Self-decoupled electromagnetic multi-dimensional force tactile sensor

Abstract

Disclosed is a self-decoupling electromagnetic multi-dimensional force tactile sensor, in which a compression and torsion sensing module PCB circuit board is fixed below a base, the compression and torsion sensing module PCB circuit board is provided with two Hall sensors arranged at an angle of 90 degrees for measuring changes in compression and torque; a hard connecting layer is connected to the base via an underlying elastic silica gel to occur compression and torsion deformation, the hard connecting layer is internally provided with a groove for placing a magnet, the magnet is arranged in the hard connecting layer to generate a bias magnetic field; an upper base is connected to the hard connecting layer through a flexible cross slide, the flexible cross slide is externally nested with an upper elastic silica gel, the flexible cross slide resists torsion deformation and does not affect tangential motion thereof; a tangential sensing module PCB circuit board is fixed to the upper base, and the tangential sensing module PCB circuit board is provided with four Hall elements uniformly distributed for measuring changes in shear force.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sensors, in particular to a self-decoupling electromagnetic multi-dimensional force tactile sensor. BACKGROUND

[0002] At present, industrial robots have not been fully automated in precise assembly, precise operation and dexterous grasping, and the breakthrough point is in "tactile perception". In order to improve the delicacy and flexibility of the robot when taking and using tools, four-dimensional force information is actually required. However, the more dimensions of sensor information mean greater challenges. The amount of information of multi-dimensional sensors is massive, and there is coupling between information, which is difficult to decouple. The increase in dimensions also increases the number of devices and the difficulty of processing, greatly increasing the cost. At the same time, the design difficulty of multi-dimensional force sensors can be said to be four times that of one-dimensional force sensors. At present, fingertip flexible force sensors mainly collect one-dimensional and two-dimensional information, and rarely design four-dimensional information. Therefore, in the face of strong market demand and precise operation requirements, a decoupled simple, low-cost and flexible fingertip multi-dimensional force sensor is urgently needed.

[0003] The information disclosed in the background section is only used to enhance the understanding of the background of the present application, and therefore can contain information that does not constitute prior art known to those of ordinary skill in the art. SUMMARY

[0004] In view of the deficiencies or shortcomings of the prior art, a self-decoupling electromagnetic multi-dimensional force tactile sensor is provided, which realizes self-decoupling through structure, can measure pressure, omnidirectional shear force and torque at the same time, and overcomes the defects of complex flexible multi-dimensional force structure, difficult decoupling and lack of torque sensing ability.

[0005] The purpose of the present application is achieved by the following technical solutions.

[0006] A self-decoupling electromagnetic multi-dimensional force tactile sensor comprises,

[0007] a base;

[0008] a pressure and torque sensing module PCB circuit board fixed below the base, the pressure and torque sensing module PCB circuit board being provided with two Hall sensors arranged at an angle of 90 degrees for measuring changes in pressure and torque;

[0009] a hard connecting layer connected to the base via an underlying elastic silica gel to occur under pressure and torsional deformation, the hard connecting layer being internally provided with a groove for placing a magnet, the magnet being arranged in the hard connecting layer to generate a bias magnetic field;

[0010] The upper substrate is connected with the hard connecting layer through a flexible cross slide, the flexible cross slide is externally nested with the upper elastic silica gel, the flexible cross slide resists torsional deformation and does not affect tangential motion thereof;

[0011] The tangential sensing module PCB circuit board is fixed to the upper substrate, and the tangential sensing module PCB circuit board is provided with four Hall elements for measuring uniform distribution of tangential force changes;

[0012] The top cover is arranged on the upper substrate.

[0013] The hard connecting layer and the base are configured in a sleeve structure to limit the tangential motion, so that only normal motion and torsional motion can occur.

[0014] The hard connecting layer and the base are configured in a sleeve structure and the flexible cross slide and the hard connecting layer are matched with each other to realize decoupling of normal, tangential and torsional motions.

[0015] The base is in a circular table structure, the upper surface of the base is provided with a first sleeve extending upward, the hard connecting layer is in a disc structure, the lower surface of the hard connecting layer is provided with a second sleeve extending downward and sleeved with the first sleeve, and the lower elastic silica gel surrounds the first sleeve.

[0016] The height of the lower elastic silica gel is greater than the sum of the heights of the sleeved first sleeve and second sleeve.

[0017] The groove is a cylindrical groove, and the magnet is a cylindrical magnet, which is biased by 2 mm in X and Y directions relative to the center of the hard connecting layer.

[0018] The Hall elements of the tangential sensing module PCB circuit board are arranged in a circumferential array, and the array center coincides with the center of the magnet.

[0019] The upper surface of the top cover is provided with a texture and is coated with RTV glue, and after the glue is air-dried, the top cover is installed as a sensor contact surface to increase the friction between the sensor surface and the contacted object.

[0020] The texture is a concentric circle texture.

[0021] The self-decoupling electromagnetic multi-dimensional force tactile sensor further comprises a single-chip microcomputer connected with the PCB circuit board of the pressure and torsion sensing module and the PCB circuit board of the tangential sensing module, which generates the tangential force, pressure and torque and displays the visualized display through the interactive interface.

[0022] Compared with the prior art, the present application has the following beneficial effects:

[0023] The present application changes the distance between the magnet and the Hall sensor to change the Hall voltage, thereby achieving the effect of measuring the external force size. By biasing the cylindrical magnet and arranging the Hall element in a ninety-degree central symmetry, the detection of the torque size and direction can be realized. Through the flexible cross slide structure and the sleeve structure, the tangential motion and the torsional motion are decoupled in structure, which reduces the difficulty of decoupling in signal processing of the sensor, reduces the decoupling error caused by the use of mathematical model, and improves the sensitivity of the sensor measurement.

[0024] The above description is only a summary of the technical scheme of the present application, in order to make the technical means of the present application more clear and understandable, and to achieve the level that the person skilled in the art can implement according to the content of the description, and in order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the following will be illustrated with specific embodiments of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0025] Various other advantages and benefits of the present application will become apparent to those of ordinary skill in the art, reading the following detailed description of the presently preferred embodiments. The accompanying drawings for the specification are for illustrative purposes only and are not deemed limiting on the present application. Obviously, the drawings described below are only some embodiments of the present application, and other drawings can be obtained from these drawings without creative labor for those of ordinary skill in the art. Moreover, the same reference numerals are used to represent the same parts throughout the drawings.

[0026] In the drawings:

[0027] Figure 1 is an explosive structure schematic diagram of the present application;

[0028] Fig. 2 (a) to Fig. 2 (c) is a flexible cross slide schematic diagram of the present application, wherein Fig. 2 (a) is a structural schematic diagram of the flexible cross slide, Fig. 2 (b) is a schematic diagram of each direction motion of the flexible cross slide, and Fig. 2 (c) is a sleeve structure schematic diagram;

[0029] Figure 3 is a schematic diagram of the Hall element array and its relative position with the magnet of the present application;

[0030] Figure 4Fig. 1 is a schematic diagram of a sensing principle of a tangential sensing module PCB circuit board according to the present application;

[0031] Figure 5 Fig. 2 is a schematic diagram of a sensing principle of a compression-torsion sensing module PCB circuit board according to the present application;

[0032] Figure 6 Fig. 3 is a structural schematic diagram of a self-decoupling electromagnetic multi-dimensional force tactile sensor according to the present application.

[0033] The present application will be further explained in conjunction with the accompanying drawings and embodiments. DETAILED DESCRIPTION

[0034] Embodiments of the present application will be described in more detail with reference to the accompanying drawings. While the present application will be described in conjunction with preferred embodiments, it will be understood that they are not intended to limit the present application to these embodiments. On the contrary, the present application covers all alternatives, modifications and equivalents falling within the scope of the present application. Various embodiments of the present application will now be described with reference to the accompanying drawings.

[0035] It should be noted that certain terms have been used throughout the specification and claims which have either been used as synonyms for, or to be understood via use in this patent document in a manner similar to, certain previously used terms. It is presumed that persons of ordinary skill in the art would be able to effectively utilize the present application as currently described, and that upon reading the disclosure, others will be able to effectuate suitable implementations of the present application without undue experimentation.

[0036] In order to understand the embodiments of the present application, the following will be further explained in conjunction with the accompanying drawings and several specific embodiments as examples, and each of the accompanying drawings does not constitute a limitation to the embodiments of the present application.

[0037] For better understanding, as shown in Figures 1 to 6 Fig. 1 is a schematic diagram of a sensing principle of a tangential sensing module PCB circuit board according to the present application;

[0038] a base 9;

[0039] a compression-torsion sensing module PCB circuit board 10 fixed below the base 9, the compression-torsion sensing module PCB circuit board 10 being provided with two Hall sensors arranged at a 90-degree angle for measuring changes in pressure and torque;

[0040] A hard connecting layer 6 connects the base 9 via the lower layer of elastic silica gel 8 to occur under pressure and torsional deformation, the hard connecting layer 6 is provided with a recess for placing the magnet 7, the magnet 7 is arranged in the hard connecting layer 6 to generate a bias magnetic field;

[0041] The upper layer of the base 3 is connected to the hard connecting layer 6 by a flexible cross slide 4, which is externally nested in the upper layer of the elastic silica gel 5, the flexible cross slide 4 resists torsional deformation and does not affect its tangential motion;

[0042] The tangential sensing module PCB circuit board 2 is fixed to the upper layer of the base 3, and the tangential sensing module PCB circuit board 2 is provided with four Hall elements for measuring the uniform distribution of shear force changes;

[0043] The top cover 1 is provided on the upper layer of the base 3.

[0044] In the preferred embodiment of the self-decoupling electromagnetic multi-dimensional force tactile sensor, the hard connecting layer 6 and the base 9 are configured in a sleeve structure to limit the tangential motion, so that only normal motion and torsional motion can occur.

[0045] In the preferred embodiment of the self-decoupling electromagnetic multi-dimensional force tactile sensor, the hard connecting layer 6 and the base 9 are configured in a sleeve structure and the flexible cross slide 4 and the hard connecting layer 6 are matched to realize the decoupling of the normal, tangential and torsional motion forms.

[0046] In the preferred embodiment of the self-decoupling electromagnetic multi-dimensional force tactile sensor, the base 9 is a circular table structure, and the upper surface thereof is provided with a first sleeve extending upward, the hard adhesive layer is a disc structure, and the lower surface thereof is provided with a second sleeve extending downward and fitted in the first sleeve, and the lower layer of the elastic silica gel 8 surrounds the first sleeve.

[0047] In the preferred embodiment of the self-decoupling electromagnetic multi-dimensional force tactile sensor, the height of the lower layer of the elastic silica gel 8 is greater than the sum of the heights of the fitted first sleeve and the second sleeve.

[0048] In the preferred embodiment of the self-decoupling electromagnetic multi-dimensional force tactile sensor, the recess is a cylindrical recess, and the magnet 7 is a cylindrical magnet 7, which is biased by 2mm in X and Y directions relative to the center of the hard connecting layer 6.

[0049] In the 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 arranged in a circumferential array, and the array center coincides with the center of the magnet 7.

[0050] In the preferred embodiment of the self-decoupling electromagnetic multi-dimensional force tactile sensor, the upper surface of the top cover 1 is textured and coated with RTV glue, and after the glue is dried, it is installed as the sensor contact surface to increase the friction between the sensor surface and the contacted object.

[0051] In the preferred embodiment of the self-decoupling electromagnetic multi-dimensional force tactile sensor, the texture is a concentric circle texture.

[0052] In the preferred embodiment of the self-decoupling electromagnetic multi-dimensional force tactile sensor, a single-chip microcomputer is further included for connecting the pressure and torque sensing module PCB circuit board 10 and the tangential sensing module PCB circuit board 2, which generates the tangential force, pressure and torque and displays them visually through an interactive interface.

[0053] In one embodiment, by converting the pressure, shear force and torque applied on the surface into voltage changes of the respective position Hall elements, the size 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. By biasing the magnetic field, high-resolution measurement of the size and direction of the torque is achieved. Combined with the calibration matrix, the size and direction information of the loaded multi-dimensional force can be obtained simultaneously.

[0054] In one embodiment, the self-decoupling electromagnetic multi-dimensional force tactile sensor includes a base 9, below which a pressure and torque sensing module PCB circuit board 10 is fixed, on which two Hall sensors arranged at a 90-degree angle are attached for measuring the changes in pressure and torque. A hard connecting layer 6 is provided on the base, which is connected to the base 9 through an underlying elastic silicone 8 for deformation under pressure and torsion. A cylindrical recess is provided inside the hard connecting layer for placing a cylindrical magnet 7. The cylindrical magnet 7 is arranged in a biasing arrangement, with a 2mm bias in the X and Y directions, for generating a bias magnetic field. An upper layer substrate 3 is provided above the hard connecting layer 6, which is connected to the hard connecting layer 6 through a flexible cross slide 4, and an upper layer elastic silicone 5 is nested outside the flexible cross slide 4. A tangential sensing module PCB circuit board 2 is fixed above the upper layer substrate, on which four Hall elements are attached for measuring the changes in shear force. A top cover 1 is provided on the top, the surface of which is textured and coated with RTV glue for increasing the friction of the contact surface. The PCB circuit boards are connected to an external STM32 single-chip microcomputer, and after the Hall voltage AD is converted, it is transmitted to the upper computer through the serial port for further filtering and processing, and the size of the force and torque is calculated by combining the calibration matrix, and displayed visually through an interactive interface.

[0055] The compression-torsion sensing module PCB circuit board 10 and the tangential sensing module PCB circuit board 2 share a cylindrical magnet, i.e. share a magnetic field source. Preferably, in order to avoid the interference of torque on the tangential sensing module PCB circuit board 2, a flexible cross slide 4 is arranged, as shown in FIG. 2(a). The flexible cross slide 4 structure is 3d printed through flexible resin (80A) 3d printing, and then obtained through ultrasonic cleaning and ultraviolet curing. As shown in FIG. 2(b), the cross slide structure can resist torsional deformation without affecting its tangential motion, so that the tangential and torsional motions can be decoupled. Further, in order to avoid the interference of the tangential force on the compression-torsion sensing module PCB circuit board 10, a sleeve structure is adopted, as shown in FIG. 2(c). The sleeve structure can realize the normal and torque motion while preventing the tangential motion, thereby realizing the decoupled measurement of the compression-torsion sensing module PCB circuit board 10 and the tangential sensing module PCB circuit board 2.

[0056] The relative position of the array of Hall elements and the magnet is shown in Figure 3 The Hall elements in the tangential sensing module PCB circuit board 2 are circumferentially distributed, and the center of the circle coincides with the center of the cylindrical magnet. The compression-torsion sensing module PCB circuit board 10 is 90-degree central symmetrically distributed, and the center line thereof is offset from the center of the magnet by a certain distance.

[0057] As shown in Figure 4 For the tangential sensing module PCB circuit board 2, when a tangential force in the Y positive direction is applied, the magnet is close to S1 and far from S4, the voltage of S1 increases, the voltage of S4 decreases, and the voltages of 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 a tangential force in the Y negative direction is applied, S1 decreases and S4 increases. When a force in the X direction is applied, S2 and S3 change in opposite directions, similar to the Y direction.

[0058] As shown in Figure 5 For the compression-torsion sensing module PCB circuit board 10, when it rotates clockwise, the magnet is close to S5 and far 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 the voltage of S6 decreases. When it rotates counterclockwise, the voltages of S5 and S6 change in opposite directions. When it is pressed vertically, the magnet is close to S5 and S6 at the same distance, so the voltages of S5 and S6 increase by the same amount. By combining the compression-torsion sensing module PCB circuit board 10 and the tangential sensing module PCB circuit board 2, decoupled measurement of multi-dimensional force can be realized. In the embodiment, the lower layer of elastic silicone is a mixture of ecoflex 10A glue and B glue in a ratio of 1:1; the upper layer of silicone is a mixture of ecoflex 50A glue and B glue in a ratio of 1:1. In the embodiment, the Hall elements are soldered to the PCB circuit board, and FPC flexible circuit board can also be selected.

[0059] The above describes the basic principles of the present application in conjunction with specific embodiments, but it should be noted that the advantages, benefits, effects and the like mentioned in the present application are only examples and are not limiting, and these advantages, benefits, effects and the like cannot be considered as necessary for each embodiment of the present application. In addition, the above specific details disclosed are only for the purpose of example and understanding, and are not limiting, and the above details do not limit the present application to be necessarily implemented with the above specific details.

[0060] The foregoing description has been presented for the purposes of illustration and description. Furthermore, the description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although several example aspects and embodiments have been discussed above, those of ordinary skill in the art will appreciate a variety of modifications, alternatives, permutations, additions, and sub-combinations of the described aspects and embodiments.

Claims

1. A self-decoupled electromagnetic multi-dimensional force tactile sensor, characterized by, It comprises, a base; a pressure and torque sensing module PCB circuit board fixed below the base, which is provided with two Hall sensors arranged at an angle of 90 degrees for measuring changes in pressure and torque; a hard connecting layer connecting the base via an underlying elastic silica gel to occur under pressure and torsional deformation, which is internally provided with a groove for placing a magnet, which is arranged in the hard connecting layer to generate a bias magnetic field; an upper substrate connected to the hard connecting layer by a flexible cross slide, which is externally nested with an upper elastic silica gel, which resists torsional deformation and does not affect its tangential motion; a tangential sensing module PCB circuit board fixed to the upper substrate, which is provided with four Hall elements for measuring changes in shear force; a top cover covering the upper substrate.

2. The self-decoupled electromagnetic multi-dimensional force tactile sensor of claim 1, wherein, Preferably, the hard connecting layer and the base are configured in a sleeve structure to limit its tangential motion, so that only normal motion and torsional motion can occur.

3. The self-decoupled electromagnetic multi-dimensional force tactile sensor of claim 2, wherein, The hard connecting layer and the base are configured in a sleeve structure, and the flexible cross slide and the hard connecting layer are matched to each other to realize decoupling of normal, tangential and torsional motion forms.

4. The self-decoupled electromagnetic multi-dimensional force tactile sensor of claim 2, wherein, The base is a circular table structure, and the upper surface is provided with a first sleeve extending upward, and the hard connecting layer is a circular disc structure, and the lower surface is provided with a second sleeve extending downward and sleeved with the first sleeve, and the underlying elastic silica gel surrounds the first sleeve.

5. The self-decoupled electromagnetic multi-dimensional force tactile sensor of claim 4, wherein, The height of the underlying elastic silica gel is greater than the sum of the heights of the sleeved first sleeve and second sleeve.

6. The self-decoupled electromagnetic multi-dimensional force tactile sensor of claim 1, wherein, The groove is a cylindrical groove, and the magnet is a cylindrical magnet, which is biased by 2mm in X and Y directions relative to the center of the hard connecting layer.

7. The self-decoupled electromagnetic multi-dimensional force tactile sensor of claim 1, wherein, The Hall elements of the tangential sensing module PCB circuit board are arranged in a circumferential array, and the array center coincides with the center of the magnet.

8. The self-decoupled electromagnetic multi-dimensional force tactile sensor of claim 1, wherein, 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 a sensor contact surface to increase the friction between the sensor surface and the contacted object.

9. The self-decoupled electromagnetic multi-dimensional force tactile sensor of claim 8, wherein, The texture is a concentric circle texture.

10. The self-decoupled electromagnetic multi-dimensional force tactile sensor of claim 1, wherein, It also includes a single-chip microcomputer connecting the pressure and torque sensing module PCB circuit board and the tangential sensing module PCB circuit board, which generates shear force, pressure and torque and displays them visually through an interactive interface.

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