A stress amplification device and its robot

Abstract

This utility model relates to a stress amplification device and its robot, including a deformation plate and a strain gauge. The deformation plate has a stress concentration groove, and the strain gauge spans the stress concentration groove and is fixedly connected to the deformation plate. When an object undergoes shear deformation, it causes the deformation plate to deform. Due to the stress concentration groove on the deformation plate, the strain formed at the stress concentration groove is larger, thus affecting the strain gauge and causing it to deform. The strain signal is then obtained from the strain gauge. This application significantly improves the detectability of small force signals and achieves high-precision force sensing by integrating a mechanical amplification structure and a printable polymer strain gauge into the structure. It is also suitable for real-time measurement of shear stress and torque in space-constrained situations such as robot joints. Compared with the prior art, the stress amplification device and its robot disclosed in this application can achieve the goals of structural miniaturization, improved detection sensitivity, and easy integration.

Description

Technical Field

[0001] This utility model relates to the field of pressure sensing technology, and in particular to a stress amplification device and its robot. Background Technology

[0002] With the rapid development of complex and highly integrated systems such as humanoid robots and industrial robots, the demand for force sensing is increasing, especially in space-constrained parts such as robot joints and end effectors. Accurate measurement of minute shear stresses and torques is required to improve the safety and precision of system control.

[0003] Existing stress sensors, such as metal strain gauges, MEMS structures, or bridge modules, often suffer from the following problems: high structural rigidity, making them difficult to attach to non-planar or curved surfaces; complex installation, requiring glue fixation and cumbersome wiring; and weak signals under low stress, making it difficult to obtain effective readings. Especially in robot joint structures, where shear stress sources are complex and space is limited, traditional sensors struggle to achieve high-precision measurements.

[0004] Therefore, there is an urgent need for a shear stress measurement device that is compact, highly sensitive, and adaptable to solve the technical bottlenecks of existing sensing methods, such as low sensitivity and difficulty in integration. Utility Model Content

[0005] To address the shortcomings of existing sensing methods, such as low sensitivity and difficulty in integration, this invention proposes a stress amplification device.

[0006] The technical solution adopted by this utility model is a stress amplification device, including a deformation plate and a strain gauge. The deformation plate has a stress concentration groove, and the strain gauge spans the stress concentration groove and is fixedly connected to the deformation plate. In the length direction of the stress concentration groove, the size of the strain gauge does not exceed the length of the stress concentration groove.

[0007] In some embodiments, the size of the strain gauge is smaller than the length of the stress concentration groove along its length.

[0008] In some embodiments, the strain gauge is located in the center of the stress concentration groove.

[0009] In some embodiments, the stress concentration groove is a through-hole groove.

[0010] In some embodiments, the edge of the deformable sheet has at least one slot.

[0011] In some embodiments, the strain gauge is fixedly connected via a flexible circuit layer and a deformation plate.

[0012] In some embodiments, the strain gauge is a printable polymer strain gauge.

[0013] In some embodiments, there are at least two stress concentration slots, the number of strain gauges is the same as the number of stress concentration slots, and multiple strain gauges are fixedly connected through the same flexible circuit layer and deformation plate.

[0014] In some embodiments, there are two stress concentration grooves and two strain gauges, with the two stress concentration grooves symmetrically distributed and set at an angle.

[0015] To address the shortcomings of existing humanoid robots and industrial robots in accurately sensing force, this invention proposes a new type of robot.

[0016] The technical solution adopted in this utility model is a robot, including the stress amplification device described above.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] This application discloses a stress amplification device and its robot, including a deformation plate and a strain gauge. The deformation plate has a stress concentration groove, and the strain gauge spans the stress concentration groove and is fixedly connected to the deformation plate. The size of the strain gauge does not exceed the length of the stress concentration groove. When an object undergoes shear deformation, it causes the deformation plate to deform. Due to the stress concentration groove on the deformation plate, the strain formed at the stress concentration groove is larger, thus affecting the strain gauge and causing it to deform. The strain signal is then acquired from the strain gauge. This application significantly improves the detectability of minute force signals and achieves high-precision force sensing by integrating a mechanical amplification structure and a printable polymer strain gauge into the structure. It is also suitable for real-time measurement of shear stress and torque in space-constrained applications such as robot joints. Compared with existing technologies, the stress amplification device and its robot disclosed in this application achieve miniaturization, improved detection sensitivity, and ease of integration. Attached Figure Description

[0019] The present invention will now be described in detail with reference to the embodiments and accompanying drawings, wherein:

[0020] Figure 1 A schematic diagram of a stress amplification device according to an embodiment of the present invention is shown;

[0021] Figure 2 A schematic diagram illustrating the amplification principle of a stress amplification device according to an embodiment of the present invention is shown.

[0022] Label Explanation:

[0023] 10. Deformation plate; 11. Stress concentration groove; 12. Groove; 13. Weld joint;

[0024] 20. Strain gauge;

[0025] 30. Flexible circuit layer; 31. Output pin. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this utility model clearer, the embodiments of this utility model will be further described in detail below with reference to the accompanying drawings. Examples of embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar components or components having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0027] This utility model discloses a stress amplification device. Please refer to [reference needed]. Figure 1 and Figure 2 The device includes a deformation plate 10 and a strain gauge 20. The deformation plate 10 has a stress concentration groove 11. The strain gauge 20 spans the stress concentration groove 11 and is fixedly connected to the deformation plate 10. In the length direction of the stress concentration groove 11, the size of the strain gauge 20 does not exceed the length of the stress concentration groove 11.

[0028] The stress amplification device of the present invention has the following significant advantages:

[0029] High sensitivity: Amplifies weak shear stress or torque through mechanical structure, improving the strength of the sensing signal; Small size and strong adaptability: Suitable for applications with limited space, such as robot joints; High integration: Employs printable polymer strain gauges 20, which can be directly printed onto the surface of the structure, eliminating the traditional patching process; Low manufacturing cost: Printed strain gauges 20 are suitable for mass production, significantly reducing manufacturing costs; Fast response and flexible structure: Suitable for integration with flexible systems (such as bionic robots and soft robots); Strong scalability: Supports multi-channel output for two-dimensional shear stress or multi-axis torque detection; Good system compatibility: Signals can be directly connected to main control platforms such as MCUs, FPGAs, and robot controllers.

[0030] When an object undergoes shear deformation, the deformation plate 10 deforms. Due to the stress concentration groove 11 on the deformation plate 10, the strain formed at the stress concentration groove 11 is larger, which is reflected in the strain gauge 20, causing the strain gauge 20 to deform, and then the strain signal is obtained from the strain gauge 20. This application, by integrating a mechanical amplification structure and a printable polymer strain gauge 20 into the structure, can significantly improve the detectability of small force signals and achieve high-precision force sensing. It is also suitable for real-time measurement of shear stress and torque in space-constrained situations such as robot joints. Compared with the prior art, the stress amplification device and robot disclosed in this application can achieve the goals of structural miniaturization, improved detection sensitivity, and easy integration.

[0031] Specifically, along the length of the stress concentration groove 11, the size of the strain gauge 20 does not exceed the length of the stress concentration groove 11. Please refer to [reference needed]. Figures 1 to 2 The stress concentration groove 11 is the part of the structure where stress concentration is most pronounced. The strain gauge 20's size does not exceed the length of the stress concentration groove 11, ensuring that the strain gauge 20 is completely within the stress concentration area. This allows the strain data measured by the strain gauge 20 to accurately reflect the true strain in this critical area, avoiding data distortion due to measurement position deviations or coverage of non-stress concentration areas. Furthermore, if the strain gauge 20's size exceeds the length of the stress concentration groove 11, the excess portion will measure the strain of the relatively uniform stress area surrounding the groove. Since the stress levels in the stress concentration area differ significantly from the surrounding area, this mixed measurement results in the strain value measured by the strain gauge 20 being a combined result of the strain in both the stress concentration area and the surrounding area, failing to accurately reflect the actual strain in the stress concentration area and introducing a large measurement error. Controlling the size of the strain gauge 20 within the length of the stress concentration groove 11 effectively avoids this error and improves measurement accuracy. It should be noted that the strain gauge 20's size not exceeding the length of the stress concentration groove 11 also includes the case where the size of the strain gauge 20 and the length of the stress concentration groove 11 are equal in length.

[0032] In some specific embodiments, the "butterfly-shaped" steel sheet has four symmetrically designed stiffness-reducing grooves to weaken the stiffness amplification signal. A stress concentration groove 11 is located in the middle to amplify concentrated stress. Its stress amplification factor is approximately equal to L / d; please refer to [reference needed]. Figure 2 The printable strain gauge 20 is attached to the FPC, which is then attached to the "butterfly" steel sheet. During installation and use, the amplifier is spot-welded to the object being measured. When the object undergoes shear deformation, the weld point 13 causes the steel sheet to deform. The resistance of the "butterfly" steel sheet changes in the same way as the measured resistance, forming a Wheatstone bridge, from which the shear strain signal can be obtained.

[0033] In addition to steel sheets, strain gauges can also be made of other metal sheets, plastic sheets, polymer material sheets, etc.

[0034] Furthermore, metal strain gauges are preferred, allowing them to be fixed to other structures via solder joints 13. In other embodiments, fixing points or adhesive bonding can also be used to fix the strain gauges.

[0035] In some embodiments, the size of the strain gauge 20 is smaller than the length of the stress concentration groove 11 along its length.

[0036] Among them, the strain gauge 20 is smaller than the length of the stress concentration groove 11, and the strain sensing effect is better when the size of the strain gauge 20 is equal to the length of the stress concentration groove 11.

[0037] In some embodiments, the strain gauge 20 is located at the center of the stress concentration groove 11.

[0038] The center of the stress concentration groove 11 is usually the area where stress is most concentrated, that is, where the maximum stress and maximum strain occur. Placing the strain gauge 20 at this position allows for direct measurement of the maximum strain value that the structure can withstand.

[0039] In some embodiments, the stress concentration groove 11 is a through-hole groove.

[0040] In other embodiments, the stress concentration groove 11 may also be a blind hole groove.

[0041] It should be noted that setting the stress concentration groove 11 as a through-hole groove allows the stress to be relatively uniform in the thickness direction of the deformable plate 10, and the stress concentration area extends from one side of the deformable plate 10 to the other side. In contrast, the blind hole groove is closed on the other side of the deformable plate 10, and its stress is mainly concentrated in a local area on the side where the opening occurs, that is, the side where the strain gauge 20 is located. Compared with the through-hole groove, the blind hole groove has higher structural strength.

[0042] In other embodiments, when the stress concentration groove 11 is a through-hole groove, a strain gauge 20 can be installed across each side of the through-hole groove, and the two strain gauges 20 can work together to detect the stress. Furthermore, when the strain gauge 20 is a printable polymer strain gauge 20, the thickness of the stress amplification device will not be significantly increased. When a higher thickness requirement is needed, a strain gauge 20 can be installed on only one side.

[0043] In some embodiments, the edge of the deformable sheet 10 is provided with at least one slot 12.

[0044] It should be noted that at least one slot 12 is provided on the edge of the deformation sheet 10. The slot 12 is provided to reduce the stiffness amplification signal of the deformation sheet 10. In some specific embodiments, the deformation sheet 10 is butterfly-shaped, and four stiffness-reducing slots are symmetrically designed on its edge to reduce the stiffness amplification signal.

[0045] In some embodiments, the strain gauge 20 is fixedly connected to the flexible circuit layer 30 and the deformation plate 10.

[0046] The flexible circuit layer 30 provides good signal interaction between the strain gauge 20 and components such as the controller and processor. Furthermore, the flexible circuit layer 30 can be freely bent, has a small thickness, and possesses excellent flexibility and bendability, easily conforming to the surface of the strain gauge 10. It can also be used in conjunction with a subsequent printable polymer strain gauge 20. The strain gauge 10 can be curved in shape in addition to a planar shape; this application does not limit its shape. The flexible circuit layer 30 outputs power through an output pin 31 at its end.

[0047] In some embodiments, strain gauge 20 is a printable polymer strain gauge 20.

[0048] Polymer materials possess unique molecular structures and physical properties, enabling printable polymer strain gauges 20 to produce significant resistance changes in response to minute strain variations. Compared to some traditional strain gauges 20 (resistance strain gauges 20, foil strain gauges 20, etc.), printable polymer strain gauges 20 can detect finer deformations. Furthermore, printable polymer strain gauges are flexible, thin, and can be easily mounted on flexible circuit layers 30.

[0049] In some embodiments, there are at least two stress concentration grooves 11, the number of strain gauges 20 is the same as the number of stress concentration grooves 11, and multiple strain gauges 20 are fixedly connected through the same flexible circuit layer 30 and deformation sheet 10.

[0050] By setting up at least two stress concentration slots 11 and equipping each slot with the same number of strain gauges 20, the stress and strain of the deformation plate 10 can be measured from multiple key locations. The stress concentration slots 11 at different locations can capture the stress distribution characteristics of the deformation plate 10 in different areas. The data from multiple strain gauges 20 corroborate and complement each other, thus more comprehensively and accurately reflecting the overall stress state of the deformation plate 10, greatly improving the accuracy and reliability of the measurement. All strain gauges 20 are fixedly connected to the deformation plate 10 through the same flexible circuit layer 30, achieving centralized integration of signal transmission lines. This accurately converges and transmits the electrical signals from each strain gauge 20, reducing the use of numerous scattered wires in traditional methods and making the entire measurement system more compact and simple.

[0051] In some embodiments, there are two stress concentration grooves 11 and two strain gauges 20, with the two stress concentration grooves 11 symmetrically distributed and arranged at an angle.

[0052] Two stress concentration grooves 11 and strain gauges 20 arranged in different directions can be combined to form a simple stress measurement matrix. According to the principles of elasticity, by measuring strain in two different directions, a system of equations can be established to solve for the magnitude and direction of shear stress. When measuring strain in a single direction, the measurement results are often affected by normal stress, leading to a large measurement error in shear stress. However, two strain gauges 20 arranged at an angle can eliminate the influence of normal stress through methods such as differential gradation, thereby extracting shear stress information more accurately. For example, when the measurement directions of the two strain gauges 20 are at a certain angle to the principal stress direction, by appropriately combining and calculating the measurement results of the two strain gauges 20, the influence of normal stress on shear stress measurement can be eliminated, improving the measurement accuracy.

[0053] To address the shortcomings of existing humanoid robots and industrial robots in accurately sensing force, this invention proposes a new type of robot.

[0054] The technical solution adopted in this utility model is a robot, including the stress amplification device described above.

[0055] In the description of this specification, the terms "Embodiment 1," "this embodiment," or "in one embodiment," etc., indicate that the specific features, structures, materials, or characteristics described in connection with that embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example; moreover, the specific features, structures, materials, or characteristics described may be combined in any appropriate manner in one or more embodiments or examples.

[0056] In the description of this specification, the terms "connection," "installation," "fixing," "setting," and "having" are interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0057] In the description of this specification, relational terms such as “first” and “second” are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase “comprising one…” does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0058] The above description of the embodiments is intended to enable those skilled in the art to understand and apply the technology of this invention. Those skilled in the art can readily make various modifications to these examples and apply the general principles described herein to other embodiments without creative effort. Therefore, this invention is not limited to the above embodiments. Modifications in the following situations should be within the scope of protection of this invention: ① New technical solutions implemented based on the technical solution of this utility model and combined with existing common knowledge, where the technical effects of the new technical solution do not exceed the technical effects of this utility model; ② Equivalent substitutions of some features of the technical solution of this utility model using known technology, resulting in the same technical effects as those of this utility model; ③ Extendable technical solutions based on the technical solution of this utility model, where the substantive content of the extended technical solution does not exceed the technical solution of this utility model; ④ Equivalent transformations made using the content of this utility model specification and drawings, directly or indirectly applied to other related technical fields.

Claims

1. A stress amplification device, characterized by, The device includes a deformation plate and a strain gauge. The deformation plate has a stress concentration groove, and the strain gauge spans the stress concentration groove and is fixedly connected to the deformation plate. In the length direction of the stress concentration groove, the size of the strain gauge does not exceed the length of the stress concentration groove.

2. The stress amplification device of claim 1, wherein, Along the length of the stress concentration groove, the size of the strain gauge is smaller than the length of the stress concentration groove.

3. The stress amplification device of claim 2, wherein, The strain gauge is located in the center of the stress concentration groove.

4. The stress amplification device of claim 1, wherein, The stress concentration groove is a through-hole groove.

5. The stress amplification device according to claim 1, characterized in that, The edge of the deformable sheet has at least one slot.

6. The stress amplification device of any one of claims 1 to 5, wherein, The strain gauge is fixedly connected to the deformation plate via a flexible circuit layer.

7. The stress amplification device of claim 6, wherein, The strain gauge is a printable polymer strain gauge.

8. The stress amplification device of claim 6, wherein, The stress concentration groove has at least two, and the number of strain gauges is the same as the number of stress concentration grooves. All strain gauges are fixedly connected through the same flexible circuit layer and the deformation sheet.

9. The stress amplification device according to any one of claims 1 to 5, characterized in that, The stress concentration groove and the strain gauge are each two in number, and the two stress concentration grooves are symmetrically distributed and set at an angle.

10. A robot, characterized in that Includes the stress amplification device according to any one of claims 1 to 9.

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