Strain generating structure and force sensor

Abstract

The present application provides a strain generating structure and a force sensor. The strain generating structure includes: at least one strain body, the strain body is configured to generate strain under the action of an external force; wherein, at least one concave-convex structure is formed on the surface of at least one strain body, the concave-convex structure has a concave portion and a convex portion adjacent to the concave portion, and the convex portion of at least one concave-convex structure is provided with at least one strain gauge, and the strain gauge is configured to sense the strain generated by the strain body; and the strain generating structure has a reference plane perpendicular to its axis, and each strain gauge of the strain generating structure is arranged parallel to the reference plane. The above-mentioned strain generating structure can attach each strain gauge to a plane that is convenient for machine operation and take into account the detection performance of the six-dimensional force sensor.

Description

Technical Field

[0001] The present invention relates to the field of force sensing technology, and in particular to a strain generating structure and a force sensor. Background Art

[0002] With the continuous deepening of artificial intelligence technology research, more and more platforms equipped with artificial intelligence technology have been rapidly developed. Among them, the robotics industry, as the top of the pyramid in the industrial field, has gradually become a hot spot for development and research in recent years with the help of artificial intelligence technology. The humanoid robot field in the robotics industry is the best platform for artificial intelligence. The humanoid robot and its supporting parts industry are developing rapidly, and it is expected to become another large-scale, platform-based, high-value-added emerging industry after the new energy vehicle industry.

[0003] There are still many technical challenges in the process of humanoid robot industrialization, one of which is the development, design and large-scale production of six-dimensional space force sensors. Six-dimensional force sensors can collect forces in the three directions of spatial coordinates X, Y, and Z and torques around these three axes. In principle, six-dimensional force sensors mostly use the resistance change effect after the resistance strain gauge is deformed to build a Wheatstone bridge and collect the voltage change on the bridge, so as to obtain the corresponding relationship between the output voltage and strain, and then determine the corresponding relationship between the output voltage and force and / or torque through calibration technology.

[0004] However, due to the high technical threshold of the application scenario, the six-dimensional force sensor has not been involved in the civilian field, the product usage is insufficient, and it is impossible to form large-scale production, so the unit price of the product has remained high. Humanoid robots have the potential for large-scale industrialization. At the same time, in order to match the industry characteristics of humanoid robots in the civilian field, it is necessary to develop a new six-dimensional force sensor to reduce the production difficulty of the six-dimensional force sensor, improve the product yield, and take into account the product performance and technical indicators of the six-dimensional force sensor. Summary of the invention

[0005] Based on this, the present invention aims to provide an improved strain generating structure and force sensor to solve at least one of the above problems.

[0006] In a first aspect, the present application provides a strain generating structure, comprising at least one strain body, wherein the strain body is configured to generate strain under the action of an external force;

[0007] Wherein, at least one concavo-convex structure is formed on the surface of at least one of the strain bodies, the concavo-convex structure having a concave portion and a convex portion adjacent to the concave portion, and at least one strain gauge is disposed on the convex portion of at least one of the concavo-convex structures, and the strain gauge is configured to sense the strain generated by the strain body;

[0008] Furthermore, the strain generating structure has a reference plane perpendicular to its axis, and each strain gauge of the strain generating structure is arranged parallel to the reference plane.

[0009] The above-mentioned strain generating structure, on the one hand, sets all strain gauges parallel to the reference plane, so that the subsequent patch process can be completed by machine, which greatly reduces the production difficulty and improves the production efficiency and product yield of the six-dimensional force sensor; on the other hand, by forming a concave-convex structure on the surface of the strain body provided with the strain gauge, when the external force is transmitted, the strain body has different stress distributions at the concave position and the convex position of the concave-convex structure, so that the strain body close to the concave part occurs smaller strain, and the strain body far from the concave part occurs larger strain. At this time, the strain gauge located at the convex part of the concave-convex structure can obtain a certain degree of available strain and output an electrical signal with a certain strength. This is conducive to ensuring the detection performance of the six-dimensional force sensor while each strain gauge is set parallel to the reference plane.

[0010] In a second aspect, the present application provides a strain generating structure, comprising: at least one strain body, which is configured to generate strain under the action of an external force; wherein, at least one of the strain bodies has at least one target surface perpendicular to the axis of the strain generating structure, at least one of the target surfaces is formed with at least one recessed portion and at least one strain gauge is provided in the non-recessed portion, and the strain gauge is configured to sense the strain generated by the strain body; and the strain gauge is not provided on the non-target surface of each of the strain bodies.

[0011] In the above-mentioned strain generating structure, on the one hand, strain gauges are only arranged at the non-depressed position of the target surface where the strain body is perpendicular to the axis of the strain generating structure, and no strain gauges are arranged on the non-target surface. In this way, the subsequent patch process can be completed by a machine, which greatly reduces the production difficulty and improves the production efficiency and product yield of the six-dimensional force sensor; on the other hand, by forming a depressed portion on the target surface where the strain gauge is arranged, the strain body has different stress distributions at the depressed portion and the non-depressed portion when external force is transmitted, thereby making the strain generated by the strain body close to the depressed portion smaller, and the strain generated by the strain body far away from the depressed portion larger. At this time, the strain gauge on the target surface outside the depressed portion can obtain a certain degree of available strain and thus output an electrical signal with a certain strength, which is conducive to ensuring the detection performance of the six-dimensional force sensor while all strain gauges are arranged on the target surface.

[0012] In a third aspect, the present application provides a strain generating structure, comprising a first rigid body, a second rigid body, and at least one strain body connected between the first rigid body and the second rigid body, the strain body being configured to generate strain under the action of an external force; wherein the strain body, and a portion of the first rigid body and a portion of the second rigid body connected to the strain body together form a passage for transmitting force and / or torque between the first rigid body and the second rigid body, at least one of the passages being formed with at least one recessed portion and at least one strain gauge being provided in the non-recessed portion; wherein the strain gauge is located on the strain body and is configured to sense the strain generated by the strain body; the strain generating structure has a reference plane perpendicular to its axis, and each of the strain gauges of the strain generating structure is arranged parallel to the reference plane.

[0013] The above-mentioned strain generating structure, on the one hand, sets all strain gauges parallel to the reference plane, so that the subsequent patch process can be completed by machine, which greatly reduces the production difficulty and improves the production efficiency and product yield of the six-dimensional force sensor; on the other hand, by forming at least one recessed portion on the path used to transmit the force and / or torque between the first rigid body and the second rigid body and providing at least one strain gauge in the non-recessed portion, the strain generated by the strain body close to the recessed portion is smaller, and the strain generated by the strain body away from the recessed portion is larger. At this time, the strain gauges located outside the recessed portion can obtain a certain degree of available strain and output an electrical signal with a certain strength. This is conducive to ensuring the detection performance of the six-dimensional force sensor while each strain gauge is set parallel to the reference plane.

[0014] In a fourth aspect, the present application provides a strain generating structure, comprising: at least one strain body, including a strain beam, wherein the strain beam is configured to generate strain under the action of an external force; wherein, at least one of the strain bodies is formed with at least one recessed portion on its surface and at least one strain gauge is provided in the non-recessed portion, each of the strain gauges is provided on the strain beam and is configured to sense the strain generated by the strain beam; and, the recessed portion satisfies the following relationship: 0.001H≤D≤0.8H, A≥W, wherein D represents the depth of the recessed portion, A represents the width of the recessed portion, H represents the height of the strain beam, and W represents the width of the strain beam; and, the strain generating structure has a reference plane perpendicular to its axis, and each of the strain gauges of the strain generating structure is arranged parallel to the reference plane.

[0015] The above-mentioned strain generating structure, on the one hand, sets all strain gauges parallel to the reference plane, so that the subsequent patch process can be completed by machine, which greatly reduces the production difficulty and improves the production efficiency and product yield of the six-dimensional force sensor; on the other hand, by forming a recessed portion on the surface of the strain beam on which the strain gauge is provided, and making the recessed portion satisfy the above-mentioned relationship, when the external force is transmitted, the strain body has different stress distributions at the recessed portion and the non-recessed portion, thereby making the strain beam close to the recessed portion smaller and the strain beam far from the recessed portion larger. At this time, the strain gauge located at the non-recessed portion can obtain a certain degree of available strain and output an electrical signal with a certain strength, which is conducive to ensuring the detection performance of the six-dimensional force sensor while each strain gauge is set parallel to the reference plane.

[0016] In a fifth aspect, the present application provides a method for preparing a strain generating structure, wherein the strain generating structure comprises at least one strain body, a first rigid body connected to one end of the strain body, and a second rigid body connected to one end of the strain body away from the first rigid body;

[0017] The preparation method comprises: opening at least one through groove on a substrate to form the first rigid body and the second rigid body which are spaced apart and at least one strain body connecting the first rigid body and the second rigid body; thinning a partial area on the strain body to form at least one concave-convex structure; attaching all strain gauges to the convex part of at least one concave-convex structure parallel to a reference plane; wherein the strain gauge is configured to sense the strain generated by the strain body, and the reference plane is perpendicular to the axis of the strain generating structure.

[0018] The preparation method of the above-mentioned strain generating structure, on the one hand, can greatly reduce the difficulty of patching by attaching all strain gauges on the strain body parallel to a reference plane, thereby improving the production efficiency and product yield of the six-dimensional force sensor; on the other hand, by thinning the partial area of ​​the corresponding variant, a concave-convex structure is formed on the surface of the strain body provided with the strain gauge, so that when the external force is transmitted, the strain body has different stress distributions at the concave position and the convex position of the concave-convex structure, thereby making the strain of the strain body close to the concave part smaller, and the strain of the strain body far away from the concave part larger. At this time, the strain gauge located at the convex part of the concave-convex structure can obtain a certain degree of available strain and output an electrical signal with a certain strength, which is conducive to ensuring the detection performance of the six-dimensional force sensor while each strain gauge is arranged parallel to the reference plane.

[0019] In a sixth aspect, the present application provides a force detection module, comprising any strain generating structure as described above and a measurement circuit coupled to each strain gauge in the strain generating structure, the measurement circuit being configured to measure the direction and magnitude of the force and / or torque exerted on the strain generating structure based on an electrical signal from at least one of the strain gauges.

[0020] In a seventh aspect, the present application provides a force sensor comprising any force detection module as described above.

[0021] In an eighth aspect, the present application provides a robot, comprising a force sensor as described above, which is arranged at at least one joint position of the robot or at a mechanical arm or mechanical pull rod position. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the implementation methods of this specification or the technical solutions in the prior art, the drawings required for use in the implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some implementation methods recorded in this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0023] Figure 1 A top view of a strain generating structure according to an embodiment of the present application;

[0024] Figure 2 It is a side view schematic diagram of a first concave-convex structure of an embodiment of the present application;

[0025] Figure 3 A side view schematic diagram of a second concave-convex structure according to an embodiment of the present application;

[0026] Figure 4 A side view schematic diagram of a third concave-convex structure according to an embodiment of the present application;

[0027] Figure 5 It is a side view schematic diagram of a fourth concave-convex structure of an embodiment of the present application;

[0028] Figure 6 A schematic side view of a combined recessed portion according to an embodiment of the present application;

[0029] Figure 7 A top view of a strain generating structure according to another embodiment of the present application;

[0030] Figure 8 A schematic side view of a combined protrusion according to an embodiment of the present application;

[0031] Fig. 9 A reference plane schematic diagram of an embodiment of the present application;

[0032] Fig.10 is a schematic diagram of each orthographic projection on a reference plane according to an embodiment of the present application;

[0033] Fig.11 A top view of a strain generating structure according to another embodiment of the present application;

[0034] Fig.12 A schematic side view of a strainer according to an embodiment of the present application;

[0035] Fig.13 This is a schematic diagram of the structure of the first specific embodiment of the present application;

[0036] Fig.14 The figure shows the deformation of the strain beam when the strain generating structure of the first specific embodiment is subjected to a force / torque parallel to the XY plane;

[0037] Fig.15 The figure shows the deformation of the strain beam when the strain generating structure of the first specific embodiment is subjected to a force / torque perpendicular to the XY plane;

[0038] Fig.16 This is a schematic diagram of the structure of the second specific embodiment of the present application;

[0039] Fig.17 It is a side view schematic diagram of various variants of the strain beam of the optional implementation mode 3 of the present application;

[0040] Fig.18 A schematic diagram of the types and connection patterns of the resistance strain gauges of the optional fourth implementation mode of the present application;

[0041] Fig.19 A top view of a strain generating structure according to another embodiment of the present application;

[0042] Fig. 20 for Fig.19 A magnified schematic diagram of the K portion;

[0043] Fig.21 This is a schematic diagram of the structure of a PCB board according to an embodiment of the present application;

[0044] Fig. 22 Schematic diagram of wire binding of a force detection module according to an embodiment of the present application. DETAILED DESCRIPTION

[0045] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0046] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0047] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0048] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0049] In the process of implementing the present invention, the inventors found that the traditional six-axis force sensor has the following problems:

[0050] 1. Low production efficiency and low yield: The elastic component of the six-dimensional force sensor is used to bear multi-dimensional forces and moments, and transfer the deformation to the resistance strain gauge through the beam structure. It is the core part of the mechanical structure design of the six-dimensional force sensor. The elastic component has developed into a variety of structures, such as T-beam structure, four-beam structure, eight-beam structure, E-type membrane structure, three-beam structure, etc. Among them, the three-beam structure has the advantages of structural stability, low processing difficulty, and the ability to achieve miniaturization. It has gradually become the mainstream application structure in current commercial products. However, the current three-beam structure requires that the four sides of each strain beam need to be mounted with resistance strain gauges. The resistance strain gauges on the opposite side of each strain beam are connected in series to form a half bridge, and the resistance strain gauges on the side must be mounted manually, resulting in low production efficiency and low yield of the product.

[0051] 2. Low product adaptability: Currently, commercial products of six-dimensional force sensors mostly use silicon-based semiconductor materials as the substrate of resistance strain gauges. Silicon-based semiconductor materials have the advantages of strong tensile strength, high sensitivity coefficient, and stable properties. However, the difficulty lies in the high processing and production difficulties, which require the use of chip slicing, photolithography, corrosion, vapor deposition and other processes. Therefore, the resistance strain gauges currently used in six-dimensional force sensors are mostly batch products purchased from outside. Such products are all single resistors with low integration and long axial dimensions, and are poorly adapted to six-dimensional force sensor products.

[0052] Based on the above problems, the present application designs a new six-dimensional force sensor through the following inventive concepts: first, each strain gauge on the elastic component is attached to a plane that is convenient for machine operation; second, the structure of the elastic component is improved so that when external force is transmitted, the elastic component can generate a strain on the attached surface of the strain gauge that is sufficient to be utilized by the bridge circuit constructed by the strain gauge; finally, the strain formed on the attached surface of the strain gauge under the influence of external force has a definite change trend.

[0053] Based on the aforementioned inventive concept, an embodiment of the present application provides an improved strain generating structure. By setting all strain gauges parallel to the reference plane, a subsequent patch process can be completed by a machine, which greatly reduces the production difficulty and improves the production efficiency and product yield of the six-dimensional force sensor. In addition, by forming a concave-convex structure on the surface of the strain body provided with strain gauges, when external force is transmitted, the strain body has different stress distributions at the concave position and the convex position of the concave-convex structure, so that the strain body close to the concave part generates smaller strain, and the strain body far away from the concave part generates larger strain. At this time, the strain gauge located at the convex part of the concave-convex structure can obtain a certain degree of available strain and output an electrical signal with a certain strength. This is conducive to ensuring the detection performance of the six-dimensional force sensor while each strain gauge is set parallel to the reference plane.

[0054] like Figure 1 and Figure 2As shown, an embodiment of the present application provides a strain generating structure 100, including at least one strain body 110, which is configured to generate strain under the action of an external force; wherein, at least one concave-convex structure 111A is formed on the surface of at least one strain body 110, and the concave-convex structure 111A has a concave portion 111A1 and a convex portion 111A2 adjacent to the concave portion 111A1, and the convex portion 111A2 of at least one concave-convex structure is provided with at least one strain gauge 112, and the strain gauge 112 is configured to sense the strain generated in the strain body 110; and, the strain generating structure 100 has a reference plane P1 perpendicular to its axis AX1, and each strain gauge 112 of the strain generating structure 100 is arranged parallel to the reference plane P1.

[0055] For example, the concave portion 111A1 in the concave-convex structure 111A represents a concave portion of the surface of the strain body 110, and the convex portion 111A2 represents a convex portion of the surface of the strain body 110 relative to the concave portion 111A1. Figures 2 to 5 It can be seen that the height of any point on the bottom or side of the concave portion 111A1 is lower than the height of any point on the top of the convex portion 111A2, and in the absence of a boundary, the concave portion 111A1 can extend in a direction away from the convex portion 111A2, and the convex portion 111A2 can extend in a direction away from the concave portion 111A1. Figure 3 As shown, the side and bottom surfaces of the concave portion 111A1 are both flat surfaces, and the side surface of the concave portion 111A1 is set at an angle to the reference plane P1. The angle α between the two surfaces can be greater than 0° and less than 180°. In particular, when the angle is 90°, the concave portion 111A1 and the convex portion 111A2 form a Figure 2 The concave-convex structure shown; optionally, as Figure 4 As shown, the surface of the concave portion 111A1 may also be a curved surface; optionally, the surface of the concave portion 111A1 is smoothly connected to the surface of the convex portion 111A2, in which case at least one of the surfaces of the concave portion 111A1 and the convex portion 111A2 is a curved surface, such as Figure 5 As shown, the surface of the concave portion 111A1 and the surface of the convex portion 111A2 are both curved and smoothly connected; optionally, the concave-convex structure can also be a notch formed on the edge of the strain body 110 (not shown in the figure). By forming a concave portion 111A1 on the surface of at least one strain body 110, a more concentrated stress distribution can be formed in the strain body 110 corresponding to the concave portion 111A1 when an external force is introduced, so that the strain on the convex portion close to the concave portion 111A1 is less than the strain on the convex portion 111A2 far from the concave portion 111A1. At this time, the strain gauge 112 provided on the convex portion 111A2 can obtain a certain degree of available strain of the strain body 110, and then output a voltage signal through the bridge circuit, and make the output voltage change in direct proportion to the force applied to the strain generating structure 100.

[0056] Exemplarily, a plurality of strain gauges are arranged on the convex part of at least one concave-convex structure, wherein at least two strain gauges are arranged at intervals. By arranging at least two strain gauges at intervals, it is convenient to detect forces and moments in different directions. Figure 1 As shown in the figure, at least one concave-convex structure 111A is formed on the surface of the strain body 110 at the lower right, and two strain gauges 112 are arranged at intervals on the convex part 111A2 of the concave-convex structure 111A in a direction perpendicular to the radial direction of the strain generating structure 100, which is conducive to making full use of the lateral space of the strain body 110 and reducing the volume of the strain generating structure 100. Figure 7 As shown, at least one concave-convex structure 111A is formed on the surface of the variant 110 on the lower right, and two strain gauges 112 are sequentially arranged at intervals in the radial direction of the strain generating structure 100 on the convex portion 111A2.

[0057] For example, Figure 1 and Figure 6 As shown, when a plurality of concave-convex structures are formed on the surface of the strain body 110, the concave portions 111A1 of at least one pair of adjacent concave-convex structures 111A can be connected or integrated to form a combined concave portion with convex portions on both sides, and at least one strain gauge is disposed on the convex portions on one side or both sides of at least one combined concave portion. Figure 6 It can be seen that the two sides of the combined concave portion are respectively bounded by the convex portions 111A2 of the two concave-convex structures 111A, thereby limiting the length of the combined concave portion. Figure 7 As shown, the combined recessed portion may be a first groove 111 that crosses the surface of the strain body 110, or a second groove 114 that forms an opening on the surface of the strain body 110. Figure 7 It can be seen that the two side walls of the second groove 114 have a first arc structure, which is beneficial to avoid stress concentration and transfer more stress to the strain body 110, and is also beneficial to improving the overload resistance of the strain generating structure 100.

[0058] Further, such as Figure 7 and Figure 8As shown, when a plurality of combined recesses are formed on the surface of the strain body 110, the protrusions between at least one pair of adjacent combined recesses can be connected or integrated to form a combined protrusion 113, and at least two strain gauges 112 are arranged on the combined protrusion 113 at intervals. In this way, it is beneficial to detect forces and moments in different directions, and it is also beneficial for the strain gauge 112 to obtain more available strains, thereby improving the detection accuracy of the six-dimensional force sensor. Furthermore, at least two strain gauges 112 are arranged on the combined protrusion 113 in sequence and at intervals along the arrangement direction of the pair of combined recesses. In this way, it is beneficial to make full use of the strain distribution brought by the combined recesses to achieve effective detection of forces and moments; at the same time, such an arrangement method can make the strain body 110 narrower, so that the strain body 110 is more susceptible to strain, which is convenient for measuring smaller forces and / or moments. For example, see Figure 8 It can be seen that the two sides of the combined protrusion 113 are respectively bounded by the combined concave portion 111 and the combined concave portion 114, so that the length of the combined protrusion 113 can be limited. In addition, the "integrally formed" described in the present application can be expressed as integrally formed.

[0059] Exemplarily, the strain gauge 112 may include one or more Wheatstone bridges. When a plurality of Wheatstone bridges are included, the distribution form of the plurality of Wheatstone bridges may be arbitrarily placed or each may be at an irregular angle, such as being distributed up and down or left and right. The Wheatstone bridge may be one of a Wheatstone full bridge circuit, a Wheatstone half bridge circuit, and a Wheatstone quarter bridge circuit. When the Wheatstone bridge is a Wheatstone full bridge circuit, a greater output voltage may be obtained. In particular, when the Wheatstone bridge is a Wheatstone half bridge circuit, a Wheatstone full bridge circuit may be constructed in combination with the circuit and resistor on the six-dimensional force sensor circuit board, or a Wheatstone half bridge circuit may be directly used without construction; when the Wheatstone bridge is a Wheatstone quarter bridge circuit, a Wheatstone full bridge circuit or a Wheatstone half bridge circuit may be constructed in combination with the circuit and resistor on the six-dimensional force sensor circuit board, and of course a Wheatstone quarter bridge circuit may be directly used without construction.

[0060] Exemplarily, the Wheatstone bridge can be composed of several resistance strain gauges. From the perspective of composition structure, the resistance strain gauge can include at least one of a single resistance strain gauge, a half-bridge resistance strain gauge, and a full-bridge resistance strain gauge, wherein the integration of the full-bridge resistance strain gauge is greater than that of the half-bridge resistance strain gauge, and the integration of the half-bridge resistance strain gauge is greater than that of the single resistance strain gauge. The higher the integration of the strain gauge, the more conducive it is to adapting to the small space and high-precision installation requirements of the six-dimensional force sensor. Specifically, the single resistance strain gauge includes a resistor and an upper pad and a lower pad respectively connected to the opposite ends of the resistor; the half-bridge resistance strain gauge includes two resistors connected in series through a middle pad and an upper pad and a lower pad respectively connected to the opposite ends of the two series resistors; the full-bridge resistance strain gauge includes two half-bridge resistance strain gauges connected in series through a bridge pad. Therefore, "the strain gauge is set parallel to the reference plane" can be expressed as the distribution surface of each resistor in the strain gauge is parallel to the reference plane, and because each resistor in the strain gauge is set on the convex part of the concave-convex structure, it can further ensure that the formation surface of the concave part and the setting surface of the strain gauge are the same surface, thereby taking into account the detection performance of the six-dimensional force sensor and the full-plane setting requirements of the strain gauge. On the other hand, when a highly integrated resistance strain gauge (half-bridge resistance strain gauge or full-bridge resistance strain gauge) is used for full-bridge assembly, it can not only ensure the consistency of the resistance value, but also eliminate the influence of temperature on the measurement; combined with the subsequent same-surface printing glue brushing process, the glue brushing thickness at different target positions can be guaranteed to be consistent, which is conducive to further reducing the error of the full-bridge circuit, thereby greatly improving the detection accuracy of the six-dimensional force sensor.

[0061] In some embodiments of the present application, Fig. 9 and Fig.10 As shown, the strain generating structure 100 has a reference plane P2 parallel to the external force input end face of the strain body 110, the external force input end face 115 of the strain body having at least one concave-convex structure has a first orthographic projection S1 on the reference plane P2, and the cross section of the strain body 110 corresponding to the concave portion 111A1 of at least one concave-convex structure 111A has a second orthographic projection S2 on the reference plane P2, and the first orthographic projection S1 covers the second orthographic projection S2. In this way, it is beneficial to ensure that the stress distribution on the surface where the strain gauge is set after the external force is transmitted to the strain body 110 is affected by the concave portion 111A1, forming a stress distribution (strain distribution) with small stress (small strain) close to the concave portion 111A1 and large stress (large strain) away from the concave portion 111A1. If the first orthographic projection S1 does not cover the second orthographic projection S2, it is easy to affect the stress distribution on the surface where the strain gauge is set, which will further affect the detection accuracy of the six-dimensional force sensor. Further, as Fig. 9 and Fig.10As shown, the cross section of the strain body 110 corresponding to the convex portion 111A2 of at least one concave-convex structure 111A has a third orthographic projection S3 on the reference plane P2, and the first orthographic projection S1 covers the third orthographic projection S3. Since the second orthographic projection S2 of the cross section of the strain body 110 corresponding to the concave portion 111A1 on the reference plane P2 is obviously smaller than the third orthographic projection S3 of the cross section of the strain body 110 corresponding to the convex portion 111A2 on the reference plane P2, by making the third orthographic projection S3 covered by the first orthographic projection S1, it is helpful to further ensure the strain distribution brought by the concave portion 111A1 when external force is introduced.

[0062] In some embodiments of the present application, see Figure 1 , the depression depth of the concave portion 111A1 of the concave-convex structure 111A is less than or equal to the first preset value. In principle, as the depression depth of the concave portion 111A1 increases, the small strain area on the surface of the strain body 110 gradually increases, which will eventually lead to insufficient available strain on the convex portion 111A2. Therefore, the depression depth of the concave portion 111A1 will have an upper limit value (i.e., the first preset value) to avoid the small strain area formed on the surface of the strain body 110 being too large. Optionally, the depression depth represents the height difference between the lowest point of the concave portion and the lowest point of the convex portion in a concave-convex structure. Optionally, the depression depth D of the concave portion 111A1 can be determined according to the height of the strain body 110 (i.e., the thickness of the strain body 110 along the z direction). Optionally, as Figure 1 As shown, when a combined recess 111 is formed on the strain body 110 , the width of the combined recess 111 may be determined according to the width of the strain body 110 , wherein the width refers to the length perpendicular to the radial direction of the strain generating structure 100 .

[0063] In some embodiments of the present application, see Figure 1 , in at least one strain gauge 112, the distance between the resistor of the concave portion 111A1 closest to the corresponding concave-convex structure 111A and the concave portion 111A1 is less than or equal to the second preset value. In this way, the resistor in the strain gauge 112 will not be too far away from the concave portion 111A1, ensuring that the resistor of the concave portion 111A1 closest to the corresponding concave-convex structure 111A is located in the small strain area formed on the surface of the strain body 110, thereby ensuring that the strain gauge 112 obtains a certain degree of available strain, thereby achieving effective detection of force and torque.

[0064] In some embodiments of the present application, see Figure 1, in at least one strain gauge 112, the distance between the resistor of the concave portion 111A1 farthest from the corresponding concave-convex structure 111A and the concave portion 111A1 is greater than or equal to the third preset value. Affected by the concave portion 111A1, the strain on the surface of the strain body 110 decreases in the direction close to the concave portion 111A1 and increases in the direction away from the concave portion 111A1. Thus, through the above arrangement, the resistor of the concave portion 111A1 farthest from the corresponding concave-convex structure 111A is located in the large strain area formed on the surface of the strain body 110, thereby ensuring that the strain gauge 112 obtains a certain degree of available strain, and realizes effective detection of force and torque.

[0065] In some embodiments of the present application, see Figure 7 , the strain body 110 has a concavo-convex structure 111A and a concavo-convex structure 111B, and at least one strain gauge 112 is arranged on a combined convex part 113 formed by connecting or integrating the convex parts of the two; wherein, the distance between at least one resistor in at least one strain gauge 112 and the center of the combined convex part 113 is less than or equal to a fourth preset value. Since at least one strain gauge 112 is arranged on the combined convex part 113 (located between the two concave parts), the strain in the central area of ​​the combined convex part 113 is the largest when the external force is transmitted to the strain body 110, so that the above arrangement can ensure that at least one resistor in the strain gauge 112 is located in the central area of ​​the combined convex part 113 with the largest strain, thereby ensuring that the strain gauge 112 obtains a certain degree of available strain, and realizes effective detection of force and torque.

[0066] In some embodiments of the present application, the strain body 110 has a first surface and a second surface that are arranged opposite to each other and parallel to the reference plane P1, and at least one concave-convex structure is formed on the first surface and / or the second surface, and at least one strain gauge 112 is provided on the convex portion 111A2 of at least one concave-convex structure 111A of each strain body 110. In this way, it is beneficial to fully utilize the strain distribution brought by the concave portion 111A1, increase the number of strain gauges 112, and further improve the detection accuracy of the six-dimensional force sensor, and at the same time, it can also meet the full-plane setting requirements of the strain gauge 112, and improve production efficiency and product yield.

[0067] In some embodiments of the present application, see Figure 1 and Figure 7The strain generating structure further includes: a first rigid body 120 connected to one end of the strain body 110; a second rigid body 130 connected to one end of the strain body 110 away from the first rigid body 120; and at least one through groove 140, which is opened between the first rigid body 120 and the second rigid body 130 and is alternately arranged with the strain body 110 along the circumferential direction of the strain generating structure 100; wherein, when the force and / or torque between the first rigid body 120 and the second rigid body 130 is transmitted to the strain body 110, the strain body 110 is strained. Optionally, the first rigid body 120 can be connected to an external fixing member, and the second rigid body 130 can be connected to an external loading member, and it is ensured that there is no coupling between the first rigid body 120 and the second rigid body 130 when no force is loaded. In this way, by applying a force to the first rigid body 120 and the second rigid body 130, a relative movement trend can be generated between the first rigid body 120 and the second rigid body 130, so that the force and / or torque between the first rigid body 120 and the second rigid body 130 is transmitted to the strain body 110, causing the strain body 110 to be strained.

[0068] Optionally, the first rigid body 120, each strain body 110, and the second rigid body 130 are integrally formed. Optionally, an elastic material can be used as a base material to prepare the strain generating structure 100. Optionally, the elastic material can be one of stainless steel, aviation aluminum, and titanium alloy. In this way, on the one hand, the above-mentioned elastic material can ensure the sensitivity of strain sensing, and on the other hand, the one-piece molded structure is also conducive to ensuring the overload resistance of the strain generating structure 100. In addition, when stainless steel is used for preparation, the preparation cost of the strain generating structure 100 is lower than that of aviation aluminum and titanium alloy, so it is conducive to the industrial preparation of six-dimensional force sensors. It can be understood that the first rigid body 120, each strain body 110, and the second rigid body 130 can also be independent components, and the strain generating structure 100 is formed by connection.

[0069] Optionally, the through slot 140 has a first slot wall at the first rigid body 120, and the through slot 140 has a second slot wall at the second rigid body 130; wherein the profile of at least part of the second slot wall matches the profile of at least part of the first slot wall. In this way, destructive interference will not occur between the first slot wall and the second slot wall under overload conditions, thereby facilitating the overload resistance of the strain generating structure 100 and extending the service life of the six-dimensional force sensor.

[0070] Optionally, the strain body 110 includes an elastic structure and a strain beam connected to the elastic structure; wherein one end of the elastic structure is connected to the first rigid body, the other end away from the first rigid body is connected to the strain beam, and one end of the strain beam away from the elastic structure is connected to the second rigid body; wherein the convex part of at least one concave-convex structure of at least one strain body is located on the strain beam. The elastic structure can be a thin plate-like structure, so that it can act as a floating beam, that is, when the strain generating structure 100 is subjected to an external force, a bending deformation is generated to reduce the inter-dimensional interference of the six-dimensional force sensor. Therefore, the introduction of the elastic structure helps to improve the measurement accuracy and stability of the sensor. Optionally, the strain body also includes a first connection portion connecting the strain beam and the elastic structure, and a second connection portion connecting the strain beam and the second rigid body, so that the concave-convex structure on the strain body 110 can be set on at least one of the first connection portion, the strain beam, and the second connection portion, and it is ensured that the convex part of at least one concave-convex structure is located on the strain beam, so that the stress distribution (strain distribution) brought by the concave part of the concave-convex structure when the external force is introduced can be formed on the strain beam and then sensed by the strain gauge.

[0071] Optionally, a notch is provided through the elastic structure, and the notch on the side of the elastic structure away from the first rigid body 120 extends radially inwardly along the strain generating structure 100 to connect with the strain beam. By providing the notch, it is helpful to block the outward transmission path of the stress, so that it is more concentrated on the strain beam, thereby increasing the available strain of the strain gauge 112 and improving the detection performance of the six-dimensional force sensor.

[0072] Optionally, a smooth and continuous second arc structure is provided at the connection position between the first rigid body 120 and the elastic structure; and / or a smooth and continuous third arc structure is provided at the connection position between the elastic structure and the strain beam; and / or a smooth and continuous fourth arc structure is provided at the connection position between the strain beam and the second rigid body 130. By providing the above arc structures, it is helpful to avoid stress concentration at the connection position of each component, so that more stress is transferred to the strain beam, increasing the available strain, and also helpful to improve the overload resistance of the strain generating structure 100.

[0073] Optionally, the first rigid body 120 and the second rigid body 130 are located at different heights of the axis of the strain generating structure 100. This is conducive to forming a cavity for accommodating a circuit board.

[0074] Optional, such as Figure 7 As shown, a through hole 131 may be provided in the central area of ​​the second rigid body 130. This is beneficial to the internal wiring of the manipulator and the robot, and realizes the concealed wiring of the manipulator and the robot. If no internal wiring is required, the through hole can be filled, and a via-free solution is adopted.

[0075] Optionally, the first rigid body 120 has a first assembly portion connected to the first object, and the second rigid body 130 has a second assembly portion connected to the second object, wherein the force and / or torque between the first object and the second object is transmitted to the strain generating structure 100 through the first assembly portion and the second assembly portion. Through the above arrangement, the strain generating structure 100 can be coupled with an external object to receive external force input. Optionally, the assembly portion can be a threaded hole, a slot, etc. Optionally, the first object can be an upper protective shell of a six-dimensional force sensor or a flange bolt of a robotic arm / robot, and the second object can be a lower protective shell of a six-dimensional force sensor or a flange bolt of a robotic arm / robot.

[0076] Based on the aforementioned inventive concept, the present application embodiment also provides another improved strain generating structure 200, such as Fig.11 and Fig.12 As shown, it includes: at least one strain body 110', the strain body 110' is configured to generate strain under the action of external force; wherein, at least one strain body 110' has at least one target surface 116 perpendicular to the axis AX2 of the strain generating structure 200, at least one target surface 116 is formed with at least one recessed portion 111' and at least one strain gauge 112 is provided in the non-recessed portion, the strain gauge 112 is configured to sense the strain generated in the strain body 110'; and, no strain gauge 112 is provided on the non-target surface of each strain body 110'.

[0077] In the strain generating structure 200, on the one hand, the strain gauge 112 is only arranged at the non-depressed portion of the target surface where the strain body 110' is perpendicular to the axis AX2 of the strain generating structure 200, and the strain gauge 112 is not arranged on the non-target surface. In this way, the subsequent patch process can be completed by a machine, which greatly reduces the production difficulty and improves the production efficiency and product yield of the six-dimensional force sensor. On the other hand, by forming a depressed portion on the target surface where the strain gauge 112 is arranged, the strain body 110' has different stress distributions at the depressed portion 111' and the non-depressed portion when the external force is transmitted, thereby making the strain of the strain body 110' close to the depressed portion 111' smaller, and the strain of the strain body 110' away from the depressed portion 111' larger. At this time, the strain gauge 112 located on the target surface outside the depressed portion 111' can obtain a certain degree of available strain and output an electrical signal with a certain strength. This is conducive to ensuring the detection performance of the six-dimensional force sensor while all the strain gauges 112 are arranged on the target surface.

[0078] In some embodiments of the present application, at least one target surface is formed with a plurality of recessed portions 111', and at least two strain gauges 112 are disposed at intervals on the target surface between at least one pair of adjacent recessed portions 111'. This is conducive to the detection of forces and moments in different directions, and is also conducive to the strain gauge 112 obtaining more available strains, thereby improving the detection accuracy of the six-dimensional force sensor.

[0079] In some embodiments of the present application, the side surface of at least one recessed portion 111' is angled with the surface of the non-recessed portion; or, the surface of at least one recessed portion 111' is a curved surface; or, the surface of at least one recessed portion 111' is smoothly connected to the surface of the non-recessed portion.

[0080] In some embodiments of the present application, see Fig.11 The strain body 110' has a first target surface 116 and a second target surface 117 which are arranged opposite to and perpendicular to the axis AX2 of the strain generating structure 200; wherein the first target surface 116 is formed with at least one recessed portion 111' and at least one strain gauge 112 is arranged in the non-recessed portion; and / or, the second target surface 117 is formed with at least one recessed portion 111' and at least one strain gauge 112 is arranged in the non-recessed portion. In this way, it is beneficial to fully utilize the strain distribution brought by the recessed portion 111', increase the number of strain gauges 112, thereby further improving the detection accuracy of the six-dimensional force sensor, and at the same time, it can also meet the full-plane setting requirements of the strain gauge 112, and improve production efficiency and product yield.

[0081] In some embodiments of the present application, the strain generating structure 200 has a reference plane (not shown in the figure, similar to the reference plane P2) parallel to the external force input end face of the strain body 110', the external force input end face of the strain body 110' formed with at least one recessed portion 111' has a fourth orthographic projection on the reference plane, and the cross section of the strain body 110' corresponding to at least one recessed portion 111' has a fifth orthographic projection on the reference plane, and the fourth orthographic projection covers the fifth orthographic projection. In this way, it is beneficial to ensure that the stress distribution on the surface where the strain gauge is set after the external force is transmitted to the strain body 110 is affected by the recessed portion 111', forming a stress distribution (strain distribution) with small stress (small strain) close to the recessed portion 111' and large stress (large strain) away from the recessed portion 111'. If the fourth orthographic projection does not cover the fifth orthographic projection, it is easy to affect the stress distribution on the surface where the strain gauge is set, which will further affect the detection accuracy of the six-dimensional force sensor.

[0082] Based on the above invention concept, Fig.13As shown, the embodiment of the present application also provides another improved strain generating structure 1, comprising a first rigid body 2, a second rigid body 6, and at least one strain body connected between the first rigid body 2 and the second rigid body 6, wherein the strain body is configured to generate strain under the action of an external force;

[0083] The strain body, and part of the first rigid body 2 and part of the second rigid body 6 connected to the strain body together form a passage R (shown by an elliptical dotted line) for transmitting force and / or torque between the first rigid body 2 and the second rigid body 6, and at least one passage R is formed with at least one recessed portion (such as Fig.16 As shown, a strain groove is formed on each passage R, and at least one strain gauge 5 is provided in the non-recessed portion;

[0084] The strain gauge 5 is located on the strain body and is configured to sense the strain generated by the strain body; the strain generating structure 1 has a reference plane perpendicular to its axis, and each strain gauge 5 of the strain generating structure 1 is arranged parallel to the reference plane.

[0085] The above-mentioned strain generating structure 1, on the one hand, sets all the strain gauges 5 parallel to the reference plane, so that the subsequent patch process can be completed by a machine, which greatly reduces the difficulty of production and improves the production efficiency and product yield of the six-dimensional force sensor; on the other hand, by forming at least one recessed portion on the passage R used to transmit the force and / or torque between the first rigid body 2 and the second rigid body 6 and providing at least one strain gauge in the non-recessed portion, the strain generated by the strain body close to the recessed portion is smaller, and the strain generated by the strain body away from the recessed portion is larger. At this time, the strain gauge located outside the recessed portion can obtain a certain degree of available strain and output an electrical signal with a certain strength. This is conducive to ensuring the detection performance of the six-dimensional force sensor while each strain gauge is set parallel to the reference plane.

[0086] In some embodiments of the present application, see Fig.13 , a recessed portion (i.e., the second strain groove 9) on the passage R is provided on the second rigid body 6, which is conducive to miniaturization of the strain generating structure 1, thereby broadening the application scope of the strain generating structure 1. Exemplarily, the width of the second strain groove 9 (i.e., the length perpendicular to the radial direction of the strain generating structure 1) is greater than the width of the strain beam 3.

[0087] In some embodiments of the present application, see Fig.13 At least two recessed portions (such as the first strain groove 8 and the second strain groove 9) are arranged at intervals on at least one passage R along the extension direction of the passage R, and at least two strain gauges 5 are arranged between at least one pair of adjacent recessed portions along the extension direction of the passage R. This is conducive to the detection of forces and moments in different directions, and is also conducive to the strain gauge 112 obtaining more available strains, thereby improving the detection accuracy of the six-dimensional force sensor.

[0088] Based on the above invention concept, Fig.19 and Fig. 20 As shown, the embodiment of the present application also provides another improved strain generating structure 300, including: at least one strain body 110', including a strain beam 118, the strain beam 118 is configured to generate strain under the action of an external force; wherein, at least one recessed portion 111' is formed on the surface of the at least one strain body 110' and at least one strain gauge 112 is provided in the non-recessed portion, each strain gauge 112 is provided on the strain beam 118 and is configured to sense the strain generated by the strain beam 118; and, the recessed portion 111' satisfies the following relationship: 0.001H≤D≤0.8H, A≥W, wherein D represents the depth of the recessed portion 111', A represents the width of the recessed portion 111', H represents the height of the strain beam 118, and W represents the width of the strain beam 118; and, the strain generating structure has a reference plane P3 perpendicular to its axis AX3, and each strain gauge 112 of the strain generating structure 300 is arranged parallel to the reference plane P3.

[0089] The strain generating structure 300, on the one hand, sets all the strain gauges 112 parallel to the reference plane P3, so that the subsequent patch process can be completed by a machine, which greatly reduces the difficulty of production and improves the production efficiency and product yield of the six-dimensional force sensor; on the other hand, by forming a recessed portion 111' on the surface of the strain body 110' provided with the strain gauge 112, and making the recessed portion 111' satisfy the above-mentioned relationship, when the external force is transmitted, the strain body 110 has different stress distributions at the recessed portion 111' and the non-recessed portion, thereby making the strain beam 118 close to the recessed portion 111' smaller, and the strain beam 118 away from the recessed portion 111' larger. At this time, the strain gauge 112 located at the non-recessed portion position can obtain a certain degree of available strain and output an electrical signal with a certain strength, which is conducive to ensuring the detection performance of the six-dimensional force sensor while each strain gauge 112 is set parallel to the reference plane P3.

[0090] For example, the depth D of the at least one recessed portion 111 ′ may be one of 0.001H, 0.01H, 0.1H, 0.2H, 0.4H, 0.6H, and 0.8H. The depth D will affect the range of the small strain region on the strain beam 118 .

[0091] In some embodiments of the present application, see Fig. 20, the strain gauge 112 also satisfies the following relationship: 0<P≤0.4L, where P represents the distance between the strain gauge 112 and the edge of the recessed portion 111', and L represents the length of the strain beam 118; and / or, the strain gauge 112 satisfies the following relationship: 0<Q≤0.4W, where Q represents the distance between the strain gauge 112 and the side edge of the strain beam 118. Exemplarily, P can be one of 0.05L, 0.1L, 0.2L, 0.3L, and 0.4L. Exemplarily, Q can be one of 0.05W, 0.1W, 0.2W, 0.3W, and 0.4W. In principle, the smaller the P and Q values, the better; on the other hand, if the P and Q values ​​are too large, the signal output strength of the bridge arm of the Wheatstone bridge will be reduced.

[0092] The invention concept and effects of the present application will be further described below through two specific embodiments. Specific embodiment 1

[0094] like Fig.13 As shown, the strain generating structure 1 is processed from a whole cylindrical metal substrate, including a first rigid body 2, a second rigid body 6, an elastic structure 4, and a strain beam 3. Among them, one end of the elastic structure 4 is connected to the first rigid body 2, and the other end away from the first rigid body 2 is connected to the strain beam 3, and the end of the strain beam 3 away from the elastic structure 4 is connected to the second rigid body 6, so that the first rigid body 2 and the second rigid body 6 are completely connected through the elastic structure 4 and the strain beam 3. The strain generating structure 1 has a total of 3 elastic structures 4 and 3 strain beams 3, and the 3 strain beams 3 are all polyhedral beam structures. The first rigid body 2 is respectively connected to the 3 elastic structures 4, and each elastic structure 4 extends inwardly to form a "T-shaped" structure. The 3 strain beams 3 are respectively connected to the "T-shaped" structure extending from the elastic structure 4. The 3 strain bodies composed of the strain beams 3 and the elastic structure 4 can be evenly distributed or at uneven angles along the circumference of the strain generating structure 1.

[0095] There are three through slots 12 between the first rigid body 2 and the second rigid body 6, and the three through slots 12 are evenly distributed or at uneven angles. In addition, the first rigid body 2 and the second rigid body 6 are respectively located at different height positions of the axis of the strain generating structure 1, so as to enclose with each elastic structure 4 and the strain beam 3 to form a cavity for accommodating the PCB board. The first rigid body 2 is the peripheral rigid body structure of the six-dimensional force sensor, which can be used to transmit the force and / or torque from the positive connection part of the Z axis. At this time, the force transmission path is that the force is transmitted from the first rigid body 2 to the elastic structure 4, and then to the top of the strain beam 3. The second rigid body 6 is the inner ring rigid body structure of the six-dimensional force sensor, which can be used to transmit the force and / or torque from the negative connection part of the Z axis. At this time, the force transmission path is from the second rigid body 6 to the bottom end of the strain beam 3. Therefore, the strain of the three strain beams 3 can characterize the force condition of the six-dimensional force sensor. In this specific embodiment, there are continuous arc structures between the second rigid body 6 and the strain beam 3, between the elastic structure 4 and the strain beam 3, and between the elastic structure 4 and the first rigid body 2, which is beneficial to avoid stress concentration and improve the overload resistance of the strain generating structure 1. A through hole 10 is opened in the center of the second rigid body 6 of this specific embodiment. The central through hole 10 is used for internal wiring of the robot arm to realize concealed wiring of the robot arm and the humanoid robot. If internal wiring is not required, the through hole 10 can be filled, and a non-via solution is adopted.

[0096] Continue to see Fig.13 , a first strain groove 8 is provided at the connection between the strain beam 3 and the elastic structure 4, and a second strain groove 9 is provided at the connection position between the strain beam 3 and the second rigid body 6. The first strain groove 8 and the second strain groove 9 are milled and formed into a polygonal or shallow groove structure with rounded corners. At least one strain gauge 5 is mounted between the first strain groove 8 and the second strain groove 9. The strain gauge 5 converts the strain of the strain beam 3 into an electrical signal. The strain gauge 5 and the strain beam 3 are cured together at high temperature using non-metallic materials, so that the strain of the strain beam 3 can be completely transmitted to the strain gauge 5. The first strain groove 8 and the second strain groove 9 function to gradually reduce the strain of the strain beam 3 near the strain groove position and gradually increase the strain away from the strain groove position when the strain generating structure is stressed. By utilizing this characteristic, by constructing a bridge circuit of the strain gauge 5, the output voltage of the strain gauge 5 can be changed in direct proportion to the stress of the elastic body. The first strain groove 8 and the second strain groove 9 can have a variety of application forms and appearance shapes, including but not limited to milling bosses and grooves on the upper and lower surfaces of the strain beam 3.

[0097] Fig.14 The deformation of the strain beam 3 when the strain generating structure 1 is subjected to a force / torque parallel to the XY plane is shown. When the elastic body is subjected to a force / torque parallel to the XY plane, the strain beam 3 divides the strains in opposite directions along the neutral layer perpendicular to the XY plane, such as Fig.14As shown, the left area of ​​the strain beam 3 is in a compressed state, and the right area is in a stretched state. At this time, the resistance of the left resistance strain gauge of the strain gauge 5 decreases, and the resistance of the right resistance strain gauge increases. The strain beam 3 is divided into three areas 1A, 1B, and 1C. Area 1A is close to the first strain slot 8, area 1C is close to the second strain slot 9, and area 1B is between area 1A and area 1C. Due to the effects of the first strain slot 8 and the second strain slot 9, the strains of areas 1A and 1C are smaller than the strains of area 1B. At this time, the resistance change amplitude of the resistance strain gauge of the strain gauge 5 located in areas 1A and 1C is smaller than the resistance change amplitude of the resistance strain gauge located in area 1B. Finally, the strain gauge 5 can use the difference in the resistance of the resistance strain gauge to construct a voltage output proportional to the strain.

[0098] Fig.15 The deformation of the strain beam 3 when the strain generating structure 1 is subjected to a force / torque perpendicular to the XY plane is shown. When the strain generating structure 1 is subjected to a force / torque perpendicular to the XY plane, the strain beam 3 divides the strains in opposite directions along the neutral layer parallel to the XY plane, such as Fig.15 As shown, the upper surface of the strain beam 3 is in a tensile state, and the lower surface is in a compressed state. At this time, the resistance values ​​of the left and right resistance strain gauges of the strain gauge 5 increase synchronously. The strain beam 3 is divided into three regions 2A, 2B, and 2C. Region 2A is close to the first strain slot 8, region 2C is close to the second strain slot 9, and region 2B is between region 2A and region 2C. Due to the effects of the first strain slot 8 and the second strain slot 9, the strains of regions 2A and 2C are smaller than the strains of region 2B. At this time, the resistance change amplitude of the resistance strain gauges of the strain gauge 5 located in regions 2A and 2C is smaller than the resistance change amplitude of the resistance strain gauge located in region 2B. Finally, the strain gauge 5 can use the difference in the resistance values ​​of the resistance strain gauges to construct a voltage output proportional to the strain. Specific embodiment 2

[0100] like Fig.16 As shown, the overall structure of the second embodiment is basically the same as that of the first embodiment, except that the second embodiment has six elastic structures 4 and corresponding six strain beams 3, and each strain beam 3 corresponds to a strain groove. Fig.16 , three strain beams 3 of the six strain beams are provided with first strain slots 8, and the other three strain beams 3 are provided with second strain slots 9. Strain gauges 5 can be mounted below the first strain slots 8 or above the second strain slots 9. The strain gauges 5 convert the strain of the strain beams 3 into electrical signals. The strain gauges 5 and the strain beams 3 are cured together at high temperature using non-metallic materials, so that the strain of the strain beams 3 can be completely transmitted to the strain gauges 5. The functions of the first strain slots 8 and the second strain slots 9 are consistent with the aforementioned three-beam structure six-dimensional force sensor strain generation structure 1, and will not be repeated here.

[0101] The following will take the specific embodiment 1 as an example to provide several optional implementation modes applicable to the above-mentioned specific embodiment 1 and specific embodiment 2.

[0102] Optional implementation method 1

[0103] like Fig.13 As shown, the elastic structure 4 is provided with a plurality of through holes, which are connected by cutout grooves 7. When the six-dimensional force sensor is subjected to a force or moment parallel to the XY plane, the strain beam 3 can obtain strains in opposite directions along the neutral layer perpendicular to the XY plane. When the six-dimensional force sensor is subjected to a force or moment perpendicular to the XY plane, the strain beam 3 can obtain strains in opposite directions along the neutral layer parallel to the XY plane.

[0104] Optional implementation method 2

[0105] like Fig.13 As shown, the first rigid body 2 is provided with a plurality of main threaded holes 14, and the first rigid body 2 is connected to the upper protective shell of the six-dimensional force sensor or directly to the flange bolt of the mechanical arm through the main threaded holes 14. The first rigid body 2 is also provided with a plurality of main pin holes 15, which are used for the upper protective shell of the six-dimensional force sensor and the flange of the mechanical arm for disassembly, positioning and anti-reverse installation. The second rigid body 6 is provided with a plurality of secondary threaded holes 16, and the second rigid body 6 is connected to the lower protective shell of the six-dimensional force sensor or directly to the flange bolt of the mechanical arm through the secondary threaded holes 16. The second rigid body 6 is also provided with a plurality of secondary pin holes 20, which are used for the lower protective shell of the six-dimensional force sensor and the flange of the mechanical arm for disassembly, positioning and anti-reverse installation. The second rigid body 6 is provided with a plurality of PCB mounting threaded holes 17, and the PCB board is fixed to the second rigid body 6 by bolts. The external mechanical connection methods of the first rigid body 2 and the second rigid body 6 include but are not limited to bolt connection, and can also be clamping, welding, etc.

[0106] Optional implementation method three

[0107] Fig.17 Various variations of the strain beam 3 and various optional arrangements of the strain gauges 5 provided on the strain beam 3 are shown.

[0108] like Fig.17 .a, the first strain groove 8 and the second strain groove 9 are both located on the upper surface of the strain beam 3, each strain beam 3 uses a strain gauge 5, and the strain gauge 5 is mounted between the first strain groove 8 and the second strain groove 9, which is a first variant of the strain beam 3. Fig.17 .b, the first strain groove 8 and the second strain groove 9 are both located on the lower surface of the strain beam 3, each strain beam 3 uses a strain gauge 5, and the strain gauge 5 is mounted between the first strain groove 8 and the second strain groove 9, which is a second variant of the strain beam 3. Fig.17.c, the first strain groove 8 and the second strain groove 9 are respectively located on the upper surface and the lower surface of the strain beam 3, and the first strain groove 8 and the second strain groove 9 are both located at the top of the strain beam 3, each strain beam 3 uses two strain gauges 5, and the strain gauges 5 are mounted below the first strain groove 8 and the second strain groove 9, which is the third variant of the strain beam 3. Fig.17 .d, the first strain groove 8 and the second strain groove 9 are respectively located on the upper surface and the lower surface of the strain beam 3, and the first strain groove 8 and the second strain groove 9 are both located at the bottom of the strain beam 3, each strain beam 3 uses two strain gauges 5, and the strain gauges 5 are mounted above the first strain groove 8 and the second strain groove 9, which is the fourth variant of the strain beam 3. Fig.17 .e, the first strain groove 8 and the second strain groove 9 are respectively located on the upper surface and the lower surface of the strain beam 3, or the first strain groove 8 is located on the lower surface of the strain beam 3, the second strain groove is located on the upper surface of the strain beam 3, the first strain groove 8 is located at the top of the strain beam 3, and the second strain groove 9 is located at the bottom of the strain beam 3. Each strain beam 3 uses two strain gauges 5, and the strain gauge 5 is mounted between the first strain groove 8 and the second strain groove 9. This is the fifth variant of the strain beam 3. Fig.17 .f, the first strain groove 8 and the second strain groove 9 are respectively located on the upper surface and the lower surface of the strain beam 3, and the first strain groove 8 is located at both the top and the bottom of the strain beam 3, and similarly, the second strain groove 9 is located at both the top and the bottom of the strain beam 3. Each strain beam 3 uses two strain gauges 5, and the strain gauge 5 is mounted between the first strain groove 8 and the second strain groove 9, which is the sixth variant of the strain beam 3.

[0109] Optional implementation method 4

[0110] Fig.18 The top view of various components of the resistance strain gauge is shown. The resistance strain gauge can be a sheet element etched out of diffused silicon.

[0111] Fig.18 .a is a single-body resistance strain gauge 510, which is composed of an upper pad 5101, a silicon chip resistor 5102, and a lower pad 5103. The silicon chip resistor 5102 is a stress sensitive element, and the resistance value of the silicon chip resistor 5102 can change with the stress. The silicon chip resistor 5102 is centered and connected to the upper pad 5101 and the lower pad 5103 respectively. The single-body resistance strain gauge 510 is connected to the external electrical circuit through the upper pad 5101 and the lower pad 5103. Fig.18.b is a half-bridge resistance strain gauge 511, which is composed of two single resistance strain gauges 510 connected in series. The middle pad 5111 connects the two single resistance strain gauges 510. The half-bridge resistance strain gauge (511) is connected to the external electrical circuit through the upper pad (5101), the middle pad (5111) and the lower pad 5103. Fig.18 .c is the first full-bridge resistance strain gauge 512, which is composed of two half-bridge resistance strain gauges 511 connected in series. Generally, the first bridge pad 5121 connects the lower pads 5103 of the two half-bridge resistance strain gauges 511 together to form a tail-to-tail connection. At this time, the first full-bridge resistance strain gauge 512 is connected to the external electrical circuit through the two upper pads 5101, the two middle pads 5111 and the first bridge pad 5121. In particular, the first bridge pad 5121 can also connect the upper pads 5101 of the two half-bridge resistance strain gauges 511 together to form a head-to-head connection. At this time, the first full-bridge resistance strain gauge 512 is connected to the external electrical circuit through the first bridge pad 5121, the two middle pads 5111 and the two lower pads 5103. Fig.18 .d is a second full-bridge resistance strain gauge 513, which is composed of two half-bridge resistance strain gauges 511 connected in series. The second bridging pad 5131 connects the lower pad 5103 and the upper pad 5101 of the two half-bridge resistance strain gauges 511 together to form a head-to-tail connection. At this time, the second full-bridge resistance strain gauge 513 is connected to the external electrical circuit through an upper pad 5101, two middle pads 5111, a lower pad 5103 and a second bridging pad 5131. The first Wheatstone bridge 501 and the second Wheatstone bridge 502 can be bridged using one or more of the above-mentioned resistance strain gauges.

[0112] An embodiment of the present application also provides a method for preparing a strain generating structure, which comprises: opening at least one through groove on a substrate to form the first rigid body and the second rigid body that are spaced apart and at least one strain body connecting the first rigid body and the second rigid body; thinning a partial area on the strain body to form at least one concave-convex structure; attaching all strain gauges to the convex portion of at least one concave-convex structure parallel to a reference plane; wherein the strain gauge is configured to sense the strain generated by the strain body, and the reference plane is perpendicular to the axis of the strain generating structure.

[0113] The above preparation method, on the one hand, can greatly reduce the difficulty of patching by attaching all strain gauges to the strain body parallel to a reference plane, thereby improving the production efficiency and product yield of the six-dimensional force sensor; on the other hand, by thinning the partial area of ​​the corresponding variant, a concave-convex structure is formed on the surface of the strain body provided with the strain gauge, so that when external force is transmitted, the strain body has different stress distributions at the concave position and the convex position of the concave-convex structure, thereby making the strain body close to the concave part smaller and the strain body far from the concave part larger. At this time, the strain gauge located at the convex part of the concave-convex structure can obtain a certain degree of available strain and output an electrical signal with a certain strength, which is conducive to ensuring the detection performance of the six-dimensional force sensor while each strain gauge is arranged parallel to the reference plane.

[0114] In some embodiments of the present application, an adhesive may be used to attach the strain gauge. Optionally, the adhesive may be glue, glass powder, etc. When glue is used for bonding, a printer may be used to apply glue of uniform thickness on the surface of the strain gauge, thereby preventing the influence of different glue thicknesses on the resistance value of the resistor in the bridge.

[0115] An embodiment of the present application also provides a force detection module, comprising any strain generating structure as described above and a measurement circuit coupled to each strain gauge in the strain generating structure, the measurement circuit being configured to measure the direction and magnitude of the force and / or torque exerted on the strain generating structure based on an electrical signal from at least one strain gauge.

[0116] Exemplarily, the strain generating structure also includes a first rigid body connected to one end of the strain body; a second rigid body connected to an end of the strain body away from the first rigid body; and at least one through groove, which is opened between the first rigid body and the second rigid body and is alternately arranged with the strain body along the circumference of the strain generating structure; wherein, when the force and / or torque between the first rigid body and the second rigid body is transmitted to the strain body, the strain body is strained, and the first rigid body and the second rigid body are located at different height positions along the axis of the strain generating structure; the measurement circuit includes: a circuit board, which is arranged in a cavity enclosed by the first rigid body, each strain body, and the second rigid body, and the circuit board is provided with wiring grooves corresponding to each strain gauge, and a group bridge pad connected to the pad of the strain gauge is arranged near the wiring groove.

[0117] Optionally, the measurement circuit includes a PCB board, which is placed in the internal cavity of the strain generating structure and is used to collect and amplify the strain electrical signal, convert it into force and torque signals, and perform direction calculation.

[0118] Optional, such as Fig.21As shown, a plurality of polygonal grooves 19 are provided on the PCB board 13, and the area enclosed by each polygonal groove 19 corresponds to the area where the strain gauge 5 of each strain beam 3 is located. A mounting through hole 22 is provided at the connection position with the second rigid body 6 on the PCB board 13, which is used to realize the mechanical connection between the PCB board 13 and the second rigid body 6. A bolt through hole 21 is provided at the position corresponding to the secondary threaded hole 16 on the PCB board 13, so that the mounting bolts of the lower protective housing or the flange of the mechanical arm can pass through the PCB board 13, thereby realizing various mechanical connection forms of the mechanical arm.

[0119] Optional, such as Fig. 22 As shown, the PCB board 13 uses a binding technology to connect the metal wire from the pad of the strain gauge 5 to the pad of the PCB board. In this embodiment, a plurality of bridge pads are provided on the PCB board 13. According to the type of the resistance strain gauge used by the first Wheatstone bridge 501 and the second Wheatstone bridge 502 on the strain gauge 5, a plurality of metal wires 18 are connected from the pad of the resistance strain gauge to the bridge pad 23 of the PCB board 13 using a corresponding binding technology. One end of the metal wire 18 is fixed on the pad of the resistance strain gauge, and the other end is fixed on the bridge pad 23 of the PCB board 13, thereby realizing the electrical connection between the strain gauge 5 and the PCB board 13.

[0120] The present application also provides a force sensor, including any force detection module as described above. The force sensor is conducive to reducing the preparation manpower while ensuring the detection accuracy, improving the production efficiency and product yield, and is also conducive to reducing the size and reducing the production cost.

[0121] An embodiment of the present application also provides a robot, comprising a force sensor as described above, which is arranged at at least one joint position of the robot or at a mechanical arm or mechanical pull rod position.

[0122] Exemplarily, the above-mentioned robots may include at least one of industrial collaborative robots, quadruped robots, transport robots, surgical robots, and humanoid robots. For example, robotic arm assembly, grinding and polishing, handling and dragging in the field of industrial production; remote surgery in the medical field; wind tunnel testing and on-orbit assembly of space stations in the field of aerospace; robotic arm control algorithm research and teaching aid development in the field of education and scientific research; when the six-dimensional force sensor is installed at the wrist and ankle position of the humanoid robot, it can provide mechanical acquisition signals for the robot and assist the force control algorithm of the humanoid robot, which is a core component in the humanoid robot assembly.

[0123] In combination with the above-mentioned embodiments of the present application, it can be seen that according to the inventive concept of the present application, it is helpful to develop a high-precision, high-resolution, miniaturized, lightweight, and low-cost six-dimensional force sensor product, thereby obtaining broad application prospects in the field of robotics.

[0124] It should be noted that the numbers representing quantities or properties used to describe and claim certain embodiments of the present application should be understood to be modified by the terms "roughly", "about", "approximately" or "substantially" in some cases. For example, unless otherwise specified, "roughly", "about", "approximately" or "substantially" can indicate a ±20% variation of the value described. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may change according to the required features of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of the present application are approximate values, in specific embodiments, the setting of such numerical values ​​is as accurate as possible within the feasible range.

[0125] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0126] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A strain generating structure, characterized in that: include: at least one strain body, the strain body being configured to be strained under an external force; in, At least one concavo-convex structure is formed on the surface of at least one of the strain bodies, the concavo-convex structure having a concave portion and a convex portion adjacent to the concave portion, at least one strain gauge is disposed on the convex portion of at least one of the concavo-convex structures, and the strain gauge is configured to sense the strain generated by the strain body; and, The strain generating structure has a reference plane perpendicular to its axis, and each of the strain gauges of the strain generating structure is arranged parallel to the reference plane; Along a direction perpendicular to the axis, at least one strain gauge is arranged on one side of the recessed portion, and the strain on the convex portion close to the recessed portion is smaller than the strain on the convex portion far from the recessed portion.

2. The strain generating structure according to claim 1, characterized in that: A plurality of the strain gauges are disposed on the convex portion of at least one of the concave-convex structures, wherein at least two of the strain gauges are disposed at intervals.

3. The strain generating structure according to claim 2, characterized in that: At least two of the strain gauges are sequentially spaced apart in a direction away from or close to the concave portion of the concave-convex structure.

4. The strain generating structure according to claim 1, characterized in that: A plurality of the concave-convex structures are formed on the surface of at least one of the strain bodies, wherein the concave portions of at least one pair of adjacent concave-convex structures are connected or integrated to form a combined concave portion with convex portions on both sides, and at least one strain gauge is arranged on the convex portion on one side or both sides of at least one of the combined concave portions.

5. The strain generating structure according to claim 4, characterized in that: A plurality of the combined recesses are formed on the surface of at least one of the strain bodies, wherein the projections between at least one pair of adjacent combined recesses are connected or integrally formed into a combined projection, and at least two strain gauges are spaced apart on the combined projection.

6. The strain generating structure according to claim 5, characterized in that: At least two of the strain gauges are sequentially and spaced apart from each other on the combined convex portion along the arrangement direction of the pair of combined concave portions.

7. The strain generating structure according to any one of claims 4 to 6, characterized in that: The type of the combined recess includes at least one of a first recess that traverses the surface of the straining body and a second recess that forms an opening on the surface of the straining body.

8. The strain generating structure according to any one of claims 4 to 6, characterized in that: At least one side wall of the combined recess has a smooth and continuous first arc structure.

9. The strain generating structure according to claim 1, characterized in that: At least one of the strain bodies has a first surface and a second surface that are opposite to each other and parallel to the reference plane, at least one of the concave-convex structures is formed on the first surface and / or the second surface, and at least one of the convex portions of the concave-convex structure is provided with at least one strain gauge.

10. The strain generating structure according to claim 1, characterized in that: The side surface of at least one concave portion in the concave-convex structure is arranged at an angle to the reference plane; or, the surface of at least one concave portion in the concave-convex structure is a curved surface; or, the surface of at least one concave portion in the concave-convex structure is smoothly connected to the surface of the convex portion.

11. The strain generating structure according to claim 1, characterized in that: The depression depth of at least one concave portion of the concave-convex structure is less than or equal to a first preset value.

12. The strain generating structure according to claim 1, characterized in that: The strain generating structure has a reference plane parallel to the external force transmitting end face of the strain body, the external force transmitting end face of the strain body having at least one of the concave-convex structures has a first orthographic projection on the reference plane, and the cross-section of the strain body corresponding to the concave portion of at least one of the concave-convex structures has a second orthographic projection on the reference plane, and the first orthographic projection covers the second orthographic projection.

13. The strain generating structure according to claim 12, characterized in that: A cross section of the strain body corresponding to at least one convex portion of the concavo-convex structure has a third orthographic projection on the reference plane, and the first orthographic projection covers the third orthographic projection.

14. The strain generating structure according to any one of claims 1 to 6, characterized in that: The strain gauge includes at least one Wheatstone bridge, and the Wheatstone bridge includes at least one of a single resistance strain gauge, a half-bridge resistance strain gauge, and a full-bridge resistance strain gauge; in, The single-body resistance strain gauge includes a resistor and an upper pad and a lower pad respectively connected to opposite ends of the resistor; The half-bridge resistance strain gauge includes two resistors connected in series through a middle pad, and an upper pad and a lower pad respectively connected to opposite ends of the two resistors connected in series; The full-bridge resistance strain gauge includes two half-bridge resistance strain gauges connected in series via a bridge pad.

15. The strain generating structure according to claim 14, characterized in that: At least one of the strain gauges, The distance between the resistor closest to the concave portion of the corresponding concave-convex structure and the concave portion is less than or equal to a second preset value, and / or the distance between the resistor farthest from the concave portion of the corresponding concave-convex structure and the concave portion is greater than or equal to a third preset value.

16. The strain generating structure according to claim 14, characterized in that: At least one of the strain bodies has a plurality of the concave-convex structures; Wherein, at least one pair of adjacent convex parts of the concave-convex structure is connected or integrated to form a combined convex part, and at least one strain gauge is arranged on the combined convex part; Wherein, the distance between at least one resistor in at least one of the strain gauges and the center of the combined protrusion is less than or equal to a fourth preset value.

17. The strain generating structure according to claim 1, characterized in that: The strain generating structure further comprises: A first rigid body connected to one end of the strain body; A second rigid body connected to an end of the strain body away from the first rigid body; and at least one through groove, which is provided between the first rigid body and the second rigid body and is arranged alternately with the strain body along the circumferential direction of the strain generating structure; in, When the force and / or moment between the first rigid body and the second rigid body is transmitted to the strain body, the strain body is strained.

18. The strain generating structure according to claim 17, characterized in that: The through slot has a first slot wall at the first rigid body, and the through slot has a second slot wall at the second rigid body; wherein the contour of at least a portion of the second slot wall matches the contour of at least a portion of the first slot wall.

19. The strain generating structure according to claim 17 or 18, characterized in that: The strain body comprises an elastic structure and a strain beam connected to the elastic structure; Wherein, one end of the elastic structure is connected to the first rigid body, and the other end away from the first rigid body is connected to the strain beam, and one end of the strain beam away from the elastic structure is connected to the second rigid body; Wherein, the convex portion of at least one of the concave-convex structures of at least one of the strain bodies is located on the strain beam.

20. The strain generating structure according to claim 19, characterized in that: A smooth and continuous second arc structure is provided at the connection position between the first rigid body and the elastic structure; and / or, A smooth and continuous third arc structure is provided at the connection position between the elastic structure and the strain beam; and / or, A smooth and continuous fourth arc structure is arranged at the connection position between the strain beam and the second rigid body.

21. The strain generating structure according to claim 19, characterized in that: A notch is provided through the elastic structure, and the elastic structure on a side of the notch away from the first rigid body extends radially inwardly along the strain generating structure to be connected to the strain beam.

22. The strain generating structure according to claim 17 or 18, characterized in that: The first rigid body has a first assembly part connected to a first object, and the second rigid body has a second assembly part connected to a second object, wherein the force and / or torque between the first object and the second object is transmitted to the strain generating structure through the first assembly part and the second assembly part.

23. A strain generating structure, characterized in that: include: at least one strain body, the strain body being configured to be strained under an external force; in, At least one of the strain bodies has at least one target surface perpendicular to the axis of the strain generating structure, at least one of the target surfaces is formed with at least one recessed portion and at least one strain gauge is provided in a non-recessed portion, and the strain gauge is configured to sense the strain generated by the strain body; and, The strain gauge is not provided on the non-target surface of each of the strain bodies; Along a direction perpendicular to the axis, at least one strain gauge is arranged on one side of the recessed portion, and the strain on the non-recessed portion close to the recessed portion is smaller than the strain on the non-recessed portion far from the recessed portion.

24. The strain generating structure according to claim 23, characterized in that: A plurality of the recessed portions are formed on at least one of the target surfaces, and at least two of the strain gauges are spaced apart and arranged on the target surface between at least one pair of adjacent recessed portions.

25. The strain generating structure according to claim 23, characterized in that: The strain generating structure has a reference plane parallel to the external force transmission end face of the strain body, the external force transmission end face of the strain body having at least one recessed portion formed thereon has a fourth orthographic projection on the reference plane, and the cross-section of the strain body corresponding to at least one recessed portion has a fifth orthographic projection on the reference plane, and the fourth orthographic projection covers the fifth orthographic projection.

26. A strain generating structure, characterized in that: The device comprises a first rigid body, a second rigid body, and at least one strain body connected between the first rigid body and the second rigid body, wherein the strain body is configured to be strained under the action of an external force; in, The strain body, and part of the first rigid body and part of the second rigid body connected to the strain body together form a passage for transmitting force and / or torque between the first rigid body and the second rigid body, at least one of the passages is formed with at least one recessed portion and at least one strain gauge is provided in a non-recessed portion; in, The strain gauge is located on the strain body and is configured to sense the strain occurring on the strain body; The strain generating structure has a reference plane perpendicular to its axis, and each strain gauge of the strain generating structure is arranged parallel to the reference plane.

27. A strain generating structure, characterized in that: include: at least one strain body including a strain beam configured to strain under an external force; in, At least one of the strain bodies has at least one recessed portion formed on its surface and at least one strain gauge is disposed on a non-recessed portion, each of the strain gauges being disposed on the strain beam and configured to sense strain occurring on the strain beam; and, The concave portion satisfies the following relationship: 0.001H≤D≤0.8H, A≥W, wherein D represents the depth of the concave portion, A represents the width of the concave portion, H represents the height of the strain beam, and W represents the width of the strain beam; as well as, The strain generating structure has a reference plane perpendicular to its axis, and each strain gauge of the strain generating structure is arranged parallel to the reference plane.

28. The strain generating structure according to claim 27, characterized in that: The strain gauge further satisfies the following relationship: 0≤P≤0.4L, wherein P represents the distance between the strain gauge and the edge of the recessed portion, and L represents the length of the strain beam; and / or, The strain gauge satisfies the following relationship: 0≤Q≤0.4W, wherein Q represents the distance between the strain gauge and the side edge of the strain beam.

29. A method for preparing a strain generating structure, characterized in that: The strain generating structure comprises at least one strain body, a first rigid body connected to one end of the strain body, and a second rigid body connected to one end of the strain body away from the first rigid body; The preparation method comprises: At least one through groove is formed on the base to form the first rigid body and the second rigid body which are spaced apart and at least one strain body connecting the first rigid body and the second rigid body; Thinning a partial area on the strain body to form at least one concave-convex structure; All strain gauges are attached to at least one convex portion of the concave-convex structure in parallel to a reference plane; wherein the strain gauge is configured to sense the strain generated by the strain body, and the reference plane is perpendicular to the axis of the strain generating structure.

30. A force detection module, characterized in that: It comprises a strain generating structure as described in any one of claims 1 to 28 and a measurement circuit coupled to each of the strain gauges in the strain generating structure, wherein the measurement circuit is configured to measure the direction and magnitude of the force and / or torque applied to the strain generating structure based on an electrical signal from at least one of the strain gauges.

31. A force sensor, characterized in that: Comprising the force detection module as described in claim 30.

32. A robot, characterized in that: It includes the force sensor as claimed in claim 31, which is arranged at at least one joint position of the robot or at the position of a mechanical arm or a mechanical pull rod.

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