JP4064164B2 - Filling detection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a filling detection device for detecting a filling state of concrete or mortar into a mold made of, for example, precast concrete.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a method of filling a concrete with a reinforcing bar disposed inside a formwork made of precast concrete (hereinafter referred to as precast concrete formwork) has been adopted for a building structure.
In recent years, the shape of precast concrete formwork has become complex due to diversification of design, etc., and a method that can easily detect whether the concrete is properly filled up to the end of the complex shape by nondestructive inspection is desired. It is rare.
[0003]
Conventionally, for example, Japanese Patent Application Laid-Open No. 7-269120, Japanese Patent Application Laid-Open No. 10-197467 or Japanese Patent No. 2836799 has been disclosed. concrete detects the potential generated when the concrete is in contact is obtained so as to detect that it has been filled in.
[0004]
In addition, as a method different from the above three methods, a thermocouple is placed in a precast concrete formwork, and the concrete filling state is discriminated by temperature change using the difference in specific heat between air and concrete. There are also things.
[0005]
[Problems to be solved by the invention]
By the way, the conventional concrete filling detection method has the following problems.
In other words, the potential between the electrodes installed in the precast concrete formwork is not constant due to the hardness of the water contained in the concrete and the influence of the ambient temperature. .
[0006]
In addition, in a case where the concrete filling state is detected using the difference in specific heat between air and concrete using a thermocouple, the concrete filling state cannot be detected accurately if the temperature difference between the concrete and the temperature is small. In particular, in a building buried in the ocean, the interior is filled with seawater, so detection by a temperature difference is difficult.
[0007]
Also, the difference between mortar and aggregated concrete cannot be identified. This is because the systems currently commercialized both detect filling using the chemical properties of mortar, and the difference between concrete and mortar is the presence or absence of aggregate. This is because it is impossible to distinguish between concrete and mortar unless it can be recognized.
[0008]
The present invention has been made in view of such circumstances, and it is easy to determine the state of filling concrete or mortar into a predetermined space such as a closed space and an open space where filling cannot be easily confirmed visually. An object of the present invention is to provide a filling detection device capable of accurately detecting.
[0009]
[Means for solving the problems]
The filling detection device of the present invention is a filling detection device in which a sensor element for converting electrical energy into mechanical energy is arranged in a mold, and the filling state of the filling in the mold is identified from the frequency characteristics of the sensor element. there, the signal applying means frequency to the sensor element to apply an electrical signal that varies with time, the frequency characteristic detecting means for detecting a frequency characteristic of the sensor element in which the electrical signal is applied, the mold within As the reference data for each filling material filled in, the peak voltage value appearing in the frequency characteristic of the sensor element when each filling material is filled and the frequency range in which the peak voltage value appears are stored, and the reference data In, at least, the reference data of concrete whose peak voltage value is 0 to 2.5 V and the frequency range is 3 to 13.0 kHz, and the peak voltage value is 3.0. Reference data of mortar whose frequency range is 4.5 to 5.5 kHz at 7.0 V, and water whose peak voltage value is 3.0 to 9.0 V and whose frequency range is 5.6 to 6.5 kHz a storage unit that contains the reference data of the frequency characteristic detecting means together determine the peak voltage value by differentiating the frequency characteristics detected is a frequency range in which the peak voltage value has appeared from the frequency characteristic And determining means for comparing the peak voltage value and frequency range with the reference data stored in the storage means to determine the filling state of the filling .
[0012]
According to this configuration, the concrete and mortar and at least the frequency position of each peak voltage value of water are mapped on the frequency characteristics, and the reference data obtained by quantifying the vibration frequency characteristics of the concrete, mortar and water , and the concrete or mortar actually. compared with mapped peak voltage value range of the region and its frequency range of the reference data and the numerical data of the frequency position of the peak voltage value and the peak voltage value of the oscillation frequency characteristic of the sensor element when filled with its Since the filling status of concrete or mortar is judged based on the comparison result, for example, when filling concrete into a formwork of a structure, whether concrete is filled or mortar is filled easily And can be identified accurately.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a filling detection apparatus according to an embodiment of the present invention.
[0020]
In this figure, the filling detection device of the present embodiment includes a synchronization signal generator 1, a variable frequency oscillator 2, an amplifier 3, a piezoelectric speaker (sensor element) 4, a resistor 5, a differential amplifier 6, A quadrant multiplier 7, a low-pass filter 8, a determination unit 9, and a display unit 10 are provided.
[0021]
The synchronization signal generator 1 generates a synchronization signal for repeatedly operating the variable frequency oscillator 2. The variable frequency oscillator 2 generates a sinusoidal electric signal whose frequency continuously changes in a predetermined frequency range (for example, 1 kHz to 20 kHz). In this case, every time a synchronization signal is output from the synchronization signal generator 1, a sine wave signal is repeatedly generated from an initial frequency (for example, 1 kHz). The amplifier 3 amplifies the sine wave signal from the variable frequency oscillator 2 to a level at which the piezoelectric speaker 4 can be driven, and outputs it as an excitation signal Vr. The synchronization signal generator 1, the variable frequency oscillator 2, and the amplifier 3 constitute a signal generation / application unit 20.
[0022]
The piezoelectric speaker 4 uses a piezoelectric element, and converts an electrical signal into a mechanical signal and outputs it. The resistor 5 is inserted in series between the amplifier 3 and the piezoelectric speaker 4, and a voltage corresponding to the current flowing through the piezoelectric speaker 4 is generated at both ends thereof. Since the current flowing through the piezoelectric speaker 4 changes according to the change in frequency, the voltage appearing at both ends of the resistor 5 reflects the frequency characteristics of the piezoelectric speaker 4.
[0023]
The differential amplifier 6 amplifies the voltage across the resistor 5 and outputs a voltage Vi. The 4-quadrant multiplier 7 multiplies the excitation signal Vr and the voltage Vi to remove the influence of noise on these voltages. The low-pass filter 8 outputs a signal (output voltage Vo) obtained by removing cos (2ωt + α + β) described below from the output signal of the 4-quadrant multiplier 7. The resistor 5, the differential amplifier 6, the four quadrant multiplier 7, and the low-pass filter 8 constitute a frequency characteristic detection unit 30.
[0024]
The determination unit 9 determines the filling state of the filler in the precast concrete mold for the piezoelectric speaker 4 from the signal output from the low-pass filter 8, and displays the result (good or bad) on the display unit 10.
[0025]
Here, the operation of the apparatus will be described before the details of the function of the determination unit 9 are described. The sine wave signal generated by the variable frequency oscillator 2 is amplified by the amplifier 3 and then applied to the piezoelectric speaker 4 as the excitation voltage Vr. When the excitation voltage Vr is applied to the piezoelectric speaker 4, mechanical vibration is generated in the piezoelectric speaker 4, and a voltage corresponding to the current flowing through the piezoelectric speaker 4 is generated in the resistor 5.
[0026]
This voltage is amplified by the differential amplifier 6 to obtain the voltage Vi, and the voltage Vi is input to the 4-quadrant multiplier 7. On the other hand, since the excitation voltage Vr is also input to the four-quadrant multiplier 7, the excitation voltage Vr and the voltage Vi from the differential amplifier 6 are multiplied to remove noise from these voltages. . The cos (2ωt + α + β) component is removed from the output signal from the 4-quadrant multiplier 7 from which noise has been removed by the low-pass filter 8 to obtain the output voltage Vo.
[0027]
This output signal Vo is a signal reflecting the frequency characteristics (amplitude and phase) of the piezoelectric speaker 4 with respect to the frequency change of the excitation voltage Vr. At this time, if the filler is not in contact with the surface of the piezoelectric speaker 4, a voltage having a peak at a frequency near the natural frequency of the piezoelectric speaker 4 appears as shown in FIG. 2 (9.7 kHz, 6 .5V peak point). On the other hand, when concrete is filled around the piezoelectric speaker 4, for example, as shown in FIG. 3, the vibration characteristics of the piezoelectric speaker 4 change and the position and magnitude of the peak voltage change (3.4kHz). , 2.3V peak point). That is, there is almost no peak voltage.
[0028]
This is concrete in which mortar (cement + sand + water) and coarse aggregate are mixed, and when the coarse aggregate contacts the piezoelectric speaker 4, a flat waveform without a peak voltage is obtained. When the mortar without coarse aggregate is contacted, the peak voltage shifts to a low frequency region as shown in FIG. 4, and the value is lowered (peak point of 4.7 kHz, 3.7 V). The determination unit 9 determines the concrete filling state from the change in the peak voltage, and displays the result on the display unit 10. As a result, the user can easily determine the concrete filling. FIG. 5 shows a state of filling concrete in a space such as a precast concrete formwork. Reference numeral 40 is coarse aggregate, 41 is mortar, and 42 is a control panel.
[0029]
Next, the operation principle will be described using mathematical expressions.
Here, it is assumed that Vr = Asin (ωt + α) and Vi = Bsin (ωt + β). However, A and B are amplitudes, ωt is a frequency, and α and β are phase shifts.
Vr × Vi = Asin (ωt + α) × Bsin (ωt + β)
= AB [cos (β-α) -cos (2ωt + α + β)] / 2 (1)
[0030]
The part of cos (β−α) in the equation (1) is a direct current component that changes in accordance with the phase difference, and includes the amplitude component of the voltage Vi. The portion of cos (2ωt + α + β) is a signal having a frequency twice that of the original excitation voltage Vr and voltage Vi. Since the necessary frequency characteristic information is the amplitude (magnitude) of the voltage Vi, only cos (β−α) in the equation (1) is sufficient. Therefore, the component of cos (2ωt + α + β) may be removed by passing through the low-pass filter 8. In this way, frequency characteristics appear in the form of voltage in the output voltage Vo.
[0031]
As shown in FIGS. 2 and 3, when concrete is filled in a space such as a precast concrete formwork, the situation can be detected by changing the peak frequency and level.
[0032]
Next, details of the determination unit 9 will be described.
FIG. 6 is a block diagram illustrating the configuration of the determination unit 9. As shown in this figure, the determination unit 9 includes an A / D (Analog to Digital) conversion unit 11, a control unit 13, a calculation unit 12, a storage unit 14, and a determination output unit 15. The The A / D converter 11 digitally converts the output voltage Vo from the low-pass filter 8. The control unit 13 outputs a control signal for controlling the frequency of the variable frequency oscillator 2 of the signal generating / applying means 20.
[0033]
The calculation unit 12 outputs the output voltage Vo output from the frequency characteristic detection unit 30 and digitally converted by the A / D conversion unit 11 in synchronization with the change timing (frequency change (sweep)) of the control signal output from the control unit 13. Are stored in the storage unit 14. Thereby, the output voltage Vo showing the frequency characteristic of the filling is obtained as digital data. In this case, since the data accumulated in the storage unit 14 includes a noise component as it is, the calculation unit 12 obtains a moving average in the data series, removes the noise, and prevents erroneous detection of peak points.
[0034]
In addition, the calculation unit 12 obtains a peak voltage within the data series of the output voltage Vo accumulated in the storage unit 14. The frequency position of the peak voltage value can be obtained from the accumulation position (address) of the peak voltage value. Further, when obtaining the peak voltage value, a data search range effective for determination is narrowed down. That is, window processing is performed. By performing this process, the influence of unnecessary data can be avoided and the processing speed can be improved. In addition, the peak point search method is not a simple magnitude comparison, but a point where the slope changes from positive to negative is detected from the differentiation of the preceding and following values, and the values are compared. By performing this differentiation process, the peak point can be detected with high accuracy.
[0035]
The determination output unit 15 compares the peak point numerical data detected by the calculation unit 12 with the reference data of the peak point shown in FIG. 7 in the peak voltage value range and the frequency range of the reference data mapping region. The filling to be performed is determined quantitatively. FIG. 7 shows the mapping of the peak voltage value and the frequency position of the peak voltage value on the frequency characteristics for each substance (reference data). In the case of concrete, the peak voltage value is 0 to 2.5 V, and the frequency position of the peak voltage value is 3 to 13.0 kHz. In the case of mortar, the peak voltage value is 3.0 to 7.0 V, and the frequency position of the peak voltage value is 4.5 to 5.5 kHz. In the case of water, the peak voltage value is 3.0 to 9.0 V, and the frequency position of the peak voltage value is 5.6 to 6.5 kHz. In the case of air, the peak voltage value is 3.0 to 9.0 V, and the frequency position of the peak voltage value is 9.0 to 11.0 kHz.
[0036]
A numerical map (reference data) indicating frequency characteristics for each filling constituent material is stored in the memory 14 </ b> A of the storage unit 14. The determination result is input to the display unit 10 and visually displayed on a display such as an LCD (liquid crystal display). As the memory 14A, a semiconductor memory such as a ROM (Read Only Memory) and an EPROM (Erasable and Programmable ROM) can be used. Further, the reference data may be read from the outside. For example, FD (Floppy Disk) and CDROM are mentioned. Further, the reference data may be read through a telecommunication line such as the Internet.
[0037]
Next, the operation of the filling detection apparatus having the above configuration will be described with reference to the flowcharts shown in FIGS.
(Filling judgment process)
First, data is acquired (step 10), and then noise removal processing (moving average processing) is performed (step 12). After removing the noise, differentiation processing is performed to detect the peak voltage value and the frequency position of the peak voltage value (step 14). After detecting the peak voltage value and the frequency position of the peak voltage value, a filling determination process (mapping comparison process) is performed (step 16).
[0038]
(Mapping comparison process)
When the process proceeds to the mapping comparison process, it is first determined whether or not the sensor (piezoelectric speaker 4) is connected (step 30). In this determination, if the sensor is not connected, the mapping comparison process is canceled as the sensor is not connected, and the process exits (step 32). On the other hand, when the sensor is connected, the process proceeds to step 34, and it is determined whether or not the peak voltage value detected at the present time is within the concrete determination region.
[0039]
In this determination, if the peak voltage value is within the concrete determination region, it is determined as concrete at step 36 and a message to that effect is displayed on the display unit 10, and if not within the concrete determination region, the process proceeds to step 38 and within the mortar determination region. Determine whether or not. In this determination, if it is within the mortar determination region, it is determined as mortar in step 40 and the fact is displayed on the display unit 10, and if not within the mortar determination region, the process proceeds to step 42 to determine whether it is within the water determination region. To do.
[0040]
In this determination, if it is within the water determination area, it is determined as water in step 44 and the fact is displayed on the display unit 10. If it is not within the water determination area, the process proceeds to step 46 to determine whether it is within the air determination area. To do. In this determination, if it is within the air determination region, it is determined as air in step 48 and the fact is displayed on the display unit 10, and if it is not within the air determination region, the process proceeds to step 50, and it is determined that it is out of the determination. Is displayed on the display unit 10. After performing the processing of step 48 or step 50, the present processing is exited.
[0041]
As described above, according to the present embodiment, reference data in which the vibration frequency characteristics of the constituent materials of the filler to be filled in the precast concrete mold are numerically prepared is prepared, and this reference data and the actual filling are prepared. Compared with numerical data of vibration frequency characteristics at the time, and the filling status in the precast concrete formwork is judged based on the comparison result, so when filling the precast concrete formwork with concrete In addition, whether the concrete is filled or the mortar is filled can be easily and accurately identified.
Further, by using the piezoelectric speaker 4 as a sensor element, an inexpensive filling detection device can be realized.
[0042]
In the above embodiment, a single sensor element is used. However, a plurality of substances may be used simultaneously so that a plurality of substances can be determined.
In the above embodiment, a sine wave having a single frequency range is used. However, a frequency range switch (not shown) for switching the frequency range is provided to selectively select a sine wave having a plurality of frequency ranges. You may be able to do it. In this case, the variable frequency oscillator 2 has a function of repeatedly generating a sine wave signal in the frequency band in the range switched by the frequency range switch. In this way, by selecting sine waves in multiple frequency ranges, the optimum frequency range for measurement can be selected according to the physical characteristics such as the structure and material of the precast concrete formwork. This allows for more accurate measurements.
[0043]
In each of the above embodiments, detection of the state of filling in a closed space such as a precast concrete formwork of concrete has been described. However, the state of filling into a formwork made of other wooden formwork or steel material is described. Needless to say, it can be used for detection and the like.
[0044]
【The invention's effect】
According to the filling detection apparatus of the present invention, the reference data obtained by quantifying the vibration frequency characteristics of the concrete, mortar, and water in which the frequency position of each peak voltage value of the concrete, mortar, and water is mapped on the frequency characteristics is stored in the memory. were allowed stored, and mapping the reference data and the numerical data of the frequency position of the peak voltage value and the peak voltage value of the oscillation frequency characteristic of the sensor element at the time of actually filled with concrete or mortar and the reference data area In comparison with the peak voltage value range and the frequency range, the concrete or mortar filling status in the mold is determined based on the comparison result. For example, when filling concrete into the structure mold, Whether it is filled with mortar, etc. It can be and accurately identified.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a filling detection apparatus according to an embodiment of the present invention.
FIG. 2 is a diagram showing an example of a measurement result obtained by the filling detection apparatus of FIG. 1, and is an output voltage waveform diagram when there is no concrete in the precast concrete formwork.
FIG. 3 is a diagram showing an example of a measurement result obtained by the filling detection apparatus of FIG. 1, and is an output voltage waveform diagram when concrete is present in a precast concrete formwork.
4 is a diagram showing an example of a measurement result obtained by the filling detection apparatus of FIG. 1, and is an output voltage waveform diagram when mortar is present in a precast concrete formwork. FIG.
FIG. 5 is a view showing a state of filling concrete in a precast concrete formwork, and is a view when a coarse aggregate is not in contact with a piezoelectric speaker.
6 is a block diagram illustrating a configuration of a determination unit of the filling detection device of FIG. 1;
7 is a diagram illustrating an example of digital data used in the determination unit of FIG. 6;
FIG. 8 is a flowchart showing a filling determination process of the filling detection device of FIG. 1;
9 is a flowchart showing a mapping comparison process during the filling determination process of FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Synchronous signal generator 2 Variable frequency oscillator 3 Amplifier 4 Piezoelectric speaker 5 Resistance 6 Differential amplifier 7 4 Quadrant multiplier 8 Low pass filter 9 Determination part 10 Display part 11 A / D conversion part 12 Operation part 13 Control part 14 Storage part 14A Memory 15 Determination output unit 15A Memory 20 Signal generation / application means 30 Frequency characteristic detection means 40 Coarse aggregate 41 Mortar 42 Control panel

Claims (1)

A sensor device for converting electrical energy into mechanical energy is disposed in a mold, and a filling detection device for identifying a filling state of a filling in the mold from a frequency characteristic of the sensor element,
A signal applying means for applying an electrical signal whose frequency changes over time to the sensor element;
A frequency characteristic detection means for detecting a frequency characteristic of the sensor element in which the electrical signal is applied,
As reference data for each filling filled in the mold, the peak voltage value appearing in the frequency characteristics of the sensor element when each filling is filled and the frequency range in which the peak voltage value appears are stored, Among the reference data, at least the peak voltage value of 0 to 2.5 V and the concrete reference data of the frequency range of 3 to 13.0 kHz, and the peak voltage value of 3.0 to 7.0 V Reference data of mortar whose frequency range is 4.5 to 5.5 kHz, and reference data of water whose peak voltage value is 3.0 to 9.0 V and whose frequency range is 5.6 to 6.5 kHz A storage means including :
The frequency characteristic detected by the frequency characteristic detection means is differentiated to obtain a peak voltage value, a frequency range in which the peak voltage value appears is obtained from the frequency characteristic, and the peak voltage value and frequency range and the storage means are obtained. Determining means for comparing the reference data stored in to determine the filling state of the filling,
Filling detection device characterized by comprising a.

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