Multidimensional force sensor patch positioning system and patch positioning method

Abstract

This application provides a patch positioning system and method for a multidimensional force sensor. The system includes a two-dimensional image acquisition device, a distance acquisition device, and a control device. The two-dimensional image acquisition device acquires two-dimensional image information of the multidimensional force sensor. The control device determines the first patch coordinates of the strain gauge on the first patch surface based on the two-dimensional image information and preset patch parameter information. The distance acquisition device acquires the distance information between the second patch surface and the distance acquisition device. The control device determines the second patch coordinates of the strain gauge on the first patch surface based on the distance information, patch parameter information, and the third position coordinates of the distance acquisition device in the second coordinate plane. Finally, the control device determines the first patch position of the strain gauge on the first patch surface based on the first patch coordinates and the second patch coordinates. This application improves the positioning accuracy of the first patch position. Furthermore, it determines the first patch position without requiring a complete image of the first patch surface, improving the system's applicability.

Description

Technical Field

[0001] This invention relates to the fields of size measurement and visual recognition, and in particular to a patch positioning system and patch positioning method based on a multi-dimensional force sensor for size measurement. Background Technology

[0002] A multidimensional force sensor is a sensor capable of simultaneously detecting forces in multiple directions. It can output forces or torques in various directions in space as corresponding electrical signals, thereby accurately sensing the force situation on the measured object. The precision of the equipment used to manufacture multidimensional force sensors directly determines the production quality of the sensors, and consequently, the measurement accuracy, stability, and lifespan of the equipment equipped with the sensors.

[0003] Strain gauges are the core sensing element of multidimensional force sensors. In the equipment and processes used to manufacture multidimensional force sensors, the strain gauge mounting process is a crucial technological step. The accuracy of the strain gauge's mounting position on the sensor's elastic beam determines the sensor's sensing sensitivity and stability.

[0004] In the production of multidimensional force sensors, the traditional strain gauge placement process relies primarily on mechanical scribing combined with manual visual alignment. However, as sensors become increasingly precise and miniaturized, the traditional manual placement method is problematic. Strain gauges are small in size and come in many different specifications, with varying placement precision requirements for different models. Manual visual alignment cannot guarantee micron-level positioning accuracy; even slight deviations in placement can increase the nonlinearity error of the sensor's output signal, potentially affecting its measurement range and lifespan. Furthermore, differences in operator habits and experience during manual placement can lead to significant fluctuations in the performance and quality of sensors from the same batch.

[0005] Therefore, traditional multidimensional force sensor production equipment faces the problem of difficulty in accurately controlling the placement position of strain gauges during the strain gauge placement process, which in turn leads to poor quality stability of the produced sensors. Summary of the Invention

[0006] The purpose of this invention is to solve the problem of difficulty in accurately controlling the patching position during the strain gauge patching process in the production equipment of multidimensional force sensors in the prior art.

[0007] To address the aforementioned problems, embodiments of the present invention disclose a patch positioning system for a multidimensional force sensor. The multidimensional force sensor includes multiple elastic beams and multiple strain gauges. At least one elastic beam has a first patch surface and a second patch surface adjacent to each other along the circumferential direction of the elastic beam, and corresponding strain gauges are respectively attached to the first patch surface and the second patch surface. Furthermore, the patch positioning system includes a two-dimensional image acquisition device, a distance acquisition device, and a control device, with the control device communicatively connected to the two-dimensional image acquisition device and the distance acquisition device. The two-dimensional image acquisition device is arranged on one side of the multidimensional force sensor, facing the second patch surface, and acquires two-dimensional image information of the multidimensional force sensor. The control device determines the position of the first patch surface in the two-dimensional image within the patch positioning system based on the two-dimensional image information. The control device determines the first position coordinates of the strain gauge on the first patch surface based on the first position coordinates in the first coordinate plane of the system coordinate system and the preset patch parameter information; the distance acquisition device is arranged on one side of the multidimensional force sensor, facing the second patch surface, and acquires the distance information between the second patch surface and the distance acquisition device; the control device determines the second position coordinates of the second patch surface in the second coordinate plane of the system coordinate system based on the distance information, and determines the second patch coordinates of the strain gauge on the first patch surface based on the second position coordinates, patch parameter information, and the third position coordinates of the distance acquisition device in the second coordinate plane; and the control device determines the first patch position of the strain gauge on the first patch surface based on the first patch coordinates and the second patch coordinates.

[0008] According to another specific embodiment of the present invention, the patch positioning system for a multi-dimensional force sensor disclosed in this embodiment includes patch parameter information including: a first reference coordinate of a first patch reference in a first coordinate plane, and a first positioning distance information between a first sheet feature element of a strain gauge and the first reference coordinate; wherein, the first sheet feature element of the strain gauge includes: an edge of the strain gauge or a first visual feature point; the first patch reference is a surface feature element of the first patch surface in the first coordinate plane, or a projection of a second visual feature point of the multi-dimensional force sensor in the first coordinate plane; and, the control device determines the vertical coordinate value of the first patch position in the first coordinate plane based on the first position coordinates, and determines the horizontal coordinate value of the first patch position in the first coordinate plane based on the first positioning distance information. Furthermore, the patch parameter information also includes a second reference coordinate of a second patch reference in a second coordinate plane, and a second positioning distance information between a first sheet feature element of the strain gauge and the second reference coordinate; wherein, the second patch reference is the projection of a surface feature element of the first patch surface in the second coordinate plane. Furthermore, the control device determines the abscissa value of the first patch position in the second coordinate plane based on the second and third position coordinates, and determines the ordinate value of the first patch position in the second coordinate plane based on the second positioning distance information, the second and third position coordinates. Additionally, the control device determines the position of the first patch based on the abscissa and ordinate values ​​of the first patch position in the first and second coordinate planes.

[0009] According to another specific embodiment of the present invention, the patch positioning system for a multi-dimensional force sensor disclosed in this embodiment further includes patch parameter information including: third reference coordinates of a third patch reference and third positioning distance information between the second sheet feature element of the strain gauge and the third reference coordinates in a first coordinate plane; wherein, the second sheet feature element of the strain gauge includes: the edge of the strain gauge or a first visual feature point; the third patch reference is the surface feature element of the second patch surface, or the projection of the second visual feature point of the multi-dimensional force sensor in the first coordinate plane. Furthermore, the control device also determines the abscissa and ordinate values ​​of the strain gauge in the first coordinate plane based on the third positioning distance information; the patch parameter information also includes the fourth reference coordinate of the fourth patch reference in the second coordinate plane, and the fourth positioning distance information between the second sheet feature element of the strain gauge and the fourth reference coordinate; wherein, the fourth patch reference is the projection of the surface feature element of the second patch surface in the second coordinate plane; the control device determines the ordinate value of the second patch position of the strain gauge on the second patch surface in the second coordinate plane based on the second position coordinate and the third position coordinate, and determines the abscissa value of the second patch position in the second coordinate plane based on the fourth positioning distance information; the control device determines the second patch position based on the abscissa and ordinate values ​​of the second patch position in the first coordinate plane, and the abscissa and ordinate values ​​of the second patch position in the second coordinate plane.

[0010] According to another specific embodiment of the present invention, the patch positioning system for a multi-dimensional force sensor disclosed in this embodiment of the present invention has a structure in which the multi-dimensional force sensor is symmetrical about an axis perpendicular to a first coordinate plane in a two-dimensional image acquired by a two-dimensional image acquisition device. Furthermore, the control device determines the tilt angle of two symmetrical first patch surfaces relative to the axis in the first coordinate plane based on the two-dimensional image information, and ensures that the ordinates of the two symmetrical first patch surfaces in the first coordinate plane are the same based on the tilt angle.

[0011] According to another specific embodiment of the present invention, the patch positioning system of the multidimensional force sensor disclosed in this embodiment of the present invention has an annular outer ring, wherein each elastic beam extends in the radial direction of the annular outer ring, one end is connected to the inner circumference of the annular outer ring, and the other end extends toward the center of the annular outer ring and is fixed relative to the center. Furthermore, a plurality of elastic beams are evenly spaced along the circumferential direction of the annular outer ring. In this arrangement, one side of each elastic beam in the circumferential direction is used as a first patch surface, and one side in the axial direction of the annular outer ring is used as a second patch surface.

[0012] According to another specific embodiment of the present invention, in the patch positioning system of the multidimensional force sensor disclosed in this embodiment, the first patch surface and the second patch surface are perpendicular to each other; and, the two-dimensional image acquisition device acquires two-dimensional image information of the multidimensional force sensor on one side of the multidimensional force sensor along a direction parallel to the first patch surface; the first coordinate plane is parallel to the second patch surface; and the second coordinate plane is parallel to the first patch surface.

[0013] According to another specific embodiment of the present invention, the patch positioning system for the multidimensional force sensor disclosed in this embodiment of the present invention includes a 2D camera as the two-dimensional image acquisition device; a laser rangefinder or an ultrasonic rangefinder as the distance acquisition device; and a PLC controller as the control device.

[0014] The present invention discloses a patch positioning method for a multidimensional force sensor. The multidimensional force sensor includes multiple elastic beams and multiple strain gauges. At least one elastic beam has a first patch surface and a second patch surface that are adjacent to each other along the circumferential direction of the elastic beam. The first patch surface and the second patch surface are respectively attached with corresponding strain gauges. Furthermore, the patch positioning method includes: acquiring two-dimensional image information of the multi-dimensional force sensor on one side, facing the second patch surface; determining the first position coordinates of the first patch surface in the first coordinate plane of the pre-calibrated system coordinate system based on the two-dimensional image information; determining the first patch coordinates of the strain gauge on the first patch surface based on the first position coordinates and preset patch parameter information; acquiring the distance information between the second patch surface and the ranging point on one side of the multi-dimensional force sensor; determining the second position coordinates of the second patch surface in the second coordinate plane of the system coordinate system based on the distance information; determining the second patch coordinates of the strain gauge on the first patch surface based on the second position coordinates, patch parameter information, and the third position coordinates of the ranging point in the second coordinate plane; and determining the first patch position of the strain gauge on the first patch surface based on the first patch coordinates and the second patch coordinates.

[0015] According to another specific embodiment of the present invention, the patch positioning method for a multi-dimensional force sensor disclosed in this embodiment includes patch parameter information including: a first reference coordinate of a first patch reference in a first coordinate plane, and a first positioning distance information between a first sheet feature element of a strain gauge and the first reference coordinate; wherein, the first sheet feature element of the strain gauge includes: the edge of the strain gauge or a first visual feature point; the first patch reference is a surface feature element of the first patch surface in the first coordinate plane, or a projection of a second visual feature point of the multi-dimensional force sensor in the first coordinate plane; and, determining the first patch coordinate of the strain gauge on the first patch surface according to the first position coordinate and the preset patch parameter information includes: determining the vertical coordinate value of the first patch position in the first coordinate plane according to the first position coordinate, and determining the horizontal coordinate value of the first patch position in the first coordinate plane according to the first positioning distance information, and determining the first patch coordinate according to the horizontal and vertical coordinate values ​​of the first patch position in the first coordinate plane. Furthermore, the patch parameter information also includes, within the second coordinate plane, the second reference coordinates of the second patch reference and the second positioning distance information between the first sheet feature element of the strain gauge and the second reference coordinates; wherein, the second patch reference is the projection of the surface feature element of the first patch surface within the second coordinate plane. Furthermore, determining the second patch coordinates of the strain gauge on the first patch surface based on the second position coordinates, the patch parameter information, and the third position coordinates of the ranging point within the second coordinate plane includes: determining the abscissa value of the first patch position within the second coordinate plane based on the second and third position coordinates; determining the ordinate value of the first patch position within the second coordinate plane based on the second positioning distance information, the second and third position coordinates; and determining the second patch coordinates based on the abscissa and ordinate values ​​of the first patch position within the second coordinate plane. Furthermore, determining the first patch position of the strain gauge on the first patch surface based on the first and second patch coordinates includes: determining the first patch position based on the abscissa and ordinate values ​​of the first patch position within the first coordinate plane, and the abscissa and ordinate values ​​of the first patch position within the second coordinate plane.

[0016] According to another specific embodiment of the present invention, the patch positioning method for a multi-dimensional force sensor disclosed in this embodiment further includes patch parameter information as follows: in a first coordinate plane, the third reference coordinate of a third patch reference, the third positioning distance information between the second sheet feature element of the strain gauge and the third reference coordinate, and in a second coordinate plane, the fourth reference coordinate of a fourth patch reference, the fourth positioning distance information between the second sheet feature element of the strain gauge and the fourth reference coordinate; wherein, the second sheet feature element of the strain gauge includes: the edge of the strain gauge or a first visual feature point; the third patch reference is the surface feature element of the second patch surface, or the projection of the second visual feature point of the multi-dimensional force sensor in the first coordinate plane; the fourth patch reference is the projection of the surface feature element of the second patch surface in the second coordinate plane. Furthermore, the patch positioning method also includes: determining the abscissa and ordinate values ​​of the strain gauge in the first coordinate plane based on the third positioning distance information; determining the ordinate value of the second patch position of the strain gauge on the second patch surface in the second coordinate plane based on the second position coordinates and the third position coordinates; determining the abscissa value of the second patch position in the second coordinate plane based on the fourth positioning distance information; and determining the second patch position based on the abscissa and ordinate values ​​of the second patch position in the first coordinate plane, as well as the abscissa and ordinate values ​​of the second patch position in the second coordinate plane.

[0017] According to another specific embodiment of the present invention, the patch positioning method for a multi-dimensional force sensor disclosed in this embodiment of the present invention has a structure in which the multi-dimensional force sensor is symmetrical about an axis perpendicular to a first coordinate plane in a two-dimensional image of the multi-dimensional force sensor. Furthermore, the patch positioning method further includes: determining the tilt angle of two mutually symmetrical first patch surfaces relative to the axis in the first coordinate plane based on the two-dimensional image information; and when the tilt angle is not within a preset angle range, controlling the multi-dimensional force sensor to rotate circumferentially about an axis perpendicular to the first coordinate plane according to the tilt angle until the tilt angle is within the angle range.

[0018] According to another specific embodiment of the present invention, the patch positioning method of the multidimensional force sensor disclosed in this embodiment of the present invention determines the tilt angle of two symmetrical first patch surfaces relative to the axis in a first coordinate plane based on two-dimensional image information, including: determining two points corresponding to the positions on the two first patch surfaces from the two-dimensional image information; and determining the tilt angle of the line connecting the two points relative to the axis.

[0019] According to another specific embodiment of the present invention, the patch positioning method of the multidimensional force sensor disclosed in this embodiment of the present invention has an annular outer ring, wherein each elastic beam extends along the radial direction of the annular outer ring, one end is connected to the inner circumference of the annular outer ring, and the other end extends toward the center of the annular outer ring and is fixed relative to the center. Furthermore, a plurality of elastic beams are evenly spaced along the circumferential direction of the annular outer ring. In this arrangement, one side of each elastic beam in the circumferential direction is used as a first patch surface, and one side in the axial direction of the annular outer ring is used as a second patch surface.

[0020] According to another specific embodiment of the present invention, in the patch positioning method of the multidimensional force sensor disclosed in this embodiment, the first patch surface and the second patch surface are perpendicular to each other; and, the two-dimensional image acquisition device acquires two-dimensional image information of the multidimensional force sensor on one side of the multidimensional force sensor along a direction parallel to the first patch surface; the first coordinate plane is parallel to the second patch surface; and the second coordinate plane is parallel to the first patch surface.

[0021] According to another specific embodiment of the present invention, the patch positioning method for a multi-dimensional force sensor disclosed in this embodiment of the present invention acquires two-dimensional image information via a two-dimensional image acquisition device, wherein the two-dimensional image acquisition device is a 2D camera; and acquires spacing information via a distance acquisition device, wherein the distance acquisition device is a laser rangefinder or an ultrasonic rangefinder, and the measuring point is the detection reference point of the distance acquisition device.

[0022] The beneficial effects of this invention are:

[0023] The patch positioning system and patch positioning method for the multidimensional force sensor provided in this application improve the measurement accuracy of the multidimensional force sensor by setting corresponding strain gauges on the first patch surface and the second patch surface of the elastic beam, so that the first patch surface and the second patch surface can independently detect the corresponding force.

[0024] Furthermore, based on two-dimensional image information, distance information, and preset patch parameter information, the three-dimensional coordinates corresponding to the position of the first patch are calculated. Compared with traditional methods of manual visual inspection and mechanical marking, this significantly improves the positioning accuracy of the first patch. Especially for some multi-dimensional force sensors, due to their small overall size or the presence of local structural obstructions, there are patch areas that the operator or vision equipment cannot directly view or obtain a complete image of. This application can determine the position of the first patch without obtaining a complete image of the first patch surface. Even if the multi-dimensional force sensor has patch areas that cannot be directly viewed or have a complete image obtained, the patch position of the strain gauge on the first patch surface where a complete image cannot be obtained can be accurately determined, thus improving the applicability of the patch positioning system.

[0025] Furthermore, the first patch coordinates of the strain gauge relative to the first coordinate plane and the second patch coordinates relative to the second coordinate plane are determined first on the first patch surface. Then, the three-dimensional coordinates corresponding to the position of the first patch are determined based on the first patch coordinates and the second patch coordinates. The position of the first patch is determined by the coordinates corresponding to the two mutually orthogonal coordinate planes, which further improves the positioning accuracy of the strain gauge. Attached Figure Description

[0026] Figure 1a This is a schematic diagram of the structure of the multi-dimensional force sensor in the patch positioning system of the multi-dimensional force sensor provided in the embodiment of the present invention;

[0027] Figure 1b This is another structural schematic diagram of the multidimensional force sensor in the patch positioning system of the multidimensional force sensor provided in the embodiment of the present invention;

[0028] Figure 2a This is another structural schematic diagram of the multidimensional force sensor in the patch positioning system of the multidimensional force sensor provided in the embodiment of the present invention;

[0029] Figure 2b This is another structural schematic diagram of the multidimensional force sensor in the patch positioning system of the multidimensional force sensor provided in the embodiment of the present invention;

[0030] Figure 3 This is a schematic diagram of the patch positioning system for a multi-dimensional force sensor provided in an embodiment of the present invention;

[0031] Figure 4 This is a measurement schematic diagram of the distance acquisition device in the patch positioning system of the multi-dimensional force sensor provided in the embodiment of the present invention;

[0032] Figure 5 This is a front view of the multi-dimensional force sensor in the patch positioning system of the multi-dimensional force sensor provided in the embodiment of the present invention;

[0033] Figure 6 This is a schematic diagram of the first patch surface in the patch positioning system of the multidimensional force sensor provided in the embodiment of the present invention;

[0034] Figure 7 This is a schematic diagram of the second patch surface in the patch positioning system of the multidimensional force sensor provided in the embodiment of the present invention;

[0035] Figure 8 This is a schematic flowchart of the patch positioning method for a multidimensional force sensor provided in an embodiment of the present invention.

[0036] Explanation of reference numerals in the attached figures:

[0037] 1. Multidimensional force sensor; 2. Elastic beam; 3. First patch surface; 4. Second patch surface; 5. Strain gauge; 6. Two-dimensional image acquisition device; 7. Distance acquisition device. Detailed Implementation

[0038] Example 1:

[0039] First, the structure of a multi-dimensional force sensor will be explained. A multi-dimensional force sensor is a force sensing element that can simultaneously detect force and torque signals in two or more directions in space and convert mechanical deformation into electrical signals for output. It can be a six-dimensional force sensor that can simultaneously detect force and torque in the XYZ directions, or a three-dimensional force sensor that can simultaneously detect force in the XYZ directions.

[0040] The multidimensional force sensor includes multiple elastic beams and multiple strain gauges. At least one elastic beam has a first patch surface and a second patch surface that are adjacent to each other along the circumferential direction of the elastic beam, and the first patch surface and the second patch surface are respectively attached with corresponding strain gauges.

[0041] An elastic beam serves as the mounting carrier for strain gauges, capable of elastic deformation under stress. Specifically, the elastic beam can be configured as a radially stressed cantilever elastic beam. Sensors with this elastic beam typically include a force-transmitting platform positioned centrally and a surrounding fixed flange. The elastic beam extends radially from the force-transmitting platform towards the fixed flange, with one end fixed to the force-transmitting platform and the other end fixed to the fixed flange. The specific number of elastic beams can be four, for example... Figure 1a The crossbeam-type multidimensional force sensor shown can also be configured with five, seven, or even more, for example... Figure 1b The image shows a spoke-type multidimensional force sensor. The shape of the fixed flange can be... Figure 1a The shape shown is roughly rectangular, or Figure 1b The circular shape shown can also be elliptical or other polygonal shapes. In other implementations, the elastic beam can be configured as a torque-sensing annular elastic beam. Sensors with this elastic beam typically include multiple connecting flanges, with the elastic beam positioned between any two connecting flanges. Specifically, the multiple connecting flanges can be configured as follows: Figure 2a The two layers shown have the elastic beam 2 connected at both ends to the upper and lower connecting flanges, respectively; more connecting flanges can also be provided, for example... Figure 2b The three-layer structure shown has a circumferentially hollowed-out cylindrical wall of the sensor to form an elastic beam 2.

[0042] The mounting surface refers to the surface on an elastic beam used to attach strain gauges. For an elastic beam, there is a first mounting surface and a second mounting surface adjacent to each other along its circumferential direction. The circumferential direction refers to the direction of circumference around the length of the elastic beam. The first and second mounting surfaces are two adjacent surfaces on the same elastic beam. The first mounting surface is the concealed working surface where the strain gauges are to be mounted; it is concealed because it cannot be directly viewed and photographed due to the sensor's structure. The second mounting surface is the unobstructed side surface that can be directly viewed and photographed. For an elastic beam with a circular cross-section, the two mounting surfaces are two adjacent arc-shaped surfaces along the circumference (the circumference is divided into multiple arc-shaped surfaces based on the number of strain gauges to be mounted; the surfaces corresponding to two adjacent strain gauges are the first and second mounting surfaces). For an elastic beam with a square cross-section, the two mounting surfaces are two perpendicular planes with an included angle of 90°. For an elastic beam with a polygonal cross-section, taking a regular hexagonal cross-section as an example, the two patch surfaces are the surfaces corresponding to two adjacent sides of the cross-section, and the included angle between the two surfaces is 120°.

[0043] At least one elastic beam means that among multiple elastic beams, only one elastic beam may have two adjacent patch surfaces, or multiple (two or more) elastic beams may all have this structure. The fact that corresponding strain gauges are attached to the first and second patch surfaces respectively means that the type, specifications, and quantity of strain gauges attached to the two perpendicular patch surfaces are adapted to the structure of the patch surfaces and the testing requirements. For example, one strain gauge can be attached to both the first and second patch surfaces, or two strain gauges can be attached to both the first and second patch surfaces, with the two strain gauges on each patch surface symmetrically arranged; one strain gauge can also be attached to the first patch surface and two strain gauges to the second patch surface; or strain gauges can be attached to each patch surface in a 2×2 array arrangement. More specifically, the strain gauge type can be a resistance strain gauge, a thin-film strain gauge, or a semiconductor strain gauge, and the type of strain gauge on each patch surface can be the same or different.

[0044] Next, with Figure 1a The following example of a cross-beam type multidimensional force sensor illustrates a specific structure of the sensor. The multidimensional force sensor 1 may include four elastic beams 2 (two along the X-axis and two along the Z-axis), arranged in a cross shape. One end of each beam 2 can be fixed to a force transmission platform located at the center of the multidimensional force sensor 1, while the other end is connected to a mounting base on the outer periphery of the sensor, thus forming a symmetrical structure. Each elastic beam 2 is a cuboid structure with a rectangular cross-section. Each elastic beam 2 has a first patch surface 3 and a second patch surface 4 that are perpendicular to each other. The first patch surface 3 consists of two surfaces of the elastic beam 2 parallel to the XOY coordinate plane, and the second patch surface 4 consists of two surfaces of the elastic beam 2 parallel to the XOZ coordinate plane.

[0045] Secondly, the patch positioning system for the multidimensional force sensor is described. This system is used to determine the patch position of the strain gauge on the elastic beam of the multidimensional force sensor. (Reference) Figure 3 The patch positioning system includes a two-dimensional image acquisition device 6, a distance acquisition device 7, and a control device. The control device is communicatively connected to the two-dimensional image acquisition device 6 and the distance acquisition device 7.

[0046] Specifically, the two-dimensional image acquisition device 6 is used to acquire two-dimensional image information of the multi-dimensional force sensor 1, and it is specifically a 2D camera. The distance acquisition device 7 is used to acquire the distance information between it and the second patch surface 4, and it can specifically be a laser rangefinder or an ultrasonic rangefinder. The control device is responsible for processing the two-dimensional image information and distance information, and calculating the patch coordinates of the strain gauge 5 on the corresponding patch surface, and it can specifically be an industrial control computer, an embedded controller, or a PLC controller.

[0047] More specifically, the two-dimensional image acquisition device 6 is disposed on one side of the multi-dimensional force sensor 1. When acquiring two-dimensional image information, it needs to be oriented towards the second patch surface 4. "Oriented towards the second patch surface 4" means that the two-dimensional image acquisition device 6 can capture a complete image of the second patch surface 4, as well as a partial image (e.g., a line or surface) of the first patch surface 3 adjacent to the second patch surface 4. That is, the shooting axis of the two-dimensional image acquisition device 6 may not be perpendicular to the second patch surface 4, but rather has an angle of <90° relative to it. In a preferred implementation, the shooting direction of the two-dimensional image acquisition device 6 is perpendicular to the second patch surface 4, for example... Figure 3 The dashed lines in the diagram illustrate the path taken by the two-dimensional image acquisition device 6 when acquiring information. This method can accurately and completely capture images of the second patch surface 4, thereby improving the positioning accuracy of the patch. Especially when the first patch surface 3 and the second patch surface 4 are perpendicular, adjusting the shooting direction to be parallel to the first patch surface 3 and perpendicular to the second patch surface 4 ensures that the captured image accurately and completely represents the second patch surface 4. Furthermore, the first patch surface 3, associated with the second patch surface 4, forms a straight line, involving fewer geometric feature elements, thus reducing computational load while improving positioning accuracy.

[0048] The distance acquisition device 7 can be set on the same side or different side from the two-dimensional image acquisition device 6, or multiple distance acquisition devices 7 can be set to simultaneously acquire the distance between the device and different elastic beams 2.

[0049] Next, the patch positioning process of this patch positioning system will be explained. It is important to note that this patch positioning process describes the method for determining the first patch position of strain gauge 5 on the first patch surface 3 (a concealed working surface that cannot be directly viewed during imaging). The first patch position specifically refers to the coordinate position of the first patch position within the system coordinate system. Specifically, the coordinates of the first patch position in the first coordinate plane (XOZ plane), i.e., the first patch coordinates, are first determined based on the two-dimensional image information and preset patch parameter information. Then, the coordinates of the first patch position in the second coordinate plane (XOY plane), i.e., the second patch coordinates, are determined based on the spacing information obtained by the distance acquisition device 7 (the spacing information between the second patch surface and the distance acquisition device), the specific position of the distance acquisition device 7 (the third position coordinates of the distance acquisition device 7 in the second coordinate plane), and the preset patch parameter information. Finally, the three-dimensional coordinates of the first patch position in the three-dimensional system coordinate system are determined based on the coordinates corresponding to the two coordinate planes.

[0050] Specifically, the system coordinate system of the patch positioning system refers to the preset coordinate system of the patch positioning system, which can be a Cartesian coordinate system (denoted as O-XYZ) or a polar coordinate system. This coordinate system is used to uniformly calibrate the positions of the two-dimensional image acquisition device 6, the distance acquisition device 7, the elastic beam 2, the strain gauge 5, etc., and its origin can be set as the mechanical reference point of the patch positioning system (e.g., the center of the operating table, the center point of the two-dimensional image acquisition device 6, or the center point of the multi-dimensional force sensor 1). In this embodiment, the Cartesian coordinate system is used as an example for explanation.

[0051] The first coordinate plane is a two-dimensional plane within the system coordinate system (the XOZ plane of the Cartesian coordinate system), which corresponds to the imaging plane of the two-dimensional image acquisition device 6; the second coordinate plane is a two-dimensional plane within the system coordinate system that is perpendicular to the first coordinate plane (the XOY plane of the Cartesian coordinate system), which is mainly used for determining the position in the depth direction.

[0052] The patch parameter information is pre-stored in the control device and adapted to the structure of the sensor to be measured and the calibration parameters of the strain gauge. It may include the characteristic elements of the strain gauge (e.g., the size of the strain gauge, the boundary position, the position of a certain feature point), the characteristic elements of the first patch surface (e.g., the size of the first patch surface, the boundary position, the position of a certain feature point), the boundary of the second patch surface (e.g., the size of the second patch surface, the boundary position, the position of a certain feature point), and the spatial positional relationship between the first patch surface and the second patch surface (e.g., the included angle, the radius, or the distance between corresponding points of the two surfaces along the X-axis, Y-axis, or Z-axis).

[0053] The positioning process of this system consists of three steps:

[0054] The first step, 2D image acquisition and first patch coordinate calculation: The 2D image acquisition device faces the second patch surface and acquires 2D image information including the elastic beam contour, the edge of the first patch surface near the second patch surface, and the complete features of the second patch surface, which is then transmitted to the control device in real time. The control device uses built-in edge extraction and feature matching algorithms to identify the contour, boundary, and other features of the first patch surface in the image. Combined with the calibration parameters of the system coordinate system, it calculates the first position coordinates of the first patch surface in the first coordinate plane of the system coordinate system, i.e., the reference center coordinates and contour boundary coordinates of the first patch surface in the 2D plane. The control device calls pre-stored patch parameter information, using the first position coordinates as the 2D positioning reference, and combines the strain gauge size, center positioning requirements, and patch area tolerances to calculate the 2D planar positioning reference of the strain gauge within the first patch surface, i.e., the first patch coordinates.

[0055] The second step, spacing measurement and second patch coordinate calculation: The distance acquisition device emits a measurement beam towards the reference measurement point on the second patch surface, acquiring the spacing information between the second patch surface and the distance acquisition device in real time, and transmitting it to the control device. Based on this spacing information and the calibration parameters of the system coordinate system, the control device calculates the second position coordinates of the second patch surface in the second coordinate plane of the system coordinate system. The second position coordinates include the absolute position coordinates of the second patch surface in the system depth direction. Since the relative positions of the first and second patch surfaces are fixed and without offset, the control device uses the second position coordinates as the depth reference, combined with the patch parameter information and the calibration third position coordinates of the distance acquisition device itself in the second coordinate plane, to calculate the depth direction positioning reference of the strain gauge on the first patch surface, and obtain the second patch coordinates. It should be noted that the second step and the first step can be performed simultaneously or sequentially (the second step first then the first step, or the first step first then the second step).

[0056] The third step is to determine the final patch position: The control device fuses the coordinates of the first patch (positioned in the two-dimensional plane) and the coordinates of the second patch (positioned in the depth direction) for calculation, filtering out positioning offsets caused by installation deviations and elastic beam processing errors, and finally obtains the first patch position of the strain gauge on the first patch surface. This first patch position can be directly output to the automatic patching equipment to control it to complete the patching operation.

[0057] refer to Figure 1a , 1b , Figure 3 The positioning method of the first patch is illustrated by taking the first patch surface 3 and the second patch surface 4 as examples, where the first patch surface 3 is perpendicular to each other and the direction of image acquisition is parallel to the first patch surface 3.

[0058] Specifically, when determining the coordinates corresponding to the first patch position within the first coordinate plane (XOZ plane), the control device first determines the first position coordinates of the first patch surface 3 within the first coordinate plane (XOZ plane) of the system coordinate system. Then, based on the first position coordinates and preset patch parameter information, it determines the first patch coordinates (x, y, z) of the strain gauge 5 on the first patch surface 3. 贴1 , z 贴1 The first position coordinates (x1, z1) refer to the position coordinates of the first patch surface 3 within the first coordinate plane. Since the projection of the first patch surface 3 into the first coordinate plane is a straight line, determining the first position coordinates hinges on determining the coordinates of the feature points of the first patch surface 3 (e.g., the two endpoints of the straight line projected onto the first coordinate plane) within the first patch surface 3. The first patch coordinates refer to the two-dimensional coordinates of the strain gauge 5 within the first patch surface 3 and within the first coordinate plane. Specifically, these coordinates can be calculated using the first position coordinates and patch parameter information. The patch parameter information includes distance-related information, specifically the distance between the edge of the strain gauge 5 and the center point of the multi-dimensional force sensor 1, or the distance between the center point of the strain gauge 5 and the center point of the multi-dimensional force sensor 1, or the distance between the edge of the strain gauge 5 and the edge of the elastic beam 2, or the distance between the center point of the strain gauge 5 and the edge of the elastic beam 2; the patch parameter information may also include angle-related information, such as the angle between the edge of the strain gauge 5 and the corresponding edge of the elastic beam 2. Specifically, the Z-axis coordinate (vertical coordinate) of the first patch coordinate is determined based on the first position coordinate, and the X-axis coordinate (horizontal coordinate) of the first patch coordinate is determined based on the first position coordinate and the patch parameter information mentioned above.

[0059] When determining the second patch coordinates corresponding to the first patch position within the second coordinate plane (XOY plane), the control device first determines the second position coordinates (x2, y2) of the second patch surface 4 within the second coordinate plane (XOY plane) of the system coordinate system, and the third position coordinates (x3, y3) of the distance acquisition device 7 within the second coordinate plane (XOY plane). Then, based on the second position coordinates, the third position coordinates, and pre-stored patch parameter information, the second patch coordinates (x2, y2) of the strain gauge 5 on the first patch surface 3 are determined. 贴2 y 贴2The spacing information refers to the distance between the measuring point of the distance acquisition device 7 and the second patch surface 4. The second patch coordinates refer to the two-dimensional coordinates of the strain gauge 5 within the first patch surface 3 and in the second coordinate plane. These coordinates can be calculated using the second position coordinates, the third position coordinates, and patch parameter information. The patch parameter information also includes dimensional information related to the sensor structure or distance-related information, such as the dimensions of the elastic beam 2 along the Y direction in the XOY plane, or the distance between the edge or center point of the strain gauge 5 and the edge of the elastic beam 2. Specifically, the control device first determines the corresponding abscissa x based on the second position coordinates of the second patch surface 4 in the second coordinate plane and the third position coordinates of the distance acquisition device 7 in the second coordinate plane. 贴2 The corresponding ordinate y is determined based on the second position coordinate, the third position coordinate, and the patch parameter information. 贴2 It should be noted that the x-coordinate of the first patch position in the first coordinate plane is the same as the x-coordinate in the second coordinate plane, that is, x... 贴1 =x 贴2 If they differ, the x-coordinate corresponding to the first patch position can be calculated using a weighted average. The weighted average involves first pre-setting weight coefficients for the two x-coordinates (e.g., 0.5 each), and then calculating the x-coordinate value corresponding to the first patch position based on these weight coefficients. 贴 =0.5x 贴1 +0.5x 贴2 .

[0060] In one implementation, refer to Figure 4 The distance acquisition device 7 can acquire the spacing information D1 along a direction parallel to the first patch surface 3. In this case, the number of distance acquisition devices 7 is set to one. Since the measurement direction is parallel to the first patch surface 3 and perpendicular to the second patch surface 4, the spacing information is the straight-line distance between the distance acquisition device 7 and the second patch surface 4 in the measurement direction, and directly corresponds to the coordinate difference in the second coordinate plane. When calculating the Y-axis component y2 of the second position coordinate, it can be directly determined based on the spacing information D1 and the Y-axis component y3 corresponding to the third position coordinate, i.e., y2 = y3 + D1.

[0061] Among other possible implementations, see [reference]. Figure 4The distance acquisition device 7 can acquire spacing information at a preset angle θ. Here, θ is the acute angle between the measurement direction of the distance acquisition device 7 and the first patch surface 3. In this case, the spacing information D2 is the oblique distance along the measurement direction, which needs to be decomposed into a component parallel to the first patch surface 3 and a component perpendicular to the first patch surface 3. Furthermore, only the parallel component needs to be used during coordinate conversion. That is, when calculating the Y-axis component y2 of the second position coordinate, it can be directly determined based on the parallel component of the spacing information D2 and the Y-axis component y3 corresponding to the third position coordinate, i.e., y2 = y3 + D2 × cosθ.

[0062] First patch coordinates (x) 贴1 , z 贴1 ) and second patch coordinates (x 贴2 y 贴2 Once determined, the position of the first patch on the first patch surface 3 of strain gauge 5 can be determined as (x, y, z) = (x 贴 y 贴2 , z 贴1 ).

[0063] By placing corresponding strain gauges on the first and second patch surfaces of the elastic beam, each patch surface can independently detect the corresponding force, thus improving the measurement accuracy of the multi-dimensional force sensor. Furthermore, a two-dimensional image acquisition device is used to acquire two-dimensional images, and a distance acquisition device 7 is used to directly measure the distance information to the second patch surface 4. Based on the two-dimensional image information, distance information, and preset patch parameter information, the three-dimensional coordinates corresponding to the first patch position are calculated. Compared to traditional methods of manual visual inspection and mechanical marking for positioning, this significantly improves the positioning accuracy of the first patch. Especially for some multi-dimensional force sensors, due to their small overall size or the presence of local structural obstructions, there are patch areas that the operator or visual equipment cannot directly view or obtain a complete image of. This application can determine the first patch position without obtaining a complete image of the first patch surface. Even if the multi-dimensional force sensor has patch areas that cannot be directly viewed or have a complete image obtained, the patch position of the strain gauge on the first patch surface where a complete image cannot be obtained can be accurately determined, improving the applicability of the patch positioning system. Furthermore, the first patch coordinates of the strain gauge relative to the first coordinate plane and the second patch coordinates relative to the second coordinate plane are determined on the first patch surface. Then, the three-dimensional coordinates corresponding to the position of the first patch are determined based on the first patch coordinates and the second patch coordinates. The position of the first patch is determined by the coordinates corresponding to the two mutually orthogonal coordinate planes. The two dimensions mutually verify and compensate for each other's errors, which can ensure the micron-level positioning accuracy of the strain gauge, further improving the positioning accuracy of the strain gauge, thereby improving the production quality and measurement accuracy of the multi-dimensional force sensor 1.

[0064] Furthermore, in this patch positioning system, the patch parameter information includes: in the first coordinate plane, the first reference coordinates of the first patch reference and the first positioning distance information between the first sheet feature element of the strain gauge and the first reference coordinates; in the second coordinate plane, the second reference coordinates of the second patch reference and the second positioning distance information between the first sheet feature element of the strain gauge and the second reference coordinates. The first sheet feature element of the strain gauge includes: the edge of the strain gauge or a first visual feature point; the first patch reference is the surface feature element of the first patch surface in the first coordinate plane, or the projection of the second visual feature point of the multi-dimensional force sensor into the first coordinate plane. The second patch reference is the projection of the surface feature element of the first patch surface into the second coordinate plane. Furthermore, the control device determines the vertical coordinate of the first patch position in the first coordinate plane based on the first position coordinates, and determines the horizontal coordinate of the first patch position in the first coordinate plane based on the first positioning distance information; it determines the horizontal coordinate of the first patch position in the second coordinate plane based on the second position coordinates and the third position coordinates, and determines the vertical coordinate of the first patch position in the second coordinate plane based on the second positioning distance information, the second position coordinates, and the third position coordinates; and it determines the position of the first patch based on the horizontal and vertical coordinates of the first patch position in the first coordinate plane, and the horizontal and vertical coordinates of the first patch position in the second coordinate plane.

[0065] The first patch reference is a reference point used to calibrate the origin of the strain gauge in the first coordinate plane. It can be a surface feature element of the first patch surface in the first coordinate plane, such as the patch surface outline or the center reference of the patch surface; or it can be the projection of the second visual feature point of the multi-dimensional force sensor in the first coordinate plane, such as the center point of the sensor or the projection point of the force transmission platform and the elastic beam.

[0066] The first sheet characteristic element of a strain gauge can be the edge of the strain gauge, such as the straight edge of the outer contour, the right-angle edge, etc.; or it can be the characteristic point of the strain gauge, such as the center point of the strain gauge, the pre-marked point on the sheet surface, or the endpoint of the strain gauge.

[0067] The second patch reference is a projection reference element in the second coordinate plane that relies on the structural features of the first patch surface. It can be a perpendicular projection surface of the center surface feature element of the first patch surface onto the second coordinate plane, or a fixed projection point of the corner contour feature element of the first patch surface onto the second coordinate plane.

[0068] Specifically, refer to Figure 5The patch parameter information may include: the first reference coordinates of the first patch reference in the first coordinate plane, and the first positioning distance information between the edge or center point of the strain gauge 5 and the first reference coordinates. The first patch reference is either one edge of the first patch surface 3 in the first coordinate plane, or the projection of the geometric center point of the multi-dimensional force sensor 1 into the first coordinate plane. The control device determines the vertical coordinate value of the first patch position in the first coordinate plane based on the first position coordinates, and determines the horizontal coordinate value of the first patch position in the first coordinate plane based on the first positioning distance information.

[0069] More specifically, the first patch reference can be the left or right edge of the first patch surface in the first coordinate plane (projected onto the XOZ plane as a projection point), or the projection of the geometric center point P of the multi-dimensional force sensor 1 into the first coordinate plane. The first reference coordinates are the coordinates of the projection point of the left or right edge of the first patch surface in the first coordinate plane, or the coordinates of the projection point of the geometric center point P. The first positioning distance information is a predetermined fixed value, determined through prior measurement and calibration, and pre-stored in the control device. The first positioning distance information includes the distance d1 between the projection of the geometric center point P of the multi-dimensional force sensor 1 into the first coordinate plane and the edge of the strain gauge 5, the distance d2 between the projection of the geometric center point P of the multi-dimensional force sensor 1 into the first coordinate plane and the center point of the strain gauge 5, the distance d3 between the center point of the strain gauge 5 and the projection of one side edge of the first patch surface 3 along the X-axis in the first coordinate plane, and the distance d4 between the edge of the strain gauge 5 and the projection of the first patch surface 3 along the X-axis in the first coordinate plane. The method for determining d3 is as follows: In the first coordinate plane (XOZ plane), the first patch surface 3 is projected along the X-axis, and the distance between one edge of the first patch surface 3 in the projection and the center point of the strain gauge is taken as d3. The method for determining d4 is as follows: In the first coordinate plane (XOZ plane), the first patch surface 3 is projected along the X-axis, and the distance between one edge of the first patch surface 3 in the projection and the edge of the strain gauge is taken as d4.

[0070] In one specific implementation, the first coordinate plane is known to be the XOZ plane, and the first position coordinates (the coordinates of the geometric center of the first patch surface 3 projected onto the XOZ plane) are (x1, z1), for example (150μm, 200μm). The first patch reference is the left edge of the first patch surface 3, and the first reference coordinates are (x1, z1). 1基 , z 1基For example, (100μm, 200μm), the first positioning distance information is that the horizontal distance between the center point of strain gauge 5 and the first reference coordinate is 50μm and the vertical distance is 0μm, that is, the first positioning distance information is (Δx1=50μm, Δz1=0μm). The control device determines the vertical coordinate value of the first patch position based on the vertical coordinate z1 of the first position coordinate. Since the vertical coordinate of the geometric center of the first patch surface 3 projected onto the XOZ plane is z1=200μm, and the vertical coordinate of the first reference coordinate is z1base=200μm (the projection point of the edge is aligned with the geometric center in the Y direction), and the vertical distance Δz1 between the center point of strain gauge 5 and the first reference coordinate is 0μm, the vertical coordinate value of the first patch position is z=z1+Δz1=200μm+0μm=200μm. It should be noted that if there is an offset between the geometric center of the first patch surface 3 and the reference point in the Z direction, the vertical coordinate value needs to be corrected based on the offset. Furthermore, the control device, based on the horizontal distance Δx1 in the first positioning distance information, combines the horizontal coordinate x of the first reference coordinates... 1基 Determine the x-coordinate value of the first patch position; the calculation formula is x. 贴1 =x 基1 +Δx1=100μm+50μm=150μm.

[0071] Specifically, refer to Figure 6 The patch parameter information also includes, within the second coordinate plane, the second reference coordinates of the second patch reference and the second positioning distance information between the edge or center point of the strain gauge 5 and the second reference coordinates. The second patch reference is the projection of the lateral edge of one side of the first patch surface 3 within the second coordinate plane. The control device determines the abscissa value of the first patch position within the second coordinate plane based on the second and third position coordinates, and determines the ordinate value of the first patch position within the second coordinate plane based on the second positioning distance information, the second position coordinates, and the third position coordinates. Specifically, the second patch reference is the projection of the lower lateral edge of the first patch surface 3 within the second coordinate plane. The second reference coordinates are the coordinates of the point on the X-axis corresponding to the center point of the strain gauge 5 on the lower lateral edge. The second positioning distance information can be the distance d5 between the edge of the strain gauge 5 and the second reference coordinates, or the distance d6 between the center point of the strain gauge 5 and the second reference coordinates.

[0072] In one specific implementation, the second coordinate plane is known to be the XOY plane; the second position coordinates (the coordinates of the point on the X-axis corresponding to the center point of the strain gauge 5 within the projection line of the second patch surface 4 on the XOY plane) are (x2, y2) = (150μm, 150μm); the third position coordinates (e.g., the coordinates of the laser rangefinder sensor transmitter on the XOY plane) are (x3, y3) = (150μm, 250μm); the second patch reference is the projection of the lower lateral edge of the first patch surface 3 (…). Figure 6 The lower horizontal edge of the first patch surface 3 in the middle, Figure 5 (closer to the front edge of the image acquisition device), the second reference coordinate is (x 2基 y 2基 = (150μm, 150μm) (same as the second position coordinates); the second positioning distance information is the horizontal distance of the center point of strain gauge 5 and the second reference coordinate of 0μm and 15μm, that is, the second positioning distance information is Δx2=0μm, Δy2=15μm. The control device determines the abscissa value of the first patch position in the second coordinate plane according to the abscissa x2 of the second position coordinate and the abscissa x3 of the third position coordinate. Since the laser rangefinder sensor emits perpendicular to the second patch surface 4, x2=x3=150μm, so the abscissa value of the first patch position is x=x2=150μm; if there is a deviation between x2 and x3 (such as installation error), the average value of the two is taken as the abscissa value, that is, x=(x2+x3) / 2. Furthermore, based on the second positioning distance information, the vertical coordinate y2 of the second position coordinate, and the vertical coordinate y3 of the third position coordinate, the control device first calculates the distance information L=y3-y2=250μm-150μm=100μm between the second patch surface 4 and the distance acquisition device 7; combined with the vertical distance Δy2=15μm of the second positioning distance information, the control device determines the vertical coordinate value y=y2+Δy2=150μm+15μm=165μm of the first patch position in the second coordinate plane.

[0073] Furthermore, in the patch positioning system of the multidimensional force sensor 1, the control device determines the position of the first patch based on the horizontal and vertical coordinate values ​​of the first patch position in the first coordinate plane, and the horizontal and vertical coordinate values ​​of the first patch position in the second coordinate plane.

[0074] Specifically, the coordinates of the first patch position can be determined using either direct correspondence fusion or error correction fusion. Direct correspondence fusion is suitable when the error between the two abscissas is less than a threshold (e.g., ±0.5μm). Assume the first coordinate plane is the XOZ plane, with an abscissa value of x=150μm and a ordinate value of z=150μm; the second coordinate plane is the XOY plane, with an abscissa value of x=150μm and a ordinate value of y=165μm. Since the abscissas in both the first and second coordinate planes correspond to the X-axis of the system coordinate system, and the error between the two abscissas is ≤±0.5μm, x=150μm is chosen. The ordinate z of the first coordinate plane corresponds to the Z-axis of the system coordinate system, and the ordinate y of the second coordinate plane corresponds to the Y-axis of the system coordinate system. The three-dimensional coordinates in the system coordinate system are (x, y, z) = (150μm, 165μm, 150μm).

[0075] More specifically, the error correction method is applicable when the error between the two abscissas exceeds a threshold. Assume the first coordinate plane is the XOZ plane, with an abscissa value of x = 150 μm and a ordinate value of z = 150 μm; the second coordinate plane is the XOY plane, with an abscissa value of x' = 152 μm and a ordinate value of y = 165 μm. First, error correction is applied to the abscissas of the two planes, and the average value is taken as the X-axis coordinate of the system coordinate system: x = (x + x') / 2 = (150 + 152) / 2 = 151 μm; the z-axis of the first coordinate plane is directly used as the Z-axis coordinate of the system coordinate system, and the y-axis of the second coordinate plane is directly used as the Y-axis coordinate of the system coordinate system. The three-dimensional coordinates in the system coordinate system are (x, y, z) = (151 μm, 165 μm, 150 μm).

[0076] Furthermore, the patch positioning system can also determine the position coordinates of the strain gauge on the second patch surface. In this patch positioning system for the multi-dimensional force sensor, the patch parameter information also includes: within the first coordinate plane, the third reference coordinates of the third patch reference and the third positioning distance information between the second sheet feature element of the strain gauge and the third reference coordinates; within the second coordinate plane, the fourth reference coordinates of the fourth patch reference and the fourth positioning distance information between the second sheet feature element of the strain gauge and the fourth reference coordinates. The second sheet feature element of the strain gauge includes: the edge of the strain gauge or a first visual feature point; the third patch reference is the surface feature element of the second patch surface, or the projection of the second visual feature point of the multi-dimensional force sensor onto the first coordinate plane; the fourth patch reference is the projection of the surface feature element of the second patch surface onto the second coordinate plane.

[0077] Furthermore, the control device also determines the abscissa and ordinate values ​​of the strain gauge in the first coordinate plane based on the third positioning distance information; determines the ordinate value of the second patch position of the strain gauge on the second patch surface in the second coordinate plane based on the second position coordinate and the third position coordinate; determines the abscissa value of the second patch position in the second coordinate plane based on the fourth positioning distance information; and determines the second patch position based on the abscissa and ordinate values ​​of the second patch position in the first coordinate plane, and the abscissa and ordinate values ​​of the second patch position in the second coordinate plane.

[0078] The second sheet feature element refers to the visually identifiable feature of the strain gauge itself, used for positioning the second patch surface. It can be the solid edge contour of the strain gauge's outer contour, such as the straight edge or right-angle side; or it can be the center point, end point, or hole position of the strain gauge produced by the process.

[0079] The third patch reference is a reference element set in the first coordinate plane for positioning the second patch surface. It can be a surface feature element of the second patch surface itself, such as the overall plane of the second patch surface, the outline of the patch surface edge, etc.; or it can be the projection of the feature points of the multi-dimensional force sensor in the first coordinate plane, such as the center point of the force transmission table, the projection point of the end of the elastic beam.

[0080] The third reference coordinate is the calibration coordinate value corresponding to the distance acquisition device.

[0081] The third positioning distance information is the distance between the second sheet feature element of the strain gauge and the third patch reference.

[0082] The fourth patch reference can be a depth dimension positioning reference set in the second coordinate plane and formed by the projection of the feature elements of the second patch surface. It can be a perpendicular projection plane of the center reference plane of the second patch surface onto the second coordinate plane; or it can be the projection mark of the contour feature points of the second patch surface onto the second coordinate plane.

[0083] Specifically, refer to Figure 7 The patch parameter information may specifically include: within the first coordinate plane, the third reference coordinate of the third patch reference, and the third positioning distance information between the edge or center point of the strain gauge 5 and the third reference coordinate. The third patch reference is the peripheral edge of the second patch surface 4, or the projection point of the geometric center point of the multi-dimensional force sensor 1 into the first coordinate plane. Furthermore, the control device determines the abscissa and ordinate values ​​of the strain gauge 5 in the first coordinate plane based on the third positioning distance information. The patch parameter information also includes within the second coordinate plane, the fourth reference coordinate of the fourth patch reference, and the fourth positioning distance information between the edge or center point of the strain gauge 5 and the fourth reference coordinate; the fourth patch reference is the projection of one longitudinal edge of the second patch surface 4 into the second coordinate plane; the control device determines the ordinate value of the second patch position of the strain gauge 5 on the second patch surface 4 in the second coordinate plane based on the second and third position coordinates, and determines the abscissa value of the second patch position in the second coordinate plane based on the fourth positioning distance information. The control device determines the position of the second patch based on the horizontal and vertical coordinates of the second patch position in the first coordinate plane, and the horizontal and vertical coordinates of the second patch position in the second coordinate plane. When multiple strain gauges 5 are provided, the third positioning distance information is determined based on the distance information between the edge or center point of each strain gauge 5 and the third reference coordinate.

[0084] The third reference points include the projections of the upper edge of the second patch surface 4, the lower edge of the second patch surface 4, the left edge of the second patch surface 4, and the right edge of the second patch surface 4 into the first coordinate plane, or the projection of the geometric center point of the multi-dimensional force sensor 1 into the first coordinate plane. The third reference coordinates can be the coordinates of reference points, such as the coordinates Q1 and Q5 of the upper edge corresponding to the center point of strain gauge 5 on the X-axis, Q3 and Q7 of the lower edge corresponding to the center point of strain gauge 5 on the X-axis, Q4 and Q8 of the left edge corresponding to the center point of strain gauge 5 on the Z-axis, Q2 and Q6 of the right edge corresponding to the center point of strain gauge 5 on the Z-axis, or the coordinates of the geometric center point of the multi-dimensional force sensor 1. All of these coordinates correspond to the coordinates of the projection points in the first coordinate plane. The third positioning distance information includes the distance between the upper edge of strain gauge 5 and the upper edge of the second patch surface 4, the distance between the lower edge of strain gauge 5 and the lower edge of the second patch surface 4, the distance between the left edge of strain gauge 5 and the left edge of the second patch surface 4, the distance between the right edge of strain gauge 5 and the right edge of the second patch surface 4, the distance between the center point of strain gauge 5 and the geometric center point of multi-dimensional force sensor 1, the distance between the upper edge of strain gauge 5 and the geometric center point of multi-dimensional force sensor 1, the distance between the lower edge of strain gauge 5 and the geometric center point of multi-dimensional force sensor 1, the distance between the left edge of strain gauge 5 and the geometric center point of multi-dimensional force sensor 1, or the distance between the right edge of strain gauge 5 and the geometric center point of multi-dimensional force sensor 1. Furthermore, the longitudinal edge of the second patch surface 4 on one side of the second coordinate plane, i.e. Figure 6 The left or right edge of the second patch surface 4. The fourth reference coordinate includes the projected coordinates of the left edge or the right edge of the second patch surface 4 in the second coordinate plane. The fourth positioning distance information includes the distance between the projected coordinates of the left edge of the strain gauge 5 and the left edge of the second patch surface 4 in the second coordinate plane, the distance between the right edge of the strain gauge 5 and the right edge of the second patch surface 4 in the second coordinate plane, the distance between the center point of the strain gauge 5 and the projected coordinates of the left edge of the second patch surface 4 in the second coordinate plane, or the distance between the center point of the strain gauge 5 and the projected coordinates of the right edge of the second patch surface 4 in the second coordinate plane.

[0085] More specifically, when determining the position of the strain gauge 5 within the second patch surface 4, the control device first determines the horizontal and vertical coordinates of the second patch position in the first coordinate plane, as well as the horizontal and vertical coordinates of the second coordinate plane. Then, it determines the corresponding three-dimensional coordinates based on the horizontal and vertical coordinates in both coordinate planes. Specifically, the horizontal coordinate in the first coordinate plane is determined based on the distance information between the left and right edges of the second patch surface 4 and the third reference coordinate, while the vertical coordinate is determined based on the distance information between the top and bottom edges of the second patch surface 4 and the third reference coordinate. The horizontal coordinate in the second coordinate plane is determined based on the fourth positioning distance information, and the vertical coordinate is determined based on the vertical coordinates corresponding to the second and third position coordinates.

[0086] In one specific implementation, assuming the right edge of the second patch surface 4 is used as the reference for the third patch, since the first coordinate plane is parallel to the second patch surface 4, the right edge is projected onto the first coordinate plane (XOZ plane). The projected straight line is parallel to the original edge and has no offset, thus serving as the reference for the third patch. The point on the Z-axis corresponding to the projection of this right edge and the center point of the strain gauge 5 is selected as the reference point, and its third reference coordinates are (x... 3基 , z 3基 For example (220μm, 200μm); the third positioning distance information includes the horizontal distance (X direction) and vertical distance (Z direction) between the center point of strain gauge 5 and the third reference coordinate. If the center point of rectangular strain gauge 5 needs to be located 30μm to the left and 20μm below the third reference point, then the third positioning distance information is Δx3=-30μm, Δz3=20μm. The control device calls the third reference coordinate (x 3基 , z 3基 Based on the third positioning distance information, the horizontal and vertical coordinates (x, z) of the rectangular strain gauge 5 in the first coordinate plane are directly calculated. Where x = x 3基 +Δx³ = 220 - 30 = 190 μm, z = z 3基 +ΔZ3=200+20=220μm.

[0087] Assume the projection of the left longitudinal edge of the second patch surface 4 onto the second coordinate plane is the reference of the fourth patch, and the projection of the left longitudinal edge onto the second coordinate plane is a point with coordinates (x...). 4基 y 4基 For example, (220μm, 200μm). The fourth positioning distance information includes the horizontal distance (X direction) between the center point of strain gauge 5 and the fourth reference coordinate. If the center point of strain gauge 5 needs to be located 30μm to the left of the fourth reference point, then the fourth positioning distance information is Δx4 = -30μm. The control device calls the x-coordinate corresponding to the fourth reference coordinate. 4基Based on the fourth positioning distance information, the abscissa x of strain gauge 5 in the second coordinate plane is directly calculated. Where x = x 4基 +Δx4=220-30=190μm. Furthermore, the ordinate y of strain gauge 5 in the second coordinate plane is directly determined based on the ordinate y2 corresponding to the second position coordinate and the ordinate y3 corresponding to the third position coordinate, i.e., y=y3-y2.

[0088] Subsequently, the coordinates of the second patch position of strain gauge 5 on the second patch surface 4 are determined based on the horizontal and vertical coordinates (x, z) of strain gauge 5 in the first coordinate plane and the horizontal and vertical coordinates (x, y) of strain gauge 5 in the second coordinate plane. The specific method of determining the system coordinates based on the plane coordinates is the same as that involved in the first patch surface 3, and will not be repeated here.

[0089] Furthermore, in this multi-dimensional force sensor patch positioning system, the multi-dimensional force sensor 1 has a symmetrical structure relative to the axis perpendicular to the first coordinate plane in the two-dimensional image acquired by the two-dimensional image acquisition device 6. The control device also determines the tilt angle of the two symmetrical first patch surfaces 3 relative to the axis in the first coordinate plane based on the two-dimensional image information, and ensures that the ordinates of the two symmetrical first patch surfaces 3 are the same in the first coordinate plane based on the tilt angle.

[0090] Specifically, an axisymmetric structure refers to the fact that the projected contour of the multi-dimensional force sensor 1 in the two-dimensional image, the arrangement of the elastic beams 2, and the positions of the first patch surface 3 and the second patch surface 4 are all mirror-symmetrical about the axis of symmetry. Two mutually symmetrical first patch surfaces 3 refer to the first patch surfaces 3 on two symmetrical elastic beams 2 having completely identical structures and dimensions, only their positions are symmetrically distributed. The symmetrical structure of the multi-dimensional force sensor 1 varies depending on the number of elastic beams 2; it can be formed by four elastic beams 2, such as... Figure 5 The cross-shaped symmetrical structure shown can be either a spoke-shaped symmetrical structure formed by eight elastic beams 2 as shown in Figure 2, or a parallel symmetrical structure formed by two parallel elastic beams 2.

[0091] More specifically, the method for calculating the tilt angle is as follows: First, identify the geometric center lines of the two symmetrical first patch surfaces 3, and use the projection line of the axis of symmetry in the two-dimensional image as the reference line. Then, calculate the angle between the geometric center line of a single first patch surface 3 and the reference line, and use this angle as the tilt angle of the corresponding single first patch surface.

[0092] The tilt angle makes the symmetrical first patch surfaces 3 have the same vertical coordinate in the first coordinate plane. Specifically, the multi-dimensional force sensor 1 can be rotated around the Y-axis in the first coordinate plane by a preset angle (the angle value corresponding to the tilt angle), so that both first patch surfaces 3 are parallel to the second coordinate plane.

[0093] In this way, by calculating the tilt angle and making the ordinates of the two symmetrical first patch surfaces 3 the same in the first coordinate plane, only the Z-axis coordinate of the first patch surface 3 on one side needs to be calculated during the actual patch positioning process, without the need for multiple measurements and calculations, thus improving the positioning efficiency.

[0094] Furthermore, in the patch positioning system of this multidimensional force sensor, reference Figure 1a , Figure 1b In one specific implementation, the multidimensional force sensor 1 has an annular outer ring, wherein each elastic beam 2 extends radially along the annular outer ring, with one end connected to the inner circumference of the annular outer ring and the other end extending toward and fixed relative to the center of the annular outer ring. Furthermore, the multiple elastic beams 2 are evenly spaced along the circumferential direction of the annular outer ring. One side of each elastic beam 2 in the circumferential direction is designated as a first patch surface 3, and one side in the axial direction of the annular outer ring is designated as a second patch surface 4.

[0095] Specifically, the annular outer ring can be circular, hexagonal, square, or other shapes. The axial direction of the annular outer ring is perpendicular to the plane of the circle, hexagon, or square, and both sides of the multi-dimensional force sensor 1 in the axial direction are planes, preferably parallel to the XOZ plane. This allows for the calculation of only the Y-axis coordinate of one patch surface during actual patch positioning, eliminating the need for multiple measurements and calculations, thus improving positioning efficiency. One end of each elastic beam 2 can be fixed to the inner circumference of the annular outer ring through integral molding, bonding, or welding, while the other end can be fixedly connected to the force transmission platform or connecting block located at the center of the sensor.

[0096] More specifically, each elastic beam 2 has four sides, two of which are parallel to each other and are the circumferential sides of the multidimensional force sensor 1, and the other two parallel sides are the axial sides of the multidimensional force sensor 1. The first patch surface 3 refers to the circumferential side, and the second patch surface 4 refers to the axial side.

[0097] Furthermore, in this patch positioning system for the multidimensional force sensor, the two-dimensional image acquisition device 6 is a 2D camera; the distance acquisition device 7 is a laser rangefinder or an ultrasonic rangefinder; and the control device is a PLC controller. In a preferred implementation, the two-dimensional image acquisition device acquires two-dimensional image information of the multidimensional force sensor on one side, along a direction parallel to the first patch surface; the first coordinate plane is parallel to the second patch surface; and the second coordinate plane is parallel to the first patch surface.

[0098] Specifically, the two-dimensional image acquisition device 6 is configured as a 2D camera. By adjusting the camera's installation angle and position so that the lens's shooting direction is directly facing the second patch surface 4, clear two-dimensional images of the edge of the first patch surface 3 and the complete second patch surface 4 can be directly acquired. This allows for positioning by combining preset patch parameter information. Compared to using a 3D camera to acquire images from the multi-dimensional force sensor 1 and directly determining the three-dimensional coordinates of the first patch position based on the 3D camera image, the first patch surface 3 is obscured by the annular outer ring when the 3D camera's lens is directly facing the second patch surface 4 due to the structural limitations of the multi-dimensional force sensor 1. This causes the 3D camera's point cloud image to lose some area data due to structural obstruction, resulting in inaccurate determination of the first patch position. This application configures the two-dimensional image acquisition device 6 as a 2D camera, which can accurately locate the strain gauge 5 on the first patch surface 3 without restoring the complete structure of the first patch surface 3, thus improving positioning accuracy.

[0099] Example 2:

[0100] This embodiment provides a patch positioning method for a multidimensional force sensor. The multidimensional force sensor includes multiple elastic beams and multiple strain gauges. At least one elastic beam has a first patch surface and a second patch surface adjacent to each other along the circumferential direction of the elastic beam, and corresponding strain gauges are attached to the first patch surface and the second patch surface, respectively. The multidimensional force sensor of Embodiment 2 is not fundamentally different from the multidimensional force sensor in Embodiment 1, and its specific structure will not be described further here.

[0101] refer to Figure 8 The patch positioning method includes:

[0102] First, two-dimensional image information of the multi-dimensional force sensor is acquired on one side of the multi-dimensional force sensor, facing the second patch surface. Based on the two-dimensional image information, the first position coordinates of the first patch surface in the first coordinate plane of the pre-calibrated system coordinate system are determined. Based on the first position coordinates and the preset patch parameter information, the first patch coordinates of the strain gauge on the first patch surface are determined.

[0103] The distance information between the second patch surface and the ranging point is obtained on one side of the multidimensional force sensor. The second position coordinate of the second patch surface in the second coordinate plane in the system coordinate system is determined based on the distance information. The second patch coordinate of the strain gauge on the first patch surface is determined based on the second position coordinate, patch parameter information, and the third position coordinate of the ranging point in the second coordinate plane.

[0104] Next, the position of the first patch on the first patch surface is determined based on the coordinates of the first patch and the coordinates of the second patch.

[0105] Specifically, the pre-calibrated system coordinate system is a Cartesian coordinate system O-XYZ, where the first coordinate plane is the XOZ plane and the second coordinate plane is the XOY plane. The two coordinate planes are perpendicular to each other, and the origin O can be set as the geometric center point of the multi-dimensional force sensor, the ranging point, or the point for acquiring two-dimensional graphic information.

[0106] In one specific implementation, the steps for determining the coordinates of the first patch include: placing a 2D camera to the left of the multi-dimensional force sensor, with the camera lens facing the first patch surface of the elastic beam, to capture two-dimensional image information of the multi-dimensional force sensor. The control device performs contour extraction on the two-dimensional image information, identifies the boundary feature points of the first patch surface, converts the pixel coordinates of the feature points into actual coordinates in the system coordinate system, and determines the first position coordinates of the first patch surface in the first coordinate plane (XOZ plane). The control device combines the first position coordinates with patch parameter information (e.g., the distance between the center point of the strain gauge and the geometric center of the multi-dimensional force sensor) to calculate the first patch coordinates of the rectangular strain gauge on the first patch surface.

[0107] The steps for determining the coordinates of the second patch include: A distance acquisition device is placed on one side of the multi-dimensional force sensor; the distance measuring point (the laser emission point of a laser rangefinder or the ultrasonic emission point of an ultrasonic rangefinder) is aligned with the second patch surface of the elastic beam; and the distance information between the second patch surface and the distance measuring point is measured. Based on the distance information and the installation position of the laser rangefinder, the control device determines the second position coordinates of the second patch surface in the second coordinate plane (XOY plane). The third position coordinates of the distance measuring point in the second coordinate plane (XOY plane) are pre-calibrated. The control device, combining the second and third position coordinates with preset patch parameter information, calculates the second patch coordinates of the rectangular strain gauge on the first patch surface.

[0108] The steps for determining the position of the first patch include: the control device integrates the coordinates of the first patch and the coordinates of the second patch to determine the first patch position of the strain gauge on the first patch surface. The three-dimensional coordinates are the attachment position of the strain gauge on the first patch surface.

[0109] Furthermore, in this patch positioning method, the patch parameter information includes: the first reference coordinates of the first patch reference in the first coordinate plane, and the first positioning distance information between the first sheet feature element of the strain gauge and the first reference coordinates; wherein, the first sheet feature element of the strain gauge includes: the edge of the strain gauge or the first visual feature point; the first patch reference is the surface feature element of the first patch surface in the first coordinate plane, or the projection of the second visual feature point of the multi-dimensional force sensor in the first coordinate plane.

[0110] Furthermore, the first patch coordinates of the strain gauge on the first patch surface are determined based on the first position coordinates and the preset patch parameter information, including: determining the vertical coordinate value of the first patch position in the first coordinate plane based on the first position coordinates, determining the horizontal coordinate value of the first patch position in the first coordinate plane based on the first positioning distance information, and determining the first patch coordinates based on the horizontal and vertical coordinate values ​​of the first patch position in the first coordinate plane.

[0111] Specifically, when determining the coordinates of the first patch, the control device determines the vertical coordinate value of the first patch position in the first coordinate plane based on the Z-axis component of the first position coordinates. It then calculates the horizontal coordinate value based on the horizontal component of the first positioning distance information and the first reference coordinates. Finally, the horizontal and vertical coordinate values ​​are combined to determine the coordinates of the first patch.

[0112] Furthermore, in this patch positioning method, the patch parameter information also includes the second reference coordinates of the second patch reference and the second positioning distance information between the first sheet feature element of the strain gauge and the second reference coordinates in the second coordinate plane; wherein, the second patch reference is the projection of the surface feature element of the first patch surface in the second coordinate plane.

[0113] Furthermore, the second patch coordinates of the strain gauge on the first patch surface are determined based on the second position coordinates, patch parameter information, and the third position coordinates of the ranging point in the second coordinate plane. This includes: determining the abscissa value of the first patch position in the second coordinate plane based on the second position coordinates and the third position coordinates; determining the ordinate value of the first patch position in the second coordinate plane based on the second positioning distance information, the second position coordinates, and the third position coordinates; and determining the second patch coordinates based on the abscissa and ordinate values ​​of the first patch position in the second coordinate plane.

[0114] Specifically, when determining the coordinates of the second patch, the control device calculates the abscissa value by averaging the X-axis components of the second and third position coordinates; and calculates the ordinate value by combining the second positioning distance information with the Y-axis components of the second and third position coordinates. The coordinates of the second patch are then determined based on the abscissa and ordinate values.

[0115] Furthermore, determining the first patch position of the strain gauge on the first patch surface based on the first patch coordinates and the second patch coordinates includes: determining the first patch position based on the horizontal and vertical coordinate values ​​of the first patch position in the first coordinate plane, and the horizontal and vertical coordinate values ​​of the first patch position in the second coordinate plane.

[0116] Specifically, the control device performs a fusion calculation based on the coordinates of the first patch and the coordinates of the second patch to obtain the three-dimensional coordinates of the position of the first patch.

[0117] Furthermore, in this patch positioning method, the patch parameter information also includes: within the first coordinate plane, the third reference coordinate of the third patch reference, the third positioning distance information between the second sheet feature element of the strain gauge and the third reference coordinate, and within the second coordinate plane, the fourth reference coordinate of the fourth patch reference, the fourth positioning distance information between the second sheet feature element of the strain gauge and the fourth reference coordinate; wherein, the second sheet feature element of the strain gauge includes: the edge of the strain gauge or the first visual feature point; the third patch reference is the surface feature element of the second patch surface, or the projection of the second visual feature point of the multi-dimensional force sensor into the first coordinate plane; the fourth patch reference is the projection of the surface feature element of the second patch surface into the second coordinate plane.

[0118] Furthermore, the patch positioning method also includes: determining the abscissa and ordinate values ​​of the strain gauge in the first coordinate plane based on the third positioning distance information; determining the ordinate value of the second patch position of the strain gauge on the second patch surface in the second coordinate plane based on the second position coordinates and the third position coordinates; determining the abscissa value of the second patch position in the second coordinate plane based on the fourth positioning distance information; and determining the second patch position based on the abscissa and ordinate values ​​of the second patch position in the first coordinate plane, as well as the abscissa and ordinate values ​​of the second patch position in the second coordinate plane.

[0119] Specifically, when determining the position of the second patch, the control device calculates the abscissa value of the second patch position in the first coordinate plane by summing the corresponding abscissas based on the third positioning distance information and the third reference coordinates, and calculates the ordinate value of the second patch position in the first coordinate plane by summing the corresponding ordinates, thus obtaining the coordinates of the second patch position in the first coordinate plane. The control device determines the ordinate value of the second patch position in the second coordinate plane based on the Y-axis components of the second and third position coordinates, and calculates the corresponding abscissa value based on the fourth positioning distance information and the fourth reference coordinates. The control device integrates the coordinates in the first and second coordinate planes to determine the three-dimensional coordinates of the second patch position.

[0120] Furthermore, in this patch positioning method, the multi-dimensional force sensor has a symmetrical structure relative to an axis perpendicular to the first coordinate plane in the two-dimensional image of the multi-dimensional force sensor. The patch positioning method also includes: determining the tilt angle of the two symmetrical first patch surfaces relative to the axis in the first coordinate plane based on the two-dimensional image information; and when the tilt angle is not within a preset angle range, controlling the multi-dimensional force sensor to rotate circumferentially around an axis perpendicular to the first coordinate plane according to the tilt angle until the tilt angle is within the preset angle range.

[0121] Furthermore, based on the two-dimensional image information, the tilt angle of the two symmetrical first patch surfaces relative to the axis in the first coordinate plane is determined, including: determining two points corresponding to the positions on the two first patch surfaces from the two-dimensional image information; and determining the tilt angle of the line connecting the two points relative to the axis.

[0122] Specifically, the multi-dimensional force sensor can be fixed by a rotary drive fixture. The rotation operation can be achieved by the control device sending a control signal to the signal input terminal of the rotary drive fixture. The rotary drive fixture analyzes the signal and generates an output torque to control the rotation of its output shaft, thereby driving the multi-dimensional force sensor to rotate around its axis in the circumferential direction until the detected tilt angle is within the preset angle range, at which point the rotation stops, ensuring the positioning accuracy of the symmetrical first patch surface.

[0123] Furthermore, the multidimensional force sensor has an annular outer ring, wherein each elastic beam extends radially along the annular outer ring, one end of which is connected to the inner circumference of the annular outer ring, and the other end extends toward the center of the annular outer ring and is fixed relative to the center. Moreover, multiple elastic beams are evenly spaced along the circumferential direction of the annular outer ring. Each elastic beam has one side in the circumferential direction as a first patch surface and one side in the axial direction of the annular outer ring as a second patch surface.

[0124] Furthermore, the two-dimensional image information is acquired via a two-dimensional image acquisition device, which is a 2D camera; the distance information is acquired via a distance acquisition device, which is a laser rangefinder or an ultrasonic rangefinder, and the distance measurement point is the detection reference point of the distance acquisition device.

[0125] While the present invention has been illustrated and described with reference to certain preferred embodiments, those skilled in the art should understand that the above description is a further detailed explanation of the invention in conjunction with specific embodiments, and should not be construed as limiting the specific implementation of the invention to these descriptions. Various changes in form and detail can be made by those skilled in the art, including several simple deductions or substitutions, without departing from the spirit and scope of the invention.

Claims

1. A patch positioning system for a multidimensional force sensor, characterized in that, The multidimensional force sensor includes multiple elastic beams and multiple strain gauges; wherein at least one elastic beam has a first patch surface and a second patch surface adjacent to each other along the circumferential direction of the elastic beam, and the first patch surface and the second patch surface are respectively attached with the corresponding strain gauges; and The patch positioning system includes a two-dimensional image acquisition device, a distance acquisition device, and a control device, wherein the control device is communicatively connected to the two-dimensional image acquisition device and the distance acquisition device; wherein The two-dimensional image acquisition device is arranged on one side of the multi-dimensional force sensor, facing the second patch surface, and acquires two-dimensional image information of the multi-dimensional force sensor. The control device determines the first position coordinates of the first patch surface in the two-dimensional image in the first coordinate plane of the system coordinate system of the patch positioning system according to the two-dimensional image information, and determines the first patch coordinates of the strain gauge on the first patch surface according to the first position coordinates and the preset patch parameter information. The distance acquisition device is arranged on one side of the multidimensional force sensor, facing the second patch surface, and acquires the distance information between the second patch surface and the distance acquisition device. The control device determines the second position coordinates of the second patch surface in the second coordinate plane of the system coordinate system based on the distance information, and determines the second patch coordinates of the strain gauge on the first patch surface based on the second position coordinates, the patch parameter information, and the third position coordinates of the distance acquisition device in the second coordinate plane. The control device determines the first patch position of the strain gauge on the first patch surface based on the first patch coordinates and the second patch coordinates.

2. The patch positioning system for a multidimensional force sensor as described in claim 1, characterized in that, The patch parameter information includes: Within the first coordinate plane, the information includes the first reference coordinates of the first patch reference, the first positioning distance between the first sheet feature element of the strain gauge and the first reference coordinates; wherein, the first sheet feature element of the strain gauge includes: the edge of the strain gauge or a first visual feature point; the first patch reference is the surface feature element of the first patch surface in the first coordinate plane, or the projection of the second visual feature point of the multi-dimensional force sensor in the first coordinate plane; and The control device determines the vertical coordinate of the first patch position in the first coordinate plane based on the first position coordinates, and determines the horizontal coordinate of the first patch position in the first coordinate plane based on the first positioning distance information; and The patch parameter information also includes, within the second coordinate plane, the second reference coordinates of the second patch reference and the second positioning distance information between the first sheet feature element of the strain gauge and the second reference coordinates; wherein, the second patch reference is the projection of the surface feature element of the first patch surface onto the second coordinate plane; The control device determines the horizontal coordinate of the first patch position in the second coordinate plane based on the second position coordinates and the third position coordinates, and determines the vertical coordinate of the first patch position in the second coordinate plane based on the second positioning distance information, the second position coordinates, and the third position coordinates; and The control device determines the position of the first patch based on the horizontal and vertical coordinates of the first patch position in the first coordinate plane, and the horizontal and vertical coordinates of the first patch position in the second coordinate plane.

3. The patch positioning system for a multidimensional force sensor as described in claim 1, characterized in that, The patch parameter information also includes: Within the first coordinate plane, the third reference coordinates of the third patch reference, the third positioning distance information between the second sheet feature element of the strain gauge and the third reference coordinates; wherein, the second sheet feature element of the strain gauge includes: the edge of the strain gauge or a first visual feature point; the third patch reference is the surface feature element of the second patch surface, or the projection of the second visual feature point of the multi-dimensional force sensor onto the first coordinate plane; and The control device also determines the horizontal and vertical coordinate values ​​of the strain gauge in the first coordinate plane based on the third positioning distance information. The patch parameter information also includes, within the second coordinate plane, the fourth reference coordinate of the fourth patch reference, and the fourth positioning distance information between the second sheet feature element of the strain gauge and the fourth reference coordinate; wherein, the fourth patch reference is the projection of the surface feature element of the second patch surface into the second coordinate plane; The control device determines the vertical coordinate value of the second patch position of the strain gauge on the second patch surface in the second coordinate plane based on the second position coordinate and the third position coordinate, and determines the horizontal coordinate value of the second patch position in the second coordinate plane based on the fourth positioning distance information; The control device determines the position of the second patch based on the horizontal and vertical coordinates of the second patch position in the first coordinate plane, and the horizontal and vertical coordinates of the second patch position in the second coordinate plane.

4. The patch positioning system for a multidimensional force sensor as described in claim 1, characterized in that, The multidimensional force sensor exhibits a structure symmetrical about an axis perpendicular to the first coordinate plane in the two-dimensional image acquired by the two-dimensional image acquisition device; and The control device also determines the tilt angle of the two symmetrical first patch surfaces relative to the axis in the first coordinate plane based on the two-dimensional image information, and makes the ordinates of the two symmetrical first patch surfaces in the first coordinate plane the same based on the tilt angle.

5. The patch positioning system for a multidimensional force sensor as described in claim 1, characterized in that, The multidimensional force sensor has an annular outer ring, wherein each of the elastic beams extends radially along the annular outer ring, one end of which is connected to the inner circumference of the annular outer ring, and the other end extends toward the center of the annular outer ring and is fixed relative to the center. The plurality of elastic beams are evenly spaced along the circumferential direction of the annular outer ring. One side of each elastic beam in the circumferential direction is used as the first patch surface, and one side in the axial direction of the annular outer ring is used as the second patch surface.

6. The patch positioning system for a multidimensional force sensor as described in claim 1, characterized in that, The first patch surface and the second patch surface are perpendicular to each other; and The two-dimensional image acquisition device acquires two-dimensional image information of the multi-dimensional force sensor on one side of the multi-dimensional force sensor, along a direction parallel to the first patch surface; The first coordinate plane is parallel to the second patch surface; the second coordinate plane is parallel to the first patch surface.

7. The patch positioning system for a multidimensional force sensor as described in claim 1, characterized in that, The two-dimensional image acquisition device is a 2D camera; The distance acquisition device is a laser rangefinder or an ultrasonic rangefinder; and The control device is a PLC controller.

8. A patch positioning method for a multidimensional force sensor, characterized in that, The multidimensional force sensor includes multiple elastic beams and multiple strain gauges; wherein at least one elastic beam has a first patch surface and a second patch surface adjacent to each other along the circumferential direction of the elastic beam, and the first patch surface and the second patch surface are respectively attached with corresponding strain gauges; and The patch positioning method includes: Two-dimensional image information of the multi-dimensional force sensor is acquired on one side of the multi-dimensional force sensor, facing the second patch surface. The first position coordinate of the first patch surface in the first coordinate plane of the pre-calibrated system coordinate system is determined based on the two-dimensional image information. The first patch coordinate of the strain gauge on the first patch surface is determined based on the first position coordinate and the preset patch parameter information. The distance information between the second patch surface and the ranging point is obtained on one side of the multidimensional force sensor. The second position coordinate of the second patch surface in the second coordinate plane in the system coordinate system is determined according to the distance information. The second patch coordinate of the strain gauge on the first patch surface is determined according to the second position coordinate, the patch parameter information, and the third position coordinate of the ranging point in the second coordinate plane. The first patch position of the strain gauge on the first patch surface is determined based on the first patch coordinates and the second patch coordinates.

9. The patch positioning method as described in claim 8, characterized in that, The patch parameter information includes: Within the first coordinate plane, the information includes the first reference coordinates of the first patch reference, the first positioning distance between the first sheet feature element of the strain gauge and the first reference coordinates; wherein, the first sheet feature element of the strain gauge includes: the edge of the strain gauge or a first visual feature point; the first patch reference is the surface feature element of the first patch surface in the first coordinate plane, or the projection of the second visual feature point of the multi-dimensional force sensor in the first coordinate plane; and Determining the first patch coordinates of the strain gauge on the first patch surface based on the first position coordinates and preset patch parameter information includes: The vertical coordinate of the first patch position in the first coordinate plane is determined based on the first position coordinates, and the horizontal coordinate of the first patch position in the first coordinate plane is determined based on the first positioning distance information. The coordinates of the first patch are then determined based on both the horizontal and vertical coordinates of the first patch position in the first coordinate plane. The patch parameter information also includes, within the second coordinate plane, the second reference coordinates of the second patch reference and the second positioning distance information between the first sheet feature element of the strain gauge and the second reference coordinates; wherein, the second patch reference is the projection of the surface feature element of the first patch surface onto the second coordinate plane; and Determining the second patch coordinates of the strain gauge on the first patch surface based on the second position coordinates, the patch parameter information, and the third position coordinates of the ranging point in the second coordinate plane includes: The horizontal coordinate of the first patch position in the second coordinate plane is determined based on the second position coordinates and the third position coordinates. The vertical coordinate of the first patch position in the second coordinate plane is determined based on the second positioning distance information, the second position coordinates, and the third position coordinates. The second patch coordinates are determined based on the horizontal and vertical coordinates of the first patch position in the second coordinate plane. Determining the first patch position of the strain gauge on the first patch surface based on the first patch coordinates and the second patch coordinates includes: The position of the first patch is determined based on the x-coordinate and y-coordinate values ​​of the first patch position in the first coordinate plane, and the x-coordinate and y-coordinate values ​​of the first patch position in the second coordinate plane.

10. The patch positioning method for a multidimensional force sensor as described in claim 8, characterized in that, The patch parameter information also includes: In the first coordinate plane, the third reference coordinates of the third patch reference, the third positioning distance information between the second sheet feature element of the strain gauge and the third reference coordinates, and in the second coordinate plane, the fourth reference coordinates of the fourth patch reference, the fourth positioning distance information between the second sheet feature element of the strain gauge and the fourth reference coordinates; wherein, the second sheet feature element of the strain gauge includes: the edge of the strain gauge or a first visual feature point; the third patch reference is the projection of the surface feature element of the second patch surface, or the second visual feature point of the multi-dimensional force sensor, onto the first coordinate plane; the fourth patch reference is the projection of the surface feature element of the second patch surface onto the second coordinate plane; and The patch positioning method further includes: The strain gauge's horizontal and vertical coordinates in the first coordinate plane are determined based on the third positioning distance information; the vertical coordinate of the strain gauge's second patch position on the second patch surface in the second coordinate plane is determined based on the second and third position coordinates; the horizontal coordinate of the second patch position in the second coordinate plane is determined based on the fourth positioning distance information; and the second patch position is determined based on the horizontal and vertical coordinates of the second patch position in the first coordinate plane and the horizontal and vertical coordinates of the second patch position in the second coordinate plane.

11. The patch positioning method for a multidimensional force sensor as described in claim 8, characterized in that, The multidimensional force sensor exhibits a structure symmetrical about an axis perpendicular to the first coordinate plane in the two-dimensional image of the multidimensional force sensor; and The patch positioning method further includes: Based on the two-dimensional image information, the tilt angles of the two symmetrical first patch surfaces relative to the axis in the first coordinate plane are determined. When the tilt angle is not within a preset angle range, the multi-dimensional force sensor is controlled to rotate around an axis perpendicular to the first coordinate plane in its circumferential direction according to the tilt angle until the tilt angle is within the angle range.

12. The patch positioning method for a multidimensional force sensor as described in claim 11, characterized in that, Determining the tilt angle of the two symmetrical first patch surfaces relative to the axis in the first coordinate plane based on the two-dimensional image information includes: Determine two points corresponding to the positions on the two first patch surfaces from the two-dimensional image information; Determine the angle of inclination of the line connecting the two points relative to the axis.

13. The patch positioning method for a multidimensional force sensor as described in claim 8, characterized in that, The multidimensional force sensor has an annular outer ring, wherein each of the elastic beams extends radially along the annular outer ring, one end of which is connected to the inner circumference of the annular outer ring, and the other end extends toward the center of the annular outer ring and is fixed relative to the center. The plurality of elastic beams are evenly spaced along the circumferential direction of the annular outer ring. One side of each elastic beam in the circumferential direction is used as the first patch surface, and one side in the axial direction of the annular outer ring is used as the second patch surface.

14. The patch positioning method for a multidimensional force sensor as described in claim 8, characterized in that, The first patch surface and the second patch surface are perpendicular to each other; and The two-dimensional image information is acquired by a two-dimensional image acquisition device, which acquires the two-dimensional image information of the multi-dimensional force sensor on one side of the multi-dimensional force sensor in a direction parallel to the first patch surface. The first coordinate plane is parallel to the second patch surface; the second coordinate plane is parallel to the first patch surface.

15. The patch positioning method for a multidimensional force sensor as described in claim 14, characterized in that, The two-dimensional image acquisition device is a 2D camera; The distance information is acquired via a distance acquisition device, wherein the distance acquisition device is a laser rangefinder or an ultrasonic rangefinder, and the distance measurement point is the detection reference point of the distance acquisition device.

Images