Self-decoupling electromagnetic multi-dimensional force tactile sensor

Abstract

According to the self-decoupling electromagnetic type multi-dimensional force tactile sensor, a pressure-torsion sensing module PCB is fixed to the lower portion of a base, and the pressure-torsion sensing module PCB is provided with two Hall sensors which are used for measuring changes of pressure and torque and are arranged at an angle of 90 degrees; the hard connecting layer is connected with the base through the lower-layer elastic silica gel so as to generate downward pressing and torsional deformation, a groove used for containing a magnet is formed in the hard connecting layer, and the magnet is arranged in the hard connecting layer in a bias mode so as to generate a bias magnetic field; the upper-layer substrate is connected with the hard connecting layer through the flexible cross-shaped sliding table, upper-layer elastic silica gel is nested outside the flexible cross-shaped sliding table, and the flexible cross-shaped sliding table resists torsional deformation and does not affect tangential movement of the flexible cross-shaped sliding table; the tangential sensing module PCB is fixed on the upper substrate, and four Hall elements which are used for measuring change of shearing force and are evenly distributed are pasted on the tangential sensing module PCB.

Description

Technical Field

[0001] The present invention relates to the field of sensor technology, in particular to a self-decoupling electromagnetic multi-dimensional force tactile sensor. Background Art

[0002] At present, industrial robots have not been fully automated in terms of precise assembly, precise operation, and dexterous grasping. The breakthrough point lies in "tactile perception". To improve the refinement and flexibility of robots when picking up and using tools, four-dimensional force information is actually required. However, the large number of dimensions of sensor information also means great challenges. The amount of information in multi-dimensional sensors is massive, and there is coupling between information, which makes it very difficult to decouple information. The increase in dimensions also increases the number of devices, increases the difficulty of processing, and greatly increases the cost. At the same time, the design difficulty of multi-dimensional force sensors can be said to be the fourth power of the difficulty of one-dimensional force sensors. At present, fingertip flexible force sensors mostly collect one-dimensional and two-dimensional information, and rarely design four-dimensional information. Therefore, in the face of strong market demand and precise operation needs, there is an urgent need for a finger surface multi-dimensional force sensor with simple decoupling, low cost, and flexibility.

[0003] The information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. Summary of the invention

[0004] In response to the shortcomings or defects of the existing technology, a self-decoupling electromagnetic multi-dimensional force tactile sensor is provided, which achieves self-decoupling through structure and can measure pressure, omnidirectional shear force and torque at the same time, overcoming the defects of the current flexible multi-dimensional force structure being complex, decoupling being difficult, and lacking the ability to perceive torque.

[0005] The purpose of the present invention is achieved through the following technical solutions.

[0006] A self-decoupling electromagnetic multi-dimensional force tactile sensor, comprising: Base; A compression-twist sensing module PCB circuit board is fixed under the base, and the compression-twist sensing module PCB circuit board is provided with two Hall sensors arranged at a 90-degree angle for measuring changes in pressure and torque; A hard connection layer, which is connected to the base via a lower layer of elastic silicone to be pressed down and twisted, and a groove for placing a magnet is provided inside the hard connection layer, and the magnet is offset in the hard connection layer to generate a bias magnetic field; An upper substrate is connected to the hard connection layer via a flexible cross slide, an upper elastic silicone is embedded outside the flexible cross slide, and the flexible cross slide resists torsional deformation and does not affect its tangential movement; A tangential sensing module PCB circuit board is fixed to the upper substrate, and the tangential sensing module PCB circuit board patch has four evenly distributed Hall elements for measuring shear force changes; A top cover is arranged on the upper base.

[0007] In the self-decoupling electromagnetic multi-dimensional force tactile sensor, a sleeve structure is constructed between the hard connection layer and the base to cooperate with each other to limit its tangential movement, so that only normal movement and torsional movement can occur.

[0008] In the self-decoupling electromagnetic multi-dimensional force tactile sensor, the hard connection layer and the base are configured to form a sleeve structure, and the flexible cross slide and the hard connection layer cooperate with each other to achieve decoupling of the three motion forms of normal, tangential and torsional.

[0009] In the self-decoupling electromagnetic multi-dimensional force tactile sensor, the base is a truncated cone structure, and a first sleeve extending upward is provided on its upper surface; the hard adhesive layer is a disc-shaped structure, and a second sleeve extending downward and fitting on the first sleeve is provided on its lower surface; the lower layer of elastic silicone surrounds the first sleeve.

[0010] In the self-decoupling electromagnetic multi-dimensional force tactile sensor, the height of the lower layer of elastic silicone is greater than the sum of the heights of the fitted first sleeve and the second sleeve.

[0011] In the self-decoupling electromagnetic multi-dimensional force tactile sensor, the groove is a cylindrical groove, and the magnet is a cylindrical magnet, which is offset by 2 mm in both the X and Y directions relative to the center of the hard connection layer.

[0012] In the self-decoupling electromagnetic multi-dimensional force tactile sensor, the Hall elements of the tangential sensing module PCB circuit board are distributed in a circular array, and the center of the array coincides with the center of the magnet.

[0013] In the self-decoupling electromagnetic multi-dimensional force tactile sensor, the upper surface of the top cover is provided with a texture and coated with RTV glue, and after the glue is air-dried, it is installed as the sensor contact surface to increase the friction between the sensor surface and the contact object.

[0014] In the self-decoupling electromagnetic multi-dimensional force tactile sensor, the texture is a concentric circle texture.

[0015] The self-decoupling electromagnetic multi-dimensional force tactile sensor also includes a single-chip microcomputer connecting the compression and torsion sensing module PCB circuit board and the tangential sensing module PCB circuit board, which generates tangential force, pressure and torque and displays them visually through an interactive interface.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The present invention changes the Hall voltage by changing the distance between the magnet and the Hall sensor to achieve the effect of measuring the size of the external force. By biasing the cylindrical magnet and arranging the Hall elements in a 90-degree central symmetry, the size and direction of the torque can be detected. Through the flexible cross slide structure and sleeve structure, the tangential motion and the torsional motion are structurally decoupled, which reduces the difficulty of decoupling when the sensor calculates the signal processing, reduces the decoupling error caused by the use of mathematical models, and improves the sensitivity of the sensor measurement.

[0017] The above description is only an overview of the technical solution of the present invention. In order to make the technical means of the present invention clearer and to achieve the extent that those skilled in the art can implement it according to the contents of the specification, and in order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are exemplified below. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] By reading the detailed description of the preferred specific embodiments below, various other advantages and benefits of the present invention will become clear to those of ordinary skill in the art. The drawings in the specification are only for the purpose of illustrating the preferred embodiments and are not considered to be limitations of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative work. Moreover, the same reference numerals are used to represent the same components throughout the drawings.

[0019] In the attached picture: Figure 1 It is a schematic diagram of the explosion structure of the present invention; Figures 2(a) to 2(c) are schematic diagrams of the flexible cross slide of the present invention, wherein Figure 2(a) is a schematic diagram of the structure of the flexible cross slide, Figure 2(b) is a schematic diagram of the directional motion of the flexible cross slide, and Figure 2(c) is a schematic diagram of the sleeve structure; Figure 3 It is a schematic diagram of the relative position of the Hall element array and the magnet of the present invention; Figure 4 It is a schematic diagram of the sensing principle of the tangential sensing module PCB circuit board of the present invention; Figure 5 It is a schematic diagram of the sensing principle of the PCB circuit board of the compression and twist sensing module of the present invention; Figure 6 It is a structural schematic diagram of the present invention.

[0020] The present invention is further explained below in conjunction with the accompanying drawings and embodiments. DETAILED DESCRIPTION

[0021] The specific embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the specific embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to enable the scope of the present invention to be fully communicated to those skilled in the art.

[0022] It should be noted that certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that technicians may use different nouns to refer to the same component. This specification and claims do not use the difference in nouns as a way to distinguish components, but use the difference in the functions of the components as the criterion for distinction. As mentioned throughout the specification and claims, "including" or "comprising" is an open term, so it should be interpreted as "including but not limited to". The subsequent description of the specification is a preferred embodiment of the present invention, but the description is based on the general principles of the specification and is not intended to limit the scope of the present invention. The scope of protection of the present invention shall be determined by the attached claims.

[0023] To facilitate understanding of the embodiments of the present invention, several specific embodiments will be further explained below with reference to the accompanying drawings, and each of the accompanying drawings does not constitute a limitation on the embodiments of the present invention.

[0024] For a better understanding, Figures 1 to 6 As shown, a self-decoupling electromagnetic multi-dimensional force tactile sensor includes: Base 9; A compression-torsion sensing module PCB circuit board 10 is fixed below the base 9. The compression-torsion sensing module PCB circuit board 10 is provided with two Hall sensors arranged at a 90-degree angle for measuring changes in pressure and torque; A hard connection layer 6, which is connected to the base 9 via a lower layer of elastic silicone 8 to be pressed down and twisted, and a groove for placing a magnet 7 is provided inside the hard connection layer 6, and the magnet 7 is offset in the hard connection layer 6 to generate a bias magnetic field; An upper substrate 3 is connected to a hard connection layer 6 via a flexible cross slide 4, an upper elastic silicone rubber 5 is nested outside the flexible cross slide 4, and the flexible cross slide 4 resists torsional deformation and does not affect its tangential movement; A tangential sensing module PCB circuit board 2 is fixed to the upper substrate 3, and the tangential sensing module PCB circuit board 2 has four evenly distributed Hall elements for measuring shear force changes; The top cover 1 is covered on the upper base 3 .

[0025] In a preferred embodiment of the self-decoupling electromagnetic multi-dimensional force tactile sensor, a sleeve structure is constructed between the hard connection layer 6 and the base 9 to cooperate with each other to limit the tangential movement thereof, so that only normal movement and torsional movement can occur.

[0026] In the preferred embodiment of the self-decoupling electromagnetic multi-dimensional force tactile sensor, the hard connection layer 6 and the base 9 are configured to form a sleeve structure and the flexible cross slide 4 and the hard connection layer 6 cooperate with each other to achieve decoupling of the three motion forms of normal, tangential and torsional.

[0027] In a preferred embodiment of the self-decoupling electromagnetic multi-dimensional force tactile sensor, the base 9 is a truncated cone-shaped structure, and a first sleeve extending upward is provided on its upper surface; the hard adhesive layer is a disc-shaped structure, and a second sleeve extending downward and fitting on the first sleeve is provided on its lower surface; the lower layer of elastic silicone 8 surrounds the first sleeve.

[0028] In a preferred embodiment of the self-decoupling electromagnetic multi-dimensional force tactile sensor, the height of the lower layer of elastic silicone 8 is greater than the sum of the heights of the fitted first sleeve and the second sleeve.

[0029] In a preferred embodiment of the self-decoupling electromagnetic multi-dimensional force tactile sensor, the groove is a cylindrical groove, and the magnet 7 is a cylindrical magnet 7 , which is offset by 2 mm in both the X and Y directions relative to the center of the hard connection layer 6 .

[0030] In a preferred embodiment of the self-decoupling electromagnetic multi-dimensional force tactile sensor, the Hall elements of the tangential sensing module PCB circuit board 2 are distributed in a circular array, and the center of the array coincides with the center of the magnet 7.

[0031] In a preferred embodiment of the self-decoupling electromagnetic multi-dimensional force tactile sensor, the upper surface of the top cover 1 is provided with a texture and coated with RTV glue, and after the glue is air-dried, it is installed as the sensor contact surface to increase the friction between the sensor surface and the contact object.

[0032] In a preferred embodiment of the self-decoupling electromagnetic multi-dimensional force tactile sensor, the texture is a concentric circle texture.

[0033] In a preferred embodiment of the self-decoupling electromagnetic multi-dimensional force tactile sensor, it also includes a single-chip microcomputer connecting the compression and torsion sensing module PCB circuit board 10 and the tangential sensing module PCB circuit board 2, which generates tangential force, pressure and torque and displays them visually through an interactive interface.

[0034] In one embodiment, by converting the pressure, shear force and torque applied on the surface into voltage changes of the Hall elements at each position, the magnitude and direction of the applied force or torque can be obtained by detecting the Hall voltage. The decoupling of pressure, omnidirectional shear force and torque can be achieved in structure. The high-resolution measurement of the magnitude and direction of the torque can be achieved through the bias magnetic field. Combined with the calibration matrix, the magnitude and direction information of the loaded multi-dimensional force can be obtained at the same time.

[0035] In one embodiment, the self-decoupling electromagnetic multi-dimensional force tactile sensor includes a base 9, a compression and torsion sensing module PCB circuit board 10 is fixed below the base 9, and the patch on the compression and torsion sensing module PCB circuit board 10 has two Hall sensors arranged at a 90-degree angle for measuring changes in pressure and torque. A hard connection layer 6 is provided on the base, and the hard connection layer 6 is connected to the base 9 through a lower layer of elastic silicone 8 for downward pressure and torsion deformation. A cylindrical groove is provided inside the hard connection layer for placing a cylindrical magnet 7. The cylindrical magnet 7 is arranged in an offset arrangement, with an X and Y direction offset of 2mm, for generating a bias magnetic field. An upper substrate 3 is provided above the hard connection layer 6, and the upper substrate 3 is connected to the hard connection layer 6 through a flexible cross slide 4, and an upper elastic silicone 5 is nested outside the flexible cross slide 4. A tangential sensing module PCB circuit board 2 is fixed above the upper substrate, and the patch on the tangential sensing module PCB circuit board 2 has four Hall elements evenly arranged for measuring shear force changes. A top cover 1 is provided on the top, and the surface of the top cover 1 is textured and coated with RTV glue to increase the friction of the contact surface. The PCB circuit boards are connected to the external STM32 microcontroller, and the Hall voltage AD conversion is transmitted to the host computer through the serial port for further filtering and other processing, and the magnitude of the force and torque is obtained by combining the calibration matrix calculation, and is visually displayed through the interactive interface.

[0036] The compression-torsion sensing module PCB circuit board 10 and the tangential sensing module PCB circuit board 2 share a cylindrical magnet, that is, a magnetic field source. Preferably, in order to prevent the tangential sensing module PCB circuit board 2 from being disturbed by torque, a flexible cross slide 4 is provided, as shown in FIG2(a). The flexible cross slide 4 structure is obtained by 3D printing with a flexible resin (80A), ultrasonic cleaning, and UV curing. As shown in FIG2(b), the cross slide structure can resist torsional deformation without affecting its tangential movement, so that the decoupling of tangential and torsional motions can be achieved. Furthermore, in order to prevent the compression-torsion sensing module PCB circuit board 10 from being disturbed by tangential forces, a sleeve structure is adopted, as shown in FIG2(c). The sleeve structure can realize normal and torque motion and prevent tangential motion, thereby realizing the decoupling measurement of the compression-torsion sensing module PCB circuit board 10 and the tangential sensing module PCB circuit board 2.

[0037] The relative position of the Hall element array and the magnet is as follows: Figure 3 As shown, the Hall elements in the tangential sensing module PCB circuit board 2 are distributed in a circle, and its center coincides with the center of the cylindrical magnet. The compression and torsion sensing module PCB circuit board 10 is distributed in a 90-degree central symmetry, and there is a certain offset distance between its connection center and the center of the magnet.

[0038] like Figure 4 As shown, for the tangential sensing module PCB circuit board 2, when subjected to a tangential force in the positive Y direction, the magnet approaches S1 and moves away from S4, the voltage of the Hall element S1 increases, S4 decreases, and S2 and S3 both increase slightly. Therefore, the tangential force in the Y direction can be measured by measuring the difference between S1 and S4. When subjected to a tangential force in the negative Y direction, S1 decreases and S4 increases. When subjected to a force in the X direction, similar to the Y direction, S2 and S3 show opposite change trends.

[0039] like Figure 5 As shown, for the compression-torsion sensing module PCB circuit board 10, when rotating clockwise, the magnet approaches S5 and moves away from S6. Since the compression-torsion sensing module PCB circuit board 10 is located at the S pole of the magnet, the voltage of S5 increases and that of S6 decreases. When rotating counterclockwise, the voltage changes in the opposite direction. When pressed vertically downward, the magnet approaches S5 and S6 at the same time, and the approach distance is the same, so S5 and S6 increase by the same amount. Combining the compression-torsion sensing module PCB circuit board 10 with the tangential sensing module PCB circuit board 2, decoupled measurement of multi-dimensional forces can be achieved. The lower layer of elastic silicone mentioned in the embodiment adopts a 1:1 mixture of ecoflex10A glue and B glue; the upper layer of silicone adopts a 1:1 mixture of ecoflex50 A glue and B glue. The Hall element mentioned in the embodiment is soldered to the PCB circuit board, and an FPC flexible circuit board can also be selected.

[0040] The basic principles of the present application are described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, effects, etc. mentioned in the present application are only examples and not limitations, and it cannot be considered that these advantages, strengths, effects, etc. are required by each embodiment of the present application. In addition, the specific details disclosed above are only for the purpose of illustration and ease of understanding, not for limitation, and the above details do not limit the present application to being implemented by adopting the above specific details.

[0041] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although multiple example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. A self-decoupling electromagnetic multi-dimensional force tactile sensor, characterized in that: These include, Base; A compression-twist sensing module PCB circuit board is fixed under the base, and the compression-twist sensing module PCB circuit board is provided with two Hall sensors arranged at a 90-degree angle for measuring changes in pressure and torque; A hard connection layer, which is connected to the base via a lower layer of elastic silicone to be pressed down and twisted, and a groove for placing a magnet is provided inside the hard connection layer, and the magnet is offset in the hard connection layer to generate a bias magnetic field; An upper substrate is connected to the hard connection layer via a flexible cross slide, an upper elastic silicone is embedded outside the flexible cross slide, and the flexible cross slide resists torsional deformation and does not affect its tangential movement; A tangential sensing module PCB circuit board is fixed to the upper substrate, and the tangential sensing module PCB circuit board patch has four evenly distributed Hall elements for measuring shear force changes; A top cover is arranged on the upper base.

2. The self-decoupling electromagnetic multi-dimensional force tactile sensor according to claim 1, characterized in that: Preferably, a sleeve structure is constructed between the hard connection layer and the base to cooperate with each other to limit the tangential movement thereof, so that only normal movement and torsional movement can occur.

3. The self-decoupling electromagnetic multi-dimensional force tactile sensor according to claim 2, characterized in that: A sleeve structure is constructed between the hard connection layer and the base, and the flexible cross slide and the hard connection layer cooperate with each other to achieve decoupling of three motion forms: normal, tangential and torsion.

4. The self-decoupling electromagnetic multi-dimensional force tactile sensor according to claim 2, characterized in that: The base is a truncated cone structure, and a first sleeve extending upward is provided on its upper surface. The hard adhesive layer is a disc-shaped structure, and a second sleeve extending downward and fitting on the first sleeve is provided on its lower surface. The lower layer of elastic silicone surrounds the first sleeve.

5. The self-decoupling electromagnetic multi-dimensional force tactile sensor according to claim 4, characterized in that: The height of the lower layer of elastic silicone is greater than the sum of the heights of the fitted first sleeve and the second sleeve.

6. The self-decoupling electromagnetic multi-dimensional force tactile sensor according to claim 1, characterized in that: The groove is a cylindrical groove, and the magnet is a cylindrical magnet, which is offset by 2 mm in both the X and Y directions relative to the center of the hard connection layer.

7. The self-decoupling electromagnetic multi-dimensional force tactile sensor according to claim 1, characterized in that: The Hall elements of the tangential sensing module PCB circuit board are distributed in a circular array, and the center of the array coincides with the center of the magnet.

8. The self-decoupling electromagnetic multi-dimensional force tactile sensor according to claim 1, characterized in that: The upper surface of the top cover is provided with textures and coated with RTV glue, and after the glue is air-dried, it is installed as the sensor contact surface to increase the friction between the sensor surface and the contact object.

9. The self-decoupling electromagnetic multi-dimensional force tactile sensor according to claim 8, characterized in that: The texture is a concentric circle texture.

10. The self-decoupling electromagnetic multi-dimensional force tactile sensor according to claim 1, characterized in that: It also includes a single chip microcomputer connecting the compression and torsion sensing module PCB circuit board and the tangential sensing module PCB circuit board, which generates tangential force, pressure and torque and displays them visually through an interactive interface.

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