JP2008171260A - Remote strain sensor system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a remote strain sensor system more excellent in continuous measurement than in the past for a civil engineering structure or the like. <P>SOLUTION: The remote strain sensor system includes a plurality of sensor devices, and a relay machine controlling information by relaying communications between the plurality of sensor device and a host device. The strain sensor device includes a strain gauge, a bridge circuit for fetching a measurement signal, an A/D converter for converting it to a digital value, and a radio device for transmitting data to a CPU for processing the data, and adapted to be directly fixable to the civil engineering structure or the like through a magnet or adhesive. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a remote strain sensor system.

  Conventionally, strain measurement for civil engineering structures, etc. requires complicated installation of strain gauges, requires high-performance data loggers, etc., and requires specialist engineers to work locally Therefore, it is not used for regular maintenance. Conventionally, a friction gauge disclosed in Non-Patent Document 1 is disclosed as a technique for facilitating strain measurement.

  Further, although not a strain measurement system, a general remote measurement / monitoring system discloses a water supply and gas periodic metering system disclosed in Patent Document 1 and a landslide monitoring system disclosed in Patent Document 2.

    As described in Non-Patent Document 1, the friction-type strain gauge includes a strain gauge part, a soft rubber layer, and a metal plate. When a vertical load is applied to the metal plate, the load is rubber. When the friction is generated between the measurement surface of the strain gauge and the measurement target surface through the layer, and the strain on the measurement target surface is distorted, the rubber layer with a very low elastic modulus is Therefore, the strain gauge can detect the strain.

    The periodic meter-reading system for water and gas in Patent Document 1 includes a headquarters station, a PHS radio device that can communicate with the headquarters station via a PHS base station, and a meter device that can communicate with the PHS radio device. An automatic meter reading system using PHS in which response data of the PHS wireless device is collected by the central station in response to a request signal from the headquarters station. A wireless communication unit that performs wireless communication by intermittent operation, and an activation control unit that activates the wireless communication unit by a PHS incoming signal from the head office.

The landslide monitoring system of Patent Document 2 includes a vibration source that generates vibration, a geophone that measures vibration, and a measurement result analyzer that analyzes the measurement result and outputs the volumetric moisture content.
Tatsuya Koshio, Kentaro Yamada, Yoshiyasu Saito, Masazo Shiina: Development of a stress stethoscope using a frictional strain gauge and its application to structural soundness diagnosis, Summary of the 60th Annual Conference of the Japan Society of Civil Engineers, 6 Department, pp. 255-256, 2005 JP 2002-171355 A JP-A-2005-30843

  However, the conventional friction gauge of Non-Patent Document 1 described above is a technology that simplifies only the mounting of a strain gauge, and the measurement method and the like of a built-in small bridge circuit are the same as before, and the entire measurement is easy. It had the problem of not becoming. In addition, the conventional water and gas periodic meter reading system of Patent Document 1 described above is similar to the system of the present invention in that the sensor unit is battery-driven and maintenance-free, but the measurement frequency is very low once a month, There is a problem that it is difficult to apply to strain measurement that always measures in terms of communication volume and power capacity. Moreover, the landslide monitoring system of Patent Document 2 is a sensor that secures a power supply by a solar cell, and there is no problem in terms of power supply. However, in strain measurement, a sensor is installed on a structure, so It had the problem that installation was difficult.

As a problem to be solved, the present invention provides a remote strain sensor system for a civil engineering structure or the like that is intended to solve the following problems a) to f) that the conventional example has. Yes.
a) In general, in strain measurement, specialized engineers must prepare and measure on-site using expensive measuring equipment.
b) The strain sensor is installed directly on an outdoor civil engineering structure, etc., but environmental resistance such as waterproofness of the entire sensor is not considered.
c) The strain sensor needs to be maintenance-free during the maintenance period of about 5 to 10 years for civil engineering structures such as bridges.
d) The bridge circuit of the sensor unit, A / D converter, CPU, wireless communication device, etc. are independent devices, and the sensor unit is configured by combining them. Since the power of each device is always on, power consumption is large and an external power supply is required.
e) Conventional strain measurement is basically wired for both power and communication lines, and the wiring is complicated, and there is a problem in workability such as the handling and the like.
f) Conventional remote sensors are based on one-way communication from the sensor to the host device, and it is not easy to change the settings of the sensor, etc., so it is not possible to perform agile operation in the event of an abnormality.

The remote strain sensor system of the first invention is:
A plurality of sensor devices, a relay device that communicates and controls the plurality of sensor devices, and a host device that processes and operates data transmitted from the relay device,
The sensor device includes a strain gauge, a bridge circuit and A / D converter for converting strain into a digital value, a CPU for data processing, and a wireless communication device for sending data. It is characterized by that.
The first invention improves the usability and environmental resistance by integrating the sensor device, eliminates the need for communication lines and power lines by internal power supply and wireless communication, and enables operation of the sensor device alone. Points a) to c) can be improved.
By integrating the sensor device and specializing functions, it is possible to use an internal power supply by reducing power consumption, so problems c) and d) can be improved, and the internal power supply can be operated without maintenance for a long time. It becomes. To improve the problem e), sensor device data is transmitted wirelessly. In order to reduce the communication load, the CPU of the sensor unit calculates statistics such as daily maximum values and frequency distribution necessary for maintenance, and accumulates data. As described above, the internal power supply and wireless communication eliminate the need for a communication line and a power line, enable operation of the sensor device alone, and improve the problem e). The repeater communicates with a plurality of sensor devices by wireless communication such as specific power-saving radio and RFID and supervises them, and with the existing communication network such as PHS telephone line and public IP network, Communicate. The repeater organizes information between the sensor device and the host device, and makes it possible to acquire data interactively and in real time by bidirectional communication with the sensor device and the host device in the event of an abnormality.
The remote strain sensor system of the second invention is provided with a vibration sensor as a trigger in the sensor device of the remote strain sensor system of the first invention, and performs measurement only while a load is applied. Can be reduced.

  The effects of the present invention will be described in the following a) to e).

a) By using wireless communication or existing communication network, it is possible to monitor and operate remotely without going to the site.
b) The function-specific integrated sensor eliminates the need for a high-performance data logger, thus reducing costs.
c) Since the sensor device operates independently, maintenance for the sensor device is not required.
d) Use of the sensor unit as an integrated device and elimination of communication lines and power supply lines will dramatically improve on-site usability.
e) Since all operations are performed at the same time on a remote host device, management can be centralized. In addition, since it is managed as digital data on the network, it is easy to share information across regions that are important in the event of a wide-area disaster.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

As shown in FIG. 2, a strain gauge, a bridge circuit and A / D converter for converting strain into a digital value, a CPU for processing data, and a wireless communication device for sending data ( (Slave unit) is integrated to produce a sensor device. As shown in FIG. 1, the sensor device is integrated by communicating with a plurality of the sensor devices produced above and a repeater installed in the vicinity of the measurement point by wireless communication such as specific power-saving radio or RFID. In addition to normal maintenance, real-time and interactive measurement and monitoring are performed in addition to normal maintenance by connecting all the host devices of the management office through two-way communication through existing communication networks such as telephone lines and public IP networks.

  The remote strain sensor system of the present invention can be used for a remote strain sensor system for civil engineering structures and the like.

It is explanatory drawing which showed the structure of the remote strain sensor system of Example 1 typically. It is explanatory drawing which showed typically the element integrated and integrated in the sensor apparatus of the remote strain sensor system of Example 1. FIG.

Claims (4)

A plurality of sensor devices, a relay device that communicates and controls the plurality of sensor devices, and a host device that processes and operates data transmitted from the relay device,
The sensor device includes a strain gauge, a bridge circuit and A / D converter for converting strain into a digital value, a CPU for data processing, and a wireless communication device for sending data. Remote strain sensor system. The remote strain sensor system according to claim 1, wherein the sensor device is provided with a vibration sensor and can perform measurement only while a load is applied. The remote strain sensor system, wherein the sensor device has a structure that can be directly fixed to a civil engineering structure or the like by a magnet or an adhesive. The sensor device is a remote strain sensor system characterized in that wiring work is unnecessary by using an internal power source and wireless communication.