JP2002168621A - Ground clinometer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ground clinometer capable of transmitting accurate sensor output to an alarming device or a data-fetching device. SOLUTION: This ground clinometer comprises a sensor section 10 which is placed at a position where occurrence of variation, fall or run-off of the ground or land is predicted, and a control section 20 which is connected to the sensor section 10 via a comparatively long cable 30. An alarming/ transmission device 40 or a recorder 50 is connected to the control section 20 at the shortest distance. The sensor section 10 converts a digital signal from a built-in sensor to an analog signal to transmit it to the control section 20 through the cable 30. The control section 20 outputs a prescribed voltage value based on the input signal and generates a detection voltage, which is varied accompanying the sensing of the sensor in the sensor section 10 by centering around the voltage value, and then the control section 20 outputs the detection voltage to the alarming device 40 or the recorder 50.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground inclinometer, and more particularly, to a ground inclinometer in which the output of a sensor for detecting ground fluctuation is input to an alarm device or a recording device without being affected by external noise. It relates to an inclinometer.

[0002]

2. Description of the Related Art FIG. 4 is a perspective view showing a configuration example of a conventional ground inclinometer. Ground 400 where debris flow is expected to occur
At a predetermined position, a ground inclinometer 401 for detecting a change in the horizontal plane of the ground 400 is installed. Ground inclinometer 401
, The alarm device 40 via the cables 402 and 403
4 and the data capturing device 405 are connected. Here, an example is shown in which both the alarm device 404 and the data capturing device 405 are installed, but either one may be used.

The alarm device 404 is provided with a siren 406. When an abnormality occurs in the surface layer of the ground 400, an output voltage is generated from the ground inclinometer 401, and when the value is higher than a certain level, an alarm is issued from the siren 406. Warning to nearby workers and evacuate them. The data acquisition device 405 processes data obtained from the ground inclinometer 401 and converts the data into data of a predetermined timing and transmission format. The data capturing device 405 transmits the converted data to the observation station 408 via the cable 407. The observation station 408 is provided with a transmission facility (not shown) and an antenna 409, and transmits data from the data acquisition device 405 to a management office (not shown) as radio waves.

[0004]

However, the conventional ground inclinometer is a digital output acceleration sensor,
The acceleration is measured from the change in the duty ratio. Therefore, when long-distance transmission is performed with the sensor output as a digital signal, the waveform becomes dull due to the floating capacitance of the transmission line (cable), and an error occurs in the acceleration measurement result. This problem is solved by converting the signal to an analog signal, and has the advantage that the scale factor can be increased as compared with the case of digital output. However, the long-distance transmission of analog signals is susceptible to external noise, and the alarm device 404 does not operate normally or an error occurs in the processing result of the data capturing device 405.

[0005] An object of the present invention is to solve the above-mentioned conventional problems, and to provide a ground inclinometer in which an accurate sensor output is transmitted to an alarm device or a data acquisition device. It is in.

[0006]

In order to achieve the above-mentioned object, a ground inclinometer according to the present invention has a sensor for outputting an electric signal indicating the occurrence of a change, collapse, runoff, etc. of the ground or terrain at an installation location. And a sensor unit for sending a digital signal from the sensor as an analog signal, and a sensor unit that is installed at a location away from the installation location and near an alarm device or a recording device, and connected to the sensor unit by a transmission line. An adjusting unit that sets an analog signal from the sensor unit to a predetermined output reference voltage, and outputs a voltage that changes with the sensitivity of the sensor around the output reference voltage to the alarm device or the recording device. It is provided.

[0007] The sensor may be a two-axis acceleration sensor, and the sensor unit and the adjustment unit may be configured to have outputs of the X axis and the Y axis.

The sensor unit may include a sensor that outputs the received acceleration as a change in the duty ratio, and a conversion adjustment circuit that converts a digital output of the sensor into an analog signal and outputs the analog signal at a predetermined level.

[0009] The adjusting section may include a filter that passes only the signal component from the transmission line, and a voltage adjusting circuit that generates the output reference voltage based on an output signal from the filter.

[0010] The sensor unit and the adjusting unit can receive power supply from the alarm device or the recording device.

According to the present invention configured as described above,
The sensor unit converts an output from the sensor into an analog signal, converts the signal into a predetermined voltage, outputs the signal, and inputs the analog signal to an adjustment unit installed at a remote place via a transmission line. The adjusting unit sets a signal from the sensor unit to a voltage value suitable for processing of the alarm device and the recording device as a predetermined output reference voltage. When the ground changes or collapses occur, the output of the sensor fluctuates, and the voltage value changes around the output reference voltage according to the sensor output. Drive the alarm device from the degree of this change,
Alternatively, the sensor output can be recorded on a recording device.
In this way, the adjustment unit that is susceptible to external noise is separated from the sensor unit and placed near the alarm device or recording device and connected, so that the accurate sensor output that eliminates the effect of external noise can be output to the alarm device or recording device. It can be output to the device.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an external view showing a ground inclinometer according to the present invention. The ground inclinometer according to the present invention includes a sensor unit 1
0, and an adjustment unit 20 connected to the sensor unit 10 by a cable 30. The alarm / transmission device 40 or the recording device 50 is connected to the adjustment unit 20 via a cable 60. Alternatively, both the alarm / transmission device 40 and the recording device 50 are connected.

The sensor unit 10 includes a sensor and a processing circuit for the sensor, and power is supplied from the adjustment unit 20. And
At the installation site, it is fixed to the ground via columns 71 and 72. The adjustment unit 20 includes a circuit for processing the voltage from the sensor unit 10 and outputting the processed voltage to the alarm / transmission device 40 and the recording device 50.

The alarm / transmission device 40 includes a housing 41, a lid 4
2. The sensor unit 10 and the adjustment unit 2 installed in the housing 41
0, a battery 43 for supplying power, an alarm connection unit 44 for connecting a plurality of sensor units 10, a siren 45 that emits an alarm sound, a red rotating light 46, and a siren 45 and a red rotation based on the output of the alarm connection unit 44. Light 46
, And a warning / transmission unit 47 including a transmission circuit for transmitting a warning signal by radio waves. As the battery 43, a rechargeable secondary battery is used, and is periodically replaced or charged by a solar cell (not shown).

The recording device 50 has a housing composed of a main body 51 and a lid 52, and a data logger 53 and a
A battery 54 for supplying power to the data logger 53
Is stored.

The sensor unit 10 is installed on the ground where debris flow is expected to occur, and the alarm / transmission device 40 and the recording device 50 are installed in a safe place away from the sensor unit 10. However, since the signal output from the sensor unit 10 is output in a signal state that is not easily affected by noise, the signal is not affected by noise even when the signal becomes longer. Thus, the cable 30 may be of considerable length (eg, 30-50
m). On the other hand, since the output signal of the adjustment unit 20 is converted into a signal that is easily affected by noise, the cable 60 cannot be lengthened, and needs to be as short as possible (for example, within 1 m).

As described above, the circuit section which is easily affected by noise is collected in the adjusting section 20 and is combined with the alarm / transmitter 40.
And the arrangement near the recording device 50, the output of the sensor 11 can be processed without being affected by noise.

FIG. 2 is a block diagram showing the circuit configuration of the ground inclinometer and alarm / transmission device 40 of FIG. Sensor part 1
0 has a sensor 11 and a conversion adjustment circuit 12. An acceleration sensor is used as the sensor 11. The acceleration sensor uses Newton's principle represented by [force = mass × acceleration], and can measure, for example, +1 G to −1 G. Further, the acceleration sensor can also measure the inclination angle of the ground. A commercially available two-axis type acceleration sensor (for example, ANALOG DEV) is used as the acceleration sensor.
“ADXL202” manufactured by ICES) is used. This two-axis acceleration sensor has a structure in which a two-axis acceleration sensor is mounted on a monolithic IC. As described above, the integration of the sensor and the IC chip allows the size of the device to be reduced. The two-axis acceleration sensor
The acceleration output of each of the X-axis and the Y-axis is output as a voltage indicated by a duty cycle (duty cycle: the ratio of the pulse width to the cycle). From the relative change between the generated pulse width T1 of the duty cycle and one cycle T2, (T1 / T2
The acceleration is calculated as (−0.5) /12.5%. Note that when the duty cycle is 50%, acceleration = 0, and the adjustment to achieve this is performed using a zero-point adjuster (neither is shown) using a reference power supply and a variable resistor. The acceleration sensor can obtain an output voltage not only for a tilt angle but also for a horizontal movement, so that a horizontal landslide or the like can be detected.

The conversion adjustment circuit 12 converts the digital output of the sensor 11 into an analog signal using an RC filter, and adjusts the output to a predetermined voltage level using a differential amplifier and outputs the adjusted signal. As described above, by converting to an analog signal, the output scale factor
(For example, 625 mV / G (G is gravity)).

The adjusting unit 20 includes a filter 21 and a voltage adjusting circuit 22, and the power thereof is supplied from the alarm / transmitter 40 or the battery of the recording device 50. Filter 21
Is an RC filter that mainly removes external noise that has entered from the cable 30. The filter 21 is connected to a voltage adjustment circuit 22 including a differential amplifier. The voltage adjusting circuit 22 amplifies the analog signal from the filter 21 and sets the constant of the differential amplifier (variable resistor) so that, for example, +2.5 V (= output reference voltage) is output at 0 G, for example. ).

When the output scale factor is 625 mV / G, the sensor output is ± 625 mV / 2 ≒ ± 0.315
V. Therefore, when the differential amplifier of the voltage adjustment circuit 22 is set to be centered at +2.5 V, when the sensor output is +1 G, the voltage is + (2.5 + 0.315) V
= +2.815 V, and + (2.5
-0.315) V = + 2.185V. This voltage is sent to the alarm / transmission device 40 or the recording device 50.
In the alarm / transmission device 40, even when detecting -1G, only the + signal may be used to determine whether or not to issue an alarm. Therefore, the absolute value circuit uses | ± 0.315 | = 0.315.
(V) and output.

The alarm / transmission device 40 includes a battery 43, an alarm / connection unit 44, a siren 45,
A red rotating light 46, an alarm / transmission unit 47 and an antenna 48 are provided. The alarm / connection unit 44 includes an input unit (three input units in FIG. 2) to which a plurality of ground inclinometers can be connected, and when the output voltage of the voltage adjustment circuit 22 exceeds a preset threshold, that is, a certain value. When the acceleration is detected, the ON signal is output by exciting a relay (not shown) and closing its contact.

The alarm / transmission unit 47 includes the contact input unit 4
7a and a transmission circuit 47b. Contact input section 47
“a” drives the siren 45 and the red rotating light 46 based on the on / off output of the alarm / connection unit 44. The transmission circuit 47b modulates an ON signal output from the alarm / connection unit 44, performs amplification, frequency conversion, and the like, performs power amplification, and transmits the signal from the antenna 48. The transmitted radio wave is received by a receiver (shown in FIG. 3) possessed by one or more of the workers at the work site. This receiver is provided with a speaker and a vibrator, and emits an alarm sound from the speaker to warn that the sensor has been activated, and at the same time, energizes the vibrator to give a warning by vibration.

FIG. 3 is an overhead view showing an installation example of the ground inclinometer and the alarm / transmission device 40 of the present invention. Sensor unit 10
Is installed on the ground near the area 301 where debris flow is expected to occur, and the adjustment unit 20 and the alarm / transmission device 40 are installed in a safe place. As the installation place of the alarm / transmission device 40, the worker 302 can see the red rotating light 46,
In addition, it is desirable to be at a position where the warning sound from the siren 45 can be heard. The sensor unit 10 and the adjustment unit 20 are connected by a cable 30, and the adjustment unit 20 and the alarm / transmission device 4
0 is connected by a cable 60. Sensor part 1
0 is arranged so that the element is horizontal to the ground. A worker 302 working downstream of an area 301 where debris flow or the like is expected to occur works while wearing the receiver 303 on a waist belt or the like.

Next, the operation of the above configuration will be described. In normal times when debris flow and the like do not occur, the sensor 11 (acceleration sensor) of the sensor unit 10 receives 50%
Is output by the conversion adjustment circuit 12 to be converted into an analog voltage, and then output to the adjustment unit 20 via the cable 30. In the adjusting unit 20, only the signal component is extracted by the filter 21, and the signal is converted into + 2.5V by the voltage adjusting circuit 22. This voltage is sent to the alarm / transmission device 40 and is compared with a threshold value by the alarm / connection unit 44.
However, since +2.5 V is equal to or less than the threshold value, it is turned off (OF
F) A signal is output. Therefore, the above-mentioned relay is not energized and the contact remains off, so that the alarm / transmission unit 47 does not operate, and the siren 45 also emits the red rotating light 46.
Is not driven and no warning is issued. The transmission circuit 47
Since the modulated radio wave is not transmitted from b, the receiver 303 does not operate to issue a warning.

Next, when a debris flow or the like occurs and a shock is applied to the sensor 11 (acceleration sensor) due to the movement of the debris, etc.,
The duty ratio of the output of the sensor 11 is 50 at the time of 0G.
Varies from%. This change appears as a change in the amplitude of the analog signal, and is output from the conversion adjustment circuit 12 to the cable 30. The voltage applied to the voltage adjusting circuit 22 via the filter 21 is equal to the acceleration applied to the sensor 11 by +
It increases and decreases with respect to 2.5V. Therefore, in the alarm / connection unit 44, the output voltage of the voltage adjustment circuit 22 exceeds the threshold value, and the relay is excited to close the contact and output an ON signal. Along with this, a modulated radio wave is transmitted from the transmission circuit 47b,
The receiver 303 possessed by the worker 302 operates and warns by sound and vibration. When the ON signal is output, the contact input portion 47a operates at the same time, so that the siren 45 and the red rotary light 46 are energized, and the siren 4
5 emits an alarm sound, and the red rotating light 46 rotates while blinking. With this alarm, an operator who does not have a receiver can be notified of the occurrence of the abnormality. The worker who knows the alarm can take measures such as evacuating from the site.

When the recording device 50 is connected, the output voltage of the voltage adjusting circuit 22 is applied to perform recording.
Since the data logger 53 can be mounted with an IC card, the measurement results can be stored and stored in the IC card. Therefore, it can be used for later accident investigations and the like.

In the above-described embodiment, the power supply to the sensor unit 10 and the adjusting unit 20 is performed from the alarm / transmission device 40 or the recording device 50. Power may be supplied from this battery. Further, although the adjustment unit 20 is configured to be independent, it may be built in the alarm / transmission device 40 or the recording device 50. And the filter 21
The filter of the conversion adjustment circuit 12 is of the RC type, but may be a filter based on another operation principle. Although a two-axis type acceleration sensor was used for the sensor 11,
The structure is not limited to the axial type, and any structure may be used as long as an event targeted by the present invention can be detected. Further, although the data logger 53 is used as the recording device 50, a notebook personal computer, a pen recorder, or the like can be used instead. In addition, the present invention
Various design changes can be made without departing from the basic technical concept.

[0029]

As described above, according to the ground inclinometer of the present invention, the output from the sensor is converted into an analog signal, and a predetermined voltage is output to the sensor unit. An adjusting unit connected and installed in a safe place is provided, and the adjusting unit sets a signal from the sensor unit to a voltage value suitable for processing of an alarm device and a recording device as a predetermined output reference voltage. So that the final output could be generated just before the alarm or recording device,
Accurate sensor output excluding the influence of external noise or the like can be output to an alarm device or a recording device.

[Brief description of the drawings]

FIG. 1 is an external view showing a ground inclinometer according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a circuit configuration of the ground inclinometer and a connected alarm / transmission device.

FIG. 3 is an overhead view showing an installation example of the ground inclinometer and a connected alarm / transmission device.

FIG. 4 is a perspective view showing a configuration example of a conventional ground inclinometer.

[Explanation of symbols]

 Reference Signs List 10 sensor unit 11 sensor 12 conversion adjustment circuit 20 adjustment unit 21 filter 22 voltage adjustment circuit 30 cable 40 alarm / transmission device 43, 54 battery 45 siren 46 red rotating light 47 alarm / transmission unit 50 recording device

Claims (5)

[Claims] 1. A sensor unit that outputs a change in the ground or terrain at an installation site, such as a change, collapse, or outflow, in the form of an electric signal, and outputs a digital signal from the sensor as an analog signal. It is installed at a location away from the installation location and near an alarm device or a recording device, is connected to the sensor unit by a transmission line, sets an analog signal from the sensor unit to a predetermined output reference voltage, and A ground inclinometer, comprising: an adjusting unit that outputs a voltage that changes in response to the sensitivity of the sensor around a reference voltage to the alarm device or the recording device. 2. The ground inclinometer according to claim 1, wherein the sensor is a two-axis acceleration sensor, and the sensor unit and the adjustment unit have respective outputs of an X axis and a Y axis. 3. The sensor unit according to claim 1, further comprising a sensor that outputs the received acceleration as a change in duty ratio, and a conversion adjustment circuit that converts a digital output of the sensor into an analog signal and outputs the analog signal at a predetermined level. The ground inclinometer according to claim 1 or 2, wherein: 4. The apparatus according to claim 1, wherein the adjusting unit includes a filter that passes only a signal component from the transmission line, and a voltage adjusting circuit that generates the output reference voltage based on an output signal from the filter. The ground inclinometer according to claim 1, wherein 5. The ground inclinometer according to claim 1, wherein the sensor unit and the adjustment unit receive power supply from the alarm device or the recording device.