Force sensor and method of manufacturing the same

Abstract

This application relates to the field of sensor technology, providing a force sensor and its fabrication method. One type of force sensor has a disk-shaped structure, including four elastic beams connected between a central support platform and an outer support ring, and multiple strain gauges on the main surfaces of the four elastic beams for measuring deformation at their respective locations. The main surfaces are parallel or substantially parallel to the disk surface of the disk-shaped structure; the four elastic beams are irregularly shaped beams and are uniformly arranged circumferentially around the central support platform; each elastic beam includes a straight rod with a uniform cross-section, with both ends of each straight rod connected to the outer support ring; both ends of each straight rod are connected to the central support platform via a first connecting member and a second connecting member; the first and second connecting members are mirror-symmetric about a reference plane; the reference plane is the cross-section at the midpoint of the straight rod along its extension direction. This force sensor achieves stable signal output by constructing a pure bending beam structure.

Description

Technical Field

[0001] This application relates to the field of sensor technology, specifically to a force sensor and its fabrication method. Background Technology

[0002] Six-dimensional force and torque synchronous detection technology in three-dimensional space is widely used in many high-end intelligent manufacturing fields such as force control at the end effector of industrial robots, precision automated assembly, motion posture load monitoring, and force sensing of bionic actuators. Most of the six-dimensional force sensors currently on the market use an elastic substrate as the core force carrier and rely on strain sensing elements attached to the surface of the elastic substrate to complete the acquisition of mechanical signals.

[0003] Its basic working principle is as follows: after the elastic matrix is ​​subjected to external force and torsional torque, it produces a small amount of elastic deformation. The deformation acts on the strain sensing element, causing its electrical parameters to change accordingly. Then, the parameter change is captured by the signal acquisition circuit. Combined with the preset solution model, the forces in three orthogonal directions and the torsional torques in the corresponding three directions are separated, thereby realizing the integrated detection of six-dimensional mechanical parameters.

[0004] With the continuous development of the precision measurement and control industry, the market has placed increasingly stringent demands on the detection accuracy, batch assembly efficiency, and adaptability of six-dimensional force sensors. Existing six-dimensional force sensors still have many shortcomings in structural design and strain gauge arrangement: On the one hand, traditional strain gauge arrangements are chaotic and irregular, with spatial obstructions and inconvenient positioning. Strain gauge installation is difficult, and both manual and automated assembly are inefficient, resulting in long assembly times and hindering large-scale mass production. On the other hand, existing strain gauge layouts easily lead to severe signal coupling between different mechanical detection dimensions, with force signals from all directions superimposing and interfering with each other. Even with optimized decoupling algorithms for data correction, it is still impossible to effectively reduce detection errors caused by dimensional crosstalk, thus limiting the overall measurement accuracy of the sensor and making it unsuitable for the actual needs of high-end applications such as ultra-high precision mechanical detection and high-precision force control debugging. Summary of the Invention

[0005] This application proposes a force sensor and its fabrication method, which not only solves the above-mentioned technical problems, but also decouples the strain gauge bridge output flexibly arranged on the main surface of the force sensor in six measurement dimensions by constructing a pure bending beam structure, and enables the measurement signal to be output stably.

[0006] In a first aspect, embodiments of this application provide a force sensor with a disk-shaped structure for measuring multidimensional components of a six-dimensional force. The force sensor includes four elastic beams connected between a central support platform and an outer support ring, and multiple strain gauges on the main surfaces of the four elastic beams for measuring deformation at their respective locations. The main surfaces are parallel or substantially parallel to the disk surface of the disk-shaped structure; the four elastic beams are irregularly shaped beams and are uniformly arranged circumferentially around the central support platform; each elastic beam includes a straight rod with a uniform cross-section, and both ends of each straight rod are connected to the outer support ring; both ends of each straight rod are connected to the central support platform via a first connecting member and a second connecting member; the first connecting member and the second connecting member are mirror-symmetrical about a reference plane; the reference plane is the cross-section at the midpoint of the straight rod along its extension direction. This force sensor achieves stable output of the measurement signal by constructing a pure bending beam structure.

[0007] This embodiment also provides different connection methods for the first and second connecting members of the linear rod to be directly or indirectly connected to the central support platform, as well as a bridging scheme for the Wheatstone bridges on the linear rod and connecting members to output various measurement dimensions, respectively reflecting the axial force, lateral force, vertical force, X-axis torque, Y-axis torque, and Z-axis torque in the sensor coordinate system.

[0008] In this embodiment, the force sensor measures strain gauges of different dimensions of the Wheatstone bridge, all of which are attached to the same main surface of the disk-shaped structure. This reduces the difficulty of the pasting operation and eliminates the need for pasting strain gauges on the side of the elastic beam or on two main surfaces, as is done in existing solutions. This helps to improve the efficiency and accuracy of the pasting process.

[0009] Secondly, embodiments of this application provide a method for fabricating a force sensor, used to fabricate the force sensor of this application embodiment. The fabrication method includes the following steps: fabricating and connecting the components of the force sensor; setting multiple strain gauges at predetermined positions on the main surface of an elastic beam; and connecting each strain gauge to a calculation circuit to obtain the force sensor. Attached Figure Description

[0010] To more clearly illustrate this embodiment or existing technical solution, the drawings used in the description of the embodiment or existing technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 A front view of a force sensor provided in an embodiment of this application;

[0012] Figure 2 for Figure 1A schematic diagram of the arrangement scheme of each strain gauge on different elastic beams in the embodiment;

[0013] Figure 3 for Figure 2 A schematic diagram of the strain gauge resistance connection of a Wheatstone bridge measuring different dimensions.

[0014] Figure 4 - Figure 8 This is an example of an alternative structure for the first and second connecting members in the force sensor structure of the embodiment shown in Figure 1;

[0015] Figure 9 Figure 1 shows an example of the deformation displacement distribution of the force sensor under a single horizontal lateral force according to the embodiment.

[0016] Figure 10 shows an example of the deformation displacement distribution of the force sensor in the embodiment of Figure 1 under a single vertical force.

[0017] Figure 11 Figure 1 shows an example of the deformation displacement distribution of the force sensor under the action of a torsional moment around the horizontal longitudinal direction in the embodiment.

[0018] Figure 12 Figure 1 shows an example of the deformation displacement distribution of the force sensor under the action of a vertical torsional moment. Detailed Implementation

[0019] The term "and / or" used in this article describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A alone, A and B simultaneously, and B alone. The symbol " / " in this article indicates that the related objects are in an "or" relationship; for example, A / B means A or B.

[0020] The terms "first" and "second," etc., used in the specification and claims herein are used to distinguish different objects, not to describe a specific order of objects. For example, "first procedure" and "second procedure," etc., are used to distinguish different procedures, not to describe a specific order of procedures.

[0021] To facilitate understanding of the solutions in the embodiments of this application, the technical terms involved in this document will be explained first.

[0022] A force sensor measures a complete load applied to it, which consists of a force vector and a torque vector, each of which is decomposed along three coordinate axes (X, Y, Z). Therefore, the output of the force sensor is a six-component F. x F y F z M x M y Mz A set of.

[0023] F x Axial force refers to the force acting along the X-axis direction calibrated by the sensor.

[0024] F y Lateral force refers to the force acting along the Y-axis direction calibrated by the sensor.

[0025] F z Vertical force refers to the force acting along the Z-axis direction calibrated by the sensor. In many installation scenarios, the Z-axis is parallel to the direction of gravity, hence it is often called "vertical force".

[0026] M x The torque generated by the horizontal rotation corresponds to the force state of the measured object when it undergoes lateral flipping and swaying along this axis.

[0027] M y The torque generated by rotation about the horizontal longitudinal axis corresponds to the force state of the measured object when it pitches and oscillates up and down along this axis.

[0028] M z The torque generated by rotation about the vertical direction corresponds to the force state of the measured object when it undergoes horizontal rotation and deflection along that axis.

[0029] It is important to note that the definitions of the above terms all rely on the coordinate system defined by the force sensor itself. The force sensor's user manual will clearly specify its coordinate origin and the directions of the X, Y, and Z axes (usually indicated by arrows or colors, e.g., red for X, green for Y, and blue for Z). When using a force sensor, or when mentioning the force sensor measuring F... x F y F z M x M y M z When calculating the numerical values, it must be clear that the values ​​are based on the coordinate system defined by the force sensor itself.

[0030] The technical solution of this application will be further described in detail below with reference to the accompanying drawings and embodiments.

[0031] This application provides a force sensor with a disk-shaped structure for measuring one or more components of a six-dimensional force.

[0032] Figure 1 A front view of the disc-shaped structure is shown.

[0033] like Figure 1 As shown, the force sensor includes four elastic beams connected between the central support platform 1 and the outer support ring 2, and multiple strain gauges on the main surface of the four elastic beams for measuring the deformation at their respective locations. Figure 1 (Not shown in the image).

[0034] The main surface is a surface that is parallel or substantially parallel to the disk surface of the force sensor's disk-shaped structure. Figure 1 The front view can be a view of one of the main surfaces.

[0035] Each elastic beam consists of straight rods 31, 32, 33, and 34 with uniform cross-sections at both ends. Under working conditions, it is subjected only to opposing moment forces at both ends, forming a pure bending stress structure with no shear force and constant bending moment.

[0036] The four elastic beams are irregularly shaped beams and are evenly distributed around the central support platform in the circumferential direction.

[0037] Each straight rod 31, 32, 33, and 34 has two fixed ends connected to two of the fixed ends 21, 22, 23, and 24 respectively. Each straight rod 31, 32, 33, and 34 has two connecting members connecting it to the central support platform 1. Specifically, straight rod 31 is connected to the central support platform 1 via first connecting member and second connecting members 51 and 61; straight rod 32 is connected to the central support platform 1 via first connecting member 52 and second connecting member 62; straight rod 33 is connected to the central support platform 1 via first connecting member 53 and second connecting member 63; and straight rod 34 is connected to the central support platform 1 via first connecting member 54 and second connecting member 64.

[0038] like Figure 1 As shown, the force sensor constructs the straight rods 31, 32, 33, and 34 as a pure bending beam structure, enabling the strain gauges mounted on them to output stable measurement signals.

[0039] In some examples, the straight rods 31, 32, 33, and 34 are preferably straight rods with a uniform cross-section throughout, thereby constructing a standard pure bending beam. This ensures that the stable output measurement signal does not require additional calculations due to the irregular cross-section of the straight rod, thus reducing the computational load.

[0040] In some examples, the extension directions of two adjacent linear rods 31, 32, 33, and 34 are orthogonal to each other, which can decouple the force / torque signals output by the strain gauges mounted on them.

[0041] In some examples, the axial force F is measured. x Lateral force F y Vertical force F z X-axis torque M x Y-axis torque M y Z-axis torque M zThe measurement signals are obtained by using different Wheatstone bridges installed on one or more straight rods or connecting members. Each Wheatstone bridge includes four strain gauges, and each strain gauge measures the axial or lateral deformation of the straight rod or connecting member it is located on. Through this example, this application provides a scheme for the arrangement of Wheatstone bridge strain gauges.

[0042] In this embodiment, the measurement signal for each measurement dimension of the six-dimensional force is obtained through a Wheatstone bridge composed of a corresponding set of strain gauges. That is, six sets of strain gauges are pre-set on the four irregularly shaped elastic beams, each set forming a Wheatstone bridge. The detection value of this Wheatstone bridge is used to estimate F. x F y F z M x M y M z The value of one of the measurement dimensions.

[0043] In this embodiment, the original readings of the digital voltage of each bridge channel are approximately decoupled, corresponding to F respectively. x F y F z M x M y M z This reduces the complexity of decoupling algorithms and calibration by introducing one measurement dimension, thereby improving the accuracy of measurement results.

[0044] In this embodiment, a sufficient number of strain gauge positions can be provided through the same main surface, thus reducing the difficulty of strain gauge mounting.

[0045] Figure 2 It shows Figure 1 The embodiment shows the arrangement of each strain gauge on different elastic beams. Figure 3 It shows Figure 2 The strain gauge resistance connection schemes for measuring Wheatstone bridges in different dimensions are presented.

[0046] The following, combined with Figure 2 , Figure 3 Explanation of force sensor measurement F x F y F z M x M y M z A dimensional Wheatstone bridge bridging scheme.

[0047] In this embodiment, each strain gauge is disposed on the same main surface and mainly on four straight rods. Therefore, two of the straight rods are preferably aligned with the X-axis in the coordinate system defined by the force sensor itself, and the other two straight rods are preferably aligned with the Y-axis in the coordinate system defined by the force sensor itself. This allows for the identification of a reasonable set of positions for strain gauges on the mutually orthogonal straight rods. The strain gauges are then combined into a Wheatstone bridge, ensuring that the output signal of each Wheatstone bridge is sensitive only to the stress / torque in the measured dimension and insensitive to the stress / torque in any other measured dimension.

[0048] Measuring axial force F x The Wheatstone bridge strain gauges FxR01-FxR04 are disposed on the same main surface of two straight rods 32 and 34 extending horizontally along the sensor coordinate system; the adjacent arm strain gauges of the first Wheatstone bridge are disposed on the same straight rod; the common arm strain gauges of the Wheatstone bridge are symmetrical about the YOZ plane in the sensor coordinate system.

[0049] Measuring lateral force F y The strain gauges FyR05-FyR08 of the Wheatstone bridge are set on the same main surface of two straight rods 31 and 33 that extend horizontally in the sensor coordinate system; the adjacent arm strain gauges of the Wheatstone bridge are set on the same straight rod; the common pole strain gauges of the Wheatstone bridge are symmetrical about the XOZ plane in the sensor coordinate system.

[0050] Measuring vertical force F z The strain gauges FzR09-FzR12 of the Wheatstone bridge are respectively set on the same main surface of the four straight rods; one set of the Wheatstone bridge strain gauges is set on two straight rods extending horizontally in the sensor coordinate system and is used to measure the lateral deformation of the straight rods; the other set of the Wheatstone bridge strain gauges is set on two straight rods extending horizontally in the sensor coordinate system and is used to measure the axial deformation of the straight rods; the adjacent strain gauges of the Wheatstone bridge strain gauges are on two adjacent straight rods.

[0051] Measuring X-axis torque M x The strain gauges MxR13-MxR16 of the Wheatstone bridge are set on the same main surface of two straight rods extending horizontally in the sensor coordinate system; the strain gauges of the opposite arms of the Wheatstone bridge are set on the same straight rod and on different sides of the YOZ plane in the sensor coordinate system; the strain gauges of the adjacent arms of the Wheatstone bridge are set on the same side of the YOZ plane.

[0052] Measuring Y-axis torque M yThe strain gauges MyR17-MyR20 of the Wheatstone bridge are set on the same main surface of two straight rods extending horizontally along the sensor coordinate system; the strain gauges of opposite arms of the Wheatstone bridge are set on the same straight rod and on different sides of the XOZ plane in the sensor coordinate system; the strain gauges of adjacent arms of the Wheatstone bridge are set on the same side of the XOZ plane.

[0053] Measuring Z-axis torque M z The strain gauges MzR21-MzR24 of the sixth Wheatstone bridge are disposed on the same main surface of the two first connecting members and the two second connecting members that extend horizontally in the sensor coordinate system; the adjacent arm strain gauges of the Wheatstone bridge strain gauges are disposed on the first connecting member and the second connecting member connected to the same straight rod; the Wheatstone bridge strain gauges are disposed on different sides of the XOZ plane in the sensor coordinate system.

[0054] It should be noted that, Figure 1 In this embodiment, the outer support ring 2 is a circular closed loop, but this application is not limited to this. The outer support ring 2 can also be a square, polygonal, or irregular closed loop.

[0055] Compared with existing technologies, Figure 1 The force sensor shown has the advantages of simple structure, symmetry and easy processing; the four straight rods are constructed as a pure bending beam, which can stably output measurement signals. Figure 2 In the preferred bridging scheme shown, all strain gauges are placed on the same main surface, which reduces the difficulty of strain gauge placement.

[0056] In this embodiment, each elastic beam includes straight rods 31, 32, 33, and 34 with equal cross-sections. Under working conditions, it is only subjected to the opposite couples at both ends, forming a pure bending stress structure with no shear force and constant bending moment.

[0057] It should be noted that this embodiment shows an outer support ring 2, but this application is not limited to this. The two ends of each straight rod 31, 32, 33, 34 can be connected to two fixed ends respectively, and then fixedly connected to the outer support ring 2. Instead of being directly connected to the outer support ring 2.

[0058] In this embodiment, the strain gauge is located on the main surface of a linear rod or connecting component, specifically referring to the entire main surface of the disk-shaped force sensor, rather than the surface of a single component such as the linear rod or connecting component. For example, the strain gauge FxR02 is positioned at the middle of a main surface of a linear rod, which is a local area of ​​the overall main surface of the disk-shaped force sensor. The middle position of this linear rod surface is not equivalent to the center position of the overall main surface of the disk-shaped force sensor. This position is merely the midpoint of the corresponding area of ​​the linear rod on the overall main surface of the sensor.

[0059] It should also be noted that the force sensor in this embodiment is not limited to using all six Wheatstone bridges, but may include one or more of the above six Wheatstone bridges. The force sensor is only used to detect one or more of the six-dimensional forces.

[0060] The following combination Figure 2 and Figure 3 Note that the output of each Wheatstone bridge in this application is only sensitive to force or torque in one direction, and is not sensitive to force or torque in other directions.

[0061] Figure 3 The arrows marked on the strain gauge indicate the direction of resistance change; an upward arrow indicates increasing resistance, and a downward arrow indicates decreasing resistance. Among these, "F" indicates... x The "Wheatstone bridge" shows the increase / decrease in resistance of strain gauges FxR01-FXR04 in response to stress deformation in the positive X-axis direction; "F y The Wheatstone bridge illustrates the increase / decrease in resistance of strain gauges FyR05-FyR08 in response to stress deformation in the positive Y-axis direction; z The "Wheatstone bridge" shows the increase / decrease in resistance of strain gauges FzR09-FzR12 in response to stress deformation in the negative Z-axis direction; "M" x The "Wheatstone bridge" shows the increase / decrease in resistance of strain gauges MxR13-MxR16 in response to torque stress deformation in the negative X-axis direction; "M y The "Wheatstone bridge" shows the increase / decrease in resistance of strain gauge MyR17-R20 in response to torque stress deformation in the negative Y-axis direction; "M z The “Wheatstone bridge” shows the increase / decrease in resistance of strain gauges MzR01-MzR04 in response to torque stress deformation in the negative Z-axis direction.

[0062] F x F y F z M x M y M z The working process of each corresponding Wheatstone bridge is as follows: in each pair of adjacent arms of the four strain gauges, one strain gauge is subjected to tension and the other to compression. The resistance of the strain gauges in the two pairs of arms changes simultaneously, and the changes in the adjacent arms are opposite, which together generate a large output signal. And through simulation verification, the position of the strain gauges and the specific bridge arrangement proposed in the above description can be sensitive only to the force or torque of the measured dimension, and not sensitive to other measurement dimensions.

[0063] It should be noted that this application does not limit the first and second connecting members to conform to the requirements. Figure 1In certain forms, it can also be adopted Figure 4 - Figure 8 The alternative example shown.

[0064] Figure 4 This illustrates a case where the first and second connecting members of the same elastic beam are symmetrical about the mid-section of the connected straight rod, but are not orthogonally connected to that rod. In this example, the forces / moments in each measurement dimension can be calculated, but not as efficiently as... Figure 1 The signal in the example is strong.

[0065] Figure 5 This example illustrates a case where a reinforcing beam is included between the first and second connecting members of the same elastic beam. This example not only allows for the calculation of force / moment in each measurement dimension but also increases the range of the force sensor under the same conditions.

[0066] Figure 6 This example illustrates a scenario where the first and second connecting members of the same elastic beam are not orthogonally connected to the connected linear rod, and the first and second connecting members intersect before being connected to the central support platform 1. This example allows for the calculation of force / torque in each measurement dimension, taking into account both the measurement signal strength and the range of the force sensor.

[0067] Figure 7 The diagram shows the first and second connecting members of the same elastic beam being orthogonally connected to the straight rod, but not directly connected to the central support platform 1.

[0068] Figure 8 The diagram illustrates a situation where the first and second connecting members of the same elastic beam are orthogonally connected to the straight rod, but not directly connected to the central bearing platform 1. Instead, they are connected to the central bearing platform 1 via other force transmission members, and the two other force transmission members connecting the first and second connecting members are not symmetrical about the mid-section of the connected straight rod.

[0069] Figure 7 and Figure 8 The examples provide different variations of the first and second connecting members, all of which achieve the desired results. Figure 1 The detection results in the example.

[0070] Figure 9 , 10 , Figure 11 , Figure 12 They are shown respectively Figure 1 Examples of deformation displacement distribution of the force sensor in this embodiment under the action of a single horizontal force, a single vertical force, a torsional moment about the horizontal longitudinal direction, and a torsional moment about the vertical direction. The color depth corresponds to the degree of deformation displacement.

[0071] pass Figures 9-12The examples show that when subjected to a force / torque in a single measurement dimension, the deformation at different positions on each straight arm exhibits different patterns for that specific measurement dimension. Based on this pattern, it can be verified that… Figure 3 The operation of each Wheatstone bridge conforms to the description of the embodiments in this application.

[0072] It should be noted that this application does not limit the strain gauges in the six Wheatstone bridges to be configured as described in the above embodiments. Figure 2 The main surface visible in the front view, or Figure 2 The main surface visible in the front view is opposite to the main surface, and it is not limited to following the main surface. Figure 3 The resistor arrangement shown can be such that the upper left arm and the lower right arm are subjected to tension and compression respectively, while the upper right arm and the lower left arm are subjected to compression and tension respectively, with the resistance of the two opposing arms changing simultaneously and the adjacent arms changing in opposite directions.

[0073] It should also be noted that the references in this application apply only to F. x F y F z M x M y M z Sensitivity in one dimension does not mean that the amplitude of the measurement signal in other measurement dimensions is 0. Rather, it means that the amplitude of the measurement signal in other measurement dimensions is negligible compared to the amplitude in the corresponding measurement dimension. This is equivalent to or close to achieving decoupling of measurement signals in different measurement dimensions of six-dimensional force, thereby simplifying the decoupling algorithm and calibration complexity and improving the accuracy of measurement results.

[0074] In some examples, the strain gauges mounted on the elastic beam are either resistance strain gauges or charge strain gauges. In this example, due to the strain of the elastic beam, the resistance / charge of the strain gauge changes, which in turn changes the measurement signal. Since the strain gauge's measurement signal has different sensitivities to different forces / torques, it is possible to estimate the values ​​of each measurement dimension based on changes in resistance / charge.

[0075] In some examples, strain gauges are positioned on the elastic beam at predetermined locations using a glass micro-fusion process or a patch process. In this example, the strain gauges are securely mounted on the elastic beam, minimizing the possibility of measurement deviations caused by minute displacements between the strain gauges and the elastic beam.

[0076] In some examples, the four irregularly shaped elastic beams of the force sensor are evenly arranged around the central support platform 1. Based on the requirement of decoupling the measurement dimensions of each group of strain gauges as much as possible, and with the principle that each group of strain gauges corresponds to a single direction of force or torque sensitivity, the positions of various strain gauges are set to improve the accuracy of the measurement results.

[0077] This application provides a method for fabricating a force sensor, which includes the following steps:

[0078] Fabricate and connect the various components of the force sensor;

[0079] Multiple strain gauges are installed at preset positions on the main surface of each elastic beam;

[0080] Connect each strain gauge to the calculation circuit to obtain the force sensor.

[0081] In some examples, the fabrication method of this force sensor further includes the following steps:

[0082] The force sensor is sealed and inspected as a finished product.

[0083] Perform finished product performance testing on the force sensor;

[0084] After the finished product passes the performance test, the force sensor is packaged.

[0085] It should be noted that this application does not limit the irregular beam to be the irregular elastic beam shown in the attached drawings, but only requires that the irregular beam includes the irregular structure of the embodiment of this application, and that strain gauges be attached to the straight arm of the irregular elastic beam to reduce interference between measurement signals in various measurement dimensions and effectively reduce F. x F y F z M x M y M z The measured values ​​should be decoupled from the actual measured signals as much as possible.

[0086] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this application. It should be understood that the above description is only a specific embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A force sensor, which has a disk-shaped structure, for measuring one or more components of a six-dimensional force, characterized in that, The force sensor includes: Outer support ring; Central support platform; Four elastic beams are connected between the central support platform and the outer support ring, and these four elastic beams generate strain when the central support platform is displaced relative to the outer support ring; and Multiple strain gauges are disposed at predetermined positions on the main surfaces of the four elastic beams and configured to generate measurement signals in response to the strain. The main surface is a surface that is parallel or substantially parallel to the disk surface of the disk-shaped structure. The four elastic beams are irregularly shaped beams and are evenly distributed around the central support platform in the circumferential direction. Each elastic beam includes a straight rod with a uniform cross-section; both ends of each straight rod are connected to the outer support ring; both ends of each straight rod are connected to the central support platform via a first connecting member and a second connecting member; the first connecting member and the second connecting member are mirror-symmetric about a reference plane; the reference plane is the cross-section at the midpoint of the straight rod along its extension direction.

2. The force sensor according to claim 1, characterized in that, The extension directions of two adjacent straight rods are orthogonal to each other.

3. The force sensor according to claim 1, characterized in that, The measurement signals for axial force, lateral force, vertical force, and torque around the X, Y, and Z axes in the sensor coordinate system are obtained by different Wheatstone bridges set on the linear rod or connecting component. Each Wheatstone bridge includes four strain gauges, and each strain gauge measures the axial or lateral deformation of the linear rod or connecting component it is located on.

4. The force sensor according to claim 1, characterized in that, One end of the first connecting member and the second connecting member are orthogonally connected to a straight rod on the same elastic beam.

5. The force sensor according to claim 4, characterized in that, The first connecting member and the second connecting member are not connected to one end of the straight rod, but are indirectly connected to the central bearing platform through other force transmission members.

6. The force sensor according to any one of claims 1 to 5, characterized in that, The strain gauges of the first Wheatstone bridge for measuring axial force are set on the same main surface of two straight rods extending horizontally longitudinally along the sensor coordinate system; The adjacent strain gauges of the first Wheatstone bridge are mounted on the same straight rod. The strain gauges of the common arms of the first Wheatstone bridge are symmetrical about the YOZ plane in the sensor coordinate system.

7. The force sensor according to any one of claims 1 to 5, characterized in that, The strain gauges of the second Wheatstone bridge for measuring lateral force are set on the same main surface of two straight rods that extend laterally in the horizontal direction along the sensor coordinate system; The adjacent strain gauges of the second Wheatstone bridge are mounted on the same straight rod. The common-arm strain gauges of the second Wheatstone bridge are symmetrical about the XOZ plane in the sensor coordinate system.

8. The force sensor according to any one of claims 1 to 5, characterized in that, The strain gauges of the third Wheatstone bridge for measuring vertical force are respectively set on the same main surface of the four straight bars; The third Wheatstone bridge strain gauge has a set of paired strain gauges set on two straight rods that extend horizontally in the sensor coordinate system, and is used to measure the lateral deformation of the straight rods. The other set of strain gauges of the third Wheatstone bridge strain gauge is set on two straight rods extending horizontally along the sensor coordinate system, and is used to measure the axial deformation of the straight rods. The adjacent strain gauges of the third Wheatstone bridge strain gauge are located on two adjacent straight rods.

9. The force sensor according to any one of claims 1 to 5, characterized in that, The strain gauges of the fourth Wheatstone bridge, which measure the torque around the X-axis in the sensor coordinate system, are set on the same main surface of two straight rods that extend horizontally in the sensor coordinate system. The strain gauges of the fourth Wheatstone bridge strain gauge are mounted on the same straight rod and on different sides of the YOZ plane in the sensor coordinate system. The adjacent strain gauges of the fourth Wheatstone bridge strain gauge are located on the same side of the YOZ plane.

10. The force sensor according to any one of claims 1 to 5, characterized in that, The strain gauges of the fifth Wheatstone bridge, which measures the torque about the Y-axis in the sensor coordinate system, are set on the same main surface of two straight rods that extend horizontally along the sensor coordinate system. The strain gauges of the fifth Wheatstone bridge strain gauge are mounted on the same straight rod and on different sides of the XOZ plane in the sensor coordinate system. The adjacent strain gauges of the fifth Wheatstone bridge strain gauge are located on the same side of the XOZ plane.

11. The force sensor according to any one of claims 1 to 5, characterized in that, The strain gauges of the sixth Wheatstone bridge, which measures the torque about the Z-axis in the sensor coordinate system, are set on the same main surface of the two first connecting members and the two second connecting members that extend horizontally in the sensor coordinate system. The adjacent strain gauges of the sixth Wheatstone bridge strain gauge are disposed on the first and second connecting members connected to the same straight rod. The adjacent strain gauges of the sixth Wheatstone bridge strain gauge are located on different sides of the XOZ plane in the sensor coordinate system.

12. A method for preparing a force sensor as described in any one of claims 1 to 11, characterized in that, Includes the following steps: Prepare and connect the components of the force sensor; The plurality of strain gauges are positioned at predetermined locations on the elastic beam; Connect each strain gauge to the calculation circuit to obtain the force sensor.

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