Capacitive triaxial force sensor calibration platform and calibration method

Abstract

The invention discloses a capacitive three-axis force sensor calibration platform and calibration method, and relates to the technical field of sensor measurement and calibration, and the capacitive three-axis force sensor calibration platform comprises a normal loading assembly, a tangential loading assembly, a leveling and centering assembly and a to-be-measured sensor fixing assembly. The to-be-tested sensor upper end transfer support plate is used for being detachably and fixedly arranged on the top face of an upper pole plate of a to-be-tested capacitive three-axis force sensor, the to-be-tested sensor upper end transfer support plate is provided with a first connecting structure and a second connecting structure, and the first connecting structure is used for completing Y-axis tangential force calibration of the to-be-tested capacitive three-axis force sensor. The second connecting structure is used for completing X-axis tangential force calibration of the capacitive three-axis force sensor to be measured; the bottom surface of the normal loading plate is used for being in contact with the top surface of a to-be-tested sensor upper end transfer plate; the tangential loading contact can be connected with the first connecting structure or the second connecting structure; according to the invention, the difficulty of applying the load to the capacitive triaxial force sensor to be measured can be effectively reduced, and the calibration efficiency and accuracy are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of sensor measurement and calibration, and particularly to a calibration platform and a calibration method for a capacitive triaxial force sensor. Background Art

[0002] The application of robotics technology is becoming increasingly widespread in various fields, especially in the fields of manufacturing, healthcare, and service industries. The demand for dexterous operation is growing day by day. Dexterous operation means that a robot can flexibly perform grasping, handling, assembly, and other complex tasks that require precise control, just like a human being. The key to achieving dexterous operation lies in the robot's perception ability and control accuracy, and the tactile force sensor plays a crucial role in the manifestation of the perception ability.

[0003] As an important part of realizing dexterous operation, the tactile force sensor can sense the axial forces applied when the robot contacts an object, thereby providing real-time feedback information for the robot. Among various tactile force sensors, the small-sized and highly sensitive capacitive triaxial force sensor can not only meet the performance requirements of high-sensitivity and high-precision sensors in dexterous operation, but its small size is also very suitable for integration on the surface of various dexterous operation terminals. During the dexterous operation process, the accuracy of the capacitive triaxial force sensor is very important, so the calibration of the capacitive triaxial force sensor is the key to ensuring accuracy. However, at present, due to the small size and thin thickness of the capacitive triaxial force sensor, it is difficult to apply a load to the capacitive triaxial force sensor during the calibration process. Summary of the Invention

[0004] The purpose of the present invention is to provide a calibration platform and a calibration method for a capacitive triaxial force sensor to solve the problems existing in the above-mentioned prior art, and can effectively reduce the difficulty of applying a load to the capacitive triaxial force sensor to be measured, and improve the calibration efficiency and accuracy.

[0005] To achieve the above purpose, the present invention provides the following solutions:

[0006] The present invention provides a calibration platform for a capacitive triaxial force sensor, which includes a normal loading component, a tangential loading component, a leveling and centering component, and a fixed component for the sensor to be measured; the leveling and centering component includes a leveling and centering device and a standard six-axis sensor, and the standard six-axis sensor is arranged at the top of the leveling and centering device; the fixed component for the sensor to be measured includes a connecting member for the sensor to be measured, a fixture for the sensor to be measured, and an upper load transfer plate for the sensor to be measured. The connecting member for the sensor to be measured is fixedly arranged on the top surface of the standard six-axis sensor. The fixture for the sensor to be measured can be detachably fixed on the top surface of the connecting member for the sensor to be measured. The fixture for the sensor to be measured can carry and fix the capacitive triaxial force sensor to be measured. The upper load transfer plate for the sensor to be measured is used to be detachably fixed on the top surface of the upper electrode plate of the capacitive triaxial force sensor to be measured. The upper load transfer plate for the sensor to be measured has a first connection structure and a second connection structure. The first connection structure is used to complete the calibration of the Y-axis tangential force of the capacitive triaxial force sensor to be measured, and the second connection structure is used to complete the calibration of the X-axis tangential force of the capacitive triaxial force sensor to be measured; the normal loading component includes a normal loading driving device and a normal loading plate. The normal loading plate is placed above the upper load transfer plate for the sensor to be measured. The bottom surface of the normal loading plate is used to contact the top surface of the upper load transfer plate for the sensor to be measured. The normal loading driving device is in transmission connection with the normal loading plate, and the normal loading driving device can drive the normal loading plate to move up or down; the tangential loading component includes a tangential loading driving device and a tangential loading contact head. The tangential loading contact head is placed on the side of the fixture for the sensor to be measured. The tangential loading contact head can be connected to the first connection structure or the second connection structure. The tangential loading driving device is in transmission connection with the tangential loading contact head. The tangential loading driving device can drive the tangential loading contact head to move forward or backward. When the tangential loading contact head is connected to the first connection structure, the moving direction of the tangential loading contact head is parallel to the Y-axis direction of the capacitive triaxial force sensor to be measured. When the tangential loading contact head is connected to the second connection structure, the moving direction of the tangential loading contact head is parallel to the X-axis direction of the capacitive triaxial force sensor to be measured.

[0007] Preferably, the first connection structure includes a first limiting hole, and the second connection structure includes a second limiting hole. Both the first limiting hole and the second limiting hole are opened on the bottom surface of the upper load transfer plate for the sensor to be measured. The tangential loading contact head has a first connection protrusion and a second connection protrusion. The first connection protrusion is used to extend upward from below the upper load transfer plate for the sensor to be measured into the first limiting hole or the second limiting hole, and the second connection protrusion can contact the outer side surface of the upper load transfer plate for the sensor to be measured.

[0008] Preferably, the first limiting hole has a first round hole part and a first long strip part. The first round hole part is communicated with the first long strip part and is connected with a smooth transition. The second limiting hole has a second round hole part and a second long strip part. The second round hole part is communicated with the second long strip part and is connected with a smooth transition. The diameters of the first round hole part and the second round hole part are larger than the outer diameter of the first connecting protrusion. The outer side surface of the first connecting protrusion can slide along the inner side surface of the first long strip part or the second long strip part.

[0009] Preferably, the normal loading plate includes a loading plate main body and a heat insulation pad. A square protrusion is provided on the bottom surface of the loading plate main body. The heat insulation pad is fixedly laid on the bottom surface of the square protrusion. The bottom surface of the heat insulation pad is used to contact the top surface of the upper transfer plate of the sensor under test. The normal loading driving device is in transmission connection with the loading plate main body. The normal loading driving device can drive the loading plate main body to move up or down.

[0010] Preferably, the normal loading driving device includes a first force control push rod motor, a first bottom positioning plate, and a first Z-axis linear module. The guide rail of the first Z-axis linear module is fixedly arranged on the first bottom positioning plate. The housing of the first force control push rod motor is fixedly connected with the slider of the first Z-axis linear module. The power output shaft of the first force control push rod motor is fixedly connected with the normal loading plate. The tangential loading driving device includes a second force control push rod motor, a second bottom positioning plate, and a second Z-axis linear module. The guide rail of the second Z-axis linear module is fixedly arranged on the second bottom positioning plate. The housing of the second force control push rod motor is fixedly connected with the slider of the second Z-axis linear module. The power output shaft of the second force control push rod motor is fixedly connected with the tangential loading contact head.

[0011] Preferably, it further includes an optical platform. The leveling and centering device is fixedly arranged on the first bottom positioning plate. Both the first bottom positioning plate and the second bottom positioning plate are fixedly arranged on the optical platform.

[0012] Preferably, it further includes a lateral positioning pin. A first lateral positioning hole is provided on the tangential loading contact head. A second lateral positioning hole is provided on one side surface of the sensor fixture under test. A third lateral positioning hole is provided on the other side surface of the sensor fixture under test. When the tangential loading contact head is connected with the first connecting structure, one end of the lateral positioning pin extends into the first lateral positioning hole, and the other end of the lateral positioning pin extends into the second lateral positioning hole. When the tangential loading contact head is connected with the second connecting structure, one end of the lateral positioning pin extends into the first lateral positioning hole, and the other end of the lateral positioning pin extends into the third lateral positioning hole.

[0013] The present invention also provides a calibration method for a capacitive triaxial force sensor, which applies the capacitive triaxial force sensor calibration platform as described above, and includes a normal force calibration process for the capacitive triaxial force sensor to be measured. The normal force calibration process for the capacitive triaxial force sensor to be measured includes the following steps:

[0014] Step 1: Before installing the normal loading plate, use a level to measure the horizontal and pitch angles of the loading surface of the normal loading driving device and record them;

[0015] Step 2: Remove the sensor fixture to be measured, place the level on the top surface of the connecting piece of the sensor to be measured, and adjust the leveling and centering device to make the horizontal angle of the top surface of the connecting piece of the sensor to be measured the same as the horizontal angle of the loading surface of the normal loading driving device, and make the pitch angle of the top surface of the connecting piece of the sensor to be measured the same as the pitch angle of the loading surface of the normal loading driving device;

[0016] Step 3: Fix and install the sensor fixture to be measured on the top surface of the connecting piece of the sensor to be measured, and install the normal loading plate on the loading surface of the normal loading driving device;

[0017] Step 4: Fix and install the capacitive triaxial force sensor to be measured on the top surface of the sensor fixture to be measured;

[0018] Step 5: Power on the capacitive triaxial force sensor to be measured and preheat it for 30 minutes. After the preheating is completed, separately save the detection data of the capacitive triaxial force sensor to be measured within 5 minutes. After observing that the detection data fluctuates stably, perform a zero-clearing operation on the capacitive triaxial force sensor to be measured;

[0019] Step 6: Fix and install the upper load transfer plate of the sensor to be measured on the top plate of the upper electrode of the capacitive triaxial force sensor to be measured, and place the normal loading plate 2 mm - 3 mm above the upper load transfer plate of the sensor to be measured through the normal loading driving device;

[0020] Step 7: Power on the standard six-axis sensor and collect the detection data of the standard six-axis sensor and the capacitive triaxial force sensor to be measured;

[0021] Step 8: Drive the normal loading plate through the normal loading driving device to perform positive and negative stepped loading on the upper load transfer plate of the sensor to be measured;

[0022] Step 9: After the end of Step 8, save the detection data of the standard six-axis sensor and the capacitive triaxial force sensor to be measured.

[0023] Preferably, it further includes a Y-axis tangential force calibration process for the capacitive triaxial force sensor to be measured. The Y-axis tangential force calibration process for the capacitive triaxial force sensor to be measured includes the following steps:

[0024] Step 1: Before installing the tangential loading contact, use a level to measure the level and pitch angle of the loading surface of the tangential loading drive device and record them;

[0025] Step 2: Remove the sensor fixture to be measured, the capacitive triaxial force sensor to be measured on the sensor fixture to be measured, and the upper load transfer plate of the sensor to be measured. Use a level to measure the level and pitch angle of the top surface of the connecting piece of the sensor to be measured, and adjust the leveling and centering device so that the level angle of the top surface of the connecting piece of the sensor to be measured is the same as the level angle of the loading surface of the tangential loading drive device, and the pitch angle of the top surface of the connecting piece of the sensor to be measured is the same as the pitch angle of the loading surface of the tangential loading drive device;

[0026] Step 3: Install the tangential loading contact on the loading surface of the tangential loading drive device, fixedly install the sensor fixture to be measured on the top surface of the connecting piece of the sensor to be measured, and fixedly install the capacitive triaxial force sensor to be measured on the sensor fixture to be measured;

[0027] Step 4: Use the tangential loading drive device to place the tangential loading contact 1 - 2 mm above the sensor fixture to be measured;

[0028] Step 5: Fixingly install the upper load transfer plate of the sensor to be measured on the top surface of the capacitive triaxial force sensor to be measured, and connect the tangential loading contact with the first connection structure;

[0029] Step 6: Perform detection data sampling on the standard six-axis sensor, adjust the leveling and centering device, and observe whether there is a coupling force in the X-axis direction on the standard six-axis sensor. If so, reduce the coupling force in the X-axis direction by adjusting the leveling and centering device;

[0030] Step 7: Power on the capacitive triaxial force sensor to be measured and preheat it for 30 minutes. After the preheating is completed, separately save the detection data of the capacitive triaxial force sensor to be measured within 5 minutes. After observing that the detection data fluctuates stably, perform a zeroing operation on the capacitive triaxial force sensor to be measured;

[0031] Step 8: Drive the tangential loading contact through the tangential loading drive device to perform positive and negative stepped loading on the upper load transfer plate of the sensor to be measured;

[0032] Step 9: After Step 8 ends, save the detection data of the standard six-axis sensor and the capacitive triaxial force sensor to be measured.

[0033] Preferably, it further includes the X-axis tangential force calibration process of the capacitive triaxial force sensor to be measured. The X-axis tangential force calibration process of the capacitive triaxial force sensor to be measured includes the following steps:

[0034] Step 1: Release the fixation of the connection part of the sensor to be measured to the fixture of the sensor to be measured. Rotate the fixture of the sensor to be measured, the capacitive triaxial force sensor to be measured fixed on the fixture of the sensor to be measured, and the upper load transfer plate of the sensor to be measured together by 90°. Then fixedly connect the fixture of the sensor to be measured with the connection part of the sensor to be measured.

[0035] Step 2: Adjust the leveling and centering device to connect the tangential loading contact head with the second connection structure.

[0036] Step 3: Use the tangential loading driving device to place the tangential loading contact head 1 - 2 mm above the fixture of the sensor to be measured.

[0037] Step 4: Conduct detection data sampling on the standard six - axis sensor. Adjust the leveling and centering device and observe whether there is a coupling force in the Y - axis direction on the standard six - axis sensor. If so, reduce the coupling force in the Y - axis direction by adjusting the leveling and centering device.

[0038] Step 5: Power on the capacitive triaxial force sensor to be measured and preheat it for 30 minutes. After the preheating is completed, separately save the detection data of the capacitive triaxial force sensor to be measured within 5 minutes. After observing that the detection data fluctuations are stable, perform a zero - clearing operation on the capacitive triaxial force sensor to be measured.

[0039] Step 6: Drive the tangential loading contact head through the tangential loading driving device to perform positive and negative stepped loading on the upper load transfer plate of the sensor to be measured.

[0040] Step 7: After the end of Step 5, save the detection data of the standard six - axis sensor and the capacitive triaxial force sensor to be measured.

[0041] The present invention has achieved the following technical effects compared with the prior art:

[0042] The capacitive triaxial force sensor calibration platform and calibration method provided by the present invention set a standard six-axis sensor to provide accurate detection values during the calibration process, which is convenient for determining the errors and offsets of the capacitive triaxial force sensor to be measured. The leveling and centering device provides support for the capacitive triaxial force sensor to be measured and the standard six-axis sensor, which is convenient for leveling and centering the capacitive triaxial force sensor to be measured and the standard six-axis sensor, and ensures the accuracy of the detection data of the capacitive triaxial force sensor to be measured and the standard six-axis sensor during loading. The normal loading driving device provides a normal standard load to accurately perform normal loading on the capacitive triaxial force sensor to be measured. The tangential loading driving device provides a tangential standard load to accurately perform tangential loading on the capacitive triaxial force sensor to be measured, so as to meet the precise loading requirements required during the calibration process. The sensor fixture to be measured fixes the capacitive triaxial force sensor to be measured to ensure that the capacitive triaxial force sensor to be measured will not be displaced or overturned during the calibration process, and ensures the stability of the capacitive triaxial force sensor to be measured. The sensor connector to be measured fixedly connects the sensor fixture to be measured with the standard six-axis sensor. The upper load transfer plate of the sensor to be measured is fixedly arranged on the top surface of the upper electrode plate of the capacitive triaxial force sensor to be measured, and the load is transferred to the capacitive triaxial force sensor to be measured by using the upper load transfer plate of the sensor to be measured. During the normal force calibration of the capacitive triaxial force sensor to be measured, the normal loading plate is driven by the normal loading driving device to apply a normal load to the upper load transfer plate of the sensor to be measured, and the normal load is transferred to the capacitive triaxial force sensor to be measured by using the upper load transfer plate of the sensor to be measured. The normal load is evenly dispersed and transferred between the normal loading plate, the upper load transfer plate of the sensor to be measured, and the upper electrode plate of the capacitive triaxial force sensor to be measured, effectively reducing the difficulty of uniform transfer of the normal load and avoiding the error influence caused by the concentration of the normal load, and completing the normal loading in the form of a uniform load. During the tangential force calibration of the capacitive triaxial force sensor to be measured, the tangential loading contact is connected to the first connection structure or the second connection structure on the upper load transfer plate of the sensor to be measured, realizing the rapid conversion of the two calibration directions of the Y-axis tangential force calibration and the X-axis tangential force calibration of the capacitive triaxial force sensor to be measured, improving the calibration efficiency, and at the same time, while ensuring the positioning accuracy, effectively reducing the influence of the manual installation error caused by repeated disassembly and assembly of the capacitive triaxial force sensor to be measured, and the tangential loading contact is driven by the tangential loading driving device to apply a tangential load to the upper load transfer plate of the sensor to be measured, and the tangential loading contact and the capacitive triaxial force sensor to be measured are indirectly connected by using the upper load transfer plate of the sensor to be measured, and the tangential load is transferred to the capacitive triaxial force sensor to be measured through the upper load transfer plate of the sensor to be measured, effectively avoiding the problem that it is difficult to achieve tangential connection and loading due to the thin thickness and small force area of the capacitive triaxial force sensor to be measured, ensuring the tangential loading accuracy, and at the same time realizing the precise transfer of the tangential standard load and reducing the difficulty of applying the tangential load. Therefore,The capacitive triaxial force sensor calibration platform and calibration method provided by the present invention can effectively reduce the difficulty of applying loads to the capacitive triaxial force sensor to be measured, and improve the calibration efficiency and accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0044] Figure 1 Schematic diagram of the capacitive triaxial force sensor calibration platform provided by the present invention;

[0045] Figure 2 For Figure 1 Schematic diagram of the leveling and centering assembly in

[0046] Figure 3 For Figure 1 Schematic diagram of the sensor to be measured fixing assembly in

[0047] Figure 4 For Figure 1 Schematic diagram of the normal loading assembly in

[0048] Figure 5 For Figure 1 Schematic diagram of the tangential loading assembly in

[0049] Figure 6 For Figure 3 Schematic diagram of the use of the sensor to be measured fixing assembly in

[0050] Figure 7 For Figure 6 Top view schematic diagram of the structure shown;

[0051] In the figure: 1 - normal loading assembly, 2 - tangential loading assembly, 3 - leveling and centering assembly, 4 - sensor to be measured fixing assembly, 5 - leveling and centering device, 6 - standard six-axis sensor, 7 - connecting piece for sensor to be measured, 8 - fixture for sensor to be measured, 9 - upper load transfer plate for sensor to be measured, 10 - capacitive triaxial force sensor to be measured, 11 - normal loading plate, 12 - tangential loading contact, 13 - first limiting hole, 14 - second limiting hole, 15 - first connecting protrusion, 16 - second connecting protrusion, 17 - heat insulation pad, 18 - first force control push rod motor, 19 - first bottom positioning plate, 20 - first Z-axis linear module, 21 - second force control push rod motor, 22 - second bottom positioning plate, 23 - second Z-axis linear module. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0052] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0053] The purpose of the present invention is to provide a calibration platform and a calibration method for a capacitive triaxial force sensor, so as to solve the problems existing in the above-mentioned prior art, and can effectively reduce the difficulty of applying a load to the capacitive triaxial force sensor to be measured, and improve the calibration efficiency and accuracy.

[0054] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0055] Embodiment 1

[0056] As Figures 1 to 7As shown, the present embodiment provides a capacitive three-axis force sensor calibration platform, including a normal loading component 1, a tangential loading component 2, a leveling and centering component 3, and a sensor fixing component 4 to be tested; the leveling and centering component 3 includes a leveling and centering device 5 and a standard six-axis sensor 6, and the standard six-axis sensor 6 is arranged on the top of the leveling and centering device 5; the sensor fixing component 4 to be tested includes a sensor connecting piece 7 to be tested, a sensor fixture 8 to be tested, and a transmission plate 9 on the upper end of the sensor to be tested, the sensor connecting piece 7 to be tested is fixedly arranged on the top surface of the standard six-axis sensor 6, and the sensor to be tested The sensor fixture 8 can be detachably fixed on the top surface of the sensor connector 7 to be tested, the sensor fixture 8 to be tested can carry and fix the capacitive three-axis force sensor 10 to be tested, the upper end carrier plate 9 of the sensor to be tested is used to be detachably fixed on the top surface of the upper plate of the capacitive three-axis force sensor 10 to be tested, and the upper end carrier plate 9 of the sensor to be tested has a first connection structure and a second connection structure, the first connection structure is used to complete the Y-axis tangential force calibration of the capacitive three-axis force sensor 10 to be tested, and the second connection structure is used to complete the X-axis tangential force calibration of the capacitive three-axis force sensor 10 to be tested. Axis tangential force calibration; the normal loading assembly 1 includes a normal loading drive device and a normal loading plate 11, the normal loading plate 11 is placed above the upper end of the sensor to be tested, the bottom surface of the normal loading plate 11 is used to contact the top surface of the upper end of the sensor to be tested, the normal loading drive device is connected to the normal loading plate 11, and the normal loading drive device can drive the normal loading plate 11 to move upward or downward; the tangential loading assembly 2 includes a tangential loading drive device and a tangential loading contact 12, the tangential loading contact 12 is placed on the side of the sensor fixture 8 to be tested, The tangential loading contact 12 can be connected to the first connecting structure or the second connecting structure, and the tangential loading drive device is transmission-connected to the tangential loading contact 12. The tangential loading drive device can drive the tangential loading contact 12 to move forward or backward. When the tangential loading contact 12 is connected to the first connecting structure, the moving direction of the tangential loading contact 12 is parallel to the Y-axis direction of the capacitive three-axis force sensor 10 to be measured. When the tangential loading contact 12 is connected to the second connecting structure, the moving direction of the tangential loading contact 12 is parallel to the X-axis direction of the capacitive three-axis force sensor 10 to be measured.

[0057] The capacitive triaxial force sensor calibration platform provided by this embodiment is provided with a standard six-axis sensor 6 to provide accurate detection values during the calibration process, facilitating the determination of the errors and offsets of the capacitive triaxial force sensor 10 to be measured. The leveling and centering device 5 provides support for the capacitive triaxial force sensor 10 to be measured and the standard six-axis sensor 6, facilitating the leveling and centering of the capacitive triaxial force sensor 10 to be measured and the standard six-axis sensor 6 (centering means that the centers of mass of the two coincide), ensuring the accuracy of the detection data of the capacitive triaxial force sensor 10 to be measured and the standard six-axis sensor 6 during loading. The normal loading driving device provides a normal standard load to precisely load the capacitive triaxial force sensor 10 to be measured in the normal direction. The tangential loading driving device provides a tangential standard load to precisely load the capacitive triaxial force sensor 10 to be measured in the tangential direction, so as to meet the precise loading requirements needed for the calibration process. The sensor fixture 8 to be measured is used to fix the capacitive triaxial force sensor 10 to be measured, ensuring that the capacitive triaxial force sensor 10 to be measured will not displace or overturn during the calibration process, and ensuring the stability of the capacitive triaxial force sensor 10 to be measured. The sensor connector 7 to be measured fixedly connects the sensor fixture 8 to be measured and the standard six-axis sensor 6. The upper load transfer plate 9 of the sensor to be measured is fixedly arranged on the top surface of the upper electrode plate of the capacitive triaxial force sensor 10 to be measured, and the upper load transfer plate 9 of the sensor to be measured is used to transfer the load to the capacitive triaxial force sensor 10 to be measured. During the normal force calibration of the capacitive triaxial force sensor 10 to be measured, the normal loading plate 11 is driven by the normal loading driving device to apply a normal load to the upper load transfer plate 9 of the sensor to be measured. The upper load transfer plate 9 of the sensor to be measured is used to transfer the normal load to the capacitive triaxial force sensor 10 to be measured. The normal load is evenly dispersed and transferred among the normal loading plate 11, the upper load transfer plate 9 of the sensor to be measured, and the upper electrode plate of the capacitive triaxial force sensor 10 to be measured, effectively reducing the difficulty of the uniform distribution transfer of the normal load and avoiding the error influence caused by the concentration of the normal load, and completing the normal loading in the form of a uniform load. During the tangential force calibration of the capacitive triaxial force sensor 10 to be measured, the tangential loading contact 12 is connected to the first connection structure or the second connection structure on the upper load transfer plate 9 of the sensor to be measured, realizing the rapid conversion between the two calibration directions of the Y-axis tangential force calibration and the X-axis tangential force calibration of the capacitive triaxial force sensor 10 to be measured, improving the calibration efficiency. At the same time, while ensuring the positioning accuracy, it can effectively reduce the influence of the manual installation error caused by repeatedly disassembling and assembling the capacitive triaxial force sensor 10 to be measured. The tangential loading contact 12 is driven by the tangential loading driving device to apply a tangential load to the upper load transfer plate 9 of the sensor to be measured. The upper load transfer plate 9 of the sensor to be measured is used to indirectly connect the tangential loading contact 12 and the capacitive triaxial force sensor 10 to be measured, and the tangential load is transferred to the capacitive triaxial force sensor 10 to be measured through the upper load transfer plate 9 of the sensor to be measured.Effectively avoid the problem that it is difficult to achieve tangential connection and loading due to the thin thickness and small stress area of the capacitive triaxial force sensor 10 to be measured, ensure the tangential loading accuracy, and at the same time achieve the accurate transmission of the tangential standard load, reduce the difficulty of applying the tangential load. Therefore, the capacitive triaxial force sensor calibration platform provided by this embodiment can effectively reduce the difficulty of applying a load to the capacitive triaxial force sensor 10 to be measured, and improve the calibration efficiency and accuracy.

[0058] As a more preferred implementation manner of this embodiment, place the sensor fixture 8 to be measured on the top surface of the sensor connector 7 to be measured. Ensure that the centroid of the sensor fixture 8 to be measured coincides with the centroid of the sensor connector 7 to be measured through the first positioning pin. Then, set the first bolts at the diagonal positions for fastening. Place the capacitive triaxial force sensor 10 to be measured on the top surface of the sensor fixture 8 to be measured. Ensure that the centroid of the capacitive triaxial force sensor 10 to be measured coincides with the centroid of the sensor fixture 8 to be measured through the second positioning pin. Then, set the second bolts at the diagonal positions for fastening. Fix the upper load transfer plate 9 of the sensor to be measured on the top surface of the upper electrode plate of the capacitive triaxial force sensor 10 to be measured through the third positioning pin to transfer the normal load or tangential load. It is necessary to ensure that the Z-axis of the capacitive triaxial force sensor 10 to be measured coincides with the Z-axis of the standard six-axis sensor 6, ensure that the X and Y axes of the capacitive triaxial force sensor 10 to be measured are parallel to the X and Y axes of the standard six-axis sensor 6 in the vertical direction, and ensure that the loading center line of the tangential loading contact 12 is coplanar with the X-axis of the capacitive triaxial force sensor 10 to be measured; The leveling and centering device 5 is preferably a five-axis displacement leveling platform.

[0059] Furthermore, the first connection structure includes a first limiting hole 13, and the second connection structure includes a second limiting hole 14. Both the first limiting hole 13 and the second limiting hole 14 are opened on the bottom surface of the upper load transfer plate 9 of the sensor to be measured. The tangential loading contact 12 has a first connection protrusion 15 and a second connection protrusion 16. The first connection protrusion 15 is used to extend upward from below the upper load transfer plate 9 of the sensor to be measured into the first limiting hole 13 or the second limiting hole 14, and the second connection protrusion 16 can contact the outer side surface of the upper load transfer plate 9 of the sensor to be measured. The structure is simple and convenient for manufacturing and use.

[0060] Furthermore, the first limiting hole 13 has a first circular hole portion and a first long strip portion, the first circular hole portion is connected to the first long strip portion and is smoothly transitioned to each other, and the second limiting hole 14 has a second circular hole portion and a second long strip portion, the second circular hole portion is connected to the second long strip portion and is smoothly transitioned to each other; the diameters of the first circular hole portion and the second circular hole portion are larger than the outer diameter of the first connecting protrusion 15, and the outer side surface of the first connecting protrusion 15 can slide along the inner side surface of the first long strip portion or the second long strip portion. When calibrating the Y-axis tangential force of the capacitive three-axis force sensor 10 to be measured, the x-axis displacement of the five-axis displacement leveling platform is adjusted to make the outer side surface of the first connecting protrusion 15 slide along the inner side surface of the first long strip portion, and observe whether the standard six-axis sensor 6 has an X-axis coupling force, and the y-axis displacement of the five-axis displacement leveling platform is adjusted to reduce the standard six-axis sensor 6X-axis coupling force to ensure that the loading center line of the tangential loading contact 12 is collinear with the loading center line of the upper end carrier plate 9 of the sensor to be tested; after the sensor fixture 8 to be tested, the capacitive three-axis force sensor 10 to be tested fixed on the sensor fixture 8 to be tested, and the upper end carrier plate 9 of the sensor to be tested are rotated 90° together, when calibrating the X-axis tangential force of the capacitive three-axis force sensor 10 to be tested, adjust the x-axis displacement of the five-axis displacement leveling platform to make the outer side surface of the first connecting protrusion 15 slide along the inner side surface of the second long strip portion, observe whether the standard six-axis sensor 6 has a Y-axis coupling force, and reduce the Y-axis coupling force of the standard six-axis sensor 6 by adjusting the y-axis displacement of the five-axis displacement leveling platform to ensure that the loading center line of the tangential loading contact 12 is collinear with the loading center line of the upper end carrier plate 9 of the sensor to be tested.

[0061] Furthermore, the normal loading plate 11 includes a loading plate body and a thermal insulation pad 17. The bottom surface of the loading plate body is provided with a square protrusion, and the bottom surface of the square protrusion is fixedly provided with a thermal insulation pad 17. The bottom surface of the thermal insulation pad 17 is used to contact the top surface of the upper end transfer plate 9 of the sensor to be tested. The normal loading drive device is transmission-connected to the loading plate body. The normal loading drive device can drive the loading plate body to move upward or downward. The thermal insulation pad 17 can achieve a thermal insulation effect during the calibration process, thereby preventing the normal loading drive device from transferring the generated heat to the capacitive three-axis force sensor 10 to be tested, thereby preventing the heat generated by the normal loading drive device from affecting the calibration accuracy of the capacitive three-axis force sensor 10 to be tested.

[0062] Further, the normal loading driving device includes a first force control push rod motor 18, a first bottom positioning plate 19, and a first Z-axis linear module 20. The guide rail of the first Z-axis linear module 20 is fixedly arranged on the first bottom positioning plate 19. The housing of the first force control push rod motor 18 is fixedly connected to the slider of the first Z-axis linear module 20 to realize the upward or downward movement of the first force control push rod motor 18, thereby adjusting the starting position of the first force control push rod motor 18 during calibration. The power output shaft of the first force control push rod motor 18 is fixedly connected to the normal loading plate 11 to meet the requirements of normal loading. The first force control push rod motor 18 is set to a closed-loop pushing mode, and positive and negative stepped loading is performed on the capacitance type three-axis force sensor 10 to be measured to complete the Y-axis tangential force calibration of the capacitance type three-axis force sensor 10 to be measured; the tangential loading driving device includes a second force control push rod motor 21, a second bottom positioning plate 22, and a second Z-axis linear module 23. The guide rail of the second Z-axis linear module 23 is fixedly arranged on the second bottom positioning plate 22. The housing of the second force control push rod motor 21 is fixedly connected to the slider of the second Z-axis linear module 23 to realize the upward or downward movement of the second force control push rod motor 21, thereby adjusting the normal displacement of the second force control push rod motor 21 during calibration, so as to facilitate adjusting the loading action point of the tangential loading contact 12 in the normal direction. The power output shaft of the second force control push rod motor 21 is fixedly connected to the tangential loading contact 12 to meet the requirements of tangential loading. The second force control push rod motor 21 is set to a closed-loop pushing mode, and positive and negative stepped loading is performed on the capacitance type three-axis force sensor 10 to be measured to complete the X-axis tangential force calibration of the capacitance type three-axis force sensor 10 to be measured. It is necessary to ensure that the tangential loading contact 12 does not interfere with the sensor to be measured fixing assembly 4 and the capacitance type three-axis force sensor 10 to be measured during tangential loading. By means of loading through the first force control push rod motor 18 or the second force control push rod motor 21, compared with the traditional manual placing weight loading method, the calibration efficiency is improved, and the human error and assembly error generated during the manual placing process and the friction of the pulley group are reduced.

[0063] Further, the capacitance type three-axis force sensor calibration platform provided in this embodiment further includes an optical platform. The leveling and centering device 5 is fixedly arranged on the first bottom positioning plate 19. The first bottom positioning plate 19 and the second bottom positioning plate 22 are both fixedly arranged on the optical platform, which is convenient for positioning and assembly.

[0064] Furthermore, the capacitive triaxial force sensor calibration platform provided in this embodiment further includes a lateral positioning pin. A first lateral positioning hole is formed in the tangential loading contact 12, a second lateral positioning hole is formed in one side surface of the sensor fixture 8 to be measured, and a third lateral positioning hole is formed in the other side surface of the sensor fixture 8 to be measured. When the tangential loading contact 12 is connected to the first connection structure, one end of the lateral positioning pin extends into the first lateral positioning hole, and the other end of the lateral positioning pin extends into the second lateral positioning hole. When the tangential loading contact 12 is connected to the second connection structure, one end of the lateral positioning pin extends into the first lateral positioning hole, and the other end of the lateral positioning pin extends into the third lateral positioning hole, which is convenient for positioning and guiding the tangential loading contact 12. Among them, the first lateral positioning hole is a long hole, or both the second lateral positioning hole and the third lateral positioning hole are long holes. As a relatively preferred implementation manner of this embodiment, both the second lateral positioning hole and the third lateral positioning hole are long holes, and the first end of the lateral positioning pin is fixedly embedded in the first lateral positioning hole. When the tangential loading contact 12 is connected to the first connection structure, the second end of the lateral positioning pin extends into the second lateral positioning hole, and the outer side surface of the second end of the lateral positioning pin contacts the inner side surface of the second lateral positioning hole. Through the cooperation between the second lateral positioning hole and the second end of the lateral positioning pin, the loading center line of the tangential loading contact 12 is coplanar with the lateral symmetry axis of the sensor fixture 8 to be measured, and the second end of the lateral positioning pin can also slide up or down along the inner side surface of the second lateral positioning hole in the second lateral positioning hole, so as to adapt to the normal displacement adjustment of the second force control push rod motor 21 and meet the clearance requirement of tangential loading. When the tangential loading contact 12 is connected to the second connection structure, the second end of the lateral positioning pin extends into the third lateral positioning hole, and the outer side surface of the second end of the lateral positioning pin contacts the inner side surface of the third lateral positioning hole. Through the cooperation between the third lateral positioning hole and the second end of the lateral positioning pin, the loading center line of the tangential loading contact 12 is coplanar with the lateral symmetry axis of the sensor fixture 8 at this time, and the second end of the lateral positioning pin can also slide up or down along the inner side surface of the third lateral positioning hole in the third lateral positioning hole, so as to adapt to the normal displacement adjustment of the second force control push rod motor 21 and meet the clearance requirement of tangential loading.

[0065] Further, the capacitive triaxial force sensor calibration platform provided in this embodiment also uses a level, a CAN communication connection board, the upper computer of the capacitive triaxial force sensor 10 to be measured, and the upper computer of the standard six-axis sensor 6. Among them, the level loading surface is used to check whether it is consistent with the horizontal and pitch angles of the sensor fixture 8 to be measured. The CAN communication connection board is used to transmit the original capacitance value output by the capacitive triaxial force sensor 10 to be measured to the upper computer of the capacitive triaxial force sensor 10 to be measured through a CAN analyzer. The upper computer of the capacitive triaxial force sensor 10 to be measured is used to receive and analyze the detection data of the capacitive triaxial force sensor 10 to be measured, and the upper computer of the standard six-axis sensor 6 is used to receive and analyze the detection data of the standard six-axis sensor 6.

[0066] Embodiment Two

[0067] This embodiment provides a calibration method for a capacitive triaxial force sensor, which applies the capacitive triaxial force sensor calibration platform in Embodiment One and includes the normal force calibration process of the capacitive triaxial force sensor 10 to be measured. The normal force calibration process of the capacitive triaxial force sensor 10 to be measured includes the following steps:

[0068] Step 1: Before installing the normal loading plate 11, use a level to measure and record the horizontal and pitch angles of the loading surface of the normal loading driving device.

[0069] Step 2: Remove the sensor fixture 8 to be measured, place the level on the top surface of the sensor connecting piece 7 to be measured, and adjust the leveling and centering device 5 so that the horizontal angle of the top surface of the sensor connecting piece 7 to be measured is the same as the horizontal angle of the loading surface of the normal loading driving device, and the pitch angle of the top surface of the sensor connecting piece 7 to be measured is the same as the pitch angle of the loading surface of the normal loading driving device.

[0070] Step 3: Fix and install the sensor fixture 8 to be measured on the top surface of the sensor connecting piece 7 to be measured, and install the normal loading plate 11 on the loading surface of the normal loading driving device.

[0071] Step 4: Fix and install the capacitive triaxial force sensor 10 to be measured on the top surface of the sensor fixture 8 to be measured.

[0072] Step 5: Power on the capacitive triaxial force sensor 10 to be measured and preheat it for 30 minutes. After the preheating is completed, save the detection data of the capacitive triaxial force sensor 10 to be measured within five minutes separately. After observing that the detection data fluctuates stably, perform a zero-clearing operation on the capacitive triaxial force sensor 10 to be measured.

[0073] Step 6: Fix and install the upper transmission plate 9 at the upper end of the sensor to be measured on the top plate of the upper electrode of the capacitive triaxial force sensor 10 to be measured, and place the normal loading plate 11 2 mm - 3 mm above the upper transmission plate 9 at the upper end of the sensor to be measured through the normal loading driving device.

[0074] Step Seven: Power on the standard six-axis sensor 6 and collect the detection data of the standard six-axis sensor 6 and the capacitive triaxial force sensor 10 to be measured;

[0075] Step Eight: Drive the normal loading plate 11 through the normal loading driving device to perform positive and negative stepped loading on the upper load transfer plate 9 of the sensor to be measured;

[0076] Step Nine: After Step Eight ends, save the detection data of the standard six-axis sensor 6 and the capacitive triaxial force sensor 10 to be measured.

[0077] Furthermore, the capacitive triaxial force sensor calibration method provided in this embodiment further includes the Y-axis tangential force calibration process of the capacitive triaxial force sensor 10 to be measured. The Y-axis tangential force calibration process of the capacitive triaxial force sensor 10 to be measured includes the following steps:

[0078] Step One: Before installing the tangential loading contact 12, use a spirit level to measure the horizontal and pitch angles of the loading surface of the tangential loading driving device and record them;

[0079] Step Two: Remove the sensor fixture 8 to be measured, the capacitive triaxial force sensor 10 on the sensor fixture 8 to be measured, and the upper load transfer plate 9 of the sensor to be measured. Use a spirit level to measure the horizontal and pitch angles of the top surface of the sensor connecting part 7 to be measured, and adjust the leveling and centering device 5 to make the horizontal angle of the top surface of the sensor connecting part 7 to be measured the same as the horizontal angle of the loading surface of the tangential loading driving device, and make the pitch angle of the top surface of the sensor connecting part 7 to be measured the same as the pitch angle of the loading surface of the tangential loading driving device;

[0080] Step Three: Install the tangential loading contact 12 on the loading surface of the tangential loading driving device, fixedly install the sensor fixture 8 to be measured on the top surface of the sensor connecting part 7 to be measured, and fixedly install the capacitive triaxial force sensor 10 to be measured on the sensor fixture 8 to be measured;

[0081] Step Four: Through the tangential loading driving device, place the tangential loading contact 12 1 - 2 mm above the sensor fixture 8 to be measured;

[0082] Step Five: Fix the upper load transfer plate 9 of the sensor to be measured on the top surface of the capacitive triaxial force sensor 10 to be measured, and connect the tangential loading contact 12 with the first connection structure;

[0083] Step Six: Perform detection data sampling on the standard six-axis sensor 6, adjust the leveling and centering device 5, and observe whether there is a coupling force in the X-axis direction on the standard six-axis sensor 6. If so, reduce the coupling force in the X-axis direction by adjusting the leveling and centering device 5;

[0084] Step 7: Power on the capacitive triaxial force sensor 10 to be measured and preheat it for 30 minutes. After the preheating is completed, separately save the detection data of the capacitive triaxial force sensor 10 to be measured within five minutes. After observing that the detection data fluctuations are stable, perform a zeroing operation on the capacitive triaxial force sensor 10 to be measured;

[0085] Step 8: Drive the tangential loading contact 12 through the tangential loading driving device to perform positive and negative stepped loading on the upper load transfer plate 9 of the sensor to be measured;

[0086] Step 9: After the end of Step 8, save the detection data of the standard six-axis sensor 6 and the capacitive triaxial force sensor 10 to be measured.

[0087] Furthermore, the capacitive triaxial force sensor calibration method provided in this embodiment further includes the X-axis tangential force calibration process of the capacitive triaxial force sensor 10 to be measured. The X-axis tangential force calibration process of the capacitive triaxial force sensor 10 to be measured includes the following steps:

[0088] Step 1: Release the fixation of the sensor connector 7 to be measured on the sensor fixture 8 to be measured, rotate the sensor fixture 8 to be measured, the capacitive triaxial force sensor 10 fixed on the sensor fixture 8 to be measured, and the upper load transfer plate 9 of the sensor to be measured together by 90°, and then fixedly connect the sensor fixture 8 to be measured with the sensor connector 7 to be measured;

[0089] Step 2: Adjust the leveling and centering device 5 to connect the tangential loading contact 12 with the second connection structure;

[0090] Step 3: Through the tangential loading driving device, place the tangential loading contact 12 1 - 2 mm above the sensor fixture 8 to be measured;

[0091] Step 4: Perform detection data sampling on the standard six-axis sensor 6, adjust the leveling and centering device 5, and observe whether there is a coupling force in the Y-axis direction on the standard six-axis sensor 6. If so, reduce the coupling force in the Y-axis direction by adjusting the leveling and centering device 5;

[0092] Step 5: Power on the capacitive triaxial force sensor 10 to be measured and preheat it for 30 minutes. After the preheating is completed, separately save the detection data of the capacitive triaxial force sensor 10 to be measured within five minutes. After observing that the detection data fluctuations are stable, perform a zeroing operation on the capacitive triaxial force sensor 10 to be measured;

[0093] Step 6: Drive the tangential loading contact 12 through the tangential loading driving device to perform positive and negative stepped loading on the upper load transfer plate 9 of the sensor to be measured;

[0094] Step 7: After the end of Step 5, save the detection data of the standard six-axis sensor 6 and the capacitive triaxial force sensor 10 to be measured.

[0095] The capacitance type three-axis force sensor calibration method provided in this embodiment sets a standard six-axis sensor 6 to provide accurate detection values during the calibration process, facilitating the determination of the errors and offsets of the capacitance type three-axis force sensor 10 to be measured. A leveling and centering device 5 provides support for the capacitance type three-axis force sensor 10 to be measured and the standard six-axis sensor 6, facilitating the leveling and centering of the capacitance type three-axis force sensor 10 to be measured and the standard six-axis sensor 6, and ensuring the accuracy of the detection data of the capacitance type three-axis force sensor 10 to be measured and the standard six-axis sensor 6 during loading. A normal loading driving device provides a normal standard load to precisely load the capacitance type three-axis force sensor 10 to be measured. A tangential loading driving device provides a tangential standard load to precisely load the capacitance type three-axis force sensor 10 to be measured, so as to meet the precise loading requirements needed in the calibration process. The capacitance type three-axis force sensor 10 to be measured is fixed by a sensor fixture 8 to be measured, ensuring that the capacitance type three-axis force sensor 10 to be measured will not be displaced or overturned during the calibration process, and ensuring the stability of the capacitance type three-axis force sensor 10 to be measured. The sensor fixture 8 to be measured is fixedly connected to the standard six-axis sensor 6 through a connecting piece 7 of the sensor to be measured. It is set that an upper load transfer plate 9 of the sensor to be measured is fixedly arranged on the top surface of the upper electrode plate of the capacitance type three-axis force sensor 10 to be measured, and the upper load transfer plate 9 of the sensor to be measured is used to transfer the load to the capacitance type three-axis force sensor 10 to be measured. During the normal force calibration of the capacitance type three-axis force sensor 10 to be measured, the normal loading plate 11 is driven by the normal loading driving device to apply a normal load to the upper load transfer plate 9 of the sensor to be measured, and the upper load transfer plate 9 of the sensor to be measured is used to transfer the normal load to the capacitance type three-axis force sensor 10 to be measured. The normal load is evenly dispersed and transferred between the normal loading plate 11, the upper load transfer plate 9 of the sensor to be measured, and the upper electrode plate of the capacitance type three-axis force sensor 10 to be measured, effectively reducing the difficulty of uniform distribution transfer of the normal load and avoiding the error influence caused by the concentration of the normal load, and completing the normal loading in the form of a uniformly distributed load. During the tangential force calibration of the capacitance type three-axis force sensor 10 to be measured, the tangential loading contact 12 is connected to the first connection structure or the second connection structure on the upper load transfer plate 9 of the sensor to be measured, realizing the rapid conversion of the two calibration directions of the Y-axis tangential force calibration and the X-axis tangential force calibration of the capacitance type three-axis force sensor 10 to be measured, improving the calibration efficiency, and while ensuring the positioning accuracy, effectively reducing the influence of the artificial installation error caused by repeatedly disassembling and assembling the capacitance type three-axis force sensor 10 to be measured. The tangential loading contact 12 is driven by the tangential loading driving device to apply a tangential load to the upper load transfer plate 9 of the sensor to be measured, and the upper load transfer plate 9 of the sensor to be measured is used to indirectly connect the tangential loading contact 12 to the capacitance type three-axis force sensor 10 to be measured, and the tangential load is transferred to the capacitance type three-axis force sensor 10 to be measured through the upper load transfer plate 9 of the sensor to be measured, effectively avoiding the problem that it is difficult to achieve tangential connection and loading due to the relatively thin thickness and small force-bearing area of the capacitance type three-axis force sensor 10 to be measured.Ensure the tangential loading accuracy, while achieving the accurate transmission of the tangential standard load and reducing the difficulty of applying the tangential load. Therefore, the calibration method of the capacitive triaxial force sensor provided in this embodiment can effectively reduce the difficulty of applying the load to the capacitive triaxial force sensor 10 to be measured, and improve the calibration efficiency and accuracy.

[0096] In the present invention, specific examples are used to illustrate the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A capacitive three-axis force sensor calibration platform, characterized in that: It includes a normal loading component, a tangential loading component, a leveling and centering component, and a sensor fixing component to be tested; The leveling and centering assembly includes a leveling and centering device and a standard six-axis sensor, and the standard six-axis sensor is arranged at the top of the leveling and centering device; The sensor fixing assembly to be tested includes a sensor connecting piece to be tested, a sensor fixture to be tested, and an upper end transmission and carrying plate of the sensor to be tested, wherein the sensor connecting piece to be tested is fixedly arranged on the top surface of the standard six-axis sensor, the sensor fixture to be tested is detachably fixedly arranged on the top surface of the sensor connecting piece to be tested, the sensor fixture to be tested is capable of carrying and fixing the capacitive three-axis force sensor to be tested, the upper end transmission and carrying plate of the sensor to be tested is used to be detachably fixedly arranged on the top surface of the upper plate of the capacitive three-axis force sensor to be tested, and the upper end transmission and carrying plate of the sensor to be tested has a first connection structure and a second connection structure, the first connection structure is used to complete the Y-axis tangential force calibration of the capacitive three-axis force sensor to be tested, and the second connection structure is used to complete the X-axis tangential force calibration of the capacitive three-axis force sensor to be tested; The normal loading assembly includes a normal loading drive device and a normal loading plate, wherein the normal loading plate is placed above the upper end transfer plate of the sensor to be tested, the bottom surface of the normal loading plate is used to contact the top surface of the upper end transfer plate of the sensor to be tested, the normal loading drive device is in transmission connection with the normal loading plate, and the normal loading drive device can drive the normal loading plate to move upward or downward; The tangential loading assembly includes a tangential loading drive device and a tangential loading contact, wherein the tangential loading contact is placed on the side of the sensor fixture to be tested, and the tangential loading contact can be connected to the first connecting structure or the second connecting structure, and the tangential loading drive device is transmission-connected to the tangential loading contact, and the tangential loading drive device can drive the tangential loading contact to move forward or backward. When the tangential loading contact is connected to the first connecting structure, the moving direction of the tangential loading contact is parallel to the Y-axis direction of the capacitive three-axis force sensor to be tested, and when the tangential loading contact is connected to the second connecting structure, the moving direction of the tangential loading contact is parallel to the X-axis direction of the capacitive three-axis force sensor to be tested.

2. The capacitive three-axis force sensor calibration platform according to claim 1, characterized in that: The first connection structure includes a first limiting hole, and the second connection structure includes a second limiting hole. The first limiting hole and the second limiting hole are both opened on the bottom surface of the upper end transmission plate of the sensor to be tested. The tangential loading contact has a first connecting protrusion and a second connecting protrusion. The first connecting protrusion is used to extend upward from the bottom of the upper end transmission plate of the sensor to be tested into the first limiting hole or the second limiting hole, and the second connecting protrusion can contact the outer side surface of the upper end transmission plate of the sensor to be tested.

3. The capacitive three-axis force sensor calibration platform according to claim 2, characterized in that: The first limiting hole has a first circular hole portion and a first long strip portion, the first circular hole portion is connected to the first long strip portion and is smoothly transitioned to the connection, and the second limiting hole has a second circular hole portion and a second long strip portion, the second circular hole portion is connected to the second long strip portion and is smoothly transitioned to the connection; the diameters of the first circular hole portion and the second circular hole portion are larger than the outer diameter of the first connecting protrusion, and the outer side surface of the first connecting protrusion can slide along the inner side surface of the first long strip portion or the second long strip portion.

4. The capacitive three-axis force sensor calibration platform according to claim 1, characterized in that: The normal loading plate includes a loading plate body and a thermal insulation pad. The bottom surface of the loading plate body is provided with a square protrusion, and the thermal insulation pad is fixedly laid on the bottom surface of the square protrusion. The bottom surface of the thermal insulation pad is used to contact the top surface of the upper end of the transfer plate of the sensor to be tested. The normal loading drive device is transmission-connected to the loading plate body, and the normal loading drive device can drive the loading plate body to move upward or downward.

5. The capacitive three-axis force sensor calibration platform according to claim 1, characterized in that: The normal loading drive device includes a first force-controlled push rod motor, a first bottom positioning plate and a first Z-axis linear module, the guide rail of the first Z-axis linear module is fixedly arranged on the first bottom positioning plate, the housing of the first force-controlled push rod motor is fixedly connected to the slider of the first Z-axis linear module, and the power output shaft of the first force-controlled push rod motor is fixedly connected to the normal loading plate; the tangential loading drive device includes a second force-controlled push rod motor, a second bottom positioning plate and a second Z-axis linear module, the guide rail of the second Z-axis linear module is fixedly arranged on the second bottom positioning plate, the housing of the second force-controlled push rod motor is fixedly connected to the slider of the second Z-axis linear module, and the power output shaft of the second force-controlled push rod motor is fixedly connected to the tangential loading contact.

6. The capacitive three-axis force sensor calibration platform according to claim 5, characterized in that: It also includes an optical platform, the leveling and centering device is fixedly arranged on the first bottom positioning plate, and the first bottom positioning plate and the second bottom positioning plate are both fixedly arranged on the optical platform.

7. The capacitive three-axis force sensor calibration platform according to claim 1, characterized in that: It also includes a lateral positioning pin, a first lateral positioning hole is formed on the tangential loading contact, a second lateral positioning hole is formed on one side of the sensor fixture to be tested, and a third lateral positioning hole is formed on the other side of the sensor fixture to be tested; when the tangential loading contact is connected to the first connecting structure, one end of the lateral positioning pin extends into the first lateral positioning hole, and the other end of the lateral positioning pin extends into the second lateral positioning hole; when the tangential loading contact is connected to the second connecting structure, one end of the lateral positioning pin extends into the first lateral positioning hole, and the other end of the lateral positioning pin extends into the third lateral positioning hole.

8. A capacitive three-axis force sensor calibration method, using the capacitive three-axis force sensor calibration platform as claimed in any one of claims 1 to 7, characterized in that: The invention comprises a normal force calibration process of a capacitive three-axis force sensor to be tested, wherein the normal force calibration process of the capacitive three-axis force sensor to be tested comprises the following steps: Step 1: Before installing the normal loading plate, use a level to measure the horizontal and pitch angles of the loading surface of the normal loading drive device and record them; Step 2: Remove the sensor fixture to be tested, place the level on the top surface of the sensor connector to be tested, and adjust the leveling and centering device to make the horizontal inclination angle of the top surface of the sensor connector to be tested the same as the horizontal inclination angle of the loading surface of the normal loading drive device, and make the pitch inclination angle of the top surface of the sensor connector to be tested the same as the pitch inclination angle of the loading surface of the normal loading drive device; Step 3: Fix the sensor fixture to be tested on the top surface of the sensor connector to be tested, and install the normal loading plate on the loading surface of the normal loading drive device; Step 4: Fix the capacitive triaxial force sensor to be tested on the top surface of the sensor fixture to be tested; Step 5: Power on the capacitive three-axis force sensor to be tested and preheat it for 30 minutes. After the preheating is completed, save the test data of the capacitive three-axis force sensor to be tested within 5 minutes separately. After observing that the test data fluctuations are stable, perform a zeroing operation on the capacitive three-axis force sensor to be tested; Step 6: The upper end transfer plate of the sensor to be tested is fixedly mounted on the top surface of the upper electrode plate of the capacitive triaxial force sensor to be tested, and the normal loading plate is placed 2mm-3mm above the upper end transfer plate of the sensor to be tested through the normal loading driving device; Step 7: Power on the standard six-axis sensor and collect the test data of the standard six-axis sensor and the capacitive three-axis force sensor to be tested; Step 8: The normal loading plate is driven by the normal loading driving device to perform positive and negative step loading on the upper end carrier plate of the sensor to be tested; Step 9: After step 8, save the test data of the standard six-axis sensor and the capacitive three-axis force sensor to be tested.

9. The capacitive three-axis force sensor calibration method according to claim 8, characterized in that: The method also includes a Y-axis tangential force calibration process of the capacitive three-axis force sensor to be tested, wherein the Y-axis tangential force calibration process of the capacitive three-axis force sensor to be tested includes the following steps: Step 1: Before installing the tangential loading contact, use a level to measure the horizontal and pitch angles of the loading surface of the tangential loading drive device and record them; Step 2: Remove the sensor fixture to be tested, the capacitive triaxial force sensor to be tested on the sensor fixture to be tested, and the upper end carrier plate of the sensor to be tested, measure the level and pitch angle of the top surface of the sensor connector to be tested by a level meter, adjust the leveling and centering device to make the horizontal angle of the top surface of the sensor connector to be tested the same as the horizontal angle of the loading surface of the tangential loading drive device, and make the pitch angle of the top surface of the sensor connector to be tested the same as the pitch angle of the loading surface of the tangential loading drive device; Step 3: Install the tangential loading contact on the loading surface of the tangential loading driving device, fix the sensor fixture to be tested on the top surface of the sensor connector to be tested, and fix the capacitive triaxial force sensor to be tested on the sensor fixture to be tested; Step 4: Use the tangential loading drive device to place the tangential loading contact 1-2 mm above the sensor fixture to be tested; Step 5: The upper end transmission carrier plate of the sensor to be tested is fixedly mounted on the top surface of the capacitive triaxial force sensor to be tested, so that the tangential loading contact is connected to the first connection structure; Step 6: Sample the test data of the standard six-axis sensor, adjust the leveling and centering device, and observe whether the standard six-axis sensor has coupling force in the X-axis direction. If so, reduce the coupling force in the X-axis direction by adjusting the leveling and centering device; Step 7: Power on the capacitive three-axis force sensor to be tested and preheat it for 30 minutes. After the preheating is completed, save the test data of the capacitive three-axis force sensor to be tested within 5 minutes separately. After the test data fluctuations are observed to be stable, perform a zeroing operation on the capacitive three-axis force sensor to be tested; Step 8: Drive the tangential loading contact through the tangential loading driving device to perform positive and negative step loading on the upper end carrier plate of the sensor to be tested; Step 9: After step 8, save the test data of the standard six-axis sensor and the capacitive three-axis force sensor to be tested.

10. The capacitive three-axis force sensor calibration method according to claim 9, characterized in that: The method also includes a calibration process of the X-axis tangential force of the capacitive three-axis force sensor to be tested, wherein the calibration process of the X-axis tangential force of the capacitive three-axis force sensor to be tested includes the following steps: Step 1: Release the fixing of the sensor fixture to be tested by the sensor connector to be tested, rotate the sensor fixture to be tested, the capacitive triaxial force sensor to be tested fixed on the sensor fixture to be tested, and the upper end carrier plate of the sensor to be tested together by 90°, and then fix the sensor fixture to be tested to the sensor connector to be tested; Step 2: Adjust the leveling and centering device to connect the tangential loading contact to the second connecting structure; Step 3: Use the tangential loading drive device to place the tangential loading contact 1-2 mm above the sensor fixture to be tested; Step 4: Sample the test data of the standard six-axis sensor, adjust the leveling and centering device, and observe whether the standard six-axis sensor has Y-axis coupling force. If yes, reduce the Y-axis coupling force by adjusting the leveling and centering device. Step 5: Power on the capacitive three-axis force sensor to be tested and preheat it for 30 minutes. After the preheating is completed, save the test data of the capacitive three-axis force sensor to be tested within 5 minutes separately. After observing that the test data fluctuations are stable, perform a zeroing operation on the capacitive three-axis force sensor to be tested; Step 6: Drive the tangential loading contact through the tangential loading driving device to perform positive and negative step loading on the upper end carrier plate of the sensor to be tested; Step 7: After step 5, save the detection data of the standard six-axis sensor and the capacitive three-axis force sensor to be tested.

Images