CN104792297A - Calibration device for extensometer - Google Patents

Abstract

The invention provides an extensometer calibration device, comprising: a fixed adjustment part, including: a body, a fixed boss, a moving boss, an adjustment unit connected with the moving boss for moving the moving boss, and the moving boss A calibration plate that is fixed and provided with a logo; the collection and adjustment unit includes: a camera for collecting image information of the logo in the horizontal direction, a lifting unit for adjusting the position of the camera, and a displacement sensor for collecting displacement information of the camera; The control part is used to control the movement of the lifting unit; and the calibration obtaining part is used to obtain the calibration result according to the measurement information and displacement information output by the extensometer, wherein, after the adjustment unit adjusts the moving boss to move a certain distance, the control part controls the movement of the lifting unit to correspond to position, so that the camera moves to the point where the currently collected image information coincides with the logo in the initially collected image information.

Description

Extensometer Calibration Device

technical field

The invention relates to an extensometer calibration device capable of calibrating the extensometer.

Background technique

In the field of material science research, material deformation is an important parameter in material research. Extensometer is the most commonly used deformation measurement sensing device, which can measure the deformation between two points in one direction of the material. The material deformation measured by the extensometer has a great influence on the material research, so the reliability of the extensometer needs to be calibrated to ensure the accuracy of the extensometer measurement. At present, the measurement range of traditional extensometers is less than 25mm. There is a commonly used extensometer calibration device on the market, which is the GWB-200JA extensometer calibration instrument of the Iron and Steel Research Institute. This calibration instrument is a purely mechanical measurement tool. Cooperating with the nut, the rotary motion of the screw is changed into a linear motion, and the reading is performed by using the proportional relationship between the linear movement amount and the rotation angle, so as to realize the calibration of the extensometer.

However, with the development of industrial technology, due to the low measurement accuracy and low efficiency of traditional extensometers, and they are not suitable for the research of materials with large deformations, large-range extensometers have been born and are more and more widely used. Gradually began to replace the traditional extensometer. However, this GWB-200JA extensometer calibrator is in direct contact with the extensometer, which will affect the calibration accuracy, and this method can only be applied to traditional small-range extensometers, and cannot calibrate large-range extensometers at all.

Contents of the invention

The present invention was made to solve the above-mentioned problems, and an object of the present invention is to provide an extensometer calibration device capable of accurately calibrating an extensometer, especially a large-capacity extensometer.

The present invention provides an extensometer calibration device, which is used for calibrating the extensometer. Fixed boss, movable boss fixed on the upper end of the body and fixed to the movable extension rod of the extensometer, an adjustment unit connected to the movable boss for moving the movable boss, fixed to the movable boss And there is a calibration plate for the logo; the collection and adjustment part includes: a camera for collecting the image information of the logo in the horizontal direction, a lifting unit for adjusting the position of the camera, and a displacement sensor for collecting the displacement information of the camera; the control part , used to control the movement of the lifting unit; and the calibration obtaining part, which obtains the calibration result according to the measurement information and displacement information output by the extensometer, wherein, after the adjustment unit adjusts the moving boss to move a certain distance, the control part controls the lifting unit to move to a corresponding position, In this way, the camera moves to the point where the currently collected image information coincides with the logo in the initially collected image information.

In the extensometer calibration device provided by the present invention, it can also have such a feature: wherein, the lifting unit includes: a vertically placed lifting platform, a guide rail arranged on the side wall of the lifting platform facing the calibration plate, and a camera for fixed installation And the mobile platform embedded on the guide rail, the motor used to drive the mobile platform to move along the guide rail, the control part is connected with the motor, and is used to control the operation of the motor so as to control the position of the camera on the guide rail.

In the extensometer calibration device provided by the present invention, it also has such a feature, and also includes: a mounting part, including: a mounting base for fixing and installing the lifting unit; Adjustment screw.

In the extensometer calibration device provided by the present invention, it may also have such a feature: wherein, the installation part further includes a level for detecting whether the installation base is on a horizontal plane.

In the extensometer calibration device provided by the present invention, it may also have such a feature: wherein, the calibration obtaining part includes: a calibration unit connected with the extensometer and the displacement sensor for comparing measurement information and displacement information and obtaining a calibration result; A display unit for displaying calibration results.

In the extensometer calibration device provided by the present invention, it may also have such a feature: wherein, the camera is a CCD camera.

In the extensometer calibration device provided by the present invention, it may also have such a feature: wherein, the shape of the mark is any one of circle, square, rectangle and rhombus.

In the extensometer calibration device provided by the present invention, it may also have such a feature: wherein, the displacement sensor adopts a grating ruler or a magnetic grating ruler.

Function and Effect of Invention

According to the extensometer calibration device involved in the present invention, because the fixed boss and the movable boss respectively clamp the fixed extension rod and the movable extension rod of the extensometer to be measured, and the calibration plate is fixed on the movable boss, the calibration board Move together with the movable extension rod of the extensometer, the camera collects the image information of the calibration plate, and takes the initial position of the logo of the calibration plate in the image information as the initial position, the lifting unit adjusts the position of the camera, and the driving unit moves the movable boss to a certain extent distance, the control unit controls the lifting unit to lift so that the position marked in the image information collected by the camera corresponds to the initial position, the displacement sensor collects the displacement information of the camera movement, and then the comparison unit compares the measurement information and displacement information output by the extensometer Therefore, the extensometer calibration device of the present invention can accurately calibrate traditional extensometers, especially can also calibrate large-range extensometers, and has the advantages of simple structure and good repeatability.

Description of drawings

Fig. 1 is the structural representation of extensometer calibration device in the embodiment of the present invention;

Fig. 2 is the structural representation of lifting unit in the embodiment of the present invention;

Fig. 3 is a schematic structural view of the installation part in an embodiment of the present invention;

Fig. 4 is a schematic diagram of image information of a camera in an embodiment of the present invention; and

Fig. 5 is a schematic diagram of a test device of an embodiment of the present invention.

Specific implementation cases

In order to make the technical means, creative features, goals and effects of the present invention easy to understand, the following embodiments will specifically illustrate the extensometer calibration device of the present invention in conjunction with the accompanying drawings.

Fig. 1 is a structural schematic diagram of an extensometer calibration device in an embodiment of the present invention.

As shown in FIG. 1 , in this embodiment, the extensometer calibration device 100 is used to accurately calibrate the extensometer 200 to be measured. The extensometer calibration device 100 includes: a fixed adjustment part 10, an acquisition adjustment part 20, a control part 30, The mounting part 40 and the calibration obtaining part 50 . The fixed adjustment part 10 is used to clamp and drive the extensometer 200 , and the acquisition adjustment part 20 is installed on the installation part 40 and is arranged corresponding to the position of the extensometer 200 .

The fixed adjustment part 10 clamps the extensometer 200 and includes: a main body 11 , a fixed boss 12 , a moving boss 13 , an adjustment unit 14 and a calibration plate 15 . The extensometer 200 is placed on the body 11 .

The fixed boss 12 is fixedly arranged at the lower end of the body 11, and the fixed boss 12 includes: a lower clamp 12a and a lower round rod 12b. The lower clamp 12a is integrated with the body 11, and the lower round rod 12b is fixedly clamped by the lower clamp 12a. The fixed extension rod 201 of the extensometer 200 is fixedly clamped on the lower end round rod 12b.

The moving boss 13 is movably arranged at the upper end of the body 11, and the moving boss 13 includes: an upper clamp 13a and an upper round rod 13b. The upper round rod 13b is fixedly clamped by the upper clamp 13a, and the movable extension rod 202 of the extensometer 200 is fixedly clamped on the upper round rod 13b.

The adjusting unit 14 is connected with the upper clamp 13a, and is used to drive the upper clamp 13a to move a certain distance in the vertical direction. In this embodiment, each function of the main body 11 , the lower clamp 12 a , the upper clamp 13 a and the adjustment unit 14 is realized by using a tensile testing machine.

The calibration plate 15 is used for position calibration. The calibration plate 15 is in the shape of a rectangular plate, and a circular mark A is marked in the middle of the calibration plate 15 .

The acquisition adjustment part 20 is arranged directly opposite to the circular mark A, and is used for correspondingly collecting the image information of the circular mark A. The collection and adjustment unit 20 includes: a camera 21 , a lifting unit 22 and a displacement sensor 23 .

The camera 21 faces the calibration plate 15 and is installed on the lifting unit 22. The camera 21 is used to collect image information of the corresponding area. In this embodiment, the camera 21 is a CCD camera.

Fig. 2 is a structural schematic diagram of the lifting unit in the embodiment of the present invention.

As shown in FIG. 2, the lifting unit 22 is used to adjust the position of the camera 21. The lifting unit 22 includes: a lifting platform 22a, a guide rail 22b, a moving platform 22c, a motor 22d and a screw rod 22e.

The lifting platform 22a is placed vertically on the ground, and the guide rail 22b is laid on the side surface of the lifting platform 22a facing the calibration plate 15 . The mobile platform 22c is fitted on the guide rail 22b and moves vertically along the guide rail 22b. In addition, the mobile platform 22c is provided with a mounting hole for installing the camera 21 . The motor 22d is connected to the mobile platform 22c through the screw rod 22e, and the motor 22d is used to drive the screw rod 22e to drive the mobile platform 22c to move along the guide rail 22b.

The displacement sensor 23 is connected with the camera 21 and used for collecting displacement information of the camera 21 . In this embodiment, the displacement sensor 23 adopts a grating ruler.

The control part 30 is connected with the camera 21 and the displacement sensor 23, and is used to control the rotation of the motor 22d in the lifting unit 22, and move the mobile platform 22c to drive the camera 21 to move.

The calibration obtaining unit 50 is connected to the extensometer 200 and the displacement sensor 23 and includes: a calibration unit 51 and a display unit 52 . The calibration unit 51 is used to compare the measurement information output by the extensometer 200 with the displacement information collected by the displacement sensor 23, and finally obtain a calibration result. The display unit 52 is used to display the calibration result. In addition, the calibration obtaining unit 50 may be manually calibrated by an operator.

Fig. 3 is a schematic structural diagram of the installation part in the embodiment of the present invention.

As shown in FIG. 3 , the mounting part 40 is used for mounting the lifting unit 22 , and the mounting part 40 includes a mounting base 41 , an adjusting screw 42 and two spirit levels 43 .

The installation base 41 includes: four feet 41a, through holes 41b and four installation holes 41c. The lifting unit 22 is installed on the installation base 41 through the four installation holes 41c, and leaves the motor 22d through the through holes 41b. The adjustment screws 42 are used to adjust the levelness of the installation base 41 , and the four adjustment screws 42 are respectively installed on the bottoms of the four feet 41a. Two spirit levels 43 are respectively arranged on the side of the installation base 41 for detecting whether the installation base 41 is on a horizontal plane.

Fig. 4 is a working flowchart of the extensometer calibration device in the embodiment of the present invention.

As shown in Figure 4, in this embodiment, the specific calibration steps of the extensometer calibration device 100 are as follows:

Step S1, firstly, adjust the adjusting screw 42 according to the position of the level bulb in the level gauge 43, so that the installation base 41 is on a horizontal plane, and then go to step S2.

Step S2, at this time, the position of the calibration plate is set as the initial position. At the initial position, the camera 21 collects the image information of the calibration plate 15 in the horizontal direction, that is, the initial image. The position coordinates of the circular mark A in the initial image are ( a, b) as shown in Figure 5; then enter step S3.

In step S3, the operator adjusts the adjustment unit 14 so that the moving boss 13 moves a predetermined distance, and then enters step S4.

In step S4, the control unit 30 controls the motor 22d to rotate, so that the mobile platform 22c drives the camera 21 to move toward the calibration plate 15, and then enters step S5.

Step S5, according to the image information currently collected by the camera 21, that is, the current image, the control unit 30 judges whether the current image overlaps with the initial image, that is, whether the circular mark A collected by the camera 21 is at the same position in the image, so that the camera The displacement moved by 21 is consistent with the displacement moved by the calibration plate 15. When it is judged that the current image does not overlap with the initial image, go to step S4; when it is judged that the current image overlaps with the initial image, go to step S6.

In step S6, the control unit 30 controls the motor 22d to stop rotating, and then proceeds to step S7.

In step S7, the displacement sensor 23 collects the displacement information of the camera 21 moving on the guide rail 22b, and then proceeds to step S8.

In step S8, the calibration unit 51 compares the measurement information output by the extensometer 200 with the displacement information collected by the displacement sensor 23 to obtain a calibration result for the extensometer 200, and then enters an end state.

Fig. 5 is a schematic diagram of a test device of an embodiment of the present invention.

As shown in FIG. 5 , a laser displacement sensor 300 is used to test the extensometer calibration device 100 of this embodiment, and a platform 301 is added on the lower round rod 12 b. Because the extensometer calibration device 100 can measure a range of 25 mm to 500 mm, and the laser displacement sensor 300 cannot maintain high-precision measurement in this range, so in the comparative use, by using three laser displacement sensors (two times are respectively one No. 20mm ~ 100mm, No. 2 100mm ~ 300mm, No. 3 300mm ~ 500mm), the maximum allowable error of the three laser displacement sensors is ±0.02%. During the test, the laser displacement sensor 300 is placed on the platform 301, and the bottom of the calibration plate 15 is used as the measured plane. At first, the moving boss 13 is adjusted to move a predetermined distance through the adjustment unit 14, and then the control unit 30 controls the camera 21 to move to Corresponding to the position, finally, using the displacement information collected by the laser displacement sensor 300 as a standard, the displacement information obtained by the displacement sensor 23 is compared with the displacement information collected by the laser displacement sensor 300. The test results show that the maximum error of the extensometer calibration device 100 is is 0.09%, so the extensometer calibration device 100 of this embodiment has relatively high precision.

Function and effect of embodiment

According to the extensometer calibration device involved in this embodiment, because the fixed boss and the movable boss hold the fixed extension rod and the movable extension rod of the extensometer respectively, and the calibration plate is fixed on the movable boss, the calibration The plate moves together with the movable extension rod of the extensometer, the camera collects the image information of the calibration plate, and takes the initial position of the mark of the calibration plate in the image information as the initial position, the lifting unit adjusts the position of the camera, and the driving unit moves the moving boss A certain distance, the control unit controls the lifting unit to lift so that the position marked in the image information collected by the camera corresponds to the initial position, the displacement sensor collects the displacement information of the camera movement, and then the comparison unit compares the measurement information and displacement information output by the extensometer Therefore, the extensometer calibration device of this embodiment can not only accurately calibrate traditional extensometers, especially large-range extensometers, but also has the advantages of simple structure and good repeatability.

In this embodiment, since the mounting part has a level and an adjusting screw, this embodiment can ensure that the lifting unit moves in the vertical direction, thereby ensuring accurate detection results.

In this embodiment, since the camera is fixedly installed on the mobile platform and moves on the guide rail, the camera can move smoothly, thereby making the image collected by the camera clearer.

The above embodiments are preferred examples of the present invention, and are not intended to limit the protection scope of the present invention.

Claims (8)

1. an extensometer calibrating installation, for calibrating extensometer, is characterized in that, comprising:

Secured adjusted portion, comprises: body, be fixedly located at described body bottom and the fixing lug boss fixed with the bar of fixedly extending of described extensometer, packaged type be fixed on described body upper end and with the activity of described extensometer extend mobile boss that bar fixes, to be connected with described mobile boss for mobile this move boss regulon, fix with described mobile boss and be provided with the scaling board of mark;

Gather adjusting portion, comprise: the camera in the horizontal direction image information of described mark gathered, for regulating the lifting unit of described camera position, for gathering the displacement transducer of the displacement information of described camera;

Control part, moves for controlling described lifting unit; And

Calibration obtaining portion, the metrical information exported according to described extensometer and institute's displacement information obtain calibration result,

Wherein, after described regulon regulates described mobile boss to move a certain distance, described control part controls described lifting unit and moves opposite position, thus make described camera move to current collection image information and initial time the image information that gathers in described mark coincide.

2. extensometer calibrating installation according to claim 1, is characterized in that:

Wherein, described lifting unit comprises: vertical place lifting table, be located at described lifting table towards the guide rail on a sidewall of described scaling board, for fixedly mounting described camera and being entrenched in mobile platform on described guide rail, for driving described mobile platform along the motor of movement on described guide rail

Described control part is connected with described motor, for controlling the running of described motor thus controlling the position of described camera at described guide rail.

3. extensometer calibrating installation according to claim 1, is characterized in that, also comprise:

Installation portion, comprises: for fixedly mount described lifting unit mounting seat, be located at described mounting seat lower end for regulating the adjustment screw of the levelness of this mounting seat.

4. extensometer calibrating installation according to claim 3, is characterized in that:

Wherein, described installation portion also comprises the level meter whether being in surface level for detecting described mounting seat.

5. extensometer calibrating installation according to claim 1, is characterized in that:

Wherein, described calibration obtaining portion comprises: be connected for more described metrical information and institute's displacement information with described extensometer with institute displacement sensors and obtain the alignment unit of described calibration result and the display unit for showing described calibration result.

6. extensometer calibrating installation according to claim 1, is characterized in that:

Wherein, described camera is CCD camera.

7. extensometer calibrating installation according to claim 1, is characterized in that:

Wherein, the shape of described mark be in circular, square, rectangle and rhombus any one.

8. extensometer calibrating installation according to claim 1, is characterized in that:

Wherein, institute's displacement sensors adopts grating scale or magnetic railings ruler.