Automatic calibration device for vibrating wire strain gauge

Abstract

The utility model relates to an automatic calibration device for a vibrating wire strain gauge, comprising a control module which is electrically connected with an execution module and an upper computer respectively, and the upper computer is electrically connected with a visual module; the execution module comprises a high-resolution grating ruler, a movable clamp, a fixed clamp and a linear movement module which controls the movable clamp to be close to and away from the fixed clamp in a linear movement mode. The high-resolution grating ruler is used for measuring the displacement amount of the linear movement module. The high-resolution grating ruler is electrically connected with the control module, and the visual module is used for shooting numerical values displayed by the vibrating wire strain gauge which is jointly clamped by the movable clamp and the fixed clamp in the loading process. The method has the beneficial effects that the efficiency of a calibration process is greatly improved by applying a visual technology and an automatic control technology, loading and unloading, displacement monitoring, data recording and the like can be automatically completed, links and time of manual operation are remarkably reduced, the working efficiency is improved, and errors caused by fatigue or negligence of an operator are also reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of instrument calibration, in particular to an automatic calibration device for a vibrating-wire strain gauge. Background Art

[0002] Vibrating-wire strain gauges are mainly used to measure the strain inside structures. They are particularly suitable for long-term burial in hydraulic structures or other concrete structures to monitor the strain changes of structures. They are widely used in disaster warning, construction quality control, structural health monitoring, etc. Therefore, vibrating-wire strain gauges need to be calibrated before being put into use to ensure the accuracy of the values ​​they measure.

[0003] At present, calibration is mostly performed through manual devices, with the micrometer as the display of the standard deformation. Manual loading is inefficient and has many human influence factors. In addition, when using a universal clamping fixture, the strain gauge and the clamping fixture are prone to slip during the loading process, which will introduce certain errors. In addition, the traditional micrometer can only display the real-time strain value, and the original record needs to be filled in manually and calculated manually. The workload is large and there is the possibility of manual reading errors or filling errors. The content of the paper form cannot be directly generated into an electronic file, which is not convenient for data processing, analysis and storage. Utility Model Content

[0004] The technical problem to be solved by the utility model is to provide an automatic calibration device for a vibrating-wire strain gauge to overcome the deficiencies in the above-mentioned prior art.

[0005] The utility model solves the above-mentioned technical problem with the following technical solution: an automatic calibration device for a vibrating-wire strain gauge, comprising: a control module, the control module is electrically connected to an execution module and a host computer respectively, and the host computer is electrically connected to a vision module; the execution module comprises: a high-resolution grating ruler, a movable fixture, a fixed fixture, and a linear motion module for controlling the movable fixture to approach and move away from the fixed fixture in a linear motion manner, the high-resolution grating ruler is used to measure the displacement of the linear motion module; the high-resolution grating ruler is electrically connected to the control module, and the vision module is used to capture the value displayed by the vibrating-wire strain gauge clamped by the movable fixture and the fixed fixture during the loading process.

[0006] On the basis of the above technical solution, the present invention can also be improved as follows.

[0007] Furthermore, the linear motion module includes: a loading platform, on which a high-precision stepper motor, a precision reducer and a precision transmission structure are fixed, the high-precision stepper motor is connected to the precision transmission structure via the precision reducer, the movable fixture is fixed on the precision transmission structure, and the fixed fixture and the high-resolution grating scale are fixed on the loading platform.

[0008] Furthermore, the precision transmission structure includes: a first fixed block, a second fixed block and a third fixed block which are fixed on the loading platform in sequence, a screw rod is arranged between the first fixed block and the second fixed block, two ends of the screw rod are respectively rotatably cooperated with the first fixed block and the second fixed block, a threaded sleeve is provided on the screw rod, a slider is fixed on the threaded sleeve, at least one guide rod parallel to the screw rod is fixed between the first fixed block and the second fixed block, and the guide rod passes through the guide hole on the slider; a movable clamp is fixed on the slider, and a high-resolution grating ruler is used to measure the displacement of the slider in the linear motion module.

[0009] Furthermore, the precision transmission structure also includes: a clamp fixing seat, the clamp fixing seat is arranged between the second fixing block and the third fixing block, the guide rod passes through the guide hole on the clamp fixing seat, at least one adjustment rod parallel to the guide rod is fixed on the slider, the clamp fixing seat is fixed to the adjustment rod via an adjustment bolt, the adjustment rod is provided with an adjustment groove distributed along its length direction at the connection point of the adjustment bolt, and the movable clamp is fixed on the clamp fixing seat.

[0010] Furthermore, at least one fixing rod parallel to the guide rod is fixed on the slide block, the fixing rod passes through the adjustment hole on the clamp fixing seat, and the fixing rod is fixed to the clamp fixing seat via a locking bolt.

[0011] Furthermore, the movable clamp includes: a fixed clamp block, which is fixed on the linear moving module, and a movable clamp block is connected to the fixed clamp block via bolts, and both the fixed clamp block and the movable clamp block have arc grooves that are compatible with the vibrating wire strain gauge.

[0012] Furthermore, the fixed fixture and the movable fixture have the same structure.

[0013] Furthermore, the control module includes: a main control unit, the main control unit is electrically connected to the communication unit, the stepper motor control unit and the interface unit respectively, the communication unit is electrically connected to the host computer, the stepper motor control unit is electrically connected to the high-precision stepper motor, and the high-resolution grating ruler is electrically connected to the interface unit.

[0014] Furthermore, the main control unit uses a 32-bit ARM processor STM32F407, and the stepper motor control unit uses a TMC5160 chip; the communication unit uses a 232 serial port chip, and the host computer uses a PC, which reads the displacement data measured by the high-resolution grating ruler through a 422 communication chip.

[0015] The beneficial effects of the utility model are:

[0016] 1) The use of visual technology and automatic control technology greatly increases the efficiency of the calibration process, and can automatically complete loading and unloading, displacement monitoring and data recording, etc., significantly reducing the links and time of manual operation, which not only improves work efficiency, but also reduces errors caused by operator fatigue or negligence;

[0017] 2) By adopting high-resolution grating scale, high-precision stepper motor, precision reducer and precision transmission structure, the whole device has high-precision characteristics, which can achieve micron-level precise displacement control, ensure the accuracy of vibrating-wire strain gauge calibration, and significantly improve the reliability of calibration results. In addition, the improvement in accuracy is particularly important for engineering applications that require high-precision measurement, and can significantly reduce calibration deviations caused by human operating errors. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a structural diagram of the automatic calibration device for vibrating wire strain gauges in the utility model;

[0019] Figure 2 It is a partial structural diagram of the automatic calibration device of the vibrating wire strain gauge in the utility model;

[0020] Figure 3 for Figure 2 Structural diagram after removing the protective cover.

[0021] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0022] 1. Control module, 11. Main control unit, 12. Communication unit, 13. Stepper motor control unit, 14. Interface unit, 2. Execution module, 21. High-resolution grating ruler, 22. Active fixture, 221. Fixed clamp, 222. Active clamp, 23. Fixed fixture, 24. Linear motion module, 241. Loading platform, 242. High-precision stepper motor, 243. Precision reducer, 244. Precision transmission structure, 24 41. First fixed block, 2442. Second fixed block, 2443. Third fixed block, 2444. Screw, 2445. Threaded sleeve, 2446. Slider, 2447. Guide rod, 2448. Fixture fixing seat, 2449. Adjusting rod, 24410. Adjusting bolt, 24411. Adjusting slot, 24412. Fixing rod, 24413. Locking bolt, 3. Host computer, 4. Visual module, 5. Vibrating-wire strain gauge. DETAILED DESCRIPTION

[0023] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0024] Example 1

[0025] like Figure 1As shown, an automatic calibration device for a vibrating-wire strain gauge includes: a control module 1, an execution module 2, a host computer 3 and a visual module 4, wherein a signal input end of the execution module 2 is electrically connected to a signal output end of the control module 1, and the control module 1 communicates with the host computer 3 in a two-way manner, that is, the control module 1 can feed back data to the host computer 3, and the host computer 3 can also send instructions to the control module 1, and the host computer 3 is electrically connected to the visual module 4, and the host computer 3 can obtain image data collected by the visual module 4;

[0026] The execution module 2 includes: a high-resolution grating ruler 21, a movable fixture 22, a fixed fixture 23 and a linear motion module 24. The movable fixture 22 and the fixed fixture 23 are used to clamp the vibrating-wire strain gauge 5 together, and the linear motion module 24 controls the movable fixture 22 to move closer to and away from the fixed fixture 23 in a linear motion manner. The high-resolution grating ruler 21 is used to measure the displacement of the linear motion module 24. The high-resolution grating ruler 21 is electrically connected to the control module 1, and the control module 1 obtains the displacement data measured by the high-resolution grating ruler 21; the visual module 4 is used to shoot the value displayed by the vibrating-wire strain gauge clamped by the movable fixture 22 and the fixed fixture 23 during the loading process;

[0027] Here’s how it works:

[0028] The calibration parameters, including target displacement, loading and unloading speed, and holding time of each calibration point, are set by the host computer 3. The host computer 3 converts the parameters input by the user into control instructions. The host computer 3 sends the control instructions to the control module 1. The control module 1 parses the instructions and controls the linear motion module 24 to move according to the instructions, so that the movable fixture 22 is moved closer to the fixed fixture 23 under the action of the linear motion module 24, so as to load the vibrating wire strain gauge 5 clamped by the movable fixture 22 and the fixed fixture 23.

[0029] For each target calibration point, the linear motion module 24 moves to make the deformation of the vibrating-wire strain gauge 5 reach a predetermined value. During this process, the control module 1 reads the displacement data measured by the high-resolution grating ruler 21 in real time. When the displacement measured by the high-resolution grating ruler 21 reaches the predetermined value, the linear motion module 24 stops moving. By obtaining the displacement data measured by the high-resolution grating ruler 21, it is determined whether the movement of the linear motion module 24 matches the actual displacement. At the same time, the visual module 4 captures the value displayed by the vibrating-wire strain gauge 5 clamped by the movable fixture 22 and the fixed fixture 23.

[0030] Automatically execute the set hold time at each calibration point. The hold time of each calibration point can be set according to the calibration requirements. Only when the target calibration point meets the ±2um stability judgment mechanism within 15s, the stability of the vibrating wire strain gauge 5 and the accuracy of the measurement data can be ensured;

[0031] After the calibration of each target calibration point is completed, it automatically enters the next target calibration point. When the entire device reaches the maximum measurement value, the loading is completed. During this period, the recording process can be carried out continuously, and the host computer 3 can record the results for subsequent analysis and correction. If the host computer 3 is configured with corresponding software, the recorded results can be plotted and a spreadsheet can be generated. The user can monitor the calibration progress and displacement changes in real time through the host computer 3. After the device loading is completed, the return instruction will be executed.

[0032] Example 2

[0033] like Figure 2 , Figure 3 As shown, this embodiment is a further improvement on the basis of embodiment 1, and the details are as follows:

[0034] The linear motion module 24 includes: a loading platform 241, on which a high-precision stepper motor 242, a precision reducer 243 and a precision transmission structure 244 are fixed, the high-precision stepper motor 242 is connected to the precision transmission structure 244 via the precision reducer 243, and the movable fixture 22 is fixed on the precision transmission structure 244. When the high-precision stepper motor 242 is started, the high-precision stepper motor 242 will drive the precision transmission structure 244 to move via the precision reducer 243, thereby controlling the movable fixture 22 to move closer to and away from the fixed fixture 23 in a linear manner, and the fixed fixture 23 and the high-resolution grating ruler 21 are fixed on the loading platform 241.

[0035] Example 3

[0036] like Figure 2 , Figure 3 As shown, this embodiment is a further improvement on the basis of embodiment 2, and the details are as follows:

[0037] The precision transmission structure 244 includes: a first fixed block 2441, a second fixed block 2442 and a third fixed block 2443 which are fixed on the loading platform 241 in sequence, a screw rod 2444 is arranged between the first fixed block 2441 and the second fixed block 2442, two ends of the screw rod 2444 are respectively rotatably matched with the first fixed block 2441 and the second fixed block 2442, a threaded sleeve 2445 is provided on the screw rod 2444, a slider 2446 is fixed on the threaded sleeve 2445, at least one guide rod 2447 parallel to the screw rod 2444 is fixed between the first fixed block 2441 and the second fixed block 2442, the guide rod 2447 passes through the guide hole on the slider 2446, the number of the guide rods 2447 is determined according to actual conditions, such as two as shown in the figure, a movable fixture 22 is fixed on the slider 2446, and a high-resolution grating ruler 21 is used to measure the displacement of the slider 2446;

[0038] Here’s how it works:

[0039] Start the high-precision stepper motor 242, and the high-precision stepper motor 242 will drive the screw rod 2444 to rotate through the precision reducer 243. When the screw rod 2444 rotates, the slider 2446 will move linearly along the length direction of the screw rod 2444. The high-precision stepper motor 242 is controlled to rotate forward and reversely to realize the reciprocating linear movement of the slider 2446 along the length direction of the screw rod 2444. The working principle of this part is the existing conventional technology, so why the slider 2446 can move along the length direction of the screw rod 2444 is not introduced in detail here; when the slider 2446 moves linearly along the length direction of the screw rod 2444, the movable clamp 22 on the slider 2446 will be able to move closer to and away from the fixed clamp 23 in a linear manner.

[0040] Furthermore, the precision transmission structure 244 also includes: a clamp fixing seat 2448, the clamp fixing seat 2448 is arranged between the second fixing block 2442 and the third fixing block 2443, the guide rod 2447 passes through the guide hole on the clamp fixing seat 2448, and at least one adjustment rod 2449 parallel to the guide rod 2447 is fixed on the slider 2446. The number of the adjustment rods 2449 is determined according to the actual situation, such as two as shown in the figure, the clamp fixing seat 2448 is fixed to the adjustment rod 2449 through the adjustment bolt 24410, and the adjustment rod 2449 is fixed on the adjustment bolt 2 The connection of 4410 is provided with an adjustment groove 24411 distributed along its length direction, and the movable clamp 22 is fixed on the clamp fixing seat 2448. By changing the position of the adjusting bolt 24410 in the adjustment groove 24411, the position of the clamp fixing seat 2448 on the adjusting rod 2449 can be adjusted. At this time, the distance between the movable clamp 22 and the fixed clamp 23 can be manually adjusted so that the cooperation between the fixed clamp 23 and the movable clamp 22 can adapt to vibrating-wire strain gauges 5 of different sizes, because the movable clamp 22 is fixed on the clamp fixing seat 2448 in this embodiment.

[0041] At least one fixing rod 24412 parallel to the guide rod 2447 is fixed on the slider 2446. The fixing rod 24412 passes through the adjustment hole on the clamp fixing seat 2448. The fixing rod 24412 is fixed to the clamp fixing seat 2448 via a locking bolt 24413. The number of fixing rods 24412 is determined according to actual conditions, such as the two fixing rods shown in the accompanying drawings. The fixing rod 24412 cooperates with the adjusting rod 2449 to ensure the stability of the clamp fixing seat 2448.

[0042] Example 4

[0043] like Figure 2 , Figure 3 As shown, this embodiment is a further improvement on any one of Embodiments 1 to 3, and the details are as follows:

[0044] The movable clamp 22 includes: a fixed clamp block 221, which is fixed on the linear moving module 24. According to the above description, the fixed clamp block 221 of the movable clamp 22 is fixed on the clamp fixing seat 2448, and the fixed clamp 23 is fixed on the third fixed block 2443. The movable clamp block 222 is connected to the fixed clamp block 221 by bolts. The fixed clamp block 221 and the movable clamp block 222 both have arc grooves that are compatible with the vibrating-wire strain gauge 5. The vibrating-wire strain gauge 5 is located in the arc grooves on the fixed clamp block 221 and the movable clamp block 222, and the bolts are tightened to clamp the vibrating-wire strain gauge 5 between the fixed clamp block 221 and the movable clamp block 222. After being clamped, the vibrating-wire strain gauge 5 is not easy to slip.

[0045] Furthermore, the structure of the fixed clamp 23 is the same as that of the movable clamp 22 , and both the movable clamp 22 and the fixed clamp 23 are detachable, so that the corresponding clamp can be selected according to actual needs.

[0046] Example 5

[0047] like Figure 1 As shown, this embodiment is a further improvement on any one of Embodiments 1 to 4, and the details are as follows:

[0048] The control module 1 includes: a main control unit 11, the main control unit 11 is electrically connected to the communication unit 12, the stepper motor control unit 13 and the interface unit 14 respectively, the communication unit 12 is electrically connected to the host computer 3, that is, the main control unit 11 communicates with the host computer 3 via the communication unit 12, the stepper motor control unit 13 is electrically connected to the high-precision stepper motor 242, and the stepper motor control unit 13 is used to control the forward and reverse rotation and speed of the high-precision stepper motor 242.

[0049] Furthermore: the main control unit 11 uses a 32-bit ARM processor STM32F407, the communication unit 12 uses a 232 serial port chip, and the host computer 3 uses a PC, that is, the main control unit 11 combines the 232 serial port chip to communicate with the PC. Considering the actual use of the PC, it can be placed nearby the execution module 2; the stepper motor control unit 13 uses the TMC5160 chip, that is, the high-power and high-precision stepper motor control chip TMC5160 controls the action of the high-precision stepper motor 242 in real time, and finally realizes automatic load control of the calibration device; the high-resolution grating ruler 21 is electrically connected to the interface unit 14.

[0050] The calibration parameters, including target displacement, loading and unloading speed, holding time of each calibration point, etc., are set by the host computer 3. The host computer 3 converts the parameters input by the user into control instructions, and sends them to the main control unit 11 through the communication unit 12. After receiving the instructions, the main control unit 11 parses the instructions through the STM32F407 processor, and configures the stepper motor control unit 13 according to the instructions, so that the stepper motor control unit 13 controls the movement of the high-precision stepper motor 242;

[0051] When the high-precision stepper motor 242 moves according to the predetermined parameters, the high-precision stepper motor 242 will control the slider 2446 to move linearly through the precision reducer 243 and the screw rod 2444, and the slider 2446 will control the fixture fixing seat 2448 to move linearly through the adjustment rod 2449 and the fixing rod 24412. Since the movable fixture 22 is fixed on the fixture fixing seat 2448, the movable fixture 22 will move linearly synchronously with the fixture fixing seat 2448 to load the vibrating wire strain gauge 5 clamped by the movable fixture 22 and the fixed fixture 23.

[0052] For each target calibration point, the deformation of the vibrating-wire strain gauge 5 reaches a predetermined value due to the action of the high-precision stepper motor 242. During this process, the main control unit 11 reads the displacement data measured by the high-resolution grating ruler 21 in real time. When the displacement measured by the high-resolution grating ruler 21 reaches the predetermined value, the high-precision stepper motor 242 stops moving. The displacement data measured by the high-resolution grating ruler 21 is obtained to determine whether the movement of the high-precision stepper motor 242 matches the actual setting. At the same time, the visual module 4 captures the value displayed by the vibrating-wire strain gauge 5 clamped by the movable fixture 22 and the fixed fixture 23.

[0053] Automatically execute the set hold time at each calibration point. The hold time of each calibration point can be set according to the calibration requirements. Only when the target calibration point meets the ±2um stability judgment mechanism within 15s, the stability of the vibrating wire strain gauge 5 and the accuracy of the measurement data can be ensured;

[0054] After the calibration of each target calibration point is completed, it automatically enters the next target calibration point. When the entire device reaches the maximum measurement value, the loading is completed. During this period, the recording process can be carried out continuously, and the host computer 3 can record the results for subsequent analysis and correction. If the host computer 3 is equipped with corresponding software, the recorded results can be plotted and a spreadsheet can be generated. The user can monitor the calibration progress and displacement changes in real time through the host computer 3. After the device loading is completed, the return instruction will be executed;

[0055] The main control unit 11 can be equipped with automatic diagnosis and error handling functions as needed to monitor the working status of the high-precision stepper motor 242 and the high-resolution grating ruler 21 in real time. Once an abnormality is found, the movement is stopped immediately and an alarm signal is sent to the host computer 3 to ensure the safety of the operation and the integrity of the vibrating-wire strain gauge 5.

[0056] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present invention. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. An automatic calibration device for a vibrating wire strain gauge, characterized in that: include: A control module (1), wherein the control module (1) is electrically connected to an execution module (2) and a host computer (3), respectively, and the host computer (3) is electrically connected to a vision module (4); the execution module (2) comprises: a high-resolution grating ruler (21), a movable fixture (22), a fixed fixture (23), and a linear motion module (24) for controlling the movable fixture (22) to move closer to and away from the fixed fixture (23) in a linear motion manner, and the high-resolution grating ruler (21) is used to measure the displacement of the linear motion module (24); the high-resolution grating ruler (21) is electrically connected to the control module (1), and the vision module (4) is used to capture the value displayed by a vibrating-wire strain gauge (5) clamped by the movable fixture (22) and the fixed fixture (23) during the loading process.

2. The automatic calibration device for a vibrating wire strain gauge according to claim 1, characterized in that: The linear motion module (24) comprises: a loading platform (241), a high-precision stepper motor (242), a precision reducer (243) and a precision transmission structure (244) are fixed on the loading platform (241), the high-precision stepper motor (242) is connected to the precision transmission structure (244) via the precision reducer (243), the movable fixture (22) is fixed on the precision transmission structure (244), and the fixed fixture (23) and the high-resolution grating ruler (21) are fixed on the loading platform (241).

3. The automatic calibration device for a vibrating wire strain gauge according to claim 2, characterized in that: The precision transmission structure (244) comprises: a first fixed block (2441), a second fixed block (2442) and a third fixed block (2443) which are fixed on the loading platform (241) in sequence; a screw rod (2444) is arranged between the first fixed block (2441) and the second fixed block (2442); two ends of the screw rod (2444) are respectively rotatably matched with the first fixed block (2441) and the second fixed block (2442); a threaded sleeve (2443) is provided on the screw rod (2444) 45), a slider (2446) is fixed on the threaded sleeve (2445), at least one guide rod (2447) parallel to the screw rod (2444) is fixed between the first fixed block (2441) and the second fixed block (2442), and the guide rod (2447) passes through the guide hole on the slider (2446); the movable clamp (22) is fixed on the slider (2446), and the high-resolution grating ruler (21) is used to measure the displacement of the slider (2446) in the linear motion module (24).

4. The automatic calibration device for a vibrating wire strain gauge according to claim 3, characterized in that: The precision transmission structure (244) also includes: a clamp fixing seat (2448), wherein the clamp fixing seat (2448) is arranged between the second fixing block (2442) and the third fixing block (2443), the guide rod (2447) passes through the guide hole on the clamp fixing seat (2448), at least one adjustment rod (2449) parallel to the guide rod (2447) is fixed on the slider (2446), the clamp fixing seat (2448) is fixed to the adjustment rod (2449) via an adjustment bolt (24410), and the adjustment rod (2449) is provided with an adjustment groove (24411) distributed along its length direction at the connection of the adjustment bolt (24410), and the movable clamp (22) is fixed on the clamp fixing seat (2448).

5. The automatic calibration device for a vibrating wire strain gauge according to claim 4, characterized in that: At least one fixing rod (24412) parallel to the guide rod (2447) is fixed on the slider (2446); the fixing rod (24412) passes through an adjustment hole on the clamp fixing seat (2448); the fixing rod (24412) is fixed to the clamp fixing seat (2448) via a locking bolt (24413).

6. The automatic calibration device for a vibrating wire strain gauge according to claim 1, characterized in that: The movable clamp (22) comprises: a fixed clamp block (221), the fixed clamp block (221) is fixed on the linear moving module (24), a movable clamp block (222) is connected to the fixed clamp block (221) via bolts, and both the fixed clamp block (221) and the movable clamp block (222) have an arc groove that is compatible with a vibrating wire strain gauge.

7. The automatic calibration device for a vibrating wire strain gauge according to claim 6, characterized in that: The fixed clamp (23) has the same structure as the movable clamp (22).

8. The automatic calibration device for vibrating wire strain gauge according to any one of claims 2 to 7, characterized in that: The control module (1) comprises: a main control unit (11), the main control unit (11) being electrically connected to a communication unit (12), a stepper motor control unit (13) and an interface unit (14) respectively; the communication unit (12) being electrically connected to a host computer (3); the stepper motor control unit (13) being electrically connected to a high-precision stepper motor (242); and the high-resolution grating ruler (21) being electrically connected to the interface unit (14).

9. The automatic calibration device for a vibrating wire strain gauge according to claim 8, characterized in that: The main control unit (11) uses a 32-bit ARM processor STM32F407, and the stepping motor control unit (13) uses a TMC5160 chip; the communication unit (12) uses a 232 serial port chip, and the host computer (3) uses a PC. The PC reads the displacement data measured by the high-resolution grating ruler (21) via a 422 communication chip.

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