impulse waves (electromagnetic waves) is started without performing the lift determination process.

Next, in step S45, in order to determine whether or not the sheet metal has been lifted, the control unit 10 uses the amplitude value at the step position of the second data obtained in step S43 to determine whether or not the sheet metal has been lifted. The maximum amplitude value at the step position of one data is subtracted, and it is determined whether or not it is less than a predetermined threshold value (-200).
Note that the determination using this predetermined threshold value (-200) takes advantage of the fact that in a configuration where there is a sheet metal directly under the transmitting antenna 11 and the receiving antenna 12, a large amplitude change occurs. Lifting of the buried object detection device 1 on the sheet metal is detected by detecting the occurrence of a change in amplitude.

Here, if it is determined that it is -200 or less, the process proceeds to step S46, and the control unit 10 determines that the buried object detection device 1 has been lifted on the sheet metal. Then, the control unit 10 stops the emission of impulse waves (electromagnetic waves) from the transmitting antenna 11 in step S17.
On the other hand, if it is determined that the value is larger than -200, the control unit 10 determines that the buried object detection device 1 is not lifted on the sheet metal and is in use, and proceeds to step S16 to start emitting electromagnetic waves. .

Further, in step S45, when proceeding to the lifting determination process on the dielectric, the control unit 10 executes lifting detection processing on the dielectric according to the flowchart shown in FIG.
That is, in step S51, the control unit 10 acquires the maximum amplitude value and the step position from 0 to 100 steps from the digital data stored in the storage unit 18 in step S31.

Next, in step S52, in order to determine whether noise is included in the received waveform for one line data, the control unit 10 determines whether the maximum amplitude value from 0 to 100 steps and the midpoint of the step position are ± Regarding the calculation result obtained by differentiating the data within the range of 30 steps, it is determined whether or not the number of ± changing points is 10 or less (10 steps).
Here, if it is determined in step S52 that the number of ± changing points is 10 or less, the control unit 10 determines that there is no noise mixed in that would reduce the accuracy of the lifting determination, and proceeds to step S53. .

On the other hand, as shown in FIG. 10, if it is determined that there are more than 10 points of change in ±, the control unit 10 proceeds to step S16, since it is recognized that there is noise that reduces the accuracy of the lifting determination. The data is excluded from the target of the lift determination process, and the emission of impulse waves (electromagnetic waves) is started without performing the lift determination process.
Next, in step S53, the control unit 10 uses the following calculation formula (1) to calculate a reference midpoint for the maximum amplitude value of the acquired received waveform.

(Maximum amplitude - 2048)/2+2048 (1)
Next, in step S54, the control unit 10 acquires the step position of the midpoint calculated in step S53 and its data value.
Next, in step S55, the control unit 10 determines whether 200 msec has elapsed since the encoder 7 stopped (the wheels 4 stopped rotating).

Here, if the elapsed time has elapsed, the process proceeds to step S56, and if the elapsed time has not elapsed, the control unit 10 determines that the buried object detection device 1 is in contact with the surface 100a of the concrete 100 and is in use. Then, the process proceeds to step S16, where emission of electromagnetic waves is started.
Next, in step S56, the next one line data (second data) at the step position of the maximum amplitude value in step S53 on one scan is acquired.

Next, in step S57, in order to determine whether or not the received waveform contains noise regarding one line data as the second data, the control unit 10 sets the maximum amplitude value of the second data from 0 to 100 steps. With respect to the calculation results obtained by differentiating data within a range of ±30 steps from the midpoint of the step position, it is determined whether the number of ± change points is 10 or less (10 steps).

Here, if it is determined in step S57 that the number of ± change points is 10 or less, the control unit 10 determines that there is no noise mixed in that would reduce the accuracy of the lifting determination, and proceeds to step S58. .
On the other hand, as shown in FIG. 10, if it is determined that there are more than 10 points of change in ±, the control unit 10 proceeds to step S16, since it is recognized that there is noise that reduces the accuracy of the lifting determination. The data is excluded from the target of the lift determination process, and the emission of impulse waves (electromagnetic waves) is started without performing the lift determination process.

Next, in step S58, in order to determine whether or not lifting on the dielectric has been performed, the control unit 10 uses the amplitude value obtained in step S54 from the amplitude value at the step position of the second data obtained in step S56. The maximum amplitude value at the step position of the first data is subtracted, and it is determined whether or not it is equal to or greater than a predetermined threshold value (35).
Here, if it is determined that the number is 35 or more, the process proceeds to step S59, and the control unit 10 determines that the buried object detection device 1 has been lifted on the dielectric. Then, the control unit 10 stops the emission of impulse waves (electromagnetic waves) from the transmitting antenna 11 in step S17.

On the other hand, if it is determined that the value is less than 35, the control unit 10 determines that there is a possibility that the buried object detection device 1 is lifted up on the metal directly under the dielectric (see FIG. 13(b)), and the Go to flow.
In the flowchart shown in FIG. 20, in step S61, data including the maximum amplitude value and the step position from 0 to 100 steps obtained in step S51 is acquired.

Next, in step S62, in order to determine whether or not the received waveform contains noise, data within a range of ±30 steps from the maximum amplitude value of the data acquired in step S51 and the midpoint of the step position is Regarding the differentiated calculation result, it is determined whether the number of ± change points is 10 or less (10 steps).
Here, if it is determined in step S62 that the number of ± changing points is 10 or less, the control unit 10 determines that there is no noise mixed in that would reduce the accuracy of the lifting determination, and proceeds to step S63. .

On the other hand, as shown in FIG. 10, if it is determined that there are more than 10 points of change in ±, the control unit 10 proceeds to step S16, since it is recognized that there is noise that reduces the accuracy of the lifting determination. The data is excluded from the target of the lift determination process, and the emission of impulse waves (electromagnetic waves) is started without performing the lift determination process.
Next, in step S63, in order to perform lifting determination on the metal buried object 101 directly under the dielectric shown in FIG. The maximum amplitude value at the step position of the first data acquired in step S51 is subtracted from the amplitude value at , and it is determined whether or not it is less than or equal to a predetermined threshold (-40).

Note that the determination in step S63 is that even if the buried object detection device 1 is lifted over the metal buried object 101 placed directly under the dielectric mentioned above, a phase shift of the received waveform does not occur when the buried object detection device 1 is lifted up. Taking this into consideration, as shown in FIG. 14, the difference between the maximum amplitude values in steps 0 to 100 is compared with a predetermined threshold (-40).
Here, if it is determined that it is -40 or less, the process proceeds to step S64, and the control unit 10 determines that the buried object detection device 1 has been lifted above the metal buried object 101 placed directly under the dielectric. . Then, the control unit 10 stops the emission of impulse waves (electromagnetic waves) from the transmitting antenna 11 in step S17.

On the other hand, if it is determined that the value is greater than -40, the control unit 10 determines that the buried object detection device 1 is not lifted above the metal buried object 101 placed directly under the dielectric, and proceeds to step S16. , starts emitting impulse waves (electromagnetic waves).
In the buried object detection device 1 and the buried object detection method of the present embodiment, as described above, in order to accurately detect the state in which the buried object detection device 1 is lifted from the exploration surface, the control unit 10 adjusts the received waveform. The presence or absence of included noise is determined, and if it is determined that a predetermined amount or more of noise is included, this data is excluded from the lifting determination process.

As a result, it is possible to suppress erroneous determination that the lift has been lifted even though the lift has not been lifted as a result of carrying out lifting determination processing based on the received waveform that includes external noise such as Wi-Fi (registered trademark). I can do it.
In addition, in the buried object detection device 1 and the buried object detection method of the present embodiment, as described above, in order to accurately detect the state in which the buried object detection device 1 is lifted from the exploration surface, the control unit 10 It detects conditions where detection becomes more difficult (on a sheet metal or on a metal placed directly below a dielectric), and performs control so that lifting judgments can be made appropriately in each condition.

Thereby, for example, even if lifting is performed on a sheet metal, by performing appropriate determination processing, the lifting determination processing can be performed accurately.
Furthermore, for example, even when lifting is performed on a metal buried object 101 placed directly under a dielectric, it is possible to accurately perform the lifting judgment process by performing the appropriate judgment process. can.

[Other embodiments]
Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various changes can be made without departing from the gist of the invention.
(A)
In the above embodiment, in the noise determination process, plus or minus The explanation has been given using an example in which it is determined that the waveform contains noise when there are 10 or more changing points. However, the present invention is not limited thereto.
For example, the threshold value regarding the number of plus/minus change points used for noise determination is not limited to 10, and may be 9 or less, or 11 or more.

(B)
In the above embodiment, in order to determine whether or not the received waveform contains noise, the control unit 10 performs a calculation by differentiating data within a range of ±30 steps from the midpoint of the step position of the acquired maximum amplitude value. An example of making a determination using the results has been explained. However, the present invention is not limited thereto.
For example, the number of steps before and after the midpoint of the step position of the acquired maximum amplitude value is not limited to ±30 steps, but may be a wider range or a narrower range.

(C)
In the above embodiment, an example has been described in which 3500 is used as the first threshold value regarding the difference in the maximum amplitude value used to determine whether scanning is performed on a sheet metal or a dielectric material. However, the present invention is not limited thereto.
For example, other numerical values may be used as the first threshold value regarding the difference in the maximum amplitude value used to determine whether scanning is performed on a sheet metal or a dielectric material.

(D)
In the above embodiment, the maximum amplitude value of the received waveform of the first data is compared with the amplitude value of the received waveform of the second data at the step position where the maximum amplitude value of the received waveform of the first data is sampled, and An example was given in which -200 was used as the predetermined value for the lifting determination process. However, the present invention is not limited thereto.

For example, the predetermined value used for determining lift on a sheet metal may be another value.
Similarly, the maximum amplitude value of the received waveform of the first data is compared with the amplitude value of the received waveform of the second data at the step position where the maximum amplitude value of the received waveform of the first data was sampled. An example has been described in which 35 is used as the predetermined value for the lifting determination process on the placed metal. However, the present invention is not limited thereto.
For example, the predetermined value used to determine lift on the metal placed directly below the dielectric may be another value.

(E)
The above embodiment has been described using an example in which an impulse wave is used as the electromagnetic wave radiated from the transmitting antenna 11. However, the present invention is not limited thereto.
For example, a configuration may be adopted in which other forms of electromagnetic waves such as sine waves are radiated from the transmitting antenna.

(F)
In the embodiment described above, an example has been described in which a buried object 101 in concrete 100 is detected using the buried object detection device 1 in which four wheels 4 are attached to the main body 2. However, the present invention is not limited thereto.
For example, the number of wheels attached to the main body is not limited to four, and may be one, two, three, or five or more.

(G)
In the above embodiment, an example has been described in which a reinforcing bar in concrete 100 is used as the buried object 101 detected by the buried object detection device 1. However, the present invention is not limited thereto, and may be used for detecting foreign substances in other materials.

(H)
In the embodiment described above, the present invention has been explained by giving an example in which the present invention is implemented as a buried object detection device 1 and a buried object detection method. However, the present invention is not limited thereto.
For example, the present invention may be implemented as a buried object detection program that causes a computer to execute each step in the buried object detection method described above.

This buried object detection program is stored in the storage unit, and the CPU reads the program stored in the storage unit to cause the hardware to execute each step.
Alternatively, the present invention may be realized as a recording medium storing this buried object detection program.

The buried object detection device of the present invention has the effect of, for example, suppressing the influence of external noise or accurately detecting lifting of the device regardless of the detection status of the buried object. It is widely applicable to devices that perform detection.

1 Buried object detection device 2 Main body 3 Handle 4 Wheels 5 Impulse control module 6 Main control module 7 Encoder (rotation detection section)
8 Display section 10 Control section 11 Transmission antenna (radiating section)
12 Receiving antenna (receiving section)
13 Impulse generation circuit 14 Delay IC (variable delay section)
15 Sampling pulse generation circuit 16 High-speed sample/hold circuit 17 A/D converter 18 Storage section 21 Receiving section 22 RF data management section 24 Buried object determination section 25 Judgment result registration section 26 Display control section 100 Concrete 100a Surface 101a to 101d Buried object

Claims (13)

A buried object detection device that detects a buried object within an object using data regarding reflected waves of electromagnetic waves emitted toward the object,
The main body and
a radiation part provided in the main body and radiating the electromagnetic wave;
a receiving section that is provided in the main body and receives reflected waves of the electromagnetic waves;
a variable delay unit that sets a delay time of a sampling pulse for sampling the reflected wave in the receiving unit;
Acquire first data for one line of the reflected wave received by the receiving unit, and a predetermined number of steps before and after a sampling step position that is the midpoint of the maximum amplitude of the waveform for one line of the reflected wave. a control unit that determines whether noise is included in the waveform based on a graph showing a calculation result obtained by differentiating data in the range;
A buried object detection device equipped with The control unit is configured such that, in a graph showing calculation results obtained by differentiating data in a range of a predetermined number of steps before and after a sampling step position that is the midpoint of the maximum amplitude value of the waveform of the reflected wave, a plus or minus change point is a predetermined point. determining that the waveform contains noise if there are more than the number of noises;
The buried object detection device according to claim 1. When the control unit determines that the waveform does not include noise, the control unit detects that the main body has been lifted from the surface of the object and makes a lifting determination to stop the emission of the electromagnetic waves from the radiation unit. carrying out processing;
The buried object detection device according to claim 1 or 2. The control unit determines whether the maximum amplitude value of the reflected wave is larger than a predetermined first threshold value, and when it is determined that the maximum amplitude value of the reflected wave is larger than the first threshold value, the control unit determines that a metal plate is being scanned. to decide,
The buried object detection device according to claim 3. a wheel that is attached to the main body and rotates while in contact with the surface of the object;
a rotation detection unit provided in the main body, connected to the wheel, and configured to detect information regarding rotation of the wheel;
Furthermore,
The control unit acquires one line of second data again after a predetermined period of time has passed since the rotation of the wheel detected by the rotation detection unit has stopped, and determines whether the waveform contains noise. determine whether
The buried object detection device according to claim 4. The control unit compares the amplitude value of the waveform of the second data at the step position where the maximum amplitude value of the waveform of the first data is sampled with the maximum amplitude value of the waveform of the first data, and If the difference is greater than or equal to the value, a lifting determination process is performed to detect that the main body has been lifted from the surface of the object on the metal plate and to stop the emission of the electromagnetic waves from the radiation part. ,
The buried object detection device according to claim 5. The control unit determines whether the maximum amplitude value of the reflected wave is larger than the first threshold value, and if it is determined that the maximum amplitude value of the reflected wave is smaller than the first threshold value, it is determined that the dielectric material is being scanned. do,
The buried object detection device according to claim 4 . a wheel that is attached to the main body and rotates while in contact with the surface of the object;
a rotation detection unit provided in the main body, connected to the wheel, and configured to detect information regarding rotation of the wheel;
Furthermore,
The control unit acquires one line of second data again after a predetermined period of time has passed since the rotation of the wheel detected by the rotation detection unit has stopped, and determines whether the waveform includes noise. determine whether
The buried object detection device according to claim 7. The control unit is configured to control the amplitude value of the second data waveform at the step of sampling an amplitude value at a midpoint having an amplitude that is half the maximum amplitude value in the first data waveform, and the amplitude value of the first data waveform. Compare the amplitude value at the midpoint and if there is a difference of more than a predetermined value, it is detected that the main body has been lifted from the surface of the object on the dielectric, and the Perform a lifting judgment process to stop the emission of electromagnetic waves,
The buried object detection device according to claim 8. The control unit is configured to control the first data when there is no difference of more than the predetermined value in a comparison of the amplitude values at the step positions where the midpoint amplitude values of the first data and the second data are sampled. The maximum amplitude value of the waveform is compared with the amplitude value of the second data waveform at the step position where the maximum amplitude value of the first data waveform is sampled, and if there is a difference of more than a predetermined value, the dielectric Lifting determination processing that detects that the main body has been lifted from the surface of the object and stops emission of the electromagnetic waves from the radiation part in a state where the buried metal object is present directly under the body. implement,
The buried object detection device according to claim 9. A buried object detection method using a buried object detection device that detects a buried object in a target object using data regarding reflected waves of electromagnetic waves emitted toward the target object,
a radiating step of radiating the electromagnetic wave from a radiating section;
a delay time setting step of setting a delay time of a sampling pulse for sampling the reflected wave;
a receiving step of receiving a reflected wave of the electromagnetic wave in a receiving section based on the delay time set in the delay time setting step;
First data for one line of the reflected wave received in the receiving step is acquired, and a predetermined number of steps before and after a sampling step position that is the midpoint of the maximum amplitude value of the waveform for one line of the reflected wave. a determination step of determining whether or not the waveform includes noise, based on a graph showing a calculation result obtained by differentiating data in the range;
A method for detecting buried objects. In the determination step, in a graph showing calculation results obtained by differentiating data in a range of a predetermined number of steps before and after the sampling step position that is the midpoint of the maximum amplitude value of the waveform of the reflected wave, the plus or minus change point is determined to be a predetermined point. determining that the waveform contains noise if there are more than the number of noises;
The buried object detection method according to claim 11 . When it is determined in the determination step that the waveform does not include noise, the buried object detection device detects that the buried object detection device is lifted from the surface of the object and stops the radiation of the electromagnetic wave from the radiation section. further comprising a lifting determination step for performing lifting determination processing;
The buried object detection method according to claim 11 or 12 .

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