Strain sensor detection jig and detection method thereof

Abstract

The invention provides a strain sensor detection jig and a detection method thereof, and the strain sensor detection jig comprises a pedestal which is provided with a fixing part used for placing a to-be-detected strain sensor; the telescopic unit comprises a driving piece arranged on the base and a moving block which extends in the first direction and is in transmission connection with the driving piece; the detection unit comprises a detection module used for detecting the strain sensor to be detected, and a cantilever module arranged on the moving block and used for connecting the detection module and the moving block; wherein the driving part is used for driving the detection module to move in a first direction so as to apply pressure with a preset numerical value to a strain sensor to be detected; the static noise, the sensitivity and the linearity of the strain sensor can be accurately detected, and the detection efficiency and the detection accuracy of the strain sensor are effectively improved.

Description

Technical Field

[0001] The present application belongs to the field of 3D printing technology, and specifically relates to a strain sensor detection jig and a detection method thereof. Background Art

[0002] A strain sensor is a sensor element used to measure the strain on the surface of an object. It is mainly based on the strain effect and piezoresistive effect of metal. The strain sensor can sensitively sense tiny deformations in the external environment and convert them into measurable electrical signals through changes in resistance. It is now widely used in the field of 3D printing technology.

[0003] During the 3D printing process, the precise movement of the nozzle, the uniformity of the extrusion of the printing consumables, and the real-time monitoring of the internal stress of the printed structure are extremely important to the quality of the final printed model. Strain sensors are usually installed at the nozzle. By accurately sensing the slight changes in resistance encountered by the nozzle when moving and extruding the consumables, the nozzle movement parameters and the amount of consumables extruded can be adjusted in a timely manner to ensure the stability and accuracy of the printing process. At the same time, strain sensors can also be installed on the printing platform to monitor the stress distribution and changes generated during the printing process in real time, avoiding printing defects caused by factors such as excessive stress concentration, thereby improving the quality and reliability of the printed model. Therefore, the sensitivity and linearity of the strain sensor are directly related to the accuracy of monitoring and controlling the printing process, and play a key role in ensuring printing quality.

[0004] However, the existing technology cannot directly and independently measure the sensitivity and linearity of the strain sensor before and after installation. It can only indirectly infer whether the strain sensor meets the performance requirements based on the net bed data obtained by the strain sensor. If the net bed data detection is inaccurate, it is difficult to locate problems related to the strain sensor, which has certain disadvantages. Summary of the Invention

[0005] The present application provides a strain sensor detection jig and a detection method thereof, which can accurately detect the static noise, sensitivity and linearity of the strain sensor, thereby improving the detection efficiency and detection accuracy of the strain sensor.

[0006] In order to solve the above technical problems, the present application provides a strain sensor detection jig, comprising:

[0007] A base, wherein the base is provided with a fixing member for placing the strain sensor to be detected;

[0008] a telescopic unit, the telescopic unit comprising a driving member disposed on the base, and a moving block extending along a first direction and transmission-connected to the driving member;

[0009] Detection unit, the detection unit includes a detection module for detecting the strain sensor to be detected, and a cantilever module provided on the moving block for connecting the detection module and the moving block;

[0010] Wherein, the driving member is used to drive the detection module to move in the first direction to apply a preset value of pressure to the strain sensor to be detected.

[0011] As a further improvement of the present application, the strain sensor to be detected at least includes a strain gauge die and / or a mounted strain gauge;

[0012] The detection module includes a first detection member disposed near the base for detecting the strain gauge die, and a second detection member disposed away from the base for detecting the mounted strain gauge.

[0013] As a further improvement of the present application, the first detection member is a detection probe, and the driving member is used to drive the detection probe to move in a direction close to the base, so that the detection probe contacts the strain gauge die provided on the fixing member and applies a preset value of pressure to the strain gauge die;

[0014] The second detection member is a detection top block, and the driving member is used to drive the detection top block to move in a direction away from the base, so that the detection top block contacts the mounted strain gauge disposed above the second detection member and applies a preset value of pressure to the mounted strain gauge.

[0015] As a further improvement of the present application, the first detection member and the second detection member are respectively disposed on opposite sides of the moving block;

[0016] Wherein, the first detection member is disposed on a side of the moving block close to the fixing member, the second detection member is disposed on a side of the moving block away from the fixing member, and the output shaft of the driving member is connected to the moving block for driving the moving block to move in the first direction.

[0017] As a further improvement of the present application, the cantilever module includes a first cantilever disposed at one end of the moving block close to the base for connecting the first detection member and the moving block, and a second cantilever disposed at one end of the moving block away from the base for connecting the second detection member and the moving block.

[0018] As a further improvement of the present application, the fixing member includes two fixing plates disposed on the base and extending in the first direction and being flush with each other;

[0019] Wherein, the height of the fixed plate in the first direction is not higher than the height of the first cantilever in the first direction, and the projection of the first detection member in the first direction falls between the two fixed plates.

[0020] Based on the above strain sensor detection jig, the present application further provides a strain sensor detection method, and the detection method includes the following steps:

[0021] Drive the first detection member or the second detection member to move in the first direction according to the type of the strain sensor to be detected, so that the first detection member or the second detection member is within a first preset distance from the strain sensor to be detected;

[0022] Drive the first detection member or the second detection member to move in the direction close to the strain sensor to be detected, and apply a first preset pressure to the strain sensor to be detected;

[0023] When the strain sensor to be detected detects the first preset pressure, drive the first detection member or the second detection member to move in the direction away from the strain sensor to be detected, so that the first detection member or the second detection member is within a second preset distance from the strain sensor to be detected; wherein, the first preset distance is greater than the second preset distance;

[0024] Determine the static noise of the strain sensor to be detected according to the fluctuation of the output data of the strain sensor to be detected.

[0025] As a further improvement of the present application, the driving the first detection member or the second detection member to move according to the type of the strain sensor to be detected includes:

[0026] When the strain sensor to be detected is a strain gauge die, place the strain gauge die on the fixing member, and drive the first detection member to move in the direction close to the strain gauge die;

[0027] When the strain sensor to be detected is a mounted strain gauge, mount the mounted strain gauge above the second detection member, and drive the second detection member to move in the direction close to the mounted strain gauge.

[0028] As a further improvement of the present application, after applying the first preset pressure to the strain sensor to be detected, it further includes:

[0029] Drive the first detection member or the second detection member to move in the direction away from the strain sensor to be detected, so that the first detection member or the second detection member retreats to a first distance;

[0030] Wherein, the first distance is less than the second preset distance.

[0031] As a further improvement of the present application, after determining the static noise of the strain sensor to be detected according to the fluctuation of the output data of the strain sensor to be detected, the method further includes:

[0032] Drive the first detection member or the second detection member to move in a direction close to the strain sensor to be detected, gradually apply pressure to the strain sensor to be detected until the first preset pressure is applied;

[0033] Collect the output data of the strain sensor to be detected under different applied pressures, and determine the sensitivity of the strain sensor to be detected according to the change of the output data.

[0034] As a further improvement of the present application, after collecting the output data of the strain sensor to be detected under different applied pressures, the method further includes:

[0035] Perform data fitting on a plurality of applied pressure data and the output data of the strain sensor to be detected under different pressure data to determine the linearity of the strain sensor to be detected.

[0036] The strain sensor detection jig and its detection method provided by the present application can drive the first detection member or the second detection member to move in the first direction through the telescopic unit, so as to apply a preset numerical pressure value to the strain sensor to be detected, and can accurately detect the static noise, sensitivity and linearity of the strain sensor, and can directly perform independent performance detection on the strain sensor before and after installation according to the type of the strain sensor, without disassembling the machine for detection, nor indirectly inferring whether the strain sensor meets the performance requirements from the obtained mesh bed data, effectively improving the detection efficiency and detection accuracy of the strain sensor; further improving the overall stability and reliability of the 3D printing device, reducing the printing quality problems caused by the poor performance of the strain sensor, and effectively improving the qualified rate of printed products. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0038] Figure 1 It is a schematic structural diagram of the strain sensor detection jig provided by the embodiment of the present application;

[0039] Figure 2 It is a schematic structural diagram of the display screen in the strain sensor detection jig provided by the embodiment of the present application;

[0040] Figure 3Schematic structural diagram of the strain sensor to be detected in the strain sensor detection jig provided by the embodiment of the present application;

[0041] Figure 4 Flowchart of the strain sensor detection method provided by the embodiment of the present application;

[0042] Figure 5 Flowchart of retracting to the first distance in the strain sensor detection method provided by the embodiment of the present application;

[0043] Figure 6 Flowchart of detecting sensitivity and linearity in the strain sensor detection method provided by the embodiment of the present application;

[0044] Explanation of reference numerals:

[0045] 10 - Base; 11 - Fixing member; 111 - Fixing plate; 12 - First knob; 13 - Second knob; 14 - Display screen;

[0046] 20 - Telescopic unit; 21 - Driving member; 22 - Moving block; 23 - Output shaft;

[0047] 30 - Detection unit; 31 - Detection module; 311 - First detection member; 312 - Second detection member; 32 - Cantilever module; 321 - First cantilever; 322 - Second cantilever; 40 - Strain gauge die; 50 - Mounted strain gauge. Detailed implementation manners

[0048] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0049] In the description of the present application, "a plurality of" means at least two, such as two, three, etc., unless otherwise specifically defined. In all the directional indications (such as up, down, left, right, front, back...) in the embodiments of the present application, they are only used to explain the relative position relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion.

[0050] To make the description of the present disclosure more detailed and complete, the following provides an illustrative description of the implementation manners and specific embodiments of the present application; however, this is not the only form for implementing or applying the specific embodiments of the present application. The implementation manners cover the features of multiple specific embodiments and the method steps and their sequences for constructing and operating these specific embodiments. However, other specific embodiments can also be used to achieve the same or equivalent functions and step sequences.

[0051] A strain sensor is a sensor element used to measure the surface strain of an object, mainly realized based on the strain effect and piezoresistive effect of metals. The strain sensor can sensitively sense minute deformations from the outside world and convert them into measurable electrical signals through changes in resistance, and is now widely used in the field of 3D printing technology.

[0052] During the 3D printing process, the precise movement of the print head, the uniformity of the extrusion of the printing consumables, and the real-time monitoring of the internal stress of the printed structure are very important for the quality of the final printed model. Usually, a strain sensor needs to be installed at the print head. By precisely sensing the minute resistance changes suffered by the print head when moving and extruding the consumables, the movement parameters of the print head and the extrusion amount of the consumables can be adjusted in a timely manner to ensure the stability and precision of the printing process; at the same time, the strain sensor can also be installed on the printing platform to real-time monitor the stress distribution and changes during the printing process, avoiding printing defects caused by factors such as excessive stress concentration, thereby improving the quality and reliability of the printed model.

[0053] It can be seen that the sensitivity and linearity of the strain sensor are directly related to the precision of the monitoring and control of the printing process and play a key role in ensuring the printing quality. However, in the prior art, the sensitivity and linearity of the strain sensor cannot be directly measured independently before and after installation. Only the bed data obtained by the strain sensor can be used to indirectly infer whether the strain sensor meets the performance requirements. In the case where the bed data detection is inaccurate, it is very difficult to locate the problems related to the strain sensor, and there are certain drawbacks.

[0054] Please refer to Figures 1-6 , the embodiment of the present application provides a strain sensor detection jig and its detection method, which can directly perform independent performance detection on the strain sensor before and after installation, effectively improving the detection efficiency and detection precision of the strain sensor.

[0055] Please refer to Figure 1 , which is a schematic structural diagram of the strain sensor detection jig provided by the embodiment of the present application. The strain sensor detection jig includes a base 10, a fixing member 11 provided on the base 10 for placing the strain sensor to be detected, a telescopic unit 20 provided on the base 10, and a detection unit 30 capable of detecting the strain sensor to be detected.

[0056] For example, please refer to Figure 3 , which is a schematic diagram of the structure of the strain sensor to be detected in the strain sensor detection jig provided in an embodiment of the present application. The types of the strain sensor to be detected include at least a bare strain gauge 40 and / or an installed strain gauge 50. Figure 3 The strain sensor directly placed on the fixing part 11 is shown as a bare strain gauge 40, and the strain sensor installed on the print head is called an installed strain gauge 50. Of course, other installation forms of installed strain gauges 50 are also feasible. This application does not impose too many restrictions on the specific type and specific installation form of the strain sensor to be detected.

[0057] As an optional implementation, please continue to refer to Figure 1 The telescopic unit 20 provided in the present application includes a driving member 21 arranged on the base 10, and a moving block 22 extending along the first direction and transmission-connected to the driving member 21, and the moving block 22 is driven by the driving member 21 to move in the first direction.

[0058] Furthermore, the above-mentioned detection unit 30 includes a detection module 31 for detecting the strain sensor to be detected, and a cantilever module 21 arranged on the moving block 22 for connecting the detection module 31 and the moving block 22. The present application fixes the detection module 31 on the moving block 22 through the cantilever module 21, and drives the detection module 31 to move in the first direction through the driving member 21, thereby applying a preset pressure value to the strain sensor to be detected.

[0059] In a specific embodiment provided in the present application, the above-mentioned first direction is defined as the height direction, and the detection module 31 is driven to move in the height direction by the driving member 21, and a preset pressure value is applied to the strain sensor to be detected. By collecting the output data of the strain sensor to be detected, the static noise, sensitivity and linearity of the strain sensor to be detected are detected.

[0060] Preferably, the present application is provided with a first detection member 311 for detecting the strain gauge bare chip 40 and a second detection member 312 for detecting the installed strain gauge 50 according to the type of strain sensor to be detected. The first detection member 311 is driven by the driving member 21 to move in the height direction, and a preset pressure value is applied to the strain gauge bare chip 40 to achieve detection of the strain gauge bare chip 40. Alternatively, the second detection member 312 is driven by the driving member 21 to move in the height direction, and a preset pressure value is applied to the installed strain gauge 50 to achieve detection of the installed strain gauge 50.

[0061] In some optional embodiments, please refer to Figure 2, which is a structural schematic diagram of the display screen in the strain sensor detection jig provided in an embodiment of the present application. In the present application, the first detection member 311 is set in the form of a detection probe, and the driving member 21 drives the detection probe to move in a direction close to the base 10, so that the detection probe contacts the strain gauge bare piece 40 provided on the fixing member 11, thereby applying a preset pressure value to the strain gauge bare piece 40.

[0062] Correspondingly, since the installed strain gauge 50 is usually large in size and is not convenient to be placed directly on the base 10, the present application sets the second detection member 312 in the form of a detection top block, and drives the detection top block to move in a direction away from the base 10 through the driving member 21, so that the detection top block contacts the installed strain gauge 50 mounted above the second detection member 312, thereby applying a preset pressure value to the installed strain gauge 50.

[0063] It is understandable that, since the strain gauge bare piece 40 is usually small in size and relatively fragile, the first detection piece 311 is set to a more delicate detection probe form, so as to accurately contact the strain gauge bare piece 40 and apply a precise pressure value to the strain gauge bare piece 40; and since the installed strain gauge 50 has been installed in the equipment, there may be other components or structures around the installed strain gauge 50, so it can withstand pressure over a certain area, and the larger contact surface of the detection top block can more evenly apply the preset pressure to the installed strain gauge 50, which is more in line with its actual stress conditions, and can also avoid damage to the installed strain gauge 50 due to pressure concentration.

[0064] Preferably, the present application arranges the first detection member 311 and the second detection member 312 on opposite sides of the movable block 22. Since the strain gauge bare sheet 40 needs to be placed on the fixed member 11 when testing the strain gauge bare sheet 40, the first detection member 311 is preferably arranged on the side of the movable block 22 close to the fixed member 11, and the second detection member 312 is arranged on the side of the movable block 22 away from the fixed member 11.

[0065] Furthermore, the output shaft 23 of the driving member 21 is connected to the moving block 22 by transmission, and the moving block 22 is driven to move in the first direction by the driving member 21, so that when the driving member 21 drives the moving block 22 to move in the first direction, it drives the first detection member 311 and / or the second detection member 312 to move in the first direction, thereby applying a preset value of pressure to the strain sensor to be predicted.

[0066] In an alternative embodiment, the cantilever module 32 provided in the present application includes a first cantilever 321 disposed at one end of the moving block 22 close to the base 10, and a second cantilever 322 disposed at one end of the moving block 22 away from the base 10. The first detecting member 311 is fixed to one end of the moving block 22 close to the base 10 through the first cantilever 321, and the second detecting member 312 is fixed to one end of the moving block 22 away from the base 10 through the second cantilever 322.

[0067] Of course, other structures of the telescopic unit 20 that can drive the first detecting member 311 and the second detecting member 312 to move in the first direction are also feasible, and the present application does not impose excessive restrictions on the specific setting form of the telescopic unit 20.

[0068] As an alternative embodiment, the fixing member 11 provided in the present application includes two fixing plates 111 disposed on the base 10. The two fixing plates 111 are extended along the first direction and the ends of the two fixing plates 111 are ensured to be flush, so that the strain gauge die 40 is mounted between the ends of the two fixing plates 11. The height of the fixing plate 11 in the first direction is restricted to be not higher than the height of the first cantilever 321 in the first direction, ensuring that the projection of the first detecting member 311 in the first direction falls between the two fixing members 11. Only in this way can the first detecting member 311 contact the strain gauge die 40 disposed between the two fixing members 11 when moving in the first direction, so as to apply a preset pressure value to the strain gauge die 40.

[0069] Further, the present application further provides a first knob 12 for switching the detection mode on the base 10, and a second knob 13 for driving the moving block 22 to move in the first direction.

[0070] It can be understood that since the detection modes corresponding to the strain gauge die 40 and the installed strain gauge 50 are different, the present application selects the specific detection mode through the first knob 12, and drives the moving block 22 to move in the first direction through the second knob 13, so as to move the first detecting member 311 or the second detecting member 312 to a preset position for the next performance detection of the strain sensor to be detected.

[0071] Please continue to refer to Figure 2 , the present application also provides a display screen 14 on the base 10 for displaying the detection state of the strain sensor, so that the operator can timely know the detection situation of the current strain sensor to be detected. Of course, other setting methods that can display or prompt the current detection state of the strain sensor are also feasible, and the present application does not impose excessive restrictions on this.

[0072] Based on the above strain sensor detection jig, please refer to Figure 4, which is a flowchart of the strain sensor detection method provided by the embodiments of the present application. The present application also provides a strain sensor detection method, which can detect the static noise, sensitivity and linearity of the strain sensor, and specifically includes the following steps:

[0073] Step S1: Drive the first detection member or the second detection member to move in the first direction according to the type of the strain sensor to be detected, so that the first detection member or the second detection member is within a first preset distance from the strain sensor to be detected;

[0074] As an optional implementation manner, driving the first detection member or the second detection member to move according to the type of the strain sensor to be detected includes:

[0075] When the strain sensor to be detected is a strain gauge die, place the strain gauge die on a fixing member, and drive the first detection member to move in a direction close to the strain gauge die;

[0076] When the strain sensor to be detected is a mounted strain gauge, mount the mounted strain gauge above the second detection member, and drive the second detection member to move in a direction close to the mounted strain gauge.

[0077] In the embodiments of the present application, the type of the strain sensor to be detected at least includes a strain gauge die and / or a mounted strain gauge. When the type of the strain sensor to be detected is a strain gauge die, place the strain gauge die between two fixing plates, and drive the first detection member to move in a direction close to the strain gauge die; when the type of the strain sensor to be detected is a mounted strain gauge, mount the mounted strain gauge above the second detection member, and drive the second detection member to move in a direction close to the mounted strain gauge.

[0078] Further, drive the first detection member or the second detection member to move in a direction close to the strain sensor to be detected, so that the first detection member or the second detection member is within a first preset distance from the strain sensor to be detected.

[0079] In an optional embodiment, it is necessary to initialize the device first, drive the first detection member or the second detection member to move in a direction close to the strain sensor to be detected, so that the first detection member or the second detection member is within 10 mm of the strain sensor to be detected.

[0080] Step S2: Drive the first detection member or the second detection member to move in a direction close to the strain sensor to be detected, and apply a first preset pressure to the strain sensor to be detected;

[0081] In an embodiment of the present application, after driving the first detection member or the second detection member within a first preset distance from the strain sensor to be detected, continue to drive the first detection member or the second detection member to move in a direction close to the strain sensor to be detected, so that the first detection member or the second detection member comes into contact with the strain sensor to be detected, and apply a first preset pressure to the strain sensor to be detected.

[0082] It can be understood that the first preset pressure here is preferably the maximum pressure value that the strain sensor to be detected can theoretically accept, and the present application does not further limit the value of the first preset pressure here.

[0083] As an alternative embodiment, please refer to Figure 5 , which is a flowchart of retreating to the first distance in the strain sensor detection method provided by the embodiment of the present application. After applying the first preset pressure to the strain sensor to be detected, the following steps are further included:

[0084] Step S21: Drive the first detection member or the second detection member to move in a direction away from the strain sensor to be detected, so that the first detection member or the second detection member retreats to a first distance;

[0085] Wherein, the first distance is less than the second preset distance.

[0086] In an embodiment of the present application, after applying the first preset pressure to the strain sensor to be detected, it is necessary to control the first detection member or the second detection member to retreat to the first distance.

[0087] It can be understood that since the strain sensor is usually made of sensitive materials, it may undergo irreversible plastic deformation when under long-term or excessive pressure, resulting in a decrease in sensitivity and linearity; and in the present application, this rebound action of retreating to the first distance after that can ensure that the load is immediately released after applying the preset pressure, avoiding performance drift of the strain sensor due to continuous stress, and ensuring that it can still maintain its original working state after detection, which is particularly important for the installed strain gauge after installation, avoiding damage to its normal use during the detection process; and retreating to the first distance here can completely release the contact pressure, enabling the strain sensor to return to a no-load state, ensuring signal stability during subsequent detection or actual operation.

[0088] Step S3: When the strain sensor to be detected detects the first preset pressure, drive the first detection member or the second detection member to move in a direction away from the strain sensor to be detected, so that the first detection member or the second detection member is within a second preset distance from the strain sensor to be detected; wherein, the first preset distance is greater than the second preset distance;

[0089] In an alternative embodiment, a pressure value of 500 g needs to be applied to the strain sensor to be detected. When the strain sensor to be detected first detects a pressure value of 500 g, lift the first detection member or the second detection member, and stop applying pressure to the strain sensor to be detected by the first detection member or the second detection member.

[0090] At the same time, drive the first detection member or the second detection member to move in a direction away from the strain sensor to be detected, so that the distance between the first detection member or the second detection member and the strain sensor to be detected is a second preset distance. It should be noted that the second preset distance here is greater than the first distance set for the above-mentioned springback and less than the first preset distance.

[0091] For example, in a specific embodiment provided in the present application, the above-mentioned first preset distance can be set to 10 mm, the above-mentioned second preset distance can be set to 1 mm, and the above-mentioned first distance can be set to 0.02 mm. That is to say, when the strain sensor to be detected detects a pressure value of 500 g, it will first drive the first detection member or the second detection member to retreat to the first distance of 0.02 mm, and then drive the first detection member or the second detection member to move in a direction away from the strain sensor to be detected, so that the distance between the first detection member or the second detection member and the strain sensor to be detected is within 1 mm.

[0092] Of course, the specific values of the above-mentioned first distance, first preset distance, and second preset distance can be adjusted according to actual test requirements, and the present application does not make further restrictions on this.

[0093] Step S4: Determine the static noise of the strain sensor to be detected according to the fluctuation of the output data of the strain sensor to be detected.

[0094] In the embodiment of the present application, when the strain sensor to be detected first detects the above-mentioned applied first preset pressure, the first detection member or the second detection member should be driven to retreat to the first distance, and continue to drive the first detection member or the second detection member to move in a direction away from the strain sensor to be detected, so that the distance between the first detection member or the second detection member and the strain sensor to be detected is the second preset distance. At the same time, collect a number of output data of the strain sensor to be detected under static no-load conditions, and determine the static noise of the strain sensor to be detected according to the fluctuation of the number of output data.

[0095] In an alternative embodiment, the fluctuation of the number of output data can be obtained by subtracting the minimum value from the maximum value among the number of output data, and the obtained difference is used as the static noise of the strain sensor to be detected for subsequent evaluation of the performance of the strain sensor to be detected.

[0096] Exemplarily, 1024 output data of the strain sensor to be detected can be collected under static and unloaded conditions, and the maximum and minimum values of this set of output data are obtained. The fluctuation of this set of output data is obtained by subtracting the minimum value from the maximum value among the 1024 output data, and the obtained difference is used as the static noise of the strain sensor to be detected.

[0097] Of course, other methods capable of obtaining the fluctuation of several output data are also feasible. The present application does not further limit the specific number of output data and the method of calculating the fluctuation of several output data.

[0098] It can be understood that static noise is one of the important parameters for evaluating a strain sensor. Static noise will affect the decision threshold and measurement accuracy of the strain sensor measurement. Therefore, the present application needs to detect the static noise of the strain sensor here.

[0099] As an alternative implementation manner, please refer to Figure 6 , which is the flowchart for detecting the sensitivity and linearity in the strain sensor detection method provided by the embodiment of the present application. After determining the static noise of the strain sensor to be detected according to the fluctuation of the output data of the strain sensor to be detected, the following steps are further included:

[0100] Step S5: Drive the first detection member or the second detection member to move in a direction close to the strain sensor to be detected, and gradually apply pressure to the strain sensor to be detected until the first preset pressure is applied.

[0101] In the embodiment of the present application, after the noise detection of the strain sensor is completed, the strain sensor can be allowed to stand still for a period of time to release the stress, so as to ensure that the measurement of the sensitivity is more accurate.

[0102] Since in step S3, the first detection member or the second detection member has been driven to move in a direction away from the strain sensor to be detected, so that the distance between the first detection member or the second detection member and the strain sensor to be detected is the second preset distance. Therefore, after the strain sensor finishes standing still, the first detection member or the second detection member will continue to be driven to move in a direction close to the strain sensor, and gradually apply pressure to the strain sensor to be detected until the first preset pressure is applied.

[0103] In an alternative embodiment, taking the first preset pressure as 500 g as an example for illustration, it is necessary to gradually apply pressure to the strain sensor to be detected starting from 0 g until the first preset pressure of 500 g is applied.

[0104] During the process of gradually applying pressure, pressure values from 0g to 500g with a step of 50g can be applied to the strain sensor to be detected. Pressure values with steps of 20g and 40g can also be gradually applied. In principle, as long as the pressure is gradually applied from 0g to 500g, this application does not impose further restrictions on this.

[0105] Step S51: Collect the output data of the strain sensor to be detected under different applied pressures, and determine the sensitivity of the strain sensor to be detected according to the change of the output data.

[0106] In the embodiment of this application, when gradually applying pressure to the strain sensor to be detected through the first detection component or the second detection component, it is necessary to collect the output data of the strain sensor to be detected under different applied pressures, and determine the sensitivity of the strain sensor to be detected according to the change of the output data.

[0107] It should be noted that the output data of the strain sensor to be detected refers to the adc (Analog-to-Digital Converter) voltage value of the strain sensor. The strain sensor is equivalent to a resistor whose resistance changes under force. The adc chip can only measure voltage. When the strain sensor is under force, the resistance changes, resulting in a voltage change on the adc chip, and thus the relative change relationship between the force on the strain sensor and the adc data can be obtained. Therefore, the adc voltage value of the strain sensor is used as the output data of the strain sensor to be detected.

[0108] When applying pressure values from 0g to 500g with a step of 50g to the strain sensor to be detected, calculate the change data of the strain sensor every 50g, and use it as the sensitivity of the strain sensor every 50g, then the sensitivity of the strain sensor to be detected can be determined.

[0109] As an optional implementation manner, after collecting the output data of the strain sensor to be detected under different applied pressures, it further includes:

[0110] Perform data fitting on several applied pressure data and the output data of the strain sensor to be detected under different pressure data to determine the linearity of the strain sensor to be detected.

[0111] In the embodiment of this application, after collecting the output data of the strain sensor to be detected under different applied pressures, data fitting can also be performed on several applied pressure data and the output data of the strain sensor to be detected under different pressure data, so as to determine the linearity of the strain sensor to be detected.

[0112] In an alternative embodiment, when a pressure value ranging from 0 g to 500 g in steps of 50 g is applied to the strain sensor to be detected, the output data of the strain sensor to be detected corresponding to each pressure data is recorded. By means of the coefficient of determination R2 of linear regression in statistics, data fitting is performed on a number of applied pressure data and the output data of the strain sensor to be detected under different pressure data, so as to determine the linearity of the strain sensor to be detected.

[0113] Of course, this application does not elaborate too much on the above specific step value and the specific steps of fitting by the coefficient of determination of linear regression. Those skilled in the art should be aware of this.

[0114] It should be noted that static noise, sensitivity, and linearity are all important parameters for evaluating strain sensors. Especially in the field of leveling of 3D printed strain sensors, static noise is essentially the unstable electrical signal output by the strain sensor when there is no external force, which determines the minimum strain value that the strain sensor can reliably detect, affects the decision threshold and measurement accuracy of the strain sensor measurement, linearity affects the stability and consistency of the measurement, and good linearity means that there is a good linear relationship between the output electrical signal of the strain sensor and the strain it receives. In this way, at different strain levels, the measurement results can maintain high accuracy and repeatability. Sensitivity affects the measurement sensitivity. A strain sensor with high sensitivity can generate a large resistance change for a small strain change, thereby improving the measurement resolution and enabling the measurement system to distinguish smaller strain differences. Therefore, this application focuses on accurately detecting the static noise, sensitivity, and linearity of the strain sensor through the above-mentioned jig, and can directly perform independent performance detection on the strain sensor before and after installation according to the type of the strain sensor, without the need for disassembly detection, nor indirectly inferring whether the strain sensor meets the performance requirements from the mesh bed data obtained by the strain sensor, effectively improving the detection efficiency and detection accuracy of the strain sensor.

[0115] For the specific details of how the strain sensor detection method achieves the above technical solution, please refer to the relevant description of the above strain sensor detection jig. This application does not elaborate too much on this.

[0116] It can be understood that the technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as within the scope described in this specification.

[0117] The above embodiments are merely exemplary embodiments adopted to illustrate the principle of the present application. However, the present application is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present application, and these modifications and improvements are also regarded as the protection scope of the present application.

Claims

1. A strain sensor detection jig, characterized in that Comprising: A base, on which a fixing member for placing a strain sensor to be detected is provided; A telescopic unit, which includes a driving member provided on the base, and a moving block extending in a first direction and drivingly connected to the driving member; A detecting unit, which includes a detecting module for detecting the strain sensor to be detected, and a cantilever module provided on the moving block for connecting the detecting module and the moving block; Wherein, the driving member is used to drive the detecting module to move in the first direction so as to apply a preset value of pressure to the strain sensor to be detected.

2. The strain sensor detection jig according to claim 1, characterized in that, The strain sensor to be detected at least includes a strain gauge die and / or a mounted strain gauge; The detecting module includes a first detecting member disposed close to the base for detecting the strain gauge die, and a second detecting member disposed away from the base for detecting the mounted strain gauge.

3. The strain sensor detection jig according to claim 2, characterized in that, The first detecting member is a detecting probe, and the driving member is used to drive the detecting probe to move in a direction close to the base so that the detecting probe contacts the strain gauge die provided on the fixing member and applies a preset value of pressure to the strain gauge die; The second detecting member is a detecting top block, and the driving member is used to drive the detecting top block to move in a direction away from the base so that the detecting top block contacts the mounted strain gauge disposed above the second detecting member and applies a preset value of pressure to the mounted strain gauge.

4. The strain sensor detection jig according to claim 2, wherein, The first detecting member and the second detecting member are respectively disposed on opposite sides of the moving block; Wherein, the first detecting member is disposed on the side of the moving block close to the fixing member, the second detecting member is disposed on the side of the moving block away from the fixing member, and the output shaft of the driving member is connected to the moving block for driving the moving block to move in the first direction.

5. The strain sensor detection jig according to claim 2, wherein, The cantilever module includes a first cantilever disposed at one end of the moving block close to the base for connecting the first detecting member and the moving block, and a second cantilever disposed at the other end of the moving block away from the base for connecting the second detecting member and the moving block.

6. The strain sensor detection fixture according to claim 5, wherein, The fixing member includes two fixing plates disposed on the base and extending in the first direction and being flush with each other; Wherein, the height of the fixing plate in the first direction is not higher than the height of the first cantilever in the first direction, and the projection of the first detecting member in the first direction falls between the two fixing plates.

7. A strain sensor detection method, characterized in that Applied to the strain sensor detecting jig according to any one of claims 2-6, the detecting method includes the following steps: Driving the first detecting member or the second detecting member to move in the first direction according to the type of the strain sensor to be detected so that the first detecting member or the second detecting member is within a first preset distance from the strain sensor to be detected; Driving the first detecting member or the second detecting member to move in a direction close to the strain sensor to be detected and applying a first preset pressure to the strain sensor to be detected; When the strain sensor to be detected detects the first preset pressure, drive the first detection member or the second detection member to move away from the strain sensor to be detected, so that the first detection member or the second detection member is within a second preset distance from the strain sensor to be detected; wherein, the first preset distance is greater than the second preset distance; Determine the static noise of the strain sensor to be detected according to the fluctuation of the output data of the strain sensor to be detected.

8. The strain sensor detection method according to claim 7, wherein, The driving the first detection member or the second detection member to move according to the type of the strain sensor to be detected includes: When the strain sensor to be detected is a bare strain gauge, place the bare strain gauge on a fixing member, and drive the first detection member to move in a direction close to the bare strain gauge; When the strain sensor to be detected is a mounted strain gauge, mount the mounted strain gauge above the second detection member, and drive the second detection member to move in a direction close to the mounted strain gauge.

9. The strain sensor detection method according to claim 7, wherein, After applying the first preset pressure to the strain sensor to be detected, it further includes: Drive the first detection member or the second detection member to move away from the strain sensor to be detected, so that the first detection member or the second detection member retreats to a first distance; Wherein, the first distance is less than the second preset distance.

10. The strain sensor detection method according to claim 7, wherein After determining the static noise of the strain sensor to be detected according to the fluctuation of the output data of the strain sensor to be detected, it further includes: Drive the first detection member or the second detection member to move in a direction close to the strain sensor to be detected, and gradually apply pressure to the strain sensor to be detected until the first preset pressure is applied; Collect the output data of the strain sensor to be detected under different applied pressures, and determine the sensitivity of the strain sensor to be detected according to the change of the output data.

11. The strain sensor detection method according to claim 10, wherein, After collecting the output data of the strain sensor to be detected under different applied pressures, it further includes: Perform data fitting on a plurality of applied pressure data and the output data of the strain sensor to be detected under different pressure data to determine the linearity of the strain sensor to be detected.

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