Strain gauge heat output compensation method and device, electronic equipment and storage medium

Abstract

The invention provides a strain gauge heat output compensation method and device, electronic equipment and a storage medium, and relates to the technical field of strain testing, and the compensation method comprises the steps: determining a circuit structure of a Wheatstone bridge according to a measurement strain gauge relational expression and a resistance curve expression of a compensation strain gauge; the resistance value of the temperature compensation resistor, the resistance value of the linear compensation resistor and the resistance value of the balance resistor are determined through the low-potential resistance value of the output end of the circuit structure; through the circuit structure of the Wheatstone bridge, the heat output of the strain gauge near the working temperature is greatly reduced, and the signal-to-noise ratio is improved. According to the resistance value of the temperature compensation resistor, the resistance value of the linear compensation resistor and the resistance value of the insulated cable resistor, the problem of sensitivity coefficient reduction caused by resistance voltage division of the bridge arm where the strain gauge is located is corrected. The output strain value of the measurement strain gauge is determined by detecting the strain value, measuring the strain value and the sensitivity coefficient correction value, and the measurement accuracy is improved.

Description

Technical Field

[0001] The present invention relates to the field of strain testing technology, and in particular to a strain gauge thermal output compensation method, device, electronic equipment and storage medium. Background Art

[0002] Strain measurement is an important part of pre-commissioning and in-service monitoring of high-temperature pressure vessels and pipelines. Strain gauge-based detection technology is currently the main means of strain measurement. However, when the strain gauge is installed on the measured object and is not subjected to external force and thermal stress, temperature changes will also cause the strain gauge to produce strain values, which are called the thermal output of the strain gauge.

[0003] Strain gauges exhibit huge heat output and large dispersion at high temperatures (greater than 600°C). Therefore, high temperatures will cause distortion of the strain gauge's measurement data. In addition, the measured object is huge, and the resistance of the mineral insulated cable (MI cable) between the strain gauge and the measuring instrument, which is tens of meters long, is large and cannot be ignored. The resistance of the insulated cable changes with temperature, which also exacerbates the distortion of the strain gauge's measurement data. Summary of the invention

[0004] The problem solved by the present invention is the technical problem of distortion of strain gauge measurement data caused by high temperature and insulation cable resistance.

[0005] In order to solve the above problems, the present invention provides a strain gauge thermal output compensation method, device, electronic equipment and storage medium.

[0006] In a first aspect, the present invention provides a strain gauge thermal output compensation method, which is applicable to a Wheatstone bridge, wherein the Wheatstone bridge comprises: a measuring strain gauge and a compensating strain gauge, and the strain gauge thermal output compensation method comprises:

[0007] Determine the measurement strain gauge relationship and the resistance curve expression of the compensation strain gauge; wherein the relationship is the relationship between the resistance of the strain gauge sensitive grid material and the temperature, the strain grid linear expansion coefficient and the linear expansion coefficient of the measured object, and the resistance curve expression is obtained by performing a calibration experiment on the compensation strain gauge with temperature changes;

[0008] Determine the circuit structure of the Wheatstone bridge according to the measurement strain gauge relationship and the resistance curve expression of the compensation strain gauge; and determine the resistance value of the temperature compensation resistor, the resistance value of the linear compensation resistor and the resistance value of the balance resistor in the circuit structure according to the resistance value of the low potential at the output end of the Wheatstone bridge circuit structure;

[0009] Detecting a detection strain value of the measuring strain gauge based on the circuit structure and measuring the measurement strain value of the measuring strain gauge by a measuring instrument;

[0010] Correcting the sensitivity coefficient of the measuring strain gauge according to the temperature compensation resistor, the linear compensation resistor and the insulation cable resistance to obtain a sensitivity coefficient correction value;

[0011] The output strain value of the measuring strain gauge is determined by the detected strain value, the measured strain value and the sensitivity coefficient correction value.

[0012] Optionally, determining the circuit structure of the Wheatstone bridge according to the measurement strain gauge relationship and the resistance curve expression of the compensation strain gauge includes:

[0013] If it is determined that the correlation coefficient between the measurement strain gauge relationship and the corresponding fitting straight line is greater than the correlation coefficient between the resistance curve expression of the compensation strain gauge and the corresponding fitting straight line, then the first circuit is determined to be the circuit structure of the Wheatstone bridge;

[0014] Wherein, the first circuit includes: a measuring strain gauge, a compensating strain gauge, a first insulating cable resistor, a second insulating cable resistor, a third insulating cable resistor, a first voltage divider resistor, a second voltage divider resistor, a temperature compensation resistor, a linear compensation resistor and a balancing resistor;

[0015] The measuring strain gauge, the first insulating cable resistor, the temperature compensation resistor, the balancing resistor, the first voltage-dividing resistor, the second voltage-dividing resistor, the second insulating cable resistor, and the compensation strain gauge are sequentially connected to form a loop;

[0016] The intersection point between the measuring strain gauge and the compensating strain gauge is connected to one end of the third insulating cable resistor, and the other end of the third insulating cable resistor is connected to one end of the linear compensation resistor;

[0017] The intersection point between the second voltage-dividing resistor and the two insulated cable resistors is connected to the other end of the linear compensation resistor.

[0018] Optionally, determining the circuit structure of the Wheatstone bridge according to the measurement strain gauge relationship and the resistance curve expression of the compensation strain gauge includes:

[0019] If it is determined that the correlation coefficient between the measurement strain gauge relationship and the corresponding fitting straight line is less than the correlation coefficient between the resistance curve expression of the compensation strain gauge and the corresponding fitting straight line, then the second circuit is determined to be the circuit structure of the Wheatstone bridge;

[0020] Wherein, the second circuit includes: a measuring strain gauge, a compensating strain gauge, a first insulating cable resistor, a second insulating cable resistor, a third insulating cable resistor, a first voltage-dividing resistor, a second voltage-dividing resistor, a temperature compensation resistor, a linear compensation resistor and a balancing resistor;

[0021] The measuring strain gauge, the first insulating cable resistor, the first voltage-dividing resistor, the second voltage-dividing resistor, the balancing resistor, the temperature compensation resistor, the second insulating cable resistor, and the compensation strain gauge are sequentially connected to form a loop;

[0022] The intersection point between the measuring strain gauge and the compensating strain gauge is connected to one end of the third insulating cable resistor, and the other end of the third insulating cable resistor is connected to one end of the linear compensation resistor;

[0023] An intersection point between the first insulated cable resistor and the first voltage-dividing resistor is connected to the other end of the linear compensation resistor.

[0024] Optionally, determining the resistance of the temperature compensation resistor, the resistance of the linear compensation resistor and the resistance of the balance resistor in the circuit structure according to the resistance of the low potential at the output end of the Wheatstone bridge circuit structure includes:

[0025] At a first temperature and a second temperature, respectively determining a first resistance value and a second resistance value of a low potential of an output end of the Wheatstone bridge circuit structure; wherein the first temperature ranges from 0°C to 100°C, and the second temperature is an operating temperature of the device under test;

[0026] Changing the total resistance of the bridge arm where the measuring strain gauge is located and the total resistance of the bridge arm where the compensating strain gauge is located multiple times, and determining the first resistance and the second resistance of the low potential of the output end of the Wheatstone bridge circuit structure multiple times;

[0027] The resistance value of the temperature compensation resistor and the resistance value of the linear compensation resistor are determined according to the resistance value of the total resistance of the bridge arm where the measurement strain gauge is located and the resistance value of the total resistance of the bridge arm where the compensation strain gauge is located when the difference between the second resistance value and the first resistance value is the smallest.

[0028] Optionally, it also includes:

[0029] The resistance value of the balancing resistor is calculated according to the first resistance value corresponding to the time when the difference between the second resistance value and the first resistance value is the smallest.

[0030] Optionally, the correcting the sensitivity coefficient of the measuring strain gauge according to the temperature compensation resistor, the linear compensation resistor and the insulation cable resistance to obtain a sensitivity coefficient correction value includes:

[0031] The sensitivity compensation coefficient is calculated according to the resistance value of the temperature compensation resistor, the resistance value of the linear compensation resistor and the resistance value of the insulation cable resistor;

[0032] The current sensitivity coefficient is corrected based on the sensitivity compensation coefficient to obtain a sensitivity coefficient correction value.

[0033] Optionally, determining the output strain value of the measuring strain gauge by using the detection strain value, the measurement strain value and the sensitivity coefficient correction value includes:

[0034] generating a strain compensation coefficient based on the sensitivity coefficient correction value; generating a strain difference between the detected strain value and the measured strain value;

[0035] The product of the strain compensation coefficient and the strain difference is determined as the output strain value of the measuring strain gauge.

[0036] In a second aspect, the present invention provides a strain gauge thermal output compensation device, comprising:

[0037] A linear module, used to determine the relationship between the measurement strain gauge and the resistance curve expression of the compensation strain gauge; wherein the relationship is the relationship between the resistance of the strain gauge sensitive grid material and the temperature, the strain grid linear expansion coefficient and the linear expansion coefficient of the measured object, and the resistance curve expression is obtained by performing a calibration experiment on the compensation strain gauge with temperature changes;

[0038] A selection module is used to determine the circuit structure of the Wheatstone bridge according to the measurement strain gauge relationship and the resistance curve expression of the compensation strain gauge; and determine the resistance value of the temperature compensation resistor, the resistance value of the linear compensation resistor and the resistance value of the balance resistor in the circuit structure according to the resistance value of the low potential at the output end of the Wheatstone bridge circuit structure;

[0039] A detection module, used for detecting a detection strain value of the measurement strain gauge based on the circuit structure and measuring the measurement strain value of the measurement strain gauge by a measuring instrument;

[0040] A correction module, used for correcting the sensitivity coefficient of the measuring strain gauge according to the temperature compensation resistor, the linear compensation resistor and the insulation cable resistance to obtain a sensitivity coefficient correction value;

[0041] The compensation module is used to determine the output strain value of the measuring strain gauge through the detection strain value, the measurement strain value and the sensitivity coefficient correction value.

[0042] In a third aspect, the present invention provides an electronic device, including a memory and a processor;

[0043] The memory is used to store computer programs;

[0044] The processor is used to implement the strain gauge thermal output compensation method as described in the first aspect when executing the computer program.

[0045] In a fourth aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the strain gauge thermal output compensation method as described in the first aspect is implemented.

[0046] The beneficial effects of the strain gauge thermal output compensation method, device, electronic device and storage medium of the present invention are: using the measurement method of the measuring strain gauge and the compensating strain gauge, the circuit structure of the Wheatstone bridge is determined according to the measuring strain gauge relationship and the resistance curve expression of the compensating strain gauge; the resistance value of the temperature compensation resistor, the resistance value of the linear compensation resistor and the resistance value of the balance resistor are determined by the resistance value of the low potential at the output end of the circuit structure; the problem of large dispersion of the thermal output of the strain gauge can be solved by the circuit structure of the Wheatstone bridge, and the thermal output of the measuring strain gauge near the working temperature can be greatly reduced, and the signal-to-noise ratio can be improved; according to the resistance value of the temperature compensation resistor, the resistance value of the linear compensation resistor and the resistance value of the insulating cable resistance, the problem of reduced sensitivity coefficient caused by the voltage division of each resistance value of the bridge arm where the measuring strain gauge is located is corrected. In summary, the present invention can solve the problem of strain gauge measurement data distortion caused by high temperature and insulating cable resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 The figure is a flow chart of a strain gauge thermal output compensation method according to an embodiment of the present invention.

[0048] Figure 2 Schematic diagram of a Wheatstone bridge in an embodiment of the present invention.

[0049] Figure 3 Schematic diagram of the circuit structure in an embodiment of the present invention.

[0050] Figure 4 The figure is a schematic structural diagram of a strain gauge thermal output compensation device according to an embodiment of the present invention.

[0051] Figure 5 The figure is a schematic diagram of the structure of an electronic device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0052] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be interpreted as being limited to the embodiments described herein. On the contrary, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are only for exemplary purposes and are not intended to limit the scope of protection of the present invention.

[0053] It should be understood that the various steps described in the method embodiments of the present invention may be performed in different orders and / or in parallel. In addition, the method embodiments may include additional steps and / or omit the steps shown. The scope of the present invention is not limited in this respect.

[0054] The term "including" and its variations used in this document are open inclusions, that is, "including but not limited to"; the term "based on" means "based at least in part on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments"; the term "optionally" means "optional embodiments". The relevant definitions of other terms will be given in the following description. It should be noted that the concepts of "first", "second", etc. mentioned in the present invention are only used to distinguish different devices, modules or units, and are not used to limit the order or interdependence of the functions performed by these devices, modules or units.

[0055] It should be noted that the modifications of "one" and "plurality" mentioned in the present invention are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise clearly indicated in the context, it should be understood as "one or more".

[0056] The names of the messages or information exchanged between multiple devices in the embodiments of the present invention are only used for illustrative purposes, and are not used to limit the scope of these messages or information.

[0057] In the related technology, strain measurement is an important part of pre-commissioning and in-service monitoring of high-temperature pressure vessels and pipelines. Since strain gauges have the characteristics of high resolution, mature technology, easy use and convenient multi-point measurement, strain gauges have become the main technical means of strain measurement. However, when the strain gauge is installed on the measured object and the strain gauge is not subjected to external force and thermal stress, the strain gauge will produce a strain value only due to temperature changes. This strain value is called thermal output. Thermal output is caused by the resistance temperature coefficient of the sensitive grid material of the strain gauge and the difference in linear expansion coefficient between the sensitive grid material and the measured object. For example: a strain gauge with platinum tungsten alloy as the grid material can have a thermal output of more than 20,000 microstrains (με) at 600°C, which is enough to annihilate the test data, resulting in a very low signal-to-noise ratio of strain measurement.

[0058] Since the strain gauge cannot be removed without loss after being installed on the DUT, it cannot be removed and reinstalled after calibrating the thermal output on the DUT. Moreover, the manufacturing process of the strain gauge causes the resistance and temperature characteristics of the strain gauge to be different. Even for strain gauges from the same batch, the thermal output dispersion can exceed one thousand microstrains. If another strain gauge is installed on the DUT to calibrate the thermal output, the residual thermal output of the strain gauge will become very large, affecting the credibility of the test data.

[0059] In addition, the size of the measured object is huge, and the resistance of the several tens of meters long insulated cable (MI cable for short) between the strain gauge and the measuring instrument is very large. The influence of this resistance and its change with temperature on the thermal output and sensitivity coefficient of the strain gauge cannot be ignored.

[0060] In view of the problems existing in the above-mentioned related technologies, the present embodiment provides a strain gauge thermal output compensation method, device, electronic device and storage medium.

[0061] like Figure 1 As shown, a strain gauge thermal output compensation method provided by an embodiment of the present invention is applicable to a Wheatstone bridge, wherein the Wheatstone bridge comprises: a measuring strain gauge and a compensating strain gauge. Before the strain gauge thermal output compensation is performed, a calibration experiment of the strain gauge and the insulation cable resistance changing with temperature should be carried out, and the calibration results of the resistance at different temperatures are fitted respectively to obtain the measured strain gauge resistance curve expression R at different temperatures. A (T), compensation strain gauge resistance curve expression R D And the insulated cable resistance curve expression R L .

[0062] Strain gauge thermal output compensation method, including:

[0063] S100: Determine the relationship between the measurement strain gauge and the resistance curve expression of the compensation strain gauge;

[0064] The relationship is the relationship between the resistance of the strain gauge sensitive grid material and the temperature, the strain grid linear expansion coefficient and the linear expansion coefficient of the measured object, and the resistance curve expression is obtained by performing a calibration experiment on the compensation strain gauge with temperature changes.

[0065] In this step, the following formula is used to calculate the relationship:

[0066] R A =R A (T)+R A (25℃)×[GF×(K m -K g ) × ΔT]

[0067] Among them, R A Indicates the resistance of the strain gauge; R A (T) represents the expression of the measured strain gauge resistance curve; R A (25℃) indicates the resistance of the strain gauge at room temperature 25℃; GF indicates the sensitivity factor; K m Indicates the linear expansion coefficient of the measured object; K g It represents the linear expansion coefficient of the strain grating; ΔT represents the difference between the working temperature T℃ and the room temperature 25℃.

[0068] In this step, it is necessary to obtain the sensitivity curve of the strain gauge's sensitivity coefficient changing with temperature (the sensitivity coefficients of the measurement strain gauge and the compensation strain gauge are the same), the coefficient curve of the linear expansion coefficient of the measured object changing with temperature, and the coefficient curve of the strain grid's linear expansion coefficient changing with temperature.

[0069] The temperature in the above resistance curve refers to the temperature from room temperature (25℃) to the maximum limit of the strain gauge. The compensation resistance is calculated for the measured object at the working temperature T℃, so that the heat output of the strain gauge is close to zero at this temperature point after compensation.

[0070] Furthermore, the measuring strain gauge and the compensating strain gauge are selected as a pair of two strain gauges with similar resistance-temperature relationship curves, so as to achieve a result of smaller heat output in a wider temperature range.

[0071] It should be noted that the linear expansion coefficient of the strain gauge is a product parameter of the strain gauge, which can be found in the instructions attached to the product. If the material of the measured object is a general material, its linear expansion coefficient can be found in the ASME specification. If it is a special material, such as special stainless steel, the linear expansion coefficient, as an important physical and chemical parameter, can be measured through physical and chemical performance testing.

[0072] S200: Determine the circuit structure of the Wheatstone bridge according to the measurement strain gauge relationship and the resistance curve expression of the compensation strain gauge; and determine the resistance value of the temperature compensation resistor, the resistance value of the linear compensation resistor and the resistance value of the balance resistor in the circuit structure according to the resistance value of the low potential at the output end of the Wheatstone bridge circuit structure.

[0073] In this step, when the circuit structure of the Wheatstone bridge is determined according to the measured strain gauge relationship and the compensation strain gauge resistance curve expression, the relationship and the curve expression are respectively fitted with straight lines, and judgment is made according to the size of the correlation coefficient with each fitting straight line.

[0074] Specifically, the measurement strain gauge relationship is fitted into a straight line using the least square method and the correlation coefficient between the relationship and the straight line is determined; the compensation strain gauge curve expression is fitted into a straight line using the least square method and the correlation coefficient between the curve expression and the straight line is determined.

[0075] To compensate the strain gauge R D Take the example to explain the compensation strain gauge R D The curve expression sequence is

[0076] The fitting straight line series is

[0077] The correlation coefficient calculation formula is:

[0078]

[0079] Among them, T k K represents the temperature point, R k Indicates the resistance value of the compensation plate at this temperature point, L k It represents the ordinate value of the curve fitted by the least squares method at this temperature point. for The mean of for The closer |r| is to 1, the greater the correlation.

[0080] Further, when the correlation coefficient between the measurement strain gauge relationship and its fitting straight line is greater than the correlation coefficient between the compensation strain gauge curve expression and its fitting straight line, the first circuit is determined to be a Wheatstone bridge circuit structure; when the correlation coefficient between the measurement strain gauge relationship and its fitting straight line is less than the correlation coefficient between the compensation strain gauge curve expression and its fitting straight line, the second circuit is determined to be a Wheatstone bridge circuit structure.

[0081] In this embodiment, the components constituting the first circuit and the second circuit are the same, and the difference is the connection method of the components. Specifically, the components of the first circuit and the second circuit include: a measuring strain gauge, a compensating strain gauge, a first insulating cable resistor, a second insulating cable resistor, a third insulating cable resistor, a first voltage divider resistor, a second voltage divider resistor, a temperature compensation resistor, a linear compensation resistor, and a balancing resistor.

[0082] In this step, the circuit structure of the Wheatstone bridge is a group of resistor circuits based on the Wheatstone bridge. By compensating the thermal output of the strain gauge through the circuit structure of the Wheatstone bridge, the thermal output of the high-temperature strain gauge near the working temperature can be greatly reduced, the signal-to-noise ratio can be improved, and the strain measurement accuracy can be improved.

[0083] See also Figure 2 The schematic diagram of the Wheatstone bridge shown in Figure 1 uses a measuring strain gauge and a compensating strain gauge to form an adjacent arm half bridge, where R A To measure the resistance of the strain gauge, R D To compensate the resistance of the strain gauge, R L is the insulated cable resistance. TC is the temperature compensation resistor, R LC is the linear compensation resistor, R BAL Is the balance resistor. Temperature compensation resistor R TC , Linear compensation resistor R LC , balancing resistance R BAL The position in the bridge is divided into two cases, namely the "+" position and the "-" position in the figure, according to the first circuit and the second circuit.

[0084] The first circuit connection method is:

[0085] Measuring strain gauge R A , first insulation cable resistance, temperature compensation resistance + R TC , balance resistance + R BAL , first voltage-dividing resistor, second voltage-dividing resistor, second insulated cable resistor, compensation strain gauge R D Connect in sequence to form a loop;

[0086] Measuring strain gauge R A With compensation strain gauge R D The intersection point is connected to one end of the third insulated cable resistor, and the other end of the third insulated cable resistor is connected to the linear compensation resistor +R LC One end of the connection;

[0087] The intersection point between the second voltage-dividing resistor and the second insulated cable resistance and the linear compensation resistor +R LC The other end of the connection.

[0088] The second circuit connection method is:

[0089] Measuring strain gauge R A , first insulated cable resistance, first voltage divider resistance, second voltage divider resistance, balancing resistance - R BAL , Temperature compensation resistor - R TC , the second insulated cable resistance, compensation strain gauge R D Connect in sequence to form a loop;

[0090] Measuring strain gauge R A With compensation strain gauge R D The intersection point is connected to one end of the third insulated cable resistor, and the other end of the third insulated cable resistor is connected to the linear compensation resistor -R LC One end of the connection;

[0091] The intersection point between the first insulated cable resistance and the first voltage-dividing resistance and the linear compensation resistance -R LC The other end of the connection.

[0092] Optionally, the temperature compensation resistor, the linear compensation resistor and the balancing resistor use a precision potentiometer, and the resistance value of the precision potentiometer can be adjusted according to the working temperature.

[0093] like Figure 3 The schematic diagram shown, Figure 3 All solid lines are fixed circuits, and the dotted lines have three states: installed resistor, short-circuited (short circuit), and suspended (open circuit). The disposal states of the eight points in the first circuit and the second circuit are shown in Table 1.

[0094] Table 1 The status of 8 points under two circuit structures

[0095]

[0096] In the first circuit: Install R between RA TC 、Install R between AB LC , Install R between B'-D' BAL , HC short-circuited, D-B' short-circuited, BC floating, C-C' floating, D-D' floating.

[0097] In the second circuit: install R between HC TC , Install R between BC LC , install R between C-C' BAL , RA short-circuited, D-D' short-circuited, AB floating, B'-D' floating, D-B' floating.

[0098] In this step, the resistance value of the temperature compensation resistor, the resistance value of the linear compensation resistor and the resistance value of the balance resistor in the circuit structure are determined according to the resistance value of the low potential of the output end of the Wheatstone bridge circuit structure, including:

[0099] A conversion relationship between the total resistance of the bridge arm where the strain gauge is measured, the total resistance of the bridge arm where the strain gauge is compensated, and the resistance value of the low potential at the output end of the Wheatstone bridge circuit structure is established.

[0100] Among them, when using the first circuit:

[0101] G=R A +R L +R TC

[0102]

[0103] When using the second circuit:

[0104]

[0105] H=R D +R L +R TC

[0106]

[0107] Where G is the total resistance of the bridge arm where the strain gauge is measured, H is the total resistance of the bridge arm where the strain gauge is compensated, J is the resistance value of the low potential at the output end of the Wheatstone bridge circuit structure, and R A To measure the resistance of the strain gauge, R D To compensate the resistance of the strain gauge, R L is the insulated cable resistance. TC is the temperature compensation resistor, R LC is the linear compensation resistor.

[0108] At the first temperature and the second temperature, the first resistance value (corresponding to the first temperature) and the second resistance value (corresponding to the second temperature) of the low potential of the output end of the Wheatstone bridge circuit structure are determined respectively; wherein the first temperature ranges from 0°C to 100°C, and the second temperature is the operating temperature of the device under test.

[0109] The total resistance value of the bridge arm where the strain gauge is measured and the total resistance value of the bridge arm where the strain gauge is compensated are changed multiple times, and the first resistance value and the second resistance value of the low potential of the output end of the Wheatstone bridge circuit structure are determined multiple times.

[0110] The resistance value of the temperature compensation resistor and the resistance value of the linear compensation resistor are determined according to the resistance value of the total resistance of the bridge arm where the corresponding measurement strain gauge is located and the resistance value of the total resistance of the bridge arm where the compensation strain gauge is located when the difference between the second resistance value and the first resistance value is the smallest.

[0111] Among them, the temperature compensation resistor R TC The optional resistance range is: R TC ∈(1Ω,20Ω); linear compensation resistor R LC The optional resistance range is: R LC ∈(2000Ω,13000Ω). In the temperature compensation resistor R TC and linear compensation resistor R LC Within the resistance range, select a set of temperature compensation resistors R whose difference between the second resistance and the first resistance is closest to zero. TC And linear compensation resistor R LC .

[0112] Specifically, use the ergodic method to substitute the resistance value J(25°C) of the low potential of the output terminal at 25°C and the resistance value J(T0) of the low potential of the output terminal at the operating temperature T0 of the device under test, and calculate:

[0113] ΔJ=|J(T0)-J(25℃)|

[0114] Wherein, ΔJ is the absolute value of the difference between the resistance value of the low potential of the output terminal at 25°C and the resistance value of the low potential of the output terminal at the operating temperature T0.

[0115] Get a set of temperature compensation resistors R with the smallest absolute value ΔJ TC And linear compensation resistor R LC .

[0116] The resistance value of the balancing resistor is calculated according to the first resistance value corresponding to when the difference between the second resistance value and the first resistance value is the smallest.

[0117] Among them, according to the requirement that the heat output of the strain gauge at room temperature after compensation is zero, the high potential of the output end is equal to the resistance value J (25°C), and the balance resistance R is calculated accordingly BAL , as follows:

[0118] When using the first circuit:

[0119]

[0120] When using the second circuit:

[0121]

[0122] S300: Detecting a detection strain value of the measuring strain gauge based on the circuit structure and measuring the measurement strain value of the measuring strain gauge by a measuring instrument.

[0123] In this step, after the measuring strain gauge is compensated by the circuit structure, the measuring strain gauge is tested to detect the detection strain value ε 热 is: 热 =2×10 -6 ×[J(25℃)-J(T)]. The measured strain value ε of the strain gauge is measured by the measuring instrument 仪 .

[0124] S400: Correcting the sensitivity coefficient of the measuring strain gauge according to the temperature compensation resistor, the linear compensation resistor and the insulation cable resistance to obtain a sensitivity coefficient correction value.

[0125] In this step, the sensitivity compensation coefficient is calculated according to the resistance value of the temperature compensation resistor, the resistance value of the linear compensation resistor and the resistance value of the insulating cable resistance. The current sensitivity coefficient is corrected by the sensitivity compensation coefficient, which corrects the problem of reduced sensitivity coefficient caused by the voltage divider of each resistance value of the bridge arm where the measuring strain gauge is located, thereby improving the measurement accuracy of the measuring strain gauge.

[0126] Specifically, when the first circuit is used, the sensitivity compensation coefficient is calculated based on the resistance of the temperature compensation resistor and the resistance of the insulating cable resistor. When the second circuit is used, the sensitivity compensation coefficient is calculated based on the resistance of the linear compensation resistor and the resistance of the insulating cable resistor.

[0127] The current sensitivity coefficient is corrected by the sensitivity compensation coefficient to obtain a sensitivity coefficient correction value, which specifically includes:

[0128] When using the first circuit:

[0129]

[0130] When using the second circuit:

[0131]

[0132] Among them, GF 修 is the sensitivity coefficient after correction, GF is the sensitivity coefficient before correction, RA To measure the resistance of the strain gauge, R L is the resistance of the insulated cable, R TC is the resistance of the temperature compensation resistor, R LC is the resistance value of the linear compensation resistor.

[0133] S500: Determine the output strain value of the measuring strain gauge according to the detected strain value, the measured strain value and the sensitivity coefficient correction value.

[0134] In this step, a strain compensation coefficient is generated based on the sensitivity coefficient correction value; and a strain difference between the detected strain value and the measured strain value is generated; and the product of the strain compensation coefficient and the strain difference is determined as the output strain value of the measuring strain gauge.

[0135] The specific calculation formula is as follows:

[0136]

[0137] Among them, ε 真 To measure the output strain value of the strain gauge after compensation, GF 修 is the corrected sensitivity coefficient, ε 仪 is the measured strain value of the strain gauge measured by the measuring instrument, ε 热 To detect the detection strain value of the strain gauge.

[0138] In this embodiment, the strain measurement of the measuring strain gauge and the compensating strain gauge is adopted, and the circuit structure of the Wheatstone bridge is determined according to the relationship between the measuring strain gauge and the resistance curve expression of the compensating strain gauge; the resistance value of the temperature compensation resistor, the resistance value of the linear compensation resistor and the resistance value of the balance resistor are determined by the resistance value of the low potential at the output end of the circuit structure; the heat output of the measuring strain gauge near the working temperature is greatly reduced by the circuit structure of the Wheatstone bridge, and the signal-to-noise ratio is improved. The problem of reduced sensitivity coefficient caused by the voltage division of each resistance value of the bridge arm where the measuring strain gauge is located is corrected according to the resistance value of the temperature compensation resistor, the resistance value of the linear compensation resistor and the resistance value of the insulating cable resistance. The output strain value of the measuring strain gauge is determined by detecting the strain value, the measuring strain value and the sensitivity coefficient correction value, and the measurement accuracy is improved.

[0139] like Figure 4 As shown, a strain gauge thermal output compensation device 400 provided in an embodiment of the present invention includes:

[0140] The linear module 410 is used to determine the relationship between the measurement strain gauge and the resistance curve expression of the compensation strain gauge; wherein the relationship is the relationship between the resistance of the strain gauge sensitive grid material and the temperature, the strain grid linear expansion coefficient and the linear expansion coefficient of the measured object, and the resistance curve expression is obtained by performing a calibration experiment on the compensation strain gauge with temperature changes;

[0141] A selection module 420 is used to determine the circuit structure of the Wheatstone bridge according to the measurement strain gauge relationship and the resistance curve expression of the compensation strain gauge; and determine the resistance value of the temperature compensation resistor, the resistance value of the linear compensation resistor and the resistance value of the balance resistor in the circuit structure according to the resistance value of the low potential at the output end of the Wheatstone bridge circuit structure;

[0142] A detection module 430, configured to detect a detection strain value of the measurement strain gauge based on the circuit structure and to measure a measurement strain value of the measurement strain gauge by a measuring instrument;

[0143] A correction module 440, configured to correct the sensitivity coefficient of the measuring strain gauge according to the temperature compensation resistor, the linear compensation resistor and the insulation cable resistance, to obtain a sensitivity coefficient correction value;

[0144] The compensation module 450 is used to determine the output strain value of the measuring strain gauge according to the detected strain value, the measured strain value and the sensitivity coefficient correction value.

[0145] Optionally, the selection module 420 is further used to determine that the correlation coefficient between the measurement strain gauge relationship and the corresponding fitting straight line is greater than the correlation coefficient between the resistance curve expression of the compensation strain gauge and the corresponding fitting straight line, and then determine that the first circuit is the circuit structure of the Wheatstone bridge;

[0146] Wherein, the first circuit includes: a measuring strain gauge, a compensating strain gauge, a first insulating cable resistor, a second insulating cable resistor, a third insulating cable resistor, a first voltage divider resistor, a second voltage divider resistor, a temperature compensation resistor, a linear compensation resistor and a balancing resistor;

[0147] The measuring strain gauge, the first insulating cable resistor, the temperature compensation resistor, the balancing resistor, the first voltage-dividing resistor, the second voltage-dividing resistor, the second insulating cable resistor, and the compensation strain gauge are connected in sequence to form a loop; the intersection between the measuring strain gauge and the compensation strain gauge is connected to one end of the third insulating cable resistor, and the other end of the third insulating cable resistor is connected to one end of the linear compensation resistor; the intersection between the second voltage-dividing resistor and the two insulating cable resistors is connected to the other end of the linear compensation resistor.

[0148] Optionally, the selection module 420 is further used to determine that the correlation coefficient between the measurement strain gauge relationship and the corresponding fitting straight line is less than the correlation coefficient between the resistance curve expression of the compensation strain gauge and the corresponding fitting straight line, and then determine that the second circuit is the circuit structure of the Wheatstone bridge;

[0149] Wherein, the second circuit includes: a measuring strain gauge, a compensating strain gauge, a first insulating cable resistor, a second insulating cable resistor, a third insulating cable resistor, a first voltage-dividing resistor, a second voltage-dividing resistor, a temperature compensation resistor, a linear compensation resistor and a balancing resistor;

[0150] The measuring strain gauge, the first insulated cable resistor, the first voltage-dividing resistor, the second voltage-dividing resistor, the balancing resistor, the temperature compensation resistor, the second insulated cable resistor, and the compensation strain gauge are connected in sequence to form a loop; the intersection between the measuring strain gauge and the compensation strain gauge is connected to one end of the third insulated cable resistor, and the other end of the third insulated cable resistor is connected to one end of the linear compensation resistor; the intersection between the first insulated cable resistor and the first voltage-dividing resistor is connected to the other end of the linear compensation resistor.

[0151] Optionally, the selection module 420 is also used to determine the first resistance value and the second resistance value of the low potential of the output end of the Wheatstone bridge circuit structure at a first temperature and a second temperature, respectively; wherein the range of the first temperature is 0°C-100°C, and the second temperature is the operating temperature of the measured object; the resistance value of the total resistance of the bridge arm where the measuring strain gauge is located and the resistance value of the total resistance of the bridge arm where the compensation strain gauge is located are changed multiple times, and the first resistance value and the second resistance value of the low potential of the output end of the Wheatstone bridge circuit structure are determined multiple times; according to the corresponding resistance value of the total resistance of the bridge arm where the measuring strain gauge is located and the resistance value of the total resistance of the bridge arm where the compensation strain gauge is located when the difference between the second resistance value and the first resistance value is the smallest, the resistance value of the temperature compensation resistor and the resistance value of the linear compensation resistor are determined.

[0152] Optionally, the selection module 420 is further configured to calculate the resistance of the balancing resistor according to the first resistance corresponding to the time when the difference between the second resistance and the first resistance is the smallest.

[0153] Optionally, the correction module 440 is further used to calculate a sensitivity compensation coefficient according to the resistance of the temperature compensation resistor, the resistance of the linear compensation resistor and the resistance of the insulated cable resistor; and to correct the current sensitivity coefficient based on the sensitivity compensation coefficient to obtain a sensitivity coefficient correction value.

[0154] Optionally, the compensation module 450 is used to generate a strain compensation coefficient based on the sensitivity coefficient correction value; generate a strain difference between the detected strain value and the measured strain value; and determine that the product of the strain compensation coefficient and the strain difference is the output strain value of the measuring strain gauge.

[0155] The strain gauge thermal output compensation device of this embodiment is used to implement the strain gauge thermal output compensation method as described above. Its advantages over the prior art are the same as the advantages of the strain gauge thermal output compensation method as described above over the prior art, and will not be repeated here.

[0156] like Figure 5 As shown, an electronic device 500 provided by an embodiment of the present invention includes a memory 520 and a processor 510; the memory 520 is used to store a computer program; the processor 510 is used to implement the strain gauge thermal output compensation method as described above when executing the computer program.

[0157] In other words, an electronic device 500 includes a memory 520 and a processor 510 coupled to the memory 520; the memory 520 is configured to store a computer program; and the processor 510 is configured to perform the following operations when executing the computer program:

[0158] Determine the measurement strain gauge relationship and the resistance curve expression of the compensation strain gauge; wherein the relationship is the relationship between the resistance of the strain gauge sensitive grid material and the temperature, the strain grid linear expansion coefficient and the linear expansion coefficient of the measured object, and the resistance curve expression is obtained by performing a calibration experiment on the compensation strain gauge with temperature changes;

[0159] Determine the circuit structure of the Wheatstone bridge according to the measurement strain gauge relationship and the resistance curve expression of the compensation strain gauge; and determine the resistance value of the temperature compensation resistor, the resistance value of the linear compensation resistor and the resistance value of the balance resistor in the circuit structure according to the resistance value of the low potential at the output end of the Wheatstone bridge circuit structure;

[0160] Detecting a detection strain value of the measuring strain gauge based on the circuit structure and measuring the measurement strain value of the measuring strain gauge by a measuring instrument;

[0161] Correcting the sensitivity coefficient of the measuring strain gauge according to the temperature compensation resistor, the linear compensation resistor and the insulation cable resistance to obtain a sensitivity coefficient correction value;

[0162] The output strain value of the measuring strain gauge is determined by the detected strain value, the measured strain value and the sensitivity coefficient correction value.

[0163] An embodiment of the present invention provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the strain gauge thermal output compensation method as described above is implemented.

[0164] In other words, a non-volatile computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the processor performs the following operations:

[0165] Determine the measurement strain gauge relationship and the resistance curve expression of the compensation strain gauge; wherein the relationship is the relationship between the resistance of the strain gauge sensitive grid material and the temperature, the strain grid linear expansion coefficient and the linear expansion coefficient of the measured object, and the resistance curve expression is obtained by performing a calibration experiment on the compensation strain gauge with temperature changes;

[0166] Determine the circuit structure of the Wheatstone bridge according to the measurement strain gauge relationship and the resistance curve expression of the compensation strain gauge; and determine the resistance value of the temperature compensation resistor, the resistance value of the linear compensation resistor and the resistance value of the balance resistor in the circuit structure according to the resistance value of the low potential at the output end of the Wheatstone bridge circuit structure;

[0167] Detecting a detection strain value of the measuring strain gauge based on the circuit structure and measuring the measurement strain value of the measuring strain gauge by a measuring instrument;

[0168] Correcting the sensitivity coefficient of the measuring strain gauge according to the temperature compensation resistor, the linear compensation resistor and the insulation cable resistance to obtain a sensitivity coefficient correction value;

[0169] The output strain value of the measuring strain gauge is determined by the detected strain value, the measured strain value and the sensitivity coefficient correction value.

[0170] An electronic device 500 that can be used as a server or client of the present invention will now be described, which is an example of a hardware device that can be applied to various aspects of the present invention. The electronic device 500 is intended to represent various forms of digital electronic computer equipment, such as laptop computers, desktop computers, workbenches, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device 500 can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples, and are not intended to limit the implementation of the present invention described and / or required herein.

[0171] The electronic device 500 includes a computing unit, which can perform various appropriate actions and processes according to a computer program stored in a read-only memory (ROM) or a computer program loaded from a storage unit into a random access memory (RAM). In the RAM, various programs and data required for the operation of the device can also be stored. The computing unit, ROM, and RAM are connected to each other via a bus. An input / output (I / O) interface is also connected to the bus.

[0172] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, the storage medium can be a disk, an optical disk, a read-only memory (ROM) or a random access memory (RAM), etc. In the present application, the unit described as a separate component may or may not be physically separated, and the component displayed as a unit may or may not be a physical unit, that is, it may be located in one place, or it may be distributed on multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the embodiment of the present invention. In addition, each functional unit in each embodiment of the present invention can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of a software functional unit.

[0173] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A strain gauge thermal output compensation method, applicable to a Wheatstone bridge, the Wheatstone bridge comprising: The measuring strain gauge and the compensating strain gauge are characterized in that the strain gauge thermal output compensation method includes: Determine the measurement strain gauge relationship and the resistance curve expression of the compensation strain gauge; wherein the relationship is the relationship between the resistance of the strain gauge sensitive grid material and the temperature, the strain grid linear expansion coefficient and the linear expansion coefficient of the measured object, and the resistance curve expression is obtained by performing a calibration experiment on the compensation strain gauge with temperature changes; Determine the circuit structure of the Wheatstone bridge according to the measurement strain gauge relationship and the resistance curve expression of the compensation strain gauge; and determine the resistance value of the temperature compensation resistor, the resistance value of the linear compensation resistor and the resistance value of the balance resistor in the circuit structure according to the resistance value of the low potential at the output end of the Wheatstone bridge circuit structure; Detecting a detection strain value of the measuring strain gauge based on the circuit structure and measuring the measurement strain value of the measuring strain gauge by a measuring instrument; Correcting the sensitivity coefficient of the measuring strain gauge according to the temperature compensation resistor, the linear compensation resistor and the insulation cable resistance to obtain a sensitivity coefficient correction value; The output strain value of the measuring strain gauge is determined by the detected strain value, the measured strain value and the sensitivity coefficient correction value.

2. The strain gauge thermal output compensation method according to claim 1, characterized in that: The circuit structure of the Wheatstone bridge is determined according to the measurement strain gauge relationship and the resistance curve expression of the compensation strain gauge, including: If it is determined that the correlation coefficient between the measurement strain gauge relationship and the corresponding fitting straight line is greater than the correlation coefficient between the resistance curve expression of the compensation strain gauge and the corresponding fitting straight line, then the first circuit is determined to be the circuit structure of the Wheatstone bridge; Wherein, the first circuit includes: a measuring strain gauge, a compensating strain gauge, a first insulating cable resistor, a second insulating cable resistor, a third insulating cable resistor, a first voltage divider resistor, a second voltage divider resistor, a temperature compensation resistor, a linear compensation resistor and a balancing resistor; The measuring strain gauge, the first insulating cable resistor, the temperature compensation resistor, the balancing resistor, the first voltage-dividing resistor, the second voltage-dividing resistor, the second insulating cable resistor, and the compensation strain gauge are sequentially connected to form a loop; The intersection point between the measuring strain gauge and the compensating strain gauge is connected to one end of the third insulating cable resistor, and the other end of the third insulating cable resistor is connected to one end of the linear compensation resistor; The intersection point between the second voltage-dividing resistor and the two insulated cable resistors is connected to the other end of the linear compensation resistor.

3. The strain gauge thermal output compensation method according to claim 1, characterized in that: The circuit structure of the Wheatstone bridge is determined according to the measurement strain gauge relationship and the resistance curve expression of the compensation strain gauge, including: If it is determined that the correlation coefficient between the measurement strain gauge relationship and the corresponding fitting straight line is less than the correlation coefficient between the resistance curve expression of the compensation strain gauge and the corresponding fitting straight line, then the second circuit is determined to be the circuit structure of the Wheatstone bridge; Wherein, the second circuit includes: a measuring strain gauge, a compensating strain gauge, a first insulating cable resistor, a second insulating cable resistor, a third insulating cable resistor, a first voltage-dividing resistor, a second voltage-dividing resistor, a temperature compensation resistor, a linear compensation resistor and a balancing resistor; The measuring strain gauge, the first insulating cable resistor, the first voltage-dividing resistor, the second voltage-dividing resistor, the balancing resistor, the temperature compensation resistor, the second insulating cable resistor, and the compensation strain gauge are sequentially connected to form a loop; The intersection point between the measuring strain gauge and the compensating strain gauge is connected to one end of the third insulating cable resistor, and the other end of the third insulating cable resistor is connected to one end of the linear compensation resistor; An intersection point between the first insulated cable resistor and the first voltage-dividing resistor is connected to the other end of the linear compensation resistor.

4. The strain gauge thermal output compensation method according to claim 1, characterized in that: The method of determining the resistance value of the temperature compensation resistor, the resistance value of the linear compensation resistor and the resistance value of the balance resistor in the circuit structure according to the resistance value of the low potential at the output end of the Wheatstone bridge circuit structure comprises: At a first temperature and a second temperature, respectively determining a first resistance value and a second resistance value of a low potential of an output end of the Wheatstone bridge circuit structure; wherein the first temperature ranges from 0°C to 100°C, and the second temperature is an operating temperature of the device under test; Changing the total resistance of the bridge arm where the measuring strain gauge is located and the total resistance of the bridge arm where the compensating strain gauge is located multiple times, and determining the first resistance and the second resistance of the low potential of the output end of the Wheatstone bridge circuit structure multiple times; The resistance value of the temperature compensation resistor and the resistance value of the linear compensation resistor are determined according to the resistance value of the total resistance of the bridge arm where the measurement strain gauge is located and the resistance value of the total resistance of the bridge arm where the compensation strain gauge is located when the difference between the second resistance value and the first resistance value is the smallest.

5. The strain gauge thermal output compensation method according to claim 4, characterized in that: Also includes: The resistance value of the balancing resistor is calculated according to the first resistance value corresponding to the time when the difference between the second resistance value and the first resistance value is the smallest.

6. The strain gauge thermal output compensation method according to claim 1, characterized in that: The step of correcting the sensitivity coefficient of the measuring strain gauge according to the temperature compensation resistor, the linear compensation resistor and the insulation cable resistance to obtain a sensitivity coefficient correction value includes: The sensitivity compensation coefficient is calculated according to the resistance value of the temperature compensation resistor, the resistance value of the linear compensation resistor and the resistance value of the insulation cable resistor; The current sensitivity coefficient is corrected based on the sensitivity compensation coefficient to obtain a sensitivity coefficient correction value.

7. The strain gauge thermal output compensation method according to claim 1, characterized in that: The step of determining the output strain value of the measuring strain gauge by using the detection strain value, the measurement strain value and the sensitivity coefficient correction value comprises: generating a strain compensation coefficient based on the sensitivity coefficient correction value; generating a strain difference between the detected strain value and the measured strain value; The product of the strain compensation coefficient and the strain difference is determined as the output strain value of the measuring strain gauge.

8. A strain gauge thermal output compensation device, characterized in that: include: A linear module, used to determine the relationship between the measurement strain gauge and the resistance curve expression of the compensation strain gauge; wherein the relationship is the relationship between the resistance of the strain gauge sensitive grid material and the temperature, the strain grid linear expansion coefficient and the linear expansion coefficient of the measured object, and the resistance curve expression is obtained by performing a calibration experiment on the compensation strain gauge with temperature changes; A selection module is used to determine the circuit structure of the Wheatstone bridge according to the measurement strain gauge relationship and the resistance curve expression of the compensation strain gauge; and determine the resistance value of the temperature compensation resistor, the resistance value of the linear compensation resistor and the resistance value of the balance resistor in the circuit structure according to the resistance value of the low potential at the output end of the Wheatstone bridge circuit structure; A detection module, used for detecting a detection strain value of the measurement strain gauge based on the circuit structure and measuring the measurement strain value of the measurement strain gauge by a measuring instrument; A correction module, used for correcting the sensitivity coefficient of the measuring strain gauge according to the temperature compensation resistor, the linear compensation resistor and the insulation cable resistance to obtain a sensitivity coefficient correction value; The compensation module is used to determine the output strain value of the measuring strain gauge through the detection strain value, the measurement strain value and the sensitivity coefficient correction value.

9. An electronic device, characterized in that: including memory and processor; The memory is used to store computer programs; The processor is used to implement the strain gauge thermal output compensation method according to any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium, characterized in that: The storage medium stores a computer program, and when the computer program is executed by the processor, the strain gauge thermal output compensation method according to any one of claims 1 to 7 is implemented.

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