Multi-axis linkage calibration device for six-dimensional force sensor

Abstract

The utility model relates to the technical field of calibration devices, in particular to a multi-axis linkage calibration device for a six-dimensional force sensor. In order to solve the problem that the calibration result is deviated from the actual application scene due to the fact that the existing six-dimensional force sensor adopts a single-axis independent loading calibration mode that a detection object is hung by a pull rope, the calibration efficiency is low and the problem of inter-dimensional coupling cannot be solved, the following technical scheme is provided: the six-dimensional force sensor comprises a bottom plate; the posture adjusting assembly is arranged above the bottom plate and is used for adjusting the posture of the six-dimensional sensor so as to calculate the stress component of the center mass of the detected object on each axis; and the detection mechanism is positioned below the six-dimensional sensor and is used for measuring the torsional rigidity of the vertical shaft. According to the utility model, the calibration efficiency and precision of the six-dimensional force sensor are obviously improved, so that the six-dimensional force sensor can accurately reflect real performance under a complex load, and the requirements of high-end manufacturing and other fields on high precision and quick response are met.

Description

A multi-axis linkage calibration device for a six-dimensional force sensor Technical Field

[0001] This utility model relates to the field of calibration device technology, and in particular to a multi-axis linkage calibration device for a six-dimensional force sensor. Background Technology

[0002] As a core component in industrial automation, robotic sensing, and precision measurement, the calibration accuracy of six-dimensional force sensors directly affects the accuracy and reliability of multi-dimensional force sensing. Currently, the calibration process for existing six-dimensional force sensors mainly adopts a single-axis independent loading method by hanging the object to be detected with a rope. This method completes the calibration process by applying single-direction loads to each of the six dimensions of the sensor (three-dimensional force and three-dimensional torque) and collecting data.

[0003] However, this traditional calibration method has significant technical bottlenecks: on the one hand, single-axis independent loading requires frequent disassembly and reinstallation of the sensor to switch the loading direction, resulting in a single calibration cycle of several hours or even longer, especially when calibrating multiple sensor models in batches, where the inefficiency is particularly prominent; on the other hand, this method completely ignores the coupling effect between the dimensions of the six-dimensional force sensor—in actual working conditions, force and torque often act on the sensor in a multi-dimensional coupling form, and single-axis independent loading cannot simulate real force scenarios, causing the calibration parameters to fail to accurately reflect the sensor's true performance under complex loads, ultimately resulting in deviations between the calibration results and the actual application scenario, making it difficult to meet the high-precision and fast-response requirements of high-end manufacturing, medical robotics, and other fields for six-dimensional force sensors. Therefore, this invention proposes a multi-axis linkage calibration device for a six-dimensional force sensor. Summary of the Invention

[0004] The purpose of this invention is to address the problems in the existing six-dimensional force sensor calibration method, which uses a single-axis independent loading method to hang the object being tested with a rope. This method has low calibration efficiency and cannot solve the problem of inter-dimensional coupling, resulting in deviations between the calibration results and the actual application scenario. Therefore, this invention proposes a multi-axis linkage calibration device for a six-dimensional force sensor.

[0005] The technical solution of this utility model is as follows: a multi-axis linkage calibration device for a six-dimensional force sensor, comprising a base plate; an attitude adjustment component disposed above the base plate, the attitude adjustment component being used to adjust the attitude of the six-dimensional sensor to calculate the force components of the detected object in different directions of the six-dimensional sensor; and a detection mechanism located below the six-dimensional sensor, the detection mechanism being used to measure the torsional stiffness of the vertical axis of the six-dimensional sensor.

[0006] Optionally, the attitude adjustment component includes a first servo motor, the output end of which is fixedly connected to a mounting plate. The mounting plate is L-shaped, and a second servo motor is mounted on the side of the mounting plate. The output end of the second servo motor passes through the mounting plate and is fixedly connected to a six-dimensional sensor.

[0007] Optionally, the rotation axis of the six-dimensional sensor is perpendicular to the rotation axis of the mounting plate.

[0008] Optionally, the detection mechanism includes a detection block fixedly connected to a six-dimensional sensor, a torque sensor is disposed below the detection block, the torque sensor is mounted on the top of the base plate, multiple sets of torsion blocks are disposed on the torque sensor, and a groove corresponding to the torsion block is opened at the bottom of the detection block.

[0009] Optionally, a lifting mechanism installed on the top of the base plate is also included, which is used to move the detection block.

[0010] Optionally, the lifting mechanism includes a vertical plate fixedly connected to the top of the base plate. A third servo motor is installed on the side of the vertical plate near the attitude adjustment component. A threaded rod is fixedly connected to the output end of the third servo motor. A threaded sleeve is threadedly connected to the threaded rod. A movable plate is fixedly connected to the side of the threaded sleeve away from the vertical plate. The first servo motor is installed on the side of the movable plate away from the threaded sleeve.

[0011] Optionally, a positioning plate is rotatably connected to the end of the threaded rod away from the third servo motor, and the positioning plate is fixedly connected to the side of the upright plate.

[0012] Optionally, the movable plate is fixedly connected to two sets of sliders on the side near the upright plate. The two sets of sliders are symmetrically arranged on both sides of the threaded sleeve. Each of the two sets of sliders is slidably connected to a slide rail, and both sets of slide rails are fixedly connected to the upright plate.

[0013] In summary, this application includes at least one of the following beneficial technical effects:

[0014] This utility model utilizes multi-axis linkage servo control technology, with the first, second, and third servo motors working in concert, and a modular structure design, allowing the lifting mechanism, attitude adjustment components, and detection mechanism to be driven independently, thus completely changing the inefficient mode of traditional single-axis independent loading that requires frequent sensor disassembly.

[0015] Furthermore, through the dual optimization of mechanical structure innovation and data calculation algorithm, the technical bottleneck of traditional single-axis calibration being unable to simulate real multi-dimensional force scenarios is effectively solved;

[0016] In summary, this invention improves the calibration efficiency and accuracy of six-dimensional force sensors, enabling them to accurately reflect the true performance under complex loads and meet the needs of high-end manufacturing and other fields for high precision and rapid response. Attached Figure Description

[0017] Figure 1 shows a schematic diagram of a multi-axis linkage calibration device for a six-dimensional force sensor.

[0018] Figure 2 is a schematic diagram of the cross-sectional structure of Figure 1.

[0019] Figure label:

[0020] 1. Base plate;

[0021] 2. Lifting mechanism; 21. Vertical plate; 22. Third servo motor; 23. Threaded rod; 24. Threaded sleeve; 25. Moving plate; 26. Positioning plate; 27. Slider; 28. Slide rail;

[0022] 3. Attitude adjustment assembly; 31. First servo motor; 32. Mounting plate; 33. Second servo motor;

[0023] 4. Six-dimensional sensor;

[0024] 5. Detection mechanism; 51. Detection block; 52. Torque sensor; 53. Torsion block; 54. Groove. Detailed Implementation

[0025] The technical solution of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this utility model, but not all embodiments.

[0026] The components of the present invention embodiments described and shown in the accompanying drawings can typically be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention.

[0027] Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0028] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0029] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0030] Example

[0031] As shown in Figures 1 and 2, the present invention proposes a six-dimensional force sensor multi-axis linkage calibration device, which includes a base plate 1. The base plate 1 has multiple sets of through holes to facilitate the fasteners to pass through and fix the device. Through the layout design of multiple sets of through holes, it can be adapted to different specifications of mounting base surfaces, which significantly improves the flexibility and stability of the device installation.

[0032] Furthermore, the aforementioned calibration device includes an attitude adjustment component 3 disposed above the base plate 1. The attitude adjustment component 3 is used to adjust the attitude of the six-dimensional sensor 4 to calculate the force components of the central mass of the detected object in each axis (i.e., different directions of the six-dimensional sensor 4). The attitude adjustment component 3 includes a first servo motor 31, which is a low-inertia DC servo motor with a response time of <20ms, enabling rapid attitude adjustment. The output end of the first servo motor 31 is fixedly connected to a mounting plate 32, which is L-shaped. A second servo motor 33 is mounted on the side of the mounting plate 32. The second servo motor 33 is equipped with an absolute encoder with an angular resolution of 0.001°, ensuring attitude positioning accuracy. The output end of the second servo motor 33 passes through the mounting plate 32 and is fixedly connected to the six-dimensional sensor 4. The rotation axis of the six-dimensional sensor 4 is perpendicular to the rotation axis of the mounting plate 32, forming an orthogonal dual-axis rotation structure that can cover the attitude adjustment range. After the first servo motor 31 and the second servo motor 33 are started, the rotation angles of the output shafts of the first servo motor 31 and the second servo motor 33 are scanned respectively, and more than 25 sets of strain voltage data at different positions are acquired. Through a high-density data sampling strategy, the statistical reliability of the data samples is improved. Based on the current position and attitude, the force components of the center mass of the detection block 51 on each axis are calculated. Combined with the spatial coordinate system transformation algorithm, the multi-dimensional load is accurately decoupled. The above data is substituted into the transformation matrix to obtain the calibration matrix data.

[0033] Furthermore, the calibration device also includes a detection mechanism 5 located below the six-dimensional sensor 4, which is used to measure the torsional stiffness of the vertical axis of the six-dimensional sensor 4. The detection mechanism 5 includes a detection block 51 fixedly connected to the six-dimensional sensor 4. The detection block 51 is made of high-strength aluminum alloy, which effectively reduces the interference of its own mass on the measurement results while ensuring structural strength. A torque sensor 52 is set below the detection block 51. The torque sensor 52 is a high-precision strain gauge sensor with a resolution of up to 0.01 N·m, which can accurately capture minute torque changes. The torque sensor 52 is installed on the top of the base plate 1 and is fixed by bolts. Pneumatic clamps or electromagnetic suction can be used to achieve quick clamping and improve assembly efficiency. Multiple sets of torsion blocks 53 are set on the torque sensor 52, which can form a precise mechanical coupling with the grooves 54 of the detection block 51. The bottom of the detection block 51 has grooves 54 corresponding to the torsion blocks 53, which facilitates the deflection of the torsion blocks 53 through the grooves 54 when the detection block 51 rotates. The torque reading of the torque sensor 52 and the strain voltage on the six-dimensional sensor 4 are read. Through the synchronous acquisition of data from the two sensors, the vertical shaft torsional stiffness can be calibrated with high precision, and the error range is controlled within ±1.5%.

[0034] Finally, the calibration device also includes a lifting mechanism 2 installed on the top of the base plate 1, which is used to move the detection block 51. The lifting mechanism 2 includes a vertical plate 21 fixedly connected to the top of the base plate 1, and the position of the vertical plate 21 is fixed. A third servo motor 22 is installed on the side of the vertical plate 21 near the attitude adjustment component 3. A threaded rod 23 is fixedly connected to the output end of the third servo motor 22. After the third servo motor 22 is started, it drives the threaded rod 23 to rotate. A threaded sleeve 24 is threadedly connected to the threaded rod 23. When the threaded rod 23 rotates, it drives the threaded sleeve 24 to move along the length direction of the threaded rod 23. A moving plate 25 is fixedly connected to the side of the threaded sleeve 24 away from the vertical plate 21. When the threaded sleeve 24 moves, it drives the moving plate 25 to move synchronously. A first servo motor 31 is installed on the side of the moving plate 25 away from the threaded sleeve 24. When the moving plate 25 moves, it drives the first servo motor 31 to move synchronously, thereby moving the detection block 51, so that the detection block 51 can move closer to or further away from the torque sensor 52. A positioning plate 26 is rotatably connected to the end of the threaded rod 23 away from the third servo motor 22. The positioning plate 26 is fixedly connected to the side of the upright plate 21, and its fixed position ensures that the threaded rod 23 rotates in its original position, improving the stability of the threaded rod 23. Two sets of sliders 27 are fixedly connected to the side of the moving plate 25 near the upright plate 21. The two sets of sliders 27 are symmetrically arranged on both sides of the threaded sleeve 24, and slide rails 28 are slidably connected to each of the two sets of sliders 27. Both sets of slide rails 28 are fixedly connected to the upright plate 21. The arrangement of the sliders 27 and slide rails 28 ensures that the moving plate 25 moves smoothly.

[0035] In this embodiment, the third servo motor 22 is first started, and the threaded sleeve 24 and the moving plate 25 are driven to move through the threaded rod 23, so as to adjust the detection block 51 to the initial position away from the torque sensor 52, so as to reserve space for subsequent loading operations.

[0036] The lifting mechanism 2 slowly moves the detection block 51, causing the groove 54 at the bottom of the detection block 51 to precisely engage with the torsion block 53 of the torque sensor 52, forming a mechanical transmission connection. The control system drives the detection block 51 to rotate, causing the groove 54 to deflect the torsion block 53. The torque sensor 52 collects torque data in real time (resolution 0.01 N·m), while the six-dimensional sensor 4 simultaneously collects strain voltage signals. Through synchronous analysis of the dual-sensor data, the torsional stiffness parameters of the vertical axis are calculated, with the error controlled within ±1.5%, completing the calibration of the vertical axis direction.

[0037] The first servo motor 31 drives the L-shaped mounting plate 32 to rotate, adjusting the horizontal rotation angle of the six-dimensional sensor 4 (response time < 20ms); the second servo motor 33 drives the six-dimensional sensor 4 to rotate itself, adjusting the vertical rotation angle (angle resolution 0.001°), forming an orthogonal dual-axis rotation structure that covers the attitude adjustment range. Through dual-axis linkage, the detection block 51 is placed in different spatial attitudes, simulating the multi-dimensional force scenario of the six-dimensional sensor 4 in actual working conditions. After each attitude adjustment, ≥25 sets of strain voltage data are acquired (high-density sampling improves statistical reliability); combined with the real-time rotation angles of the first servo motor 31 and the second servo motor 33, the force components of the center mass of the detection block 51 in each axis (three-dimensional force, three-dimensional torque) are calculated through a spatial coordinate system transformation algorithm, achieving precise decoupling of multi-dimensional loads.

[0038] By integrating the vertical axis torsional stiffness data with the strain voltage and force component data under multi-axis linkage attitude, a multidimensional dataset is constructed. By repeatedly loading typical working conditions, the output accuracy of the six-dimensional sensor 4 before and after calibration is compared to confirm the effectiveness of the calibration matrix.

[0039] The above specific embodiments are merely optional embodiments of this utility model. Based on the technical solution of this utility model and the relevant teachings of the above embodiments, those skilled in the art can make various alternative improvements and combinations to the above specific embodiments.

Claims

1. A multi-axis linkage calibration device for a six-dimensional force sensor, characterized in that, include: A base plate (1); an attitude adjustment component (3) disposed above the base plate (1), the attitude adjustment component (3) being used to adjust the attitude of the six-dimensional sensor (4) to calculate the force components of the object being detected in different directions of the six-dimensional sensor (4); and a detection mechanism (5) located below the six-dimensional sensor (4), the detection mechanism (5) being used to measure the torsional stiffness of the vertical axis of the six-dimensional sensor (4).

2. The six-dimensional force sensor multi-axis linkage calibration device according to claim 1, characterized in that, The attitude adjustment component (3) includes a first servo motor (31), the output end of the first servo motor (31) is fixedly connected to a mounting plate (32), the mounting plate (32) is L-shaped, a second servo motor (33) is mounted on the side of the mounting plate (32), the output end of the second servo motor (33) passes through the mounting plate (32) and is fixedly connected to the six-dimensional sensor (4).

3. The six-dimensional force sensor multi-axis linkage calibration device according to claim 2, characterized in that, The rotation axis of the six-dimensional sensor (4) is perpendicular to the rotation axis of the mounting plate (32).

4. The six-dimensional force sensor multi-axis linkage calibration device according to claim 3, characterized in that, The detection mechanism (5) includes a detection block (51) fixedly connected to the six-dimensional sensor (4). A torque sensor (52) is provided below the detection block (51). The torque sensor (52) is installed on the top of the base plate (1). Multiple sets of torsion blocks (53) are provided on the torque sensor (52). A groove (54) corresponding to the torsion block (53) is opened at the bottom of the detection block (51).

5. A six-dimensional force sensor multi-axis linkage calibration device according to claim 4, characterized in that, It also includes a lifting mechanism (2) installed on the top of the base plate (1), which is used to move the detection block (51).

6. The six-dimensional force sensor multi-axis linkage calibration device according to claim 5, characterized in that, The lifting mechanism (2) includes a vertical plate (21) fixedly connected to the top of the base plate (1). A third servo motor (22) is installed on the side of the vertical plate (21) near the attitude adjustment component (3). A threaded rod (23) is fixedly connected to the output end of the third servo motor (22). A threaded sleeve (24) is threadedly connected to the threaded rod (23). A movable plate (25) is fixedly connected to the side of the threaded sleeve (24) away from the vertical plate (21). The first servo motor (31) is installed on the side of the movable plate (25) away from the threaded sleeve (24).

7. A six-dimensional force sensor multi-axis linkage calibration device according to claim 6, characterized in that, The threaded rod (23) is rotatably connected to a positioning plate (26) at the end away from the third servo motor (22), and the positioning plate (26) is fixedly connected to the side of the upright plate (21).

8. A six-dimensional force sensor multi-axis linkage calibration device according to claim 7, characterized in that, The movable plate (25) is fixedly connected to two sets of sliders (27) on the side near the upright plate (21). The two sets of sliders (27) are symmetrically arranged on both sides of the threaded sleeve (24). Each of the two sets of sliders (27) is slidably connected to a slide rail (28), and both sets of slide rails (28) are fixedly connected to the upright plate (21).

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