JP6137678B2 - Strain measuring device - Google Patents

Description

  The present invention relates to a strain measuring device, and more particularly, a strain sensor having a remote sensing function among strain sensors composed of a bridge circuit formed of strain gauges or a strain sensor having an information storage medium storing strain sensor information. In any case, the present invention relates to a strain measuring apparatus that is used in connection.

Conventionally, a strain measurement system has a strain sensor composed of a bridge circuit formed of a strain gauge for detecting a physical quantity and converting it into an electrical signal, and a strain for signal processing of the electrical signal output from the strain sensor. Measuring equipment such as an amplifier is required. At this time, as a connector for connecting the strain sensor and the measuring device, a 7-pin connector defined in the standard is often used from the viewpoint of reliability and versatility.
Five of the terminal configurations of the 7-pin connector are used for application of bridge power to the strain sensor, for bridge output from the strain sensor, and for shielding. The remaining two of the 7-pin connector terminals are allocated for bridge voltage detection for remote sensing or for information storage media such as TEDS in which information related to strain sensors is stored. Since the configuration of the terminals of the 7-pin connector is defined by the standard, it is also used in many sensors.
In strain measurement, a remote sensing function may be used to perform measurement that requires high accuracy. The remote sensing function is a function that can stabilize the bridge voltage by correcting an error due to the influence of a cable conductor resistance, ambient temperature change, and the like.

A strain sensor having a remote sensing function using a 7-pin connector is shown in FIG. The sensor body 11 shown in FIG. 6 has a strain bridge 12 composed of a Wheatstone bridge circuit composed of four strain gauges 12a, 12b, 12c and 12d. The bridge circuit of the strain bridge 12 includes six cable terminals 13 and is connected to a sensor-side connector 15 that is a 7-pin connector. Sensor side connector terminals 15a and 15c are positive and negative bridge power supply terminals, sensor side connector terminals 15b and 15d are negative and positive side bridge output terminals, sensor side connector terminal 15e is a cable shield terminal, sensor side Connector terminals 15f and 15g are assigned as positive and negative shared terminals. The sensor-side connector terminal 15e is connected to the shield wire 14.
In the figure, 31a, 31b, 31c, 31d, 31f, and 31e represent cable resistances, which are collectively referred to as a cable resistance 31.
In recent years, a function of electronically storing information related to a strain sensor called TEDS (Transducer Electronic Data Sheet) and having the information stored in the strain sensor can be read by a TEDS-compatible measuring device. With this function, it is possible to perform appropriate measurement without manual setting input, and there are advantages such as shortening the time required for inputting calibration values and preventing erroneous input.

Next, a strain sensor having a TEDS function using a 7-pin connector is shown in FIG. The sensor body 11 shown in FIG. 7 has the same assignment with respect to the sensor body 11 having the remote sensing function shown in FIG. 6 and the cable terminals 13a to 13d, but the cable terminals 13f and 13g have strain bridges. 12 and is connected to both ends of the TEDS 16 and the sensor-side connectors 15f and 15g.
As described above, since the remote sensing function and the TEDS function have their respective advantages, a strain measuring apparatus corresponding to both functions is desired.
The applicant first measures physical quantities or mechanical quantities such as strain, displacement, acceleration, torque, etc. of the measurement object, and enables reading of information stored in an information storage medium such as TEDS. In addition, the number of wires required for connection to the measuring instrument can be maintained at the same prescribed number as before and the cost can be reduced as much as possible, and the strain measuring device using the sensor body The present invention is filed as Japanese Patent Application No. 2005-373559, which is disclosed in Japanese Patent Application Laid-Open No. 2007-179107 (Patent Document 1).

More specifically, in Patent Document 1, as a sensor body, a strain sensor composed of a Wheatstone bridge circuit formed of a strain gauge and an information storage medium capable of reading and writing information on the strain sensor are integrated or in the vicinity. A sensor body arranged in
An analog signal according to the physical quantity to be measured output from the strain sensor and a digital signal output according to the information stored in the information storage medium are selectively output to two common output terminals. A mode switching circuit for causing
Two input terminals for supplying bridge power to the Wheatstone bridge circuit;
The output terminal of the Wheatstone bridge circuit and the output terminal of the information storage medium are provided with the two output terminals connected in common.

And as a strain measuring device of patent documents 1,
A strain measuring device using the sensor body, a bridge power supply for supplying a bridge voltage to the input terminal,
An input switch interposed between the input terminal and the bridge power supply;
A pair of differential amplifiers for detecting a difference in output of the bridge circuit;
An output switch interposed between the differential amplifier and the output terminal;
A negative potential supply switch that selectively supplies a negative potential lower than the ground potential to the positive output terminal;
Reading means for reading information stored in the information storage medium;
A reading switch interposed between the reading means and the positive side of the output terminal;
A grounding switch for selectively grounding the negative side of the output terminal;
It has.

JP 2007-179107 A

The strain measuring apparatus according to Patent Document 1 described above measures the physical quantity to be measured and the mechanical quantity without increasing the number of wires (number of cores) necessary for connection between the sensor body and the strain measuring apparatus, and TEDS. It is possible to read the information stored in the information storage medium such as TEDS, etc., especially in the state where the strain sensor having the remote sensing function is used as it is with the specified number of wires (usually 7). The information stored in the storage medium can be read and written.
However, in the strain measuring device according to Patent Document 1, a strain sensor formed of a Wheatstone bridge circuit formed of a strain gauge and an information storage medium capable of reading and writing information on the strain sensor are disposed integrally or in the vicinity. It is a strain measurement device using the sensor body, and even if either a strain sensor with a remote sensing function or a strain sensor without a remote sensing function is connected to the strain measurement device, the difference cannot be determined. .
In addition, there is a disadvantage that it cannot be applied to strain sensors other than a dedicated strain sensor in which an information storage medium as described above is incorporated.

That is, when a strain sensor other than the above-described dedicated strain sensor is used, the sensor having the remote sensing function or the TEDS function shown in FIG. 6 or 7 is connected to the positive side common terminal 17f and the negative side common terminal. It will be connected to 17g.
Therefore, the current strain measuring apparatus corresponding to both functions requires switching of the circuit inside the strain measuring apparatus in order to correspond to each function. At this time, since it is necessary to select a function in advance in order to match the function of the sensor, it takes time to set the function. Further, in the strain measuring apparatus, there is a risk of failure of TEDS due to erroneous connection of a sensor having a TEDS function when setting the remote sensing function.
The present invention has been made in view of the above-described circumstances, and the first object thereof is to increase the number of wires (number of cores) necessary for connection between the strain sensor and the strain measuring device, The connector specified in the standard can be used, and it is always possible to detect whether the strain sensor connected to the input has a remote sensing function, and the remote sensing function can be automatically enabled or disabled. It is in providing a strain measuring device.

  In addition, the second object of the present invention is that a connector specified in the standard can be used without increasing the number of wires (number of cores) necessary for connection between the strain sensor and the strain measuring device, Determines whether the strain sensor connected to the input has a remote sensing function and a function for reading information from an information storage medium, and automatically enables or disables the remote sensing function. Another object of the present invention is to provide a strain measuring apparatus that automatically disables the remote sensing function when a strain sensor having an information storage medium is connected to an input, and enables reading of data from the information storage medium.

In order to achieve the first object described above, the strain measuring device according to claim 1 is a device-side connector for connecting to a sensor-side connector of a strain bridge, a bridge power source, and a bridge voltage from the bridge power source. Bridge voltage supply means for receiving a supply and supplying a bridge voltage to a bridge power supply terminal of the device-side connector , and receiving a bridge output detected by the strain bridge via the bridge output terminal of the device-side connector A strain amplifier, and
In a strain measuring device comprising:
Reading means for reading data from the information storage medium, a reading switch interposed between the reading means and the common terminal of the device-side connector, and an insertion between the bridge voltage supply means and the common terminal Correction switch
Control means for controlling the correction switch and the reading switch;
With
The control means, can with the strain sensor with remote sensing is connected to the device side connector, wherein the enable correction switch with remote sensing function by controlling the read switch, the sensor having a remote sensing function is removed In this case, the remote sensing function is disabled.

Moreover, in order to achieve the second object described above, the strain measuring device according to claim 2 is a device-side connector for connecting to the sensor-side connector of the strain bridge;
Bridge power supply,
Bridge voltage supply means for receiving a bridge voltage from the bridge power source and supplying a bridge voltage to a bridge power terminal of the device-side connector;
In a strain measuring apparatus comprising: a strain amplifier that receives a bridge output detected by the strain bridge via a bridge output terminal of the device-side connector and performs signal processing;
An information storage medium in which information about the sensor is stored;
Reading means for reading data from the information storage medium, a reading switch interposed between the reading means and the common terminal of the apparatus-side connector, and between the bridge voltage supply means and the common terminal A correction switch to be inserted,
Control means for controlling the correction switch and the reading switch;
With
When the strain sensor having a remote sensing function is connected to the device-side connector, the control means turns on the correction switch, turns off the reading switch, and activates the remote sensing function.
When a strain sensor not having a remote sensing function is connected to the device-side connector, and the information storage medium is connected to a common terminal of the device-side connector,
The correction switch is turned off, the reading switch is turned on, the remote sensing function is disabled, and the data stored in the information storage medium can be read by the reading means via the reading switch. It is said.

Further, in the strain measuring device according to claim 3, the bridge voltage supply unit includes:
A first operational amplifier having an output terminal connected to a positive bridge power supply terminal of the apparatus side connector, and having a positive terminal connected to a positive electrode of the bridge power supply; an output terminal of the first operational amplifier; A first feedback resistor interposed between the negative terminal of the first operational amplifier and an output terminal connected to the negative bridge power supply terminal of the device-side connector and connected to the negative electrode of the bridge power supply A voltage follower circuit having a second operational amplifier having a positive terminal and a second feedback resistor interposed between the output terminal of the second operational amplifier and the negative terminal of the second operational amplifier. It is characterized by.
The strain measuring device according to claim 4, wherein the control means includes an input line connected to the shield terminal of the device-side connector via a grounding resistor and connected to the positive-side common terminal. Receiving the output of the first comparator and the output of the second comparator having an input line connected to the output terminal of the first operational amplifier, and controlling the correction switch and the reading switch. It is a feature.

The strain measuring apparatus according to claim 5, wherein the reading means is controlled by the control means when the information storage medium is connected to the positive side common terminal and the negative side common terminal, and the read switch is turned on. age,
The positive-side shared terminal is connected to a reading line, and the negative-side shared terminal is connected to a reference potential so that data can be read from the information storage medium.
The strain measurement apparatus according to claim 6, wherein the device-side connector includes the positive-side bridge power supply terminal, the negative-side bridge power supply terminal, a positive-side bridge output terminal, a negative-side bridge output terminal, It is a 7-pin connector of a shield terminal, the positive side common terminal, and the negative side common terminal.
The strain measuring apparatus according to claim 7 is characterized in that the information storage medium is TEDS (abbreviation of Transducer Electronic Data Sheet) in which information of the sensor is digitized and stored in the sensor. .

According to the invention described in claim 1, and a device connector for connecting to the sensor connector of the strain bridge, and the bridge power supply, receives the supply of the bridge voltage from the bridge power supply, a bridge power supply terminal of the device-side connector A bridge voltage supply means for supplying a bridge voltage to the distortion amplifier, a distortion amplifier that receives the bridge output detected by the distortion bridge via the bridge output terminal of the device-side connector and performs signal processing;
In a strain measuring device comprising:
Reading means for reading data from the information storage medium, a reading switch interposed between the reading means and the common terminal of the device-side connector, and an insertion between the bridge voltage supply means and the common terminal Correction switch
Control means for controlling the correction switch and the reading switch;
With
The control means, can with the strain sensor with remote sensing is connected to the device side connector, wherein the enable correction switch with remote sensing function by controlling the read switch, the sensor having a remote sensing function is removed Since the remote sensing function is disabled, the number of wires required for connection between the strain sensor and the strain measuring device is not increased, and the specified in the standard with high reliability and versatility. A connector with a pin count can be used, and when a strain sensor connected to the input has a remote sensing function, the remote sensing function is enabled and the internal circuit is automatically switched. To select the function manually according to the function of the strain sensor connected to the input. The not required, to reduce the labor required for setting, it is possible to eliminate an erroneous operation.

Moreover, according to the invention of Claim 2, the apparatus side connector for connecting to the sensor side connector of a strain bridge,
Bridge power supply,
Bridge voltage supply means for receiving a bridge voltage from the bridge power source and supplying a bridge voltage to a bridge power terminal of the device-side connector;
In a strain measuring apparatus comprising: a strain amplifier that receives a bridge output detected by the strain bridge via a bridge output terminal of the device-side connector and performs signal processing;
An information storage medium in which information about the sensor is stored;
Reading means for reading data from the information storage medium, a reading switch interposed between the reading means and the common terminal of the apparatus-side connector, and between the bridge voltage supply means and the common terminal A correction switch to be inserted,
Control means for controlling the correction switch and the reading switch;
With
When the strain sensor having a remote sensing function is connected to the device-side connector, the control means turns on the correction switch, turns off the reading switch, and activates the remote sensing function.
When a strain sensor not having a remote sensing function is connected to the device-side connector, and the information storage medium is connected to a common terminal of the device-side connector,
Since the correction switch is turned off, the reading switch is turned on, the remote sensing function is disabled, and the data stored in the information storage medium can be read by the reading means via the reading switch. Without increasing the number of wires required to connect the sensor to the strain measuring device, a connector with a specified number of pins specified in a highly reliable and versatile standard can be used, and the strain connected to the input A strain sensor having an information storage medium that automatically determines whether the sensor has a remote sensing function or an information storage medium, and can automatically enable or disable the remote sensing function. When the is connected to the input, the remote sensing function is automatically disabled and As enabling data read, the failure of the information storage medium according to both erroneous input when save labor to select the function manual as required can be prevented.

It is a circuit diagram which shows the circuit structure of the distortion | strain measuring apparatus which concerns on the 1st Embodiment of this invention. 6 is a circuit diagram showing a configuration of a strain measurement system according to a second embodiment in a state where a strain sensor having a remote sensing function shown in FIG. 6 is connected to the strain measurement device according to the first embodiment shown in FIG. is there. FIG. 8 is a circuit diagram illustrating a configuration of a strain measurement system according to a third embodiment in a state where a strain sensor having a TEDS function illustrated in FIG. 7 is connected to the strain measurement apparatus according to the first embodiment illustrated in FIG. 1. . It is a flowchart which shows the switching operation in the case where the distortion | strain sensor which has a remote sensing function is connected to the distortion | strain measuring apparatus based on this invention, and when it removes. It is a flowchart which shows the switching operation in the case where the distortion | strain sensor which has a TEDS function is connected to the distortion | strain measuring apparatus which concerns on this invention, and when it removes. It is a circuit diagram which shows the circuit structure of the strain sensor which has a remote sensing function. It is a circuit diagram which shows the circuit structure of the strain sensor which has a TEDS function.

Hereinafter, embodiments of a strain measuring device and a strain measuring system of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a circuit diagram showing a circuit configuration of a strain measuring apparatus according to the first embodiment of the present invention.
FIG. 2 shows a strain measurement system according to the second embodiment in a state where the strain sensor having the remote sensing function shown in FIG. 6 is connected to the strain measurement apparatus according to the first embodiment shown in FIG. FIG. 3 is a circuit diagram showing a circuit configuration. FIG. 3 shows a third example in which a strain sensor having a TEDS function shown in FIG. 7 is connected to the strain measuring apparatus according to the first embodiment of the invention shown in FIG. It is a circuit diagram which shows the circuit structure which concerns on the distortion | strain measurement system which concerns on embodiment.
First, the configuration of the strain measuring apparatus according to the first embodiment of the present invention will be described with reference to FIG.
A device-side connector 17 shown in FIG. 1 is a 7-pin connector of a strain measuring device, and 17a to 17g in the drawing are device-side connector terminals. More specifically, the device side connector terminals 17a and 17c are a positive side bridge power supply terminal and a negative side bridge power supply terminal. The device side connector terminals 17b and 17d are a negative side bridge output terminal and a positive side bridge output terminal.

  The device side connector terminal 17e is a shield terminal. The device-side connector terminals 17f and 17g are voltage detection terminals used for the remote sensing function or reading terminals used for the TEDS function, and are a positive-side shared terminal and a negative-side shared terminal used for both functions. The first operational amplifier 21 forms a voltage follower with the first feedback resistor 18 and applies the same voltage as the voltage source 28 as a bridge power supply to the device-side connector terminal 17a. The second operational amplifier 22 forms a voltage follower with the second feedback resistor 19 and applies a negative voltage of the voltage source 28 to the device-side connector terminal 17c. The component that supplies the bridge voltage to the bridge power supply terminal is referred to as bridge voltage supply means. The device side connector terminals 17b and 17d detect the negative side bridge output signal and the positive side bridge output signal from the strain sensor. The detected output signal is processed by the distortion amplifier 32. The device-side connector terminal 17e is grounded to the reference potential 29. The device side connector terminals 17f and 17g are a positive side common terminal and a negative side common terminal used for the remote sensing function and the TEDS function. The CPU 27 has five signal lines 27a to 27e. The first comparator 25 and the second comparator 26 have input lines 25a and 26a, respectively, and are connected to the device side connector terminals 17f and 17a. The first comparator 25 operates when it is detected that the voltage of the input line 25a is equal to or higher than the first predetermined voltage. When the first comparator 25 operates, the first comparator 25 instructs the CPU 27 to enable the remote sensing function via the signal line 27b.

  Upon receiving this command, the CPU 27 controls the correction switch 23 to be turned on from the signal line 27a. The second comparator 26 operates when it is detected that the voltage of the input line 26a is equal to or higher than a second predetermined voltage. When the second comparator 26 operates, the second comparator 26 commands the CPU 27 to disable the remote sensing function via the signal line 27c. Upon receiving this command, the CPU 27 controls the correction switch 23 to be turned off via the signal line 27a. That is, the CPU 27 enables the remote sensing function when the first comparator 25 operates, and disables the remote sensing function when the second comparator 26 operates, via the signal line 27a. Control. Here, when a strain sensor having a remote sensing function is connected to the device side connectors 17f and 17g, the correction switch 23 is turned on to enable the remote sensing function, and when the strain sensor is removed, the remote sensing function is disabled. These components are referred to as control means. In this state, when the TEDS reading means is executed, the CPU 27 controls the reading switch 24 to be turned on from the signal line 27d. At this time, the CPU 27 accesses the device side connector terminal (positive side common terminal) 17f from the signal line 27e via the TEDS driver 30 and the switching terminal 24a of the reading switch 24.

When the TEDS 16 is connected to the device side connector (positive side common terminal) 17f and the device side connector (negative side common terminal) 17g, for example, the manufacturer name, sensor document, model, serial number, Read one of the calibration values. However, when the remote sensing function is enabled in the strain measuring device, the CPU 27 controls the reading switch 24 not to be turned on even if the reading unit is executed. That is, the CPU 27 does not control the reading switch 24 to be ON when the correction switch 23 is controlled to be ON. The correction switch 23 and the reading switch 24 are both double-pole single-throw switches, and have two contacts, contacts 23a and 23b and contacts 24a and 24b, respectively, and are turned ON or OFF simultaneously.
FIG. 2 is a circuit diagram relating to a strain measurement system according to a second embodiment, showing a configuration when a sensor having a remote sensing function is connected to the strain measurement device according to the first embodiment of the present invention. It is. 6 shows a state in which the sensor-side connector 15 shown in FIG. 6 and the device-side connector 17 shown in FIG. 1 are connected. 31a to 31d, 31f, and 31g in the figure connect the strain sensor (sensor body 11) and the strain measuring device. Indicates the cable resistance. Here, the cable resistors 31 a to 31 d and 31 f and 31 g are collectively referred to as a cable resistor 31.

  The input line 25 a of the first comparator 25 is connected to the reference potential 29 through the ground resistor 20. When a sensor having a remote sensing function (see FIG. 6) is connected, it is connected to the output terminal 21a of the first operational amplifier 21 and the input line 25a of the comparator 25 via the cable resistors 31a and 31f. At this time, the first comparator 25 detects a voltage equal to or higher than the first predetermined voltage V1 via the input line 25a, and instructs the signal line 27b of the CPU 27 to enable the remote sensing function. In response to this command, the CPU 27 as the control means controls the correction switch 23 to be turned on via the signal line 27a. In the first operational amplifier 21, since the contact 23a of the correction switch 23 is turned ON, the negative terminal 21b of the first operational amplifier 21 and the sensor side cable terminal 13f are connected. Similarly, in the second operational amplifier 22, since the contact 23b of the correction switch 23 is turned ON, the negative terminal 22b of the second operational amplifier 22 and the sensor side cable terminal 13g are connected. At this time, the first operational amplifier 21 and the second operational amplifier 22 newly constitute a voltage follower, correct the influence of the cable resistors 31a and 31c as the applied voltage to the strain bridge 12, and The same voltage is supplied to the negative side input terminal and the positive side input terminal of the strain bridge 12, respectively.

Next, an embodiment when a sensor having a remote sensing function is removed will be described. In the strain measuring apparatus according to the present invention, when the sensor having the remote sensing function is removed when the remote sensing function is enabled, the circuit configuration shown in FIG. 2 is obtained. At this time, since the remote sensing function is enabled, the correction switch 23 remains ON. Therefore, the first operational amplifier 21 forms a non-inverting amplifier circuit with the first feedback resistor 18 and the ground resistor 20. When the resistance value of the first feedback resistor 18 is R18 and the resistance value of the ground resistor 20 is R20, the output voltage 21a of the first operational amplifier 21 increases to (R18 + R20) / R20 times that of the voltage source 28. At this time, the second comparator 26 detects a voltage equal to or higher than the second predetermined voltage V2 via the input line 26a, and instructs the signal line 27c of the CPU 27 to disable the remote sensing function. In response to this command, the CPU 27 controls the correction switch 23 to be turned off from the signal line 27a.
From the above, the strain measuring device according to the present invention enables the remote sensing function when a sensor having a remote sensing function is connected, and disables the remote sensing function when the sensor having the remote sensing function is removed thereafter. It works to switch automatically.

  FIG. 3 shows a circuit configuration of the strain measuring system according to the third embodiment when the strain sensor having the TEDS function shown in FIG. 7 is connected to the strain measuring apparatus according to the first embodiment of the present invention. FIG. The input line 25a of the first comparator 25 is connected to the TEDS 16 via the device-side connector 17f and the sensor-side connector 15f, but since the ground resistor 20 is connected to the reference potential 29, the same potential as the reference potential 29 is obtained. become. At this time, since the voltage higher than the first predetermined voltage does not occur on the input line 25a of the first comparator 25, the first comparator 25 does not operate. At this time, since the CPU 27 keeps controlling the correction switch 23 to OFF, the remote sensing function is invalid. In this state, when the reading means of the TEDS 16 is executed, the CPU 27 controls the reading switch 24 to be turned on by outputting a control signal from the signal line 27d. Thereafter, the CPU 27 accesses the TEDS 16 from the reading line 27e via the TEDS driver 30 and reads the data stored therein. When the reading is completed, the CPU 27 outputs a control signal from the signal line 27d and controls the reading switch 24 to be turned off. That is, the reading switch 24 is controlled by the CPU 27 so as to be turned on only from the start of reading of data by the reading means to the completion thereof.

FIG. 4 is a flowchart showing a remote sensing switching control operation in the strain measuring apparatus according to the present invention.
At the start of the processing in step S1, the strain sensor having the remote sensing function is not connected to the strain measuring device. In this state, the CPU 27 is in a state of controlling the correction switch 23 to be OFF (step S2). Here, while the strain sensor having the remote sensing function is not connected, the voltage of the input line 25a of the first comparator 25 does not reach the first predetermined voltage, so step S3 is branched to NO and step S2 is performed. Return and continue that state.
When the strain sensor having the above remote sensing function is connected to the strain measuring device, the voltage of the input line 25a of the first comparator 25 becomes equal to or higher than the first predetermined voltage V1, so that the process branches to YES in step S3. The process proceeds to step S4. In step S4, the CPU 27 turns on the correction switch 23, the remote sensing function is started, and the measurement operation is executed. Thereafter, the process proceeds to step S5.
In step S5, it is monitored whether a strain sensor having a remote sensing function is connected. Unless the strain sensor having the remote sensing function is removed from the strain measuring device, the process branches to NO and returns to step S4 to continue the same operation.

If the strain sensor having the remote sensing function is removed from the strain measuring device, the voltage of the input line 26a of the second comparator 26 becomes equal to or higher than the second predetermined voltage V2 in step S5, so that the process branches to YES. Then, the process returns to the first step S2, and the CPU 27 controls the correction switch 23 to OFF and waits at step S2 again until a strain sensor having a remote sensing function is connected again.
Next, with reference to FIG. 5, the control operation when the TEDS is connected to and removed from the strain measurement apparatus according to the present invention will be described based on a flowchart.
In step S11 at the start of processing, it is unknown whether it is a strain sensor having a remote sensing function or a strain sensor having a TEDS function.
In step S12, the CPU 27 determines whether or not the correction switch 23 is controlled to be OFF. If the correction switch 23 is ON, a strain sensor having a remote sensing function is connected to the strain measurement device. If it is determined that the process has been performed, the process is terminated (step S16).

If the CPU 27 is controlling the correction switch 23 to be OFF, the process proceeds to step S13, the reading switch 24 is controlled to be ON by the CPU 27, and the process proceeds to step S14. In step S14, the CPU 27 accesses the TEDS 16 via the TEDS driver 30 to read various data.
When the data reading operation is finished (step S15), the CPU 27 controls the reading switch 24 to be OFF, and the processing is finished (step S16).
As described above, according to the strain measuring device shown in the embodiment according to the first embodiment of the present invention, in the strain measuring device using the 7-pin connector as the input connector (device-side connector), the remote sensing function is provided. Whether or not the strain sensor is connected is always detected, and if it is determined that it is connected, the remote sensing function is enabled. Also, when the strain sensor is removed or when a sensor that does not have a remote sensing function is connected, the remote sensing function is invalidated. At this time, the internal circuit is automatically switched according to whether the remote sensing function is valid or invalid. By automatically switching the internal circuit, it is not necessary to manually select the function according to the function of the sensor connected to the connector on the device side, so the setting time can be shortened. Incorrect setting can be prevented. In addition, when a sensor having a TEDS function is connected, the remote sensing function is controlled so as not to be effective, so that the possibility of a TEDS failure due to erroneous input can be avoided.

In addition, this invention is not limited to embodiment mentioned above, In the range which does not deviate from the summary, it can implement in various deformation | transformation.
That is, in the above-described embodiment, the strain sensor has been described. However, a strain gauge type transducer using a strain gauge, such as a displacement transducer, a pressure transducer, an acceleration transducer, a torque transducer, an inclinometer, and a soil pressure gauge. In addition, the present invention can also be applied to a case where a strain gauge is directly bonded to a portion to be measured and the strain at that portion is detected.
Although an example using TEDS as an information storage medium has been shown, it has a readable / writable memory inside, can store necessary information related to the sensor itself and its use, and can supply a negative potential. Anything that can read information can be used regardless of its name.

11 Sensor body 12, 12a-12d Strain bridge 13, 13a, 13b, 13c, 13d, 13f, 13g Cable terminal 14 Shielded wire 15 Sensor side connector 16 TEDS
17 device side connector 17a positive side bridge power supply terminal 17b negative side bridge output terminal 17c negative side bridge power supply terminal 17d positive side bridge output terminal 17e shield terminal 17f positive side common terminal 17g negative side common terminal 18 first feedback resistor 19 second Feedback resistor 20 ground resistor 21 first operational amplifier 22 second operational amplifier 23 correction switch 23a, 23b contact 24 read switch 24a, 24b contact 25 first comparator 26 second comparator 27 CPU
28 (Bridge power supply) Voltage source 29 Reference potential 30 TEDS driver 31 Cable resistance 32 Strain amplifier

Claims (7)

Bridge voltage supply for receiving a bridge voltage from the device side connector for connecting to the sensor side connector of the strain bridge, a bridge power supply, and the bridge power supply and supplying a bridge voltage to the bridge power supply terminal of the device side connector Means, and a strain amplifier that receives and processes the bridge output detected by the strain bridge via the bridge output terminal of the device-side connector;
In a strain measuring device comprising:
Reading means for reading data from the information storage medium, a reading switch interposed between the reading means and the common terminal of the device-side connector, and an insertion between the bridge voltage supply means and the common terminal Correction switch
Control means for controlling the correction switch and the reading switch;
With
The control means, can with the strain sensor with remote sensing is connected to the device side connector, wherein the enable correction switch with remote sensing function by controlling the read switch, the sensor having a remote sensing function is removed The strain measuring device is configured so that the remote sensing function is invalidated. A device side connector for connecting to the sensor side connector of the strain bridge; and
Bridge power supply,
Bridge voltage supply means for receiving a bridge voltage from the bridge power source and supplying a bridge voltage to a bridge power terminal of the device-side connector;
In a strain measuring apparatus comprising: a strain amplifier that receives a bridge output detected by the strain bridge via a bridge output terminal of the device-side connector and performs signal processing;
An information storage medium in which information about the sensor is stored;
Reading means for reading data from the information storage medium, a reading switch interposed between the reading means and the common terminal of the apparatus-side connector, and between the bridge voltage supply means and the common terminal A correction switch to be inserted,
Control means for controlling the correction switch and the reading switch;
With
When the strain sensor having a remote sensing function is connected to the device-side connector, the control means turns on the correction switch, turns off the reading switch, and activates the remote sensing function.
When a strain sensor not having a remote sensing function is connected to the device-side connector, and the information storage medium is connected to a common terminal of the device-side connector,
The correction switch is turned off, the reading switch is turned on, the remote sensing function is disabled, and the data stored in the information storage medium can be read by the reading means via the reading switch. Strain measuring device. The bridge voltage supply means includes
A first operational amplifier having an output terminal connected to a positive bridge power supply terminal of the apparatus side connector, and having a positive terminal connected to a positive electrode of the bridge power supply; an output terminal of the first operational amplifier; A first feedback resistor interposed between the negative terminal of the first operational amplifier and an output terminal connected to the negative bridge power supply terminal of the device-side connector and connected to the negative electrode of the bridge power supply A voltage follower circuit is configured by a second operational amplifier having a positive terminal, and a second feedback resistor interposed between the output terminal of the second operational amplifier and the negative terminal of the second operational amplifier. The strain measuring device according to claim 1 or 2, wherein   The control means is connected to a shield terminal of the device-side connector via a ground resistor, and has an output of a first comparator having an input line connected to the positive side common terminal, and the first operational amplifier 3. The strain measurement according to claim 1, wherein the correction switch and the reading switch are controlled in response to an output of a second comparator having an input line connected to the output terminal. apparatus. The reading means is controlled by the control means when the information storage medium is connected to the positive shared terminal and the negative shared terminal, and turns on the read switch,
3. The data storage device according to claim 1, wherein the positive side common terminal is connected to a reading line, and the negative side common terminal is connected to a reference potential so that data can be read from the information storage medium. Strain measuring device.   The device-side connector includes the positive bridge power supply terminal, the negative bridge power supply terminal, a positive bridge output terminal, a negative bridge output terminal, the shield terminal, the positive shared terminal, and the negative common terminal. The strain measuring device according to any one of claims 1 to 5, wherein the strain measuring device is a 7-pin connector of a side shared terminal.   The information storage medium is TEDS (abbreviation of Transducer Electronic Data Sheet) in which the sensor information is digitized and stored in the sensor. The strain measuring apparatus described.

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