CN213090699U

CN213090699U - Strain measuring device

Info

Publication number: CN213090699U
Application number: CN202021530062.0U
Authority: CN
Inventors: 吕志忠; 刘武; 葛亮; 刘宸希; 马维龙
Original assignee: Southwest Petroleum University
Current assignee: Southwest Petroleum University
Priority date: 2020-07-29
Filing date: 2020-07-29
Publication date: 2021-04-30
Anticipated expiration: 2030-07-29

Abstract

The utility model discloses a strain measurement device, including guide rail base, slider, spring, magnet steel, move grating, quiet grating, support, shell, light source, first lens, second lens, CCD sensor and measuring circuit. The guide rail base and the sliding block are assembled together, magnetic steel is installed at the bottom of the guide rail base, the static grating is installed on the guide rail base, the movable grating is installed on the sliding block, the light source and the first lens are installed on one side of the movable grating, the second lens, the CCD sensor, the measuring circuit and the battery are installed on one side of the static grating, and when the guide rail and the sliding block move relatively, the strain can be measured through the CCD sensor and the measuring circuit. The measuring circuit comprises a voltage stabilizing circuit, a single chip microcomputer circuit, a light source driving circuit, a wireless communication circuit, a CCD sensor, a CCD driving circuit and a battery. The utility model discloses only need place the grating measurement sensor that meets an emergency on being surveyed the piece, just can directly measure the atress of material and the size of meeting an emergency.

Description

Strain measuring device

Technical Field

The utility model belongs to the technical field of the measuring sensor technique of meeting an emergency and specifically relates to indicate a strain measurement device.

Background

The strain is the degree of deformation and deformation of an object under the action of external force, the strain of the object is usually measured by applying a load to the object to be measured in engineering to determine the working performance of the object to be measured, the strain is usually used for detecting the safety of the object to be measured, for example, the safety test of a derrick is that the strain is measured by applying a corresponding load to the derrick, a corresponding model is established according to the change conditions of the strain and the load to judge the safety of the derrick and the capacity of lifting the load, and a tester climbs the derrick to perform high-altitude operation such as steel frame grinding, strain sheet sticking, field measurement wiring and the like according to the measurement requirement, so that the life safety of the tester is directly endangered.

At present, most methods for measuring strain adopt a strain gauge to measure, before measurement, dirt such as oil, paint and the like on the surface of a measured object needs to be cleaned, the strain gauge is adhered to the surface of the measured object by resin glue, measurement can be carried out only after the adhesive glue is dried completely, in the adhering process, strict training needs to be carried out on adhesion personnel, if the adhesion is not ideal, wiring is incorrect, welding is not good and other factors directly cause inaccurate measuring results, the processes are repeated again to polish again, clean the surface and adhere the strain gauge, field measurement becomes more difficult, protective layers such as paint and the like on the surface of the measured object are damaged due to the requirement of adhering the strain gauge, and accelerated damage of the measured object is increased.

At present, there is also a measuring device which is made of a strain gauge alone, the strain gauge is directly clamped or mounted on the surface of a measured object to realize measurement, a measuring sensor is also made of a material with small elastic modulus, the service life is short due to the characteristics of the strain gauge, the measuring sensor is ensured not to be subjected to plastic deformation during mounting, otherwise the measuring data is unreliable or cannot be measured, the clamping and mounting which are generally adopted during mounting directly influence the service life due to the fact that the measuring sensor is greatly influenced by the environment, the elastic modulus is small and the like, and the measuring sensor is required to be mounted by professional workers, otherwise the measuring sensor is easily damaged.

At present, the measurement modes have various problems in measurement and use, the requirements of quick, safe, reliable and nondestructive measurement cannot be met, and a strain measurement device with large deformation, safety, reliability and nondestructive measurement is urgently needed.

In view of the above, the present application has resulted.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a strain measurement device realizes measuring simple and conveniently, measures accurately, and safety realizes nondestructive measurement to the measured object, satisfies the installation simply, measures conveniently, engineering strain measurement device that the reliability is high.

To achieve the above object, the solution of the present invention is:

a strain measuring device includes a slide member, an optical member, a measuring circuit, an auxiliary member, and measuring software;

the sliding component comprises a guide rail base, a sliding block, magnetic steel and a spring; slider accessible spring is connected with the guide rail base and is fixed in the definite position, all install magnet steel (also can be installing support) bottom guide rail base and slider, when the measuring device that meets an emergency puts on the measured object, the magnet steel adsorbs the measuring device that meets an emergency on the measured object surface through suction, when the measured object takes place elastic deformation, just produce relative movement between guide rail base and the slider, thereby realize the measurement of meeting an emergency, when the measuring device that meets an emergency takes off from the measured object, receive the spring action between guide rail base and the slider, guide rail base and slider just automatic recovery are to zero point position, use when supplying to measure next time.

The optical component comprises a light source, a first lens, a static grating, a dynamic grating, a second lens and a CCD sensor; the light source passes through the first lens, the point light source is changed into a parallel light source, the parallel light source irradiates the static grating and the dynamic grating, after two gratings penetrate through the light source, parallel light forms moire fringes, the moire fringes can be imaged on the CCD sensor through the second lens (the lens can be removed according to needs) and can not be used, the displacement of the moire fringes on the CCD sensor can be detected through the CCD sensor, the CCD sensor adopts a linear array CCD sensor, the distance between every two adjacent pixels is determined, the moving distance of the fringes can be calculated by calculating the number of the moire fringes moving on the CCD sensor, the displacement between the sliding block and the guide rail base is calculated, and the displacement is divided by the distance between the magnetic steel on the guide rail base and the magnetic steel on the sliding block base so as to be strain. The utility model discloses also can be used to the measurement of trace displacement.

The strain object can generate certain deformation under the action of external force, and the deformation degree is according to a positive strain formula

In this formula, L is the ascending distance of the magnet steel of guide rail base and slider in the measuring power side in the formula, and Δ L is the displacement volume of guide rail base and slider between when measuring the utility model discloses in, the magnet steel of guide rail base and slider base's magnet steel are the fixed value at ascending distance L of measuring side, and displacement volume Δ L between guide rail base and the slider is imaged to the CCD sensor after through grating amplification on, and the pixel interval of establishing the CCD sensor is alpha, and the pixel quantity that moire fringe removed is n, and the magnification of moire fringe is B, then the amount of movement of slider and guide rail base is:

the distance between the slide block and the magnetic steel between the guide rails is determined L, so that the strain quantity is calculated as follows:

the magnification factor B of the moire fringes can be large, the distance alpha between pixel points of the CCD sensor is several micrometers, so that nanoscale measurement can be realized, and when the distance L between the sliding block and the guide rail is large, the value of na is also large, and high-precision strain epsilon measurement can be realized.

The measuring circuit consists of a voltage stabilizing circuit, a single chip microcomputer circuit, a light source driving circuit, a wireless communication circuit, a CCD sensor, a CCD driving circuit and a battery; the voltage stabilizing circuit is used for providing a circuit module of the working voltage of the strain measuring device; the single chip microcomputer circuit is a core component of the measuring circuit, the driving control and the calculation analysis of each module are realized, and the driving, the analysis and the calculation programs related to the measuring circuit are stored in a memory inside the single chip microcomputer; the light source driving circuit is used for driving the light source in the utility model, when the strain measuring device works, the driving light source emits light, and when the strain measuring device is in a non-measuring state, the light source is extinguished, thereby saving electricity and prolonging the service life of the strain measuring device; the wireless communication module is used for transmitting the measurement data to other receiving equipment and receiving control instructions of other equipment, such as information of measurement, zero clearing, transmission of measurement strain values and the like; the CCD sensor receives image information of the moire fringes and detects the movement displacement of the light fringes or the dark fringes on the CCD sensor to realize the detection of the movement distance of the moire fringes; the CCD driving circuit drives the CCD sensor through the time sequence of the single chip microcomputer, receives image information output by the CCD sensor through the single chip microcomputer, judges the moving distance and the moving direction of the moire fringes according to the state of each pixel point signal in the image information, and converts the moving distance of the moire fringes into a strain value after the moire fringes are processed by the single chip microcomputer to realize strain measurement; the battery is used for supplying power required by the strain measuring device, and other power sources can be used for supplying power required by the strain measuring device.

The auxiliary component comprises a machine shell, a mounting bracket and a bolt; the device is mainly used for correctly mounting and fixing the whole device.

The measurement software comprises a light source driving program, a CCD sensor driving program, an AD acquisition program, a digital quantity acquisition program, a parameter setting program, a wireless communication program, a strain calculation program and the like. The light source driving program is used for lightening and adjusting the intensity of light during measurement, so that the image on the CCD sensor of the moire fringes is clear and stable; the CCD driving program is a sequence generated by driving the CCD sensor by the singlechip according to the working time sequence of the CCD sensor, so that the CCD sensor can normally work, the AD acquisition program of the CCD sensor is a program for measuring the brightness value output by the pixel point of the CCD sensor so as to conveniently master the brightness value formed on the CCD sensor during Moire fringe imaging during debugging, and is convenient for adjusting an adjustable resistor during comparing a binary signal in a circuit, and the digital quantity acquisition program of the CCD sensor is a program for directly acquiring the binary signal of the CCD sensor after passing through a comparator through an IO interface of the singlechip so as to directly acquire a light and dark signal in the CCD sensor through high and low levels; the parameter setting program is a program for receiving system data of relevant parameters such as pixel point spacing, spacing between magnetic steel of the guide rail base and magnetic steel of the slider and the like sent to the strain measuring device by other measuring control equipment, and reading, modifying and storing the data. The wireless communication procedure is a procedure for completing data exchange between the strain measurement device and the receiving equipment. Strain calculation analysis program is used for the moire fringe to carry out the analysis at CCD sensor formation of image back pixel change state to calculate the distance that the moire fringe moved on CCD sensor, the utility model discloses well CCD sensor adopts the linear array CCD sensor, and its output can be grey information, and the grey scale change level is 0-255, through analyzing every output pixel, but the number of the pixel that the automatic identification moire fringe moved calculates the displacement distance of moire fringe, and combines CCD sensor pixel interval, the magnification of moire fringe and the distance between guide rail base and slider, calculates the strain of testee.

After the scheme is adopted, the utility model discloses a gain effect lies in:

the utility model adopts the guide rail and the slide block structure, the inaccuracy of the measured data caused by the external factors such as material deformation, temperature and humidity of the measured object can be avoided, and the measuring precision has good retentivity; the displacement change is amplified by moire fringes formed by the grating and then converted into larger displacement, the displacement of the moire fringes is directly measured by the CCD sensor, the distance between pixel points of the CCD sensor is very accurate, the measured displacement is also accurate and reliable, the output of the CCD sensor can be gray signals, the gray signals are processed into binary signals by a comparison circuit to form digital signals, the IO port of a single chip microcomputer can be conveniently and directly read, and the moving distance of the moire fringes on the CCD sensor can be accurately judged. In the measuring circuit, all the signals are converted into digital signals, the working performance is reliable, the measured data is accurate, and the influence of zero drift and temperature and humidity during analog quantity measurement of the strain gauge is avoided.

Second, the magnet steel of installation on slider and guide rail, only need directly adsorb the measuring device that meets an emergency on the surface of testee during the measurement, can not produce additional damage to the testee in the measurement process, after the measurement is accomplished, the measuring device that will meet an emergency directly take off alright, can carry out used repeatedly, in the measurement process, no consumptive material loss, energy-concerving and environment-protective.

Third, benefit from that strain measurement device is an overall structure, has the wireless data communication function, adopts the magnet steel to adsorb in the testee surface, during the field measurement, need not polish, paster, wiring, welding work such as welding to the testee, only need directly adsorb on the testee surface, through wireless receiver alright directly read its measured data, have simple to operate, measure swiftly, greatly alleviateed survey crew's intensity of labour.

And fourthly, the strain measuring device has small structure and small volume and light weight, and can be installed only by a robot when measuring at high altitude without manual work, thereby ensuring the life and property safety of measuring personnel.

Fifth, benefiting from this whole of the strain measurement device, it is convenient to install, while measuring and installing, need professional field installation not.

Sixth, the utility model discloses except being used for the strain measurement, still can be used to the measurement of trace displacement.

Drawings

Fig. 1 is a schematic front view of an embodiment of the present invention.

Fig. 2 is a schematic perspective view of an embodiment of the present invention (omitting the housing and the bolt).

Fig. 3 is a schematic top view of an embodiment of the present invention.

Fig. 4 is a schematic bottom view of an embodiment of the present invention.

Fig. 5 is a block diagram of a control circuit according to an embodiment of the present invention.

Fig. 6 is a circuit diagram of an embodiment of the present invention.

FIG. 7 is a software block diagram of an embodiment of the present invention

Description of reference numerals: 10-sliding part 11-sliding block 12-spring 13 guide rail base 14-magnetic steel 20 optical part 21-first lens 22-moving grating 23-static grating 24-second lens 30 measuring circuit 31-light source 32-CCD sensor 33-battery 34-measuring circuit board 40-auxiliary part 41-CCD grating support 42-static grating support 43-moving grating support 44-light source support 43

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

Referring to fig. 1, the present invention provides a strain measuring device, which includes a sliding component 10, an optical component 20, a measuring circuit 30, an auxiliary component 40 and software 50;

the sliding component 10 comprises a guide rail base 13, a sliding block 11, a spring 12 and magnetic steel 14; the optical component 20 comprises a first lens 21, a static grating 22, a dynamic grating 23 and a second lens 24; the measuring circuit 30 comprises a light source 31, a CCD sensor 32, a battery 33 and a measuring circuit board 34; the auxiliary component 40 includes a light source support 44, a moving grating support 43, a static grating support 42, a CCD sensor support 41, a housing (not shown in the figure), and a bolt (not shown in the figure);

the measurement circuit board 34 comprises a single chip microcomputer 342, a memory 343, a CCD drive circuit 241, a light source drive circuit 344, a power management circuit 346, a wireless communication module 345 and a battery 347; the software comprises a light source driving program, a CCD sensor driving program, a reading program, a communication program and a strain calculation program, and is stored in a memory of the measuring circuit board.

The sliding component 10 is provided with a magnetic steel 14 (or an installation frame) at the bottom of a guide rail base 13, a sliding block 11 is arranged in a guide rail of the guide rail base 13, the magnetic steel 14 (or the installation frame) is arranged at the bottom of the sliding block 11, the magnetic steel 14 at the bottom of the sliding block 11 and the magnetic steel 14 of the guide rail base are on the same plane, the relative position of the guide rail base 13 and the sliding block 11 at the initial time is determined by a spring 12, a light source support 44 is arranged on the guide rail base 13, a light source 31 and a first lens 21 are arranged on the light source support, a static grating 23 is arranged on the static grating support 42, only one grating line is arranged on the static grating 23, a second lens 24, a CCD sensor 32, a battery 33 and a measuring circuit board 34 are arranged on a CCD sensor support 41, the components are respectively fixed and installed by bolts, then a shell is arranged outside the sliding block, the rest parts are all fixed and sealed.

The optical component 20 changes point-scattered light emitted by the light source 31 into parallel light after passing through the first lens 21, the parallel light forms moire fringes after passing through the movable grating 22 and the static grating 23 and is imaged on the CCD sensor 32 through the second lens, in order to realize strain measurement, only one grating line is arranged on the static grating 23, one moire fringe is formed on the CCD sensor 32, the moving distance of the moire fringes on the CCD sensor 32 can be calculated through the number of moving pixel points, and the moving distance of the moire fringes on the pixel points is calculated because the distance between the pixel points is fixed and unchanged, and can be converted into the strain size after calculation.

When the measuring circuit 30 is used for measuring, the light source 31 is driven to emit light, only one grating line is arranged on the static grating 23 after passing through the optical component 20, and only one moire fringe moves on the CCD sensor 32, so that an output signal of a pixel point on the linear array CCD sensor 32 is converted into high and low level output after being subjected to binarization processing, and if the output of the bright fringe is high level, the output of a pixel in a dark fringe or a no light area is low level. The binarization processing of the pixel output signals is convenient for the IO port of the single chip microcomputer to directly read the pixel signals of the CCD sensing equipment 32 for processing. When the output signal of the linear array CCD sensor 32 is read as a high level signal, the position of the bright fringe is present, and the calculation of the moving distance and strain of the moire fringe is specifically referred to in the contents of the utility model. After the driving and signal processing of the measuring circuit board 34, the number of pixel points of the moire fringe moving on the grating is directly measured, the calculation of the moving distance is realized, and after the processing of a program in a memory of the measuring circuit board 34, the strain of the measured object is automatically calculated. The measuring circuit board 34 reads the program in the memory 343 by the single chip 342, realizes the work of the CCD driving circuit 241 and the light source driving circuit 344 according to the corresponding program processing function, completes the measuring work of the strain measuring device, and automatically calculates the measured strain value, transmits the measured value through the wireless communication module 345, realizes the on-site wireless measurement, simplifies the on-site testing scheme, and the battery 347 provides the voltage and current required by the test for the strain measuring device through the voltage stabilizing circuit 346, thereby ensuring the normal work of the strain measuring device.

The measuring circuit is mainly shown in fig. 5 and 6 and comprises a voltage stabilizing circuit, a single chip circuit, a light source driving circuit, a wireless communication circuit, a CCD sensor, a CCD driving circuit and a battery. The strain measurement circuit is powered by a battery B11 through a switch S11, and a voltage stabilizing circuit consisting of a voltage stabilizing chip U1, a capacitor C11, a capacitor C12, a capacitor C13, a capacitor C14, a capacitor C15 and a capacitor C16 provides power and voltage required by the strain measurement device; the single electromechanical circuit consists of a singlechip U2, capacitors C21 and C22, a crystal oscillator X21 and a program download interface JP21, and a memory is arranged in the singlechip U2; the wireless communication circuit consists of a communication module U3; the CCD drive circuit consists of capacitors C41 and C42 and an IO port connected with a singlechip U6, so that the time sequence drive of a CCD sensor U4 is realized, and an output signal of the CCD sensor U4 consists of an operational amplifier U5, a resistor U6, a resistor R41, a resistor R42, a resistor R43, a resistor R44, a resistor R45, a resistor R46, a resistor R47, a resistor R48, an adjustable resistor R49 and a triode Q3, so that the functions of amplifying and binary conversion of a CCD sensor U4 signal are realized; the light source driving circuit consists of resistors R21, R22 and a triode Q21, and the driving control of the light source L21 is realized through the singlechip U2.

When the switch S11 is switched on, the battery B11 sends electricity to the voltage stabilizing chip U1 through the switch S11 to be converted into voltage required by the strain measuring device, capacitors on the left side and the right side of the voltage stabilizing chip U1 play the roles of voltage stabilization and filtering in a circuit to guarantee the reliable work of the strain measuring device, and when the switch S11 is switched off, the strain measuring device stops working.

The single chip microcomputer circuit and the single chip microcomputer U2 are a processing center of the whole strain measuring device, the external capacitors C21 and C22 and the crystal oscillator X21 form the working oscillation frequency of the single chip microcomputer to provide a frequency signal for normal work of the single chip microcomputer, the memory is arranged in the single chip microcomputer U2, and the measuring program is downloaded into the memory of the single chip microcomputer U2 through the program downloading interface JP2, so that the single chip microcomputer completes corresponding work according to the programmed program.

The light source driving circuit is controlled by a pin 1 of the singlechip U2, when the light source driving circuit is at a high level, the high level is added to a base electrode of a triode Q21 through a resistor R21, so that the triode Q21 works in a conducting state, voltage flows back to a power ground through a resistor R22, a light source L21 and a triode Q21 and drives a light source L21 to emit light, similarly, when the pin 1 output of the singlechip U2 is at a low level, low level is added to a base electrode of a triode Q21 through a resistor R21, so that a triode Q21 works in a blocking state, voltage cannot flow back to the power ground through a resistor R22, a light source L21 and a triode Q21, and the light source L21 is extinguished.

The wireless communication circuit is composed of a single chip microcomputer U21 and a wireless communication module U3, the single chip microcomputer U4 controls the wireless communication module U3 through an IO interface, data receiving and data sending functions of external equipment and the just-changed measuring device are achieved, and wireless transmission of data is achieved.

The CCD driving circuit is composed of an IO port of a singlechip U2 and an IO port of a CCD sensor U4, the working time sequence required by the CCD sensor U4 is output through the IO port of the singlechip U2, so that the CCD sensor can work normally, and moire signals are received, when the signals received by the CCD sensor U4 are output sequentially through a 21 st pin of the CCD sensor U4 according to the time sequence of the singlechip U2, the signals are amplified through an amplifying circuit composed of resistors R41, R42, R43 and a triode Q3 and are amplified again through an amplifying circuit composed of resistors R44, R45, R46 and an operational amplifier, one path of signals is sent to an AD port of the singlechip U2 through a resistor R47 to be received and collected by another analog signal, the singlechip analyzes and uses the analog signals received by the moire fringes of the CCD sensor U4 through the resistor R48 and is sent to a comparison circuit composed of an adjustable resistor R49 and an operational amplifier U6, the pixel signal output by the CCD sensor U4 is converted into a high-low level signal, the adjustable resistor R49 is adjusted, the threshold value for converting the pixel output signal of the CCD sensor U4 can be adjusted, namely, a threshold value is set for the brightness value of moire fringes received by the CCD sensor U4, when the brightness value is larger than the set threshold value, the pixel output signal is high level, when the brightness value is smaller than the set threshold value, the pixel output signal is low level, therefore, the analog quantity signal output by the pixel is converted into a digital signal, the high-low level signal can be directly measured through an IO interface of a single chip microcomputer U2, so that the light and dark signal in the CCD sensor can be directly obtained, and the pixel output signal of the CCD sensor U4 is directly received, analyzed.

The program of the strain measuring device is downloaded into a memory of the single chip microcomputer U2 through a program downloading interface JP2, the single chip microcomputer completes corresponding equipment driving, signal acquisition and calculation according to the functions of the program, and measurement data are exchanged with other receiving equipment through the wireless communication module U3, so that strain measurement is completed.

The measurement software comprises a light source driving program, a CCD sensor driving program, an AD acquisition program, a digital quantity acquisition program, a parameter setting program, a wireless communication program, a strain calculation program and the like.

The light source driving program is used for lighting and adjusting the intensity of light during measurement, so that the image on the CCD sensor of the moire fringes is clear and stable, and the light source lamp is turned off when the measurement is stopped, so that the power loss of the measuring device is saved.

The CCD driving program is a program which is generated by driving the CCD sensor according to the working time sequence of the CCD sensor by the singlechip and is generated according to the time sequence relation required by the working of the CCD sensor, so that the CCD sensor can normally work, and after the CCD sensor normally works, the pixel points of the CCD sensor can normally receive image information to finish the acquisition of images; the AD acquisition program is used for acquiring the brightness value (or color value) output by the pixel point of the CCD sensor through the AD acquisition device to acquire the brightness value of each pixel point, so that the adjustable resistor in the comparison circuit can be conveniently adjusted to enable the binary signal output by the CCD sensor to meet the test requirement; the CCD sensor digital quantity acquisition program directly acquires a binary signal of the CCD sensor after passing through the comparator through an IO interface of the single chip microcomputer, and counts high and low levels of effective output pixel points, if a signal with low level is output when dark stripes or no light exists, and the output of bright stripes is high level, the number of pixel points at which the high level is positioned when a first frame is output is n₁When the second frame is output, the number of pixel point outputs at the high level position is n₂The moving displacement of the phase moire fringe on the CCD sensor is (n)₁-n₂) Alpha (alpha is pixel point interval), and the position of the bright stripe on the CCD sensor can be quickly analyzedSetting and moving distance; the parameter setting program is a program for receiving relevant parameters such as the pixel point distance, the distance between the magnetic steel of the guide rail base and the magnetic steel of the sliding block and the like sent to the strain measuring device by other measuring control equipment, and reading, modifying and storing the data. The wireless communication procedure is a procedure for completing data exchange between the strain measurement device and the wireless receiving equipment. The strain calculation and analysis program is used for analyzing the change state of pixel points of the moire fringes after the moire fringes are imaged on the CCD sensor so as to calculate the moving distance of the moire fringes on the CCD sensor, and the strain of the measured object is calculated by combining the pixel point distance of the CCD sensor, the amplification factor of the moire fringes and the distance between the guide rail base and the sliding block.

The utility model discloses the detection that geology removed in also can be used to the measurement of small displacement volume and the geological disasters.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the design of the present application, and all equivalent changes made according to the design key of the present application fall within the protection scope of the present application.

Claims

1. A strain measuring device is characterized by comprising a sliding component, an optical component, a measuring circuit, an auxiliary component and measuring software;

the sliding component comprises a guide rail base, a sliding table, magnetic steel and a spring; the guide rail base and the sliding table are fixed at determined relative positions through springs, magnetic steel is arranged at the bottoms of the guide rail base and the sliding table, and the magnetic steel is adsorbed on the surface of a measured object during measurement; the optical component comprises a first lens, a static grating, a dynamic grating and a second lens; the light source driven by the measuring circuit changes a point light source into a parallel light source through the first lens, the parallel light source irradiates the static grating and the movable grating to form moire fringes, the moire fringes are imaged on the CCD sensor through the second lens, the moving distance of the moire fringes on the CCD sensor is measured through the measuring circuit, and the measurement of micro displacement or strain can be realized; the auxiliary component comprises a bolt, a light source support, a static grating support, a dynamic grating support, a CCD support and a shell, and is an installation component required for meeting the requirement of the strain measurement device for realizing the measurement function.

2. The strain measuring device according to claim 1, wherein a spring is installed between the rail base and the slide table to determine the relative position thereof.

3. The strain measuring device according to claim 1, wherein the guide rail base and the slide table are respectively provided with a static grating and a dynamic grating, and a smaller included angle is formed between the two gratings.

4. A strain gauge according to claim 1, wherein the static grating has only 1 grating line.

5. A strain gauge according to claim 1, wherein the moire pattern of the grating is imaged onto a CCD sensor, and the distance traveled by the moire pattern is measured by the CCD sensor.

6. A strain gauge according to claim 1, wherein: the measuring circuit consists of a voltage stabilizing circuit, a single chip microcomputer circuit, a light source driving circuit, a wireless communication circuit, a CCD sensor, a CCD driving circuit and a battery; the measuring circuit is powered by a battery B11 through a switch S11, and a voltage stabilizing circuit is formed by a voltage stabilizing chip U1, capacitors C11, C12, C13, C14, C15 and C16 and is used for providing a power supply and voltage required by the strain measuring device; the single electromechanical circuit consists of a singlechip U2, capacitors C21 and C22, a crystal oscillator X21 and a program download interface JP21, and a memory is arranged in a program memory inside the singlechip U2; the wireless communication circuit consists of a communication module U3; the CCD drive circuit is composed of capacitors C41 and C42 and an IO interface connected with a single chip microcomputer U6, so that time sequence drive of a CCD sensor U4 is realized, an output signal of the CCD sensor U4 is composed of operational amplifiers U5 and U6, resistors R41, R42, R43, R44, R45, R46, R47, R48, an adjustable resistor R49 and a triode Q3, and the functions of amplification and binarization conversion of signals of the CCD sensor U4 are realized; the light source driving circuit consists of resistors R21, R22 and a triode Q21, and the driving control of the light source L21 is realized through the singlechip U2.

7. A strain gauge according to claim 6, wherein: the CCD sensor in the measuring circuit adopts a linear array CCD sensor.

8. A strain gauge according to claim 6, wherein: the analog signal of the CCD in the measuring circuit is divided into two paths after being amplified, one path is input to an analog quantity input interface of the single chip microcomputer U2, and the other path of the binary signal after passing through the comparison circuit is sent to an IO interface of the single chip microcomputer U2 to be directly processed, so that the processing capacity of the single chip microcomputer on the output signal of the CCD sensor is improved.