Three-component force sensor calibration device based on high-strength fiber material

Abstract

The utility model provides a three-component force sensor calibration device based on a high-strength fiber material, which comprises a base, a standard force measuring platform, a lifting platform, a mounting platform, a clamp, a radial loading module and an axial loading module, the base comprises a main base, a secondary base and a clamping device, the clamp comprises a top clamp and a bottom clamp, a short shaft extends out of the top clamp; the radial loading module comprises an adjustable standard force value weight set and a first flexible connecting mechanism, and the standard force value weight set is detachably hung on the short shaft through the first flexible connecting mechanism; the axial loading module comprises a module base body and a plurality of flexible loading heads which are evenly distributed in the circumferential direction about the horizontal axis, the axial ends of the flexible loading heads are fixedly connected to the module base body, and the module base body is connected to the secondary base through a second flexible connecting mechanism. According to the utility model, the flexible loading head and the second flexible connecting mechanism are arranged to realize a dual decoupling mechanism, and the axial loading module is ensured not to introduce parasitic frictional resistance to the tested sensor.

Description

Technical Field

[0001] The utility model belongs to the field of mechanical measurement, and in particular relates to a three-component force sensor calibration device based on high-strength fiber material. Background Art

[0002] With the continuous improvement of productivity, multi-component force sensors including three-component force sensors have been more and more widely used in artificial intelligence, robotics, aerospace, automotive industry, heavy machinery, intelligent manufacturing, advanced medical and other fields. The value traceability problem of three-component force sensors has also emerged: when using traditional force standard machines for calibration, special fixtures need to be customized to limit the displacement of the sensor under test in the direction of the test component, and there are problems such as the need for repeated installation, limited positioning accuracy, inability to test coupling errors, and complex operation procedures; when using a special calibration device for six-component force sensors, it will face the problem of reduced accuracy caused by redundant degrees of freedom and customization of additional adapter components. Therefore, it is necessary to design a special calibration device based on the technical characteristics of the three-component force sensor.

[0003] According to the comparison standard, the mainstream multi-component force sensor calibration devices at home and abroad can be divided into: 1. Calibration device with weight gravity as the comparison standard; 2. Calibration device with single-component standard dynamometer as the comparison standard; 3. Calibration device with multi-component force sensor as the comparison standard. The calibration device with weight gravity as the comparison standard usually uses a steel cable as the connection between the loading head and the force source. In order to ensure the test accuracy, and at the same time limited by the weight volume, the calibration device has a large installation space requirement, so its measurement upper limit generally does not exceed 400kN, which cannot meet the calibration requirements of large-value sensors, and this type of device can only be loaded in stages, and is mainly aimed at special force sensors with slender geometric appearances that are common in the aerospace field, and it is difficult to test general sensors. The calibration device with a single-component standard dynamometer as the comparison standard has a relatively wider range of force sources, so it can greatly increase the test range while ensuring a smaller installation space, and the operation is also more convenient. However, since the force value is generally transmitted from the force source system to the sensor under test through a rigid structural member, a large error will be generated due to parasitic friction resistance when testing the coupling error. The calibration device using the multi-component force sensor as the comparison standard is calibrated by directly comparing the output of the sensor under test and the multi-component force sensor of the device itself. However, because the geometric centers of the two sensors cannot coincide in at least one direction, the direct measurement results are inherently subject to systematic errors caused by geometric shape and position. In order to ensure good sensitivity, the stiffness of the multi-component force sensor used as the comparison standard in the six degrees of freedom of space will not be too large. The error introduced by the deformation of the calibration device during actual measurement cannot be ignored, thereby reducing the calibration accuracy. In addition, the multi-component force sensor itself also has the disadvantage of difficult traceability, which will have an adverse effect on the subsequent maintenance of the device. In addition, the latter two types of calibration devices require additional force source modules, and most common modules are based on electric cylinders or hydraulic cylinders, which lack the ability to provide high output accuracy within a small force range.

[0004] To sum up, at present, how to reduce the space occupied by the multi-component force sensor calibration device and maximize the flexibility of subsequent traceability of the device while enhancing versatility, reducing crosstalk errors, and improving test accuracy are technical problems that need to be urgently solved for this type of calibration device. Utility Model Content

[0005] In view of the defects of the above-mentioned prior art, the purpose of the utility model is to provide a three-component force sensor calibration device based on high-strength fiber material and a calibration method thereof - especially for small-range three-component force sensors - while ensuring the individual and precise loading of multi-component forces and the loading of two-by-two combinations, the device structure is greatly simplified and the manufacturing cost is reduced; based on the phase difference principle, the selectable force direction of the calibration device on the sub-coordinate xy plane where the sensor under test is located is greatly improved; a dual decoupling mechanism is set to improve the decoupling level of the calibration device under the combined loading conditions of the radial loading module and the circumferential loading module; and a corresponding calibration method is provided to meet the needs of users.

[0006] To achieve the above purpose, the utility model provides a three-component force sensor calibration device based on high-strength fiber material, which establishes a sub-rectangular coordinate system with the center of the sensor under test as the origin, the z-axis is parallel to the longitudinal arrangement of the sensor under test, and the x-axis or y-axis is arranged along the gravity direction, including:

[0007] The base includes a main base, a secondary base and a clamping device, wherein the main base includes a horizontal mounting surface, the clamping device cooperates with the horizontal mounting surface to limit and fix the secondary base, and the secondary base includes a vertical mounting surface arranged perpendicular to the horizontal mounting surface, defining a horizontal axis, and the horizontal axis is suitable for passing through the center of the vertical mounting surface, and the horizontal axis coincides with the z-axis.

[0008] A standard force measuring platform is suitable as a comparison standard. In order to ensure that the standard force measuring platform has sufficient rigidity in the z-axis direction, it is composed of several groups of high-precision single-component standard force sensors or a single spoke-type standard force sensor. The standard force sensors are evenly distributed around the horizontal axis.

[0009] The lifting platform is suitable for approaching or moving away from the vertical installation surface along the horizontal axis direction under the driving of the driving device, and is suitable for supporting the standard force measuring platform.

[0010] The mounting platform is arranged parallel to the lifting platform and is suitable for detachably connecting the sensor to be measured and the standard force measuring platform in series along the horizontal axis direction. The standard force measuring sensor is suitable for outputting a standard force value for comparison with the measured force value output by the sensor to be measured.

[0011] The fixture comprises a top fixture and a bottom fixture which are suitable for clamping at the longitudinal ends of the sensor to be tested, wherein the bottom fixture is detachably mounted on the mounting platform, and a short axis extends from the center of the top fixture along the horizontal axis direction.

[0012] A radial loading module comprises an adjustable standard force weight group and a first flexible connection mechanism, wherein the first flexible connection mechanism comprises a high-strength fiber material, the standard force weight group is detachably suspended on the short shaft through the first flexible connection mechanism, and the force value of the sensor under test is loaded by the gravity of the standard force weight group.

[0013] An axial loading module comprises a module base and a plurality of flexible loading heads uniformly distributed circumferentially about the horizontal axis, wherein the module base presents a centrally symmetrical structure, an axial end of the flexible loading head is fixedly connected to the module base, and the module base is connected to the secondary base through a plurality of second flexible connection mechanisms uniformly distributed circumferentially about the horizontal axis, wherein the second flexible connection mechanisms comprise high-strength fiber material.

[0014] The lifting platform is suitable for driving the sensor under test to approach the module base through the mounting platform. When the other axial end of the flexible loading head contacts the top clamp, the second flexible connection mechanism is in a tensioned state, and the second flexible connection mechanism is kept tight along the horizontal axis direction to limit the displacement of the module base. The lifting platform is suitable for further applying force to the sensor under test through the flexible loading head.

[0015] Preferably, the vertical mounting surface extends two first threaded columns along the z-axis direction, the lifting platform is provided with a first internal threaded sleeve suitable for cooperating with the first threaded column, the back of the secondary base is provided with a first rotating wheel, and the secondary base is provided with a first transmission mechanism. The first rotating wheel is manually rotated to serve as a power source, and the first threaded column is driven to rotate through the first transmission mechanism, thereby driving the first internal threaded sleeve to drive the lifting platform to reciprocate along the axial direction of the first threaded column.

[0016] Specifically, the first internally threaded sleeve is fixedly connected to the interior of the lifting platform. The first transmission mechanism includes a first transmission shaft and a first gear mechanism, the first gear mechanism includes a first gear and a first matching gear, the first matching gear is fixedly connected to the first threaded column, the first rotating wheel drives the first gear mechanism to rotate through the first transmission shaft, the first gear meshes with the first matching gear, and then drives the first threaded column to rotate, so that the lifting platform is driven to move along the axial direction of the first threaded column through the threaded cooperation between the first threaded column and the first internally threaded sleeve.

[0017] Preferably, a global rectangular coordinate system is defined, the positive direction of the Z axis is arranged along the opposite direction of gravity, the X axis is parallel to the Z axis and the positive direction of the X axis is arranged along the positive direction of the Z axis,

[0018] The main base comprises a secondary base limiting groove suitable for allowing part of the secondary base to be detachably embedded, and the secondary base limiting groove is suitable for limiting the X-direction displacement of the secondary base;

[0019] The clamping device includes a second threaded column, a movable beam, and a knife-bearing positioning tool. The knife-bearing positioning tool is assembled on the movable beam and arranged facing the secondary base. The second threaded columns are arranged side by side on both sides of the secondary base. A second internal threaded sleeve is arranged in the movable beam. The second threaded column and the second internal threaded sleeve are threadedly matched to guide the movable beam to reciprocate along the Z axis, thereby driving the knife-bearing positioning tool to cooperate with the secondary base limiting groove to clamp the secondary base to limit its Z-direction displacement, and the knife-bearing positioning tool is suitable for limiting the Y-direction displacement of the secondary base.

[0020] Preferably, the clamping device includes a second rotating wheel arranged at the top of the movable beam, and a second transmission mechanism is arranged inside the movable beam. The second rotating wheel is manually rotated to serve as a power source, and the second internal threaded sleeve is driven to engage with the second threaded column thread through the second transmission mechanism, thereby driving the movable beam to approach or move away from the secondary base.

[0021] Specifically, the second transmission mechanism includes a second transmission shaft and a second gear mechanism, the second gear mechanism includes a second gear and a second matching gear, and the middle outer contour of the second internally threaded sleeve is suitable for forming the second matching gear. The second rotating wheel drives the second gear to rotate through the second transmission shaft, and the second gear meshes with the second matching gear, thereby driving the second internally threaded sleeve to threadably engage with the second threaded column, thereby realizing the axial reciprocating motion of the moving beam along the second threaded column.

[0022] Preferably, the mounting platform comprises a regular polygonal groove, the bottom fixture has a regular polygonal outer contour and is embedded in the regular polygonal groove; and / or, the secondary base has a circumferential outer contour of a regular polygon, and the knife-type positioning fixture is suitable for matching the circumferential outer contour of the secondary base to limit its Y-direction displacement.

[0023] Therefore, the application of standard force values ​​for different radial angles of the sensor under test relative to the z-axis can be achieved by adjusting the placement angle of the bottom fixture and / or by adjusting the placement angle of the secondary base.

[0024] Preferably, the regular polygonal outer contour of the secondary base should have an odd number of sides.

[0025] Preferably, the main base further comprises a counterweight suitable for maintaining the balance of the device.

[0026] Preferably, the knife-type positioning tool can be customized and replaced according to the outer contour of the secondary base.

[0027] Preferably, the two longitudinal ends of the sensor under test are respectively embedded in the bottom clamp and the top clamp. Specifically, the bottom clamp has a bottom groove consistent with the contour of one longitudinal end of the sensor under test, and the lower surface of the top clamp is provided with a top groove consistent with the contour of the other longitudinal end of the sensor under test.

[0028] Preferably, an annular limiting groove is formed on the upper surface of the top clamp, the horizontal axis is suitable for passing through the center of the limiting groove, and one axial end of the flexible loading head is suitable for extending into the limiting groove and forming a radial limit. A low-friction needle bearing suitable for supporting the short shaft is fastened and embedded in the center of the top clamp.

[0029] Preferably, the radial loading module comprises a tray suitable for supporting the standard force weight set, the standard force weight set can be placed on the tray for loading operation according to actual calibration requirements, and the tray is detachably connected to the first flexible connection mechanism.

[0030] Preferably, the high-strength fiber material may be Kevlar aramid fiber.

[0031] Preferably, four second flexible connection mechanisms are evenly arranged around the module base.

[0032] Preferably, the flexible loading head should have a cross hinge structure.

[0033] Preferably, when designing the number of sides m and n of the regular polygon, it should be ensured that the first flexible connection mechanism included in the radial loading module, the second flexible connection mechanism included in the axial loading module, and the flexible loading head will not interfere with each other at any angle.

[0034] The beneficial effects of the utility model are:

[0035] (1) According to the working principle and working mode of the three-component force sensor, the installation process of the sensor to be tested is simplified by simplifying the design of the axial loading module, radial loading module, sub-base and bottom fixture geometry, reducing the manufacturing cost, ensuring the individual and precise loading of the component forces and the combination of two components, and achieving different ranges of F x ,F y ,F z The calibration of the three positive forces is carried out without interfering with each other, thus achieving F x ,F y ,F zThe combined calibration of the three components can truly reflect the state of three-component force coupling in real life.

[0036] (2) Based on the phase difference principle, the utility model designs the bottom fixture and the sub-base with positive polyhedral geometric shapes with different numbers of sides, thereby improving the detectable angle range of the sensor under test on its sub-coordinate xy plane, reducing the requirements of the calibration device on the number of loading modules or the steering mechanism in the radial direction, and reducing the manufacturing cost.

[0037] (3) A double decoupling mechanism is realized by setting a flexible loading head and a second flexible connection mechanism to ensure that the axial loading module does not introduce parasitic friction resistance to the sensor under test, thereby achieving the purpose of improving the measurement accuracy of the coupling error. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 A schematic structural diagram of a three-component force sensor calibration device based on high-strength fiber material provided by the utility model.

[0039] Figure 2 This is a schematic structural diagram of a three-component force sensor calibration device based on high-strength fiber material provided by the utility model, viewed from a side perspective.

[0040] Figure 3 This is a structural exploded stereoscopic diagram of a main base, a secondary base and a clamping device in a three-component force sensor calibration device based on high-strength fiber material provided by the utility model.

[0041] Figure 4 This is a structural exploded stereoscopic diagram of a lifting platform in a three-component force sensor calibration device based on high-strength fiber material provided by the utility model.

[0042] Figure 5 The utility model provides a schematic structural diagram of an axial loading module in a three-component force sensor calibration device based on high-strength fiber material.

[0043] Figure 6 A schematic diagram of angle adjustment of a sensor under test in a three-component force sensor calibration device based on high-strength fiber material provided by the utility model.

[0044] Figure 7 This is a schematic structural diagram of a bottom fixture in a three-component force sensor calibration device based on high-strength fiber material provided by the utility model.

[0045] In the figure, main base 1, second threaded column 2, moving beam 3, secondary base 4, first threaded column 5, lifting platform 6, mounting platform 7, bottom fixture 8, sensor to be measured 9, flexible loading head 10, top fixture 11, module base 12, tray 13, standard force value weight set 14, counterweight block 15, second rotating wheel 16, mounting bracket 17, first rotating wheel 18, short shaft 19, secondary base limit groove 20, needle bearing 21, standard force measuring platform 22, second flexible connecting mechanism 23, first flexible connecting mechanism 24, knife-type positioning fixture 25, screw 26, limit groove 27. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0047] It should also be noted that, in order to avoid obscuring the present invention due to unnecessary details, only structures and / or processing steps closely related to the scheme of the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0048] In addition, it should be noted that the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.

[0049] like Figure 1-7 As shown, for the sake of convenience and understanding, a sub-rectangular coordinate system is established with the center of the sensor 9 as the origin, the z-axis is arranged parallel to the longitudinal direction of the sensor 9, and the x-axis or y-axis is arranged along the gravity direction. A global rectangular coordinate system is defined, the z-axis is arranged along the gravity direction, the x-axis is parallel to the z-axis and the positive direction of the x-axis is arranged along the z-axis.

[0050] A three-component force sensor calibration device based on high-strength fiber material includes a base suitable for installing a sensor 9 to be measured, a standard force measuring platform 22 suitable for outputting a standard force value for comparison with the measured force value output by the sensor 9 to be measured, a radial loading module suitable for providing a radial load, and an axial loading module suitable for providing an axial load.

[0051] The base includes a main base 1, a secondary base 4 and a clamping device. The main base 1 includes a horizontal mounting surface. The clamping device cooperates with the horizontal mounting surface to limit and fix the secondary base 4. The secondary base 4 includes a vertical mounting surface arranged perpendicular to the horizontal mounting surface, defining a horizontal axis. The horizontal axis is suitable for passing through the center of the vertical mounting surface, and the horizontal axis coincides with the z-axis. In order to ensure that the standard force measuring platform 22 has sufficient rigidity in the z-axis direction, the standard force measuring platform 22 includes four groups of high-precision single-component standard force sensors as comparison standards. The standard force sensors are columnar structures and are uniformly distributed around the horizontal axis. The lifting platform 6 is suitable for approaching or moving away from the vertical mounting surface along the horizontal axis direction under the drive of the driving device, and is suitable for supporting the standard force measuring platform 22. The mounting platform 7 is arranged parallel to the lifting platform 6, and is suitable for detachably connecting the sensor 9 to be measured and the standard force measuring platform 22 in series along the horizontal axis direction. The fixture includes a top fixture 11 and a bottom fixture 8 suitable for clamping at both longitudinal ends of the sensor 9 to be measured, and the bottom fixture 8 is detachably assembled on the mounting platform 7. The longitudinal ends of the sensor 9 under test are respectively embedded in the bottom clamp 8 and the top clamp 11. Specifically, the bottom clamp 8 has a bottom groove consistent with the contour of one longitudinal end of the sensor 9 under test, and the lower surface of the top clamp 11 is provided with a top groove consistent with the contour of the other longitudinal end of the sensor 9 under test.

[0052] In this embodiment, a low-friction needle bearing 21 is fastened and embedded in the center of the top fixture 11, and the needle bearing 21 is suitable for supporting a short shaft 19 extending along the horizontal axis. The radial loading module includes an adjustable standard force weight group 14, a tray 13 suitable for supporting the standard force weight group 14, and a first flexible connection mechanism. The standard force weight group 14 can be placed on the tray 13 for loading according to actual calibration requirements. The tray 13 is detachably suspended on the short shaft 19 through the first flexible connection mechanism, and the force value of the sensor 9 under test is loaded by the gravity of the standard force weight group 14. When a certain number of standard force weight groups 14 are loaded on the tray 13, the radial force value will be transmitted to the top fixture 11 along the high-strength fiber material.

[0053] In this embodiment, an annular limiting groove 27 suitable for resisting the axial loading module is formed on the upper surface of the top clamp 11, and the horizontal axis is suitable for passing through the center of the limiting groove 27. The axial loading module includes a module base 12 and four groups of flexible loading heads 10 uniformly distributed circumferentially about the horizontal axis. The module base 12 is a centrally symmetrical structure, and the module base 12 is connected to the secondary base 4 through four groups of second flexible connection mechanisms uniformly distributed circumferentially about the horizontal axis. The first flexible connection mechanism and the second flexible connection mechanism are made of high-strength fiber material, preferably Kevlar aramid fiber. The flexible loading head 10 has a cross hinge structure, and one axial end of the flexible loading head 10 is fixed to the module base 12, and one axial end of the flexible loading head 10 is suitable for extending into the limiting groove 27 and forming a radial limit. The above design is intended to minimize the parasitic friction resistance that may exist between the axial loading module and the top clamp 11, and prevent the parasitic friction resistance from affecting the accuracy of applying radial force. The lifting platform 6 is suitable for driving the sensor 9 to be tested close to the module base 12 through the mounting platform 7. When the other axial end of the flexible loading head 10 contacts the top clamp 11, the second flexible connection mechanism is in a tensioned state, and the second flexible connection mechanism is kept tight along the horizontal axis direction to limit the displacement of the module base 12. The lifting platform 6 is suitable for further applying force to the sensor 9 to be tested through the flexible loading head 10.

[0054] The working principle of the utility model is that the top clamp 11 constitutes a force-bearing fixture of the sensor 9 to be measured, and two forces are synchronously applied to the top clamp 11 in the axial and radial directions through a radial loading device and an axial loading device. After the top clamp 11 bears the forces in two directions, it couples them to form a vector force and rigidly transmits it to the sensor 9 to be measured, thereby realizing the synchronous combined loading and calibration of multi-component forces.

[0055] In this embodiment, two first threaded columns 5 and two mounting brackets 17 suitable for fixing the first threaded columns 5 are extended from the vertical mounting surface along the z-axis direction. The lifting platform 6 is relatively fixedly connected with the first internal threaded sleeve. The back of the secondary base 4 is provided with a first rotating wheel 18. The secondary base 4 is provided with a first transmission mechanism. The first rotating wheel 18 is manually rotated to serve as a power source, and the first transmission mechanism drives the first threaded column 5 to rotate, thereby driving the first internal threaded sleeve to drive the lifting platform 6 to reciprocate along the axial direction of the first threaded column 5. When the top clamp 11 contacts the flexible loading head 10 and the second flexible connection mechanism 23 is tightened, the axial force value will be transmitted from the secondary base 4 along the second flexible connection mechanism 23 to the axial loading module, and then transmitted to the top clamp 11 through the flexible loading head 10.

[0056] Specifically, the first internal threaded sleeve is fixedly connected to the inside of the lifting platform 6. The first transmission mechanism includes a first transmission shaft and a first gear mechanism, the first gear mechanism includes a first gear and a first matching gear, the first matching gear is fixedly connected to the first threaded column 5, the first rotating wheel 18 drives the first gear to rotate through the first transmission shaft, the first gear is meshed with the first matching gear, and then drives the first threaded column 5 to rotate, so that the lifting platform 6 is driven to move along the axial direction of the first threaded column 5 through the threaded cooperation between the first threaded column 5 and the first internal threaded sleeve.

[0057] In this embodiment, the main base 1 includes a sub-base limiting groove 20 suitable for a part of the sub-base 4 to be detachably embedded and a counterweight 15 suitable for maintaining the balance of the device. The sub-base limiting groove 20 is suitable for limiting the X-direction displacement of the sub-base 4. The clamping device includes a second threaded column 2, a movable beam 3, and a knife-bearing type positioning tool 25. The knife-bearing type positioning tool 25 is assembled on the movable beam 3 and arranged facing the sub-base 4. The second threaded column 2 is arranged side by side on both sides of the sub-base 4. The movable beam 3 is provided with a second internal threaded sleeve inside. The second threaded column 2 is threadedly matched with the second internal threaded sleeve and guides the movable beam 3 to reciprocate along the Z axis, thereby driving the knife-bearing type positioning tool 25 to match the sub-base limiting groove 20 to clamp the sub-base 4 to limit its Z-direction displacement, and the knife-bearing type positioning tool 25 is suitable for matching the circumferential outer contour of the sub-base 4 to limit its Y-direction displacement. Further, the knife-bearing type positioning tool 25 can be customized and replaced in accordance with the outer contour of the sub-base 4. The clamping device includes a second rotating wheel 16 arranged at the top of the moving beam 3. A second transmission mechanism is arranged inside the moving beam 3. The second rotating wheel 16 is manually rotated to serve as a power source, and the second internal threaded sleeve is driven to engage with the second threaded column 2 through the second transmission mechanism, thereby driving the moving beam 3 to approach or move away from the secondary base 4.

[0058] Specifically, the second transmission mechanism includes a second transmission shaft and a second gear mechanism, the second gear mechanism includes a second gear and a second matching gear, and the middle outer contour of the second internally threaded sleeve is suitable for forming the second matching gear. The second rotating wheel 16 drives the second gear to rotate through the second transmission shaft, and the second gear meshes with the second matching gear, thereby driving the second internally threaded sleeve to threadably engage with the second threaded column 2, thereby realizing the axial reciprocating motion of the moving beam 3 along the second threaded column 2.

[0059] In this embodiment, the mounting platform 7 includes a regular polygonal groove, the bottom fixture 8 has a regular octagonal outer contour and is embedded in the regular polygonal groove, the sub-base 4 has a circumferential outer contour of a regular polygon, and the sub-base limiting groove 20 is suitable for matching the circumferential outer contour of the sub-base 4. Further, the regular polygonal outer contour of the sub-base 4 should have an odd number of sides, and the sub-base 4 has a regular enneagonal outer contour. In order to increase the number of installation postures of the sensor 9 under test after rotating a certain angle around its axis, so that the sensor 9 under test can withstand radial forces at more angles on its sub-coordinate xy plane, the sub-base 4 and the bottom fixture 8 are designed as regular polygons with different numbers of sides, so that the standard force value application for different radial angles of the sensor 9 under test relative to the z-axis can be achieved by adjusting the placement angle of the bottom fixture 8 and / or by adjusting the placement angle of the sub-base 4.

[0060] First, the following relationship needs to be clarified: the bottom fixture 8 is a regular octagon, the secondary base 4 is a regular pentagon, the first unit angle α = 2π / 8 = 45°, the second unit angle β = 2π / 9 = 40°, and the deflection angle θ between the vertical line where the radial loading module is located when it is unconstrainedly drooping under the action of gravity and the positive x-axis of the sub-coordinate system of the sensor 9 under test can take a set of discrete values ​​Θ on the closed interval [0,2π], which is any linear combination of α and β, that is, span (α, β) = {0°, 5°, 10°, 15°, 20°, ..., 350°, 355°, 360°}. 1. The z-direction force calibration of the sub-coordinate where the sensor 9 under test is located includes the following steps:

[0061] 1) Confirm the z-axis force range of the sensor 9 under test, assuming it is (100-500)N;

[0062] 2) According to the measuring range of the sensor 9 under test, confirm that the points to be calibrated are 100N, 200N, 300N, 400N, and 500N;

[0063] 3) Remove the tray 13 of the radial force loading module with a weight of 10N;

[0064] 4) Install the sensor 9 to be tested on the calibration device mounting platform 7 through the bottom fixture 8;

[0065] 5) Install the top fixture 11;

[0066] 6) Clear the z-direction force output of the sensor 9 under test and the output of the standard force sensor and record them as the zero point;

[0067] 7) Rotate the first rotating wheel 18 of the secondary base 4 until the top clamp 11 contacts the flexible loading head 10 of the axial loading module; at this time, the high-strength fiber material arranged around should be in a tensioned state;

[0068] 8) Manually adjust the axial loading module to ensure that all four flexible loading heads 10 fall into the limiting grooves 27 - that is, the horizontal axis is suitable for passing through the center of the module base 12;

[0069] 9) Continue to rotate the first rotating wheel 18 until the output value of the standard force sensor reaches exactly 100N;

[0070] 10) Record the z-direction force output value of the sensor 9 under test at this time;

[0071] 11) Repeat steps 9) to 10) until all calibration points have been tested.

[0072] 2. The x-direction / y-direction force calibration of the sub-coordinate where the sensor 9 is located includes the following steps:

[0073] 1) Confirm the component output and range of the sensor 9 to be calibrated. Let's assume that the sensor 9 to be calibrated

[0074] The positive y-direction force of the sub-coordinate has a range of (40~200)N;

[0075] 2) According to the measuring range of the sensor 9 under test, the points to be calibrated are determined to be 40N, 80N, 120N, 160N, and 200N;

[0076] 3) Move the module base 12 to any position that does not hinder the calibration activity and fix it;

[0077] 4) Install the sensor 9 to be tested on the mounting platform 7 so that the y-axis of the sub-coordinate where it is located is consistent with the direction of gravity;

[0078] 5) Install the top fixture 11;

[0079] 6) Clear the y-direction force output of the sensor 9 under test at this time and record it as zero point;

[0080] 7) Connecting the radial loading module tray 13 weighing 10N to the first flexible connection mechanism 24;

[0081] 8) At this time, if the weight of the tray 13 has not yet reached the value of 40N at the first calibration point, then continue to add the standard force weight set 14 with a total weight of 30N, and record the y-direction force output value of the sensor 9 under test at this time;

[0082] 9) Continue to add weights until the sum of the gravity of the tray 13 and the weights on it is completely consistent with the value of the next point to be calibrated, and record the output of the sensor 9 under test at this time;

[0083] 10) Repeat step 9) until all calibration points have been tested.

[0084] 3. Arbitrary spatial force (F) of the sub-coordinate where the sensor 9 is located x,F y ,F z ) The calibration includes the following steps:

[0085] 1) Determine the standard force point (F x ,F y ,F z ), let’s assume it is (100N, 200N, 300N).

[0086] 2) Calculate the target deflection angle

[0087] Where ε is a step function, which takes the value of 1 when the independent variable is positive and 0 in other cases.

[0088] 3) According to the formula argmin[(θ i -θ aim ) 2 ] Solve to obtain the deflection angle θ from the target in the reachable set Θ aim The closest approximation to the deflection angle θ adj =65°.

[0089] 4) Examine the approximate deflection angle θ adj The expansion of θ adj =c adj α+d adj ·β=65°=5·45°+(-4)·40° Coefficient c adj and d adj The positive and negative of c adj =5 is positive, indicating that the bottom fixture 8 rotates clockwise; d adj =-4 is negative, indicating that the sub-base 4 rotates counterclockwise.

[0090] 5) Rotate the secondary base 4 160° counterclockwise and fix it with a clamping device.

[0091] 6) After the sensor 9 to be tested is connected to the bottom fixture 8, the bottom fixture 8 is rotated 225° clockwise and then installed in the groove of the installation platform 7.

[0092] 7) Install the top fixture 11 to the sensor 9 under test. At this time, the top fixture 11 is neither in contact with the axial loading module nor connected to the radial loading module tray 13.

[0093] 8) Rotate the first rotating wheel 18 provided on the secondary base 4 until the top clamp 11 contacts the axial loading module and the four high-strength fiber materials are in a tensioned state, and observe whether the four flexible loading heads 10 fall into the limiting grooves 27;

[0094] If not, make corresponding adjustments.

[0095] 9) Clear all outputs of the sensor 9 under test and record them as zero.

[0096] 10) Continue to rotate the first rotating wheel 18 until the output value of the standard force sensor is equal to the target axial force F z =300N.

[0097] 11) Suspend the tray 13 on the high-strength fiber material 24.

[0098] 12) Add a standard force weight set 14 to the tray 13 until the total gravity of the tray 13 and the weights is equal to the target radial force.

[0099] The difference is less than the minimum force value weight 1N, that is, a weight of 214N is added to the tray 13 with a weight of 10N. At this time, the actual total weight F real =224N.

[0100] 13) Record the output value corresponding to the sensor 9 under test, and correct the standard force value point to be calibrated to (F real ·cosθ adj ,F real sinθ adj ,F z )=(224N·cos65°, 224N·sin65°, 300N)=(94.67N, 203.01N, 300N).

[0101] 14) Repeat the above steps to calibrate each calibration point in turn until data collection has been completed for all standard force points to be measured.

[0102] The above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model is described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the utility model.

Claims

1. A three-component force sensor calibration device based on high-strength fiber material, characterized in that: A sub-rectangular coordinate system is established with the center of the sensor under test as the origin, the z-axis is arranged parallel to the longitudinal direction of the sensor under test, and the x-axis or y-axis is arranged along the gravity direction, including: The base comprises a main base, a secondary base and a clamping device, wherein the main base comprises a horizontal mounting surface, the clamping device cooperates with the horizontal mounting surface to limit and fix the secondary base, the secondary base comprises a vertical mounting surface arranged perpendicular to the horizontal mounting surface, and defines a horizontal axis, the horizontal axis is suitable for passing through the center of the vertical mounting surface, and the horizontal axis coincides with the z-axis, A standard force measuring platform, which is suitable for use as a comparison standard, is composed of a plurality of groups of high-precision single-component standard force sensors or a single spoke-type standard force sensor, wherein the standard force sensors are uniformly distributed around the horizontal axis. A lifting platform, which is suitable for approaching or moving away from the vertical mounting surface along the horizontal axis direction under the driving of the driving device, and is suitable for supporting the standard force measuring platform, The mounting platform is arranged parallel to the lifting platform and is suitable for detachably connecting the sensor to be measured and the standard force measuring platform in series along the horizontal axis direction. The standard force measuring sensor is suitable for outputting a standard force value to compare with the measured force value output by the sensor to be measured. A fixture, comprising a top fixture and a bottom fixture suitable for clamping at both longitudinal ends of the sensor to be tested, wherein the bottom fixture is detachably mounted on the mounting platform, and a short axis extends from the center of the top fixture along the horizontal axis direction. A radial loading module comprises an adjustable standard force weight set and a first flexible connection mechanism, wherein the first flexible connection mechanism comprises a high-strength fiber material, and the first flexible connection mechanism is suitable for transmitting force along its axial direction, and the standard force weight set is detachably suspended on the short shaft through the first flexible connection mechanism, and the force value of the sensor under test is loaded by the gravity of the standard force weight set. An axial loading module comprises a module base and a plurality of flexible loading heads uniformly distributed circumferentially about the horizontal axis, wherein the module base is a centrally symmetrical structure, an axial end of the flexible loading head is fixedly connected to the module base, and the module base is connected to the secondary base through a plurality of second flexible connection mechanisms uniformly distributed circumferentially about the horizontal axis, wherein the second flexible connection mechanism comprises a high-strength fiber material, and the second flexible connection mechanism is suitable for transmitting force along its axial direction. The lifting platform is suitable for driving the sensor under test to approach the module base through the mounting platform. When the other axial end of the flexible loading head contacts the top clamp, the second flexible connection mechanism is in a tensioned state, and the second flexible connection mechanism is kept tight along the horizontal axis direction to limit the displacement of the module base. The lifting platform is suitable for further applying force to the sensor under test through the flexible loading head.

2. A three-component force sensor calibration device based on high-strength fiber material according to claim 1, characterized in that: Two first threaded columns extend from the vertical mounting surface along the z-axis direction, a first internal threaded sleeve suitable for matching with the first threaded column is provided inside the lifting platform, a first rotating wheel is provided on the back of the secondary base, and a first transmission mechanism is provided inside the secondary base. The first rotating wheel is manually rotated to serve as a power source, and the first threaded column is driven to rotate through the first transmission mechanism, thereby driving the first internal threaded sleeve to drive the lifting platform to reciprocate along the axial direction of the first threaded column.

3. A three-component force sensor calibration device based on high-strength fiber material according to claim 2, characterized in that: Define a global rectangular coordinate system, with the positive direction of the Z axis set in the opposite direction of gravity, the X axis parallel to the Z axis and the positive direction of the X axis set in the positive direction of the Z axis, The main base comprises a secondary base limiting groove suitable for allowing part of the secondary base to be detachably embedded, and the secondary base limiting groove is suitable for limiting the X-direction displacement of the secondary base; The clamping device includes a second threaded column, a movable beam, and a knife-bearing positioning tool. The knife-bearing positioning tool is assembled on the movable beam and arranged facing the secondary base. The second threaded columns are arranged side by side on both sides of the secondary base. A second internal threaded sleeve is arranged in the movable beam. The second threaded column is threadedly matched with the second internal threaded sleeve and guides the movable beam to reciprocate along the Z axis, thereby driving the knife-bearing positioning tool to cooperate with the secondary base limiting groove to clamp the secondary base to limit its Z-direction displacement, and the knife-bearing positioning tool is suitable for limiting the Y-direction displacement of the secondary base.

4. A three-component force sensor calibration device based on high-strength fiber material according to claim 3, characterized in that: The clamping device includes a second rotating wheel arranged at the top end of the movable beam, and a second transmission mechanism is arranged inside the movable beam. The second rotating wheel is manually rotated to serve as a power source, and the second internal threaded sleeve is driven to engage with the second threaded column thread through the second transmission mechanism, thereby driving the movable beam to approach or move away from the secondary base.

5. A three-component force sensor calibration device based on high-strength fiber material according to claim 4, characterized in that: The mounting platform comprises a regular polygonal groove, the bottom fixture has a regular polygonal outer contour and is embedded in the regular polygonal groove; and / or, the secondary base has a circumferential outer contour of a regular polygon, and the knife-type positioning fixture is suitable for matching the circumferential outer contour of the secondary base to limit its Y-direction displacement, Therefore, the application of standard force values ​​for different radial angles of the sensor under test relative to the z-axis can be achieved by adjusting the placement angle of the bottom fixture and / or by adjusting the placement angle of the secondary base.

6. A three-component force sensor calibration device based on high-strength fiber material according to claim 5, characterized in that: At least one of the following conditions must be met: The main base also includes a counterweight suitable for maintaining the balance of the device; The knife-type positioning tool can be customized and replaced in accordance with the outer contour of the secondary base. The two longitudinal ends of the sensor to be tested are respectively embedded in the bottom fixture and the top fixture. Specifically, the bottom fixture has a bottom groove consistent with the contour of one longitudinal end of the sensor to be tested, and the lower surface of the top fixture is provided with a top groove consistent with the contour of the other longitudinal end of the sensor to be tested; An annular limiting groove is formed on the upper surface of the top clamp, the horizontal axis is suitable for passing through the center of the limiting groove, and one axial end of the flexible loading head is suitable for extending into the limiting groove and forming a radial limit; a low-friction needle bearing suitable for supporting the short shaft is fastened and embedded in the center of the top clamp; The radial loading module comprises a tray suitable for supporting the standard force value weight set. The standard force value weight set can be placed on the tray for loading operation according to actual calibration requirements. The tray is detachably connected to the first flexible connection mechanism.

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