JP2001033561A - Data logger and vibration measurement system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a data logger that can input and output a signal for time correction to the outside, and at the same time, to provide a vibration measurement system that can easily correct the time of other data loggers by one data logger at low costs. SOLUTION: A data logger 1 is a portable recording device being accommodated into a case that is approximately of the size of B5 paper, is connected to a detector 20 for detecting vibration through a cable 40, and records measurement data on vibration (earthquake). Also, a GPS(global positioning system) receiver 3 can be incorporated into the data logger 1. In this case, the time of a clock 14 is corrected based on a time signal in a GPS signal being received by the GPS receiver 3 or the like, and at the same time, the time signal is outputted to other data loggers. Also, when the GPS receiver 3 is not incorporated into the data logger 1, the time signal being outputted from other data loggers is inputted for correcting the time of the clock 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data logger and the like for recording measurement data of vibration related to an earthquake.

[0002]

2. Description of the Related Art A data logger for seismic measurement is a device permanently installed on site together with a detector, and is connected to the detector via a cable. Then, when an electric signal (analog signal) related to the earthquake, that is, the vibration detected by the detector is transmitted to the data logger via the cable, the data logger numerically represents the received analog signal as a vibration value. It is converted into measurement data (digital signal) and recorded as measurement data.

[0003] The data logger used for this earthquake measurement is used not only for measuring naturally occurring earthquakes (hereinafter referred to as natural earthquakes). In plants, factories, construction sites, etc., as a vibration measurement system,
Several to hundreds of detectors and data loggers are installed,
An earthquake (hereinafter, referred to as an artificial earthquake) due to operation of a plant or the like is measured. Conversely, it is also used to immediately stop the operation of a plant or the like when a natural earthquake occurs.

[0004]

However, when a plurality of detectors and data loggers are installed at multiple points to measure a natural earthquake or an artificial earthquake, a problem occurs when an earthquake occurs. Since the data loggers are independent of each other, it is necessary to accurately set and calibrate the clock of each data logger, and to synchronize the data loggers. Incidentally, an error of the measurement time generally required for the earthquake measurement is about 1 microsecond.

To solve this problem, a GPS (Glob)
al Positioning System) It is conceivable to incorporate a receiver into a data logger, extract a time signal from a GPS signal received by a GPS receiver, and accurately calibrate a clock in the data logger.

However, as described above, in a vibration measuring system in a plant or the like, the number of data loggers installed on the premises may be several hundreds. That is, in order for each data logger to have the function of receiving a GPS signal, it is necessary to add a GPS receiver and install a GPS antenna for each data logger, which increases the cost of the entire system. In addition, after the data logger is installed, it is necessary to confirm the reception of the GPS signal for each data logger, and therefore, it is difficult to realize the maintenance in terms of maintenance.

An object of the present invention is to provide a data logger capable of externally inputting and outputting a time calibration signal,
An object of the present invention is to provide a vibration measurement system that can easily and at low cost perform time calibration of another data logger using one data logger.

[0008]

According to the first aspect of the present invention,
In a data logger that records predetermined measurement data relating to vibration in association with the time of an internal clock (for example, clock 14 in FIG. 1), external input means (for example, an input terminal in FIG. 1) that inputs a time signal from outside. IN), input switching means (for example, switch 4 in FIG. 1) for switching the input state of the time signal, and calibration means (for example, CPU 2 in FIG. 1) for calibrating the time of the internal clock based on the time signal. A recording unit (for example, the storage medium 13 of FIG. 1) for recording the measurement data in association with the time of the internal clock calibrated by the calibration unit, and a receiving unit for receiving the time / time signal (For example, the GPS receiver 3 in FIG. 1) can be incorporated, and the input switching means inputs a time signal from the receiving means when the receiving means is incorporated. When the receiving means has not been incorporated so that the switching to input a time signal from said external input means is performed, it is characterized by.

According to the first aspect of the present invention, in a data logger for recording predetermined measurement data relating to vibration in association with the time of an internal clock, the external input means inputs a time signal from outside, The input switching unit switches an input state of the time signal, the calibration unit calibrates the time of the internal clock based on the time signal, and the recording unit corresponds to the time of the internal clock calibrated by the calibration unit. In addition, the measurement data is recorded, and further configured to be able to incorporate a receiving unit that receives the time and time signal,
The input switching means inputs a time signal from the receiving means when the receiving means is incorporated, and inputs a time signal from the external input means when the receiving means is not incorporated. Switching is performed.

Therefore, according to the first aspect of the present invention, when the receiving means is incorporated, for example, G
The PS signal is received by the receiving means, and the time of the internal clock is calibrated. Further, even when the receiving means is not incorporated, since a time signal can be inputted from the outside, the same time calibration can be performed.

According to a second aspect of the present invention, in the data logger according to the first aspect, a clock signal relating to an internal operation is synchronized based on a time signal input by switching by the input switching means. Synchronization means (for example, CPU 2 in FIG. 1) may be further provided.

According to the second aspect of the present invention, since the clock signal relating to the internal operation is synchronized based on the time signal, it is possible to minimize the error in the internal operation of the data logger.

Further, as in the third aspect of the present invention, the data logger according to the first or second aspect may be housed in a portable case.

According to the third aspect of the present invention, the data logger is housed in a portable case, so that the data logger can be easily transported and exchanged. Regardless of the data logger, the application range of the data logger can be expanded.

According to a fourth aspect of the present invention, there is provided an external output means for outputting a time signal received by the receiving means to the outside (for example, the time signal amplifier 5 and the output terminal OU shown in FIG. 1).
A vibration measurement system including a plurality of data loggers according to any one of claims 1 to 3, further comprising: T)
Of the plurality of data loggers, by connecting the external output unit of one data logger to the external input unit of another data logger, Are characterized by using the same time signal.

According to the fourth aspect of the present invention, the plurality of data loggers according to any one of claims 1 to 3, further comprising external output means for outputting the time signal received by said receiving means to the outside. In the vibration measurement system including, out of the plurality of data loggers, the external output means of one data logger, the external input means of another data logger is connected, so in all data loggers The same time signal is used.

Therefore, according to the fourth aspect of the present invention, the data logger can output the time signal to the outside, so that if there is one data logger incorporating the receiving means, the other data loggers can use the receiving means. No need to incorporate. That is, by connecting to a data logger incorporating the receiving means, it is possible to calibrate the internal clock even in a data logger not incorporating the receiving means. Therefore, time calibration in a vibration measurement system including a plurality of data loggers can be realized easily and at low cost.

According to a fifth aspect of the present invention, there is provided an external output means (for example, a time signal amplifier 5 shown in FIG. 4) for outputting a time signal input by switching by the input switching means.
A vibration measurement system (for example, the vibration measurement system 100 ′ in FIG. 5) including the plurality of data loggers according to claim 1, further comprising an output terminal OUT). The same time signal is used in all data loggers by daisy-chain connection in which the external output means and the external input means of each data logger are connected with the data logger at the head.

According to the fifth aspect of the present invention, there is further provided an external output means for outputting a time signal input by switching by the input switching means to the outside.
4. A vibration measuring system including a plurality of data loggers according to any one of claims 1 to 3, wherein the data logger incorporating the receiving means is at the head, and the daisy is connected to the external output means and the external input means of each data logger. Because of the chain connection, the same time signal is used in all data loggers.

Therefore, according to the fifth aspect of the present invention, the data logger can output the time signal to the outside, so that if there is one data logger incorporating the receiving means, the other data logger has the receiving means. No need to incorporate. That is, by connecting to a data logger incorporating the receiving means, it is possible to calibrate the internal clock even in a data logger not incorporating the receiving means. Therefore, time calibration in a vibration measurement system including a plurality of data loggers can be realized easily and at low cost.

Further, since each data logger inputs / outputs a time signal for another data logger, one data logger incorporating receiving means outputs a time signal for all other data loggers. No need to do. Therefore,
Inexpensive amplifiers and the like with low amplification characteristics can be used, the unit price of each data logger can be reduced, and the cost of the entire system can be reduced.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 to 5, an embodiment of a data logger 1 to which the present invention is applied and a vibration measuring system 100 configured by connecting a plurality of data loggers 1 will be described below in detail. Will be described.

First, the configuration will be described. FIG. 1 is a block diagram showing an internal configuration of a data logger 1 to which the present invention is applied.

The data logger 1 is a portable recording device housed in a casing of about B5 size, and is connected via a cable 40 to a detector 20 for detecting vibration.
It is permanently installed on site together with the detector 20. Then, by converting an electrical signal (analog signal) related to vibration transmitted from the detector 20 at all times into measurement data (digital signal) represented by a numerical value as a vibration value, recording of measurement data related to vibration (earthquake) I do. Also, data logger 1 has
The GPS receiver 3 can be built-in. When the GPS receiver 3 is built-in, the time of the clock 14 is calibrated based on the time signal in the GPS signal received by the GPS receiver 3 and the like, and the data is recorded in another data logger. The time signal is output. When the GPS receiver 3 is not built in, the time of the clock 14 is calibrated by inputting a time signal output from another data logger 1.

In FIG. 1, a data logger 1 has a CPU
2, a GPS receiver 3, a switch 4, a time signal amplifier 5, a detection signal amplifier 6, an A / D converter 7,
Input unit 8, display unit 9, ROM 10, RAM 11
, A storage unit 12, a storage medium 13, and a clock 14.

CPU (Central Processing Unit) 2
Is an IPL (Initial Prog) stored in the ROM 10.
ram Loader) program, a recording processing program stored in the storage medium 13, a time calibration processing program, and the like are executed, and the processing results are temporarily stored in a work memory area in the RAM 11 and displayed on the display unit 9. I do.

As a recording process, the CPU 2 executes A /
Measurement data (digital signal) input from the D converter 7
Is output and recorded on the storage medium 13.

The CPU 2 performs a time calibration process as follows:
Based on the time signal input from the switch 4, the clock 1
4 is calibrated, and a clock signal related to the internal operation of the data logger 1 is synchronized based on the one-second pulse of the time signal. The time signal is a signal synchronized with an atomic clock (an error of 1 / 1,000,000 second) transmitted from a GPS satellite, and is one of the GPS signals received by the GPS receiver 3 or the like.

Here, the correlation between the time signal and the clock signal related to the internal operation will be described with reference to FIG.
FIG. 2A is a diagram illustrating a schematic waveform of a one-second pulse of the time signal, and FIG. 2B is a diagram illustrating a schematic waveform of a clock signal related to an internal operation of the data logger 1. In FIG. 2, the time signal is a signal that transitions between the H level and the L level in a one-second cycle, and the L level signal further includes a signal representing time information and the like. The clock signal is a signal related to the internal operation of the data logger 1, and for example,
It is a signal of several MHz to several hundred MHz which is the operating frequency of PU2. In FIG. 2, 5 Hz is used for simplicity.
As shown. In FIG. 2, when the CPU 2 forcibly aligns the rise of the clock signal at the rise of the time signal, the internal operation of the data logger 1, that is, the error relating to the vibration detection and the recording time can be minimized.

The GPS receiver 3 is a function module that can be built in the data logger 1. When built in the data logger 1, the GPS receiver 3 extracts a time signal from a GPS signal received by the GPS antenna 3a. And switch 4
, And the time signal amplifier 5. still,
The GPS received by the GPS receiver 3 may be DGPS (Differential GPS) combining terrestrial waves such as FM broadcasts, and the GPS receiver 3 transmits position information and altitude information based on the received GPS signal. It may be calculated and output.

The switch 4 has a contact INT or a contact EXT
And the switch INT is connected to the fixed contact 4a, the contact INT is connected to the GPS receiver 3, and the contact E
XT is connected to the input terminal IN. When the contact INT is connected to the fixed contact 4a (hereinafter, the connection is referred to as ON, and the connection is not referred to as OFF),
The time signal input from the GPS receiver 3 is
is output to the CPU 2 via a. When the contact EXT is turned ON, a time signal from another data logger input from the input terminal IN is output to the CPU 2.

The switch 4 may be set in advance with the contact EXT turned ON, and the contact INT may be automatically turned ON when the GPS receiver 3 is built-in. In that case, a malfunction due to switching of the switches can be prevented.

The time signal amplifier 5 is an amplifier that amplifies the time signal input from the GPS receiver 3 and outputs the amplified signal to the output terminal OUT.

The input terminal IN is connected to an output terminal OUT of another data logger provided with the GPS receiver 3 via a cable, and is a connection terminal for inputting a time signal from the other data logger. , Is connected via a cable to an input terminal IN of another data logger not provided with the GPS receiver 3 and outputs a time signal to the other data logger.

The detection signal amplifier 6 is an amplifier for amplifying an electric signal which is an analog signal constantly transmitted from the detector 20. The A / D converter 7 converts the amplified electric signal (analog signal) into an analog signal. An A / D converter that converts the vibration value into measurement data, which is a digital signal represented by a numerical value, and outputs the measurement data to the CPU 2.

The input unit 8 is composed of input keys for inputting various set values and the like.
Output to 2. The display unit 9 is an LCD (Liquid Crystal D)
The data logger 1 is configured to display an operation state, a current time, and the like of the data logger 1 input from the CPU 2.

The ROM (Read Only Memory) 10 has a CP
IP executed when U2 starts data logger 1
Stores initial setting values of various processing programs in addition to the L program.

The RAM (Random Access Memory) 11
A buffer area for temporarily storing measurement data constantly input from the detector 20 via the detection signal amplifier 6 and the like, and a work memory area for storing various data relating to various processes such as a time calibration process are formed. I have.

The storage unit 12 has a storage medium 13 for storing a recording processing program, a time calibration processing program, and measurement data. The storage medium 13 is a magnetic or optical storage medium or a semiconductor memory. It is configured. The storage medium 13 is fixedly provided in the storage unit 12 or is detachably mounted.

The clock 14 is composed of a quartz clock or the like having a small error. In the recording processing executed by the CPU 2, the time recorded in association with the measurement data is set to a CP.
Output to U2. The time of the clock 14 is calibrated based on a time signal by a time calibration process executed by the CPU 2.

Next, the operation will be described. First, the operation of the data logger 1 relating to the recording process will be described. Regardless of the occurrence of an earthquake, an electrical signal (analog signal) is constantly transmitted from the detector 20 to the data logger 1, and the data logger 1 converts the received analog signal into a detection signal amplifier 6.
And the A / D converter 7 converts the data into measurement data which is a digital signal. Then, the measured data is C
When input to the PU 2, the CPU 2 stores the measurement data in the storage medium 13. The above is the recording process.

Next, the operation related to the time calibration process will be described. FIG. 3 is a diagram showing a schematic configuration of the vibration measurement system 100. The vibration measurement system 100 is composed of the same n (n is a natural number) data loggers as the data logger 1, and only the data logger 1-1 includes the GPS receiver 3-1. The output terminal OUT-1 of the data logger 1-1 is connected to the input terminals IN of all other data loggers. Also, data logger 1-1
The contact INT is ON only for the switch 4-1.
In other data logger switches, the contact EXT is ON.

In FIG. 3, the data logger 1-1 has a G
The GPS receiver 3-1 extracts a time signal from the GPS signal received by the PS antenna 3a-1, and outputs the time signal to another data logger via the output terminal OUT-1 or the like. Further, the data logger 1-1, based on the time signal,
The time of the internal clock is calibrated, and the clock signal and the time signal relating to the internal operation are synchronized.

On the other hand, in another data logger, the time signal output from the data logger 1-1 is supplied to the input terminal I.
By inputting via N or the like, the time of the internal clock is calibrated, and the clock signal relating to the internal operation and the time signal are synchronized.

Therefore, even a data logger without a built-in GPS receiver can be connected to a data logger with a built-in GPS receiver and perform a time calibration process by externally inputting a time signal.

As described above, the data logger 1 to which the present invention is applied can incorporate the GPS receiver 3.
Because it is configured so that the time signal can be input and output externally,
If there is one data logger with a built-in GPS receiver 3,
Other data loggers do not need to have a built-in GPS receiver. By connecting to a data logger with a built-in GPS receiver, it is possible to calibrate the internal clock. Therefore, time calibration in a vibration measurement system including a plurality of data loggers can be realized easily and at low cost.

It should be noted that the present invention is not limited to the contents of the above embodiment, but can be appropriately changed without departing from the spirit of the present invention.
The configuration in the data logger may be changed so that the connection between the data loggers at 00 becomes a daisy chain. FIG. 4 is a block diagram showing an internal configuration of a data logger 1 ′ which is a modification of the data logger 1.

In FIG. 4, the data logger 1 'has a switch INT having a contact INT connected to the GPS receiver 3, a contact EXT connected to the input terminal IN, and a fixed contact 4a having a CP.
It is connected to U2 and the time signal amplifier 5. Other configurations are the same as those of the data logger 1. FIG. 5 shows a vibration measurement system 100 using the data logger 1 'of FIG.
FIG.

In FIG. 5, a vibration measuring system 100 '
Is the GPS receiver 3-1 'only for the data logger 1-1'
Is built-in. The connection between each data logger is
An output terminal OUT-1 'of the data logger 1-1' is connected to an input terminal IN-2 'of the data logger 1-2',
The output terminal OUT-2 'of the data logger 1-2' is connected to the input terminal of the next data logger to form a daisy chain.

In this case, there is no need for one data logger incorporating a GPS receiver to amplify and output a time signal for all other data loggers. Therefore, it is possible to use an inexpensive time signal amplifier with low amplification characteristics, thereby reducing the unit price of each data logger,
The cost of the entire system can be reduced.

[0051]

According to the first aspect of the present invention, when the receiving means is incorporated, for example, the GPS signal is received by the receiving means, and the time of the internal clock is calibrated.
Further, even when the receiving means is not incorporated, since a time signal can be inputted from the outside, the same time calibration can be performed.

According to the second aspect of the present invention, since the clock signal related to the internal operation is synchronized based on the time signal, it is possible to minimize the error in the internal operation of the data logger.

According to the third aspect of the present invention, since the data logger is housed in a portable case, it can be easily transported and replaced, and the installation area is small because the installation area is small. Regardless, the scope of application of the data logger can be expanded.

According to the fourth aspect of the present invention, since the data logger can output the time signal to the outside, if one data logger incorporating the receiving means is provided, the other data logger is provided with the receiving means. No need to incorporate. That is, by connecting to a data logger incorporating the receiving means, it is possible to calibrate the internal clock even in a data logger not incorporating the receiving means. Therefore, time calibration in a vibration measurement system including a plurality of data loggers can be realized easily and at low cost.

According to the fifth aspect of the invention, similarly to the effect of the fourth aspect of the invention, the time calibration in the vibration measuring system including a plurality of data loggers can be realized easily and at low cost. Also, since each data logger inputs and outputs a time signal for another data logger, one data logger incorporating the receiving means needs to output a time signal for all other data loggers. Absent. Therefore, an inexpensive amplifier or the like having low amplification characteristics can be used, the unit price of each data logger can be reduced, and the cost of the entire system can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an internal configuration of a data logger 1 to which the present invention is applied.

FIG. 2A is a diagram showing a schematic waveform of a one-second pulse of a time signal. FIG. 2B is a diagram illustrating a schematic waveform of a clock signal related to an internal operation of the data logger 1.

FIG. 3 is a vibration measurement system 10 using the data logger 1.
FIG.

FIG. 4 is a block diagram showing an internal configuration of a data logger 1 '.

FIG. 5 is a vibration measurement system 1 using a data logger 1 ′.
The figure which shows the structure of 00 '.

[Explanation of symbols]

 Reference Signs List 1 data logger 2 CPU 3 GPS receiver 4 switch 5 time signal amplifier 6 detection signal amplifier 7 A / D converter 8 input unit 9 display unit 10 ROM 11 RAM 12 storage unit 13 storage medium 14 clock 20 detector 100 vibration Measurement system

Continued on front page F term (reference) 2F070 AA01 BB05 CC03 CC11 DD14 FF02 FF12 FF13 GG07 HH10 2G064 AB02 AB19 BA02 BD02 CC54 CC62 DD18 DD29 5K048 AA06 BA24 DA09 DB01 DC02 DC04 EA01 EA11 EB05 EB11 FB09

Claims (5)

[Claims] 1. A data logger for recording predetermined measurement data relating to vibration in association with the time of an internal clock, an external input means for inputting a time signal from outside, and an input switching means for switching an input state of the time signal. A calibration unit that calibrates the time of the internal clock based on the time signal; and a recording unit that records the measurement data in association with the time of the internal clock calibrated by the calibration unit. A receiving unit for receiving the time / time signal is configured to be incorporated, and the input switching unit inputs a time signal from the receiving unit when the receiving unit is incorporated, and the receiving unit is incorporated. If not, switching is performed to input a time signal from the external input means. 2. The data logger according to claim 1, further comprising a synchronizing means for synchronizing a clock signal relating to an internal operation based on a time signal input by switching by said input switching means. 3. The data logger according to claim 1 or 2,
A data logger characterized by being housed in a portable case. 4. A vibration measurement system including a plurality of data loggers according to claim 1, further comprising external output means for outputting a time signal received by said reception means to outside. By connecting the external output means of one data logger to the external input means of another data logger among the plurality of data loggers, the same time signal is used in all data loggers. Vibration measurement system. 5. The vibration measuring system according to claim 1, further comprising external output means for outputting a time signal inputted by switching by said input switching means to the outside. With the data logger incorporating the receiving means at the head, the same time signal is used in all data loggers by a daisy chain connection connecting the external output means and the external input means of each data logger. Characteristic vibration measurement system.