Curved-surface electromagnetic touch sensor, electronic skin and robot
By embedding a magnetic source and magnetic field measurement electronic components within a flexible body, the curved electromagnetic tactile sensor solves the problems of insufficient sensitivity and poor stability in existing technologies, achieving fast response and high signal-to-noise ratio force detection.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- BEIJING TASHAN TECHNOLOGY CO LTD
- Filing Date
- 2025-05-30
- Publication Date
- 2026-05-12
AI Technical Summary
Existing electromagnetic tactile sensors have shortcomings in force detection sensitivity and stability, are easily affected by temperature and humidity, and are difficult to optimize due to structural complexity.
A curved electromagnetic tactile sensor was designed, which uses a flexible body to embed a magnetic source and magnetic field measurement electronic components. It detects external force by deforming the curved surface of the flexible structure. Combined with analog-to-digital conversion circuit and capacitance/piezoelectric/piezoresistive measurement circuit, it achieves high sensitivity and stable force detection.
It achieves force detection with fast response, low noise ratio, high signal-to-noise ratio and high sensitivity. It has a simple structure and good stability, and can adapt to various environmental changes.
Smart Images
Figure CN224231143U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to machine tactile perception, and more particularly to a curved electromagnetic tactile sensor, electronic skin, and robot. Background Technology
[0002] Electromagnetic tactile sensing, as an emerging tactile sensing technology, is sensitive to minute forces / deformations based on electromagnetic principles and is not easily affected by temperature and humidity.
[0003] JP6703728B2 proposes a proximity tactile sensor in which a magnetic body is suspended on a magnetic detection element by a foam material. The bottom surface of the foam material is flat, and the flexible deformation relies solely on the deformation of the foam itself, which reduces the force detection sensitivity.
[0004] CN119880234A proposes a hemispherical magnetic tactile sensor, in which a neodymium iron boron magnetic cylinder is embedded in a silicone elastomer shell, and four TMRs are arranged underneath. The silicone elastomer shell protrudes upward to form a curved surface that is easy to bear force, and the bottom contact surface with the TMR is also a flat surface.
[0005] CN119238587A proposes a magnetic sensor in which a magnetic source is placed on the inner surface of a flexible hemisphere, the inner cavity of the flexible hemisphere is filled with air, and a magnetic detection element is placed in the inner cavity of the flexible hemisphere. Adaptive deformation is achieved by utilizing the air gap. Although this improves flexibility, changes in external air pressure caused by altitude and temperature can easily lead to unexpected deformation of the shell, introducing interference. At the same time, when the flexible hemisphere deforms, the magnetic source may undergo unexpected displacement or rotation, resulting in disordered magnetic field direction and increasing the complexity of model solution. Utility Model Content
[0006] To address the shortcomings of existing technologies, a curved electromagnetic tactile sensor is provided.
[0007] As a solution, the curved electromagnetic tactile sensor provided by this utility model includes a measurement branch, a processing module, and at least one sensing unit. Each sensing unit is provided with a flexible body for contacting external objects, and a force detection component is disposed within the area contained in the flexible body. The flexible body has a downwardly protruding flexible structure, and the surface of the flexible structure is curved. The force detection component includes a magnetic source for actively generating a magnetic field and at least one magnetic field measuring electronic element. The magnetic source is embedded in the flexible structure, and the magnetic field measuring electronic element is located below the flexible structure. The magnetic field measuring electronic element is in direct or indirect contact with the curved surface of the flexible structure. The deformation of the flexible body under external force causes the curved surface of the flexible structure to change the direct or indirect contact area with the magnetic field measuring electronic element. The measurement branch includes an analog-to-digital conversion circuit. The processing module is coupled to each magnetic field measuring electronic element through the analog-to-digital conversion circuit to output an electrical signal characterizing the contact force based on the magnetic flux of the magnetic field measuring electronic element changed by the deformation of the flexible structure.
[0008] This utility model provides a curved electromagnetic tactile sensor, and also includes the following auxiliary solutions:
[0009] The magnetic field measuring electronic element has at least three components, and each magnetic field measuring electronic element is distributed around the flexible structure.
[0010] The lower surface of the flexible structure is axially symmetric, and all the magnetic field measuring electronic components are located in the same plane and are uniformly distributed around the axis of symmetry of the lower surface of the flexible structure.
[0011] The flexible body is a cover with its surface converging upwards, and the flexible structure is fixed to the inner surface of the cover; and / or, the flexible body and the flexible structure are integrally formed or separately set.
[0012] The surface of the flexible structure is either spherical or ellipsoidal.
[0013] The flexible body is made of a non-ferromagnetic conductive material and serves as a proximity detection electrode. The measurement branch includes a capacitance-to-digital conversion circuit, which is coupled to the flexible body to obtain the capacitance change caused by the approach of an external object. The processing module is coupled to the capacitance-to-digital conversion circuit and is used to output a proximity sensing signal based on the capacitance change.
[0014] The flexible body has at least two measurement points, which are arranged at different positions on the corresponding flexible body to form a sensing array of sensing units. Each measurement point in the sensing array is used to detect the spatial position of the force application point of the corresponding sensing unit flexible body. The measurement branch is coupled with a force detection component to obtain a first type of detection data, and a switch array is used to couple each measurement point to obtain a second type of detection data. The processing module is coupled with the measurement branch to output a three-dimensional force signal based on the first type of detection data and a spatially resolved signal based on the second type of detection data.
[0015] Each measurement point includes a first electrode and a second electrode stacked vertically, with the projection of the first electrode relative to the second electrode covering at least a portion of the area of the second electrode. The measurement branch includes a capacitance-to-digital conversion circuit, which couples the first and second electrodes at each point via a switch array to acquire the mutual capacitance between the first and second electrodes at each point. The first and second electrodes serve as capacitance sensing electrodes. Alternatively, each measurement point may have a piezoelectric material and first and second electrodes disposed on the upper and lower surfaces of the piezoelectric material. The piezoelectric material at each measurement point may be integral or separate. The first and second electrodes serve as signal output electrodes for the corresponding piezoelectric material at each point. The measurement branch includes a piezoelectric measurement circuit, which couples the first and second electrodes at each point via a switch array to acquire the electrical signal between the first and second electrodes at each point. The piezoelectric measurement circuit includes a charge amplifier to amplify the electrical signal. Furthermore, the projection of the first electrode relative to the second electrode at least covers a portion of the area of the second electrode; the measurement branch includes a capacitance-to-digital conversion circuit, which couples the first and second electrodes at each point via a switch array to acquire the mutual capacitance between the first and second electrodes at each point. The first and second electrodes serve as multiplexed electrodes for both capacitance sensing and piezoelectric material signal output. Furthermore, each measurement point includes at least a first electrode, and the measurement branch includes a capacitance-to-digital conversion circuit. This circuit couples the first electrode at each point via a switch array to acquire the self-capacitance of the first electrode and / or the mutual capacitance between the first electrodes at two points. The first electrode serves at least as a proximity detection electrode. Alternatively, each measurement point is provided with a piezoresistive material, and each measurement point's piezoresistive material is provided with a corresponding first electrode and second electrode. The first and second electrodes are respectively disposed on the upper and lower surfaces of the piezoresistive material or coplanarly disposed on the piezoresistive material, and the first and second electrodes serve as signal output electrodes of the piezoresistive material at the corresponding point. The measurement branch includes a piezoresistive measurement circuit, which couples the first and second electrodes at each point through a switch array to acquire the electrical signal between the first and second electrodes at each point when an object comes into contact with it. Further, the piezoresistive materials between each measurement point or between the aggregated areas formed by several measurement points are separately insulated. The second electrode serves as the near-ground end of the measurement point, and a selector switch is connected in series between the second electrode and ground. The measurement branch includes a capacitance-to-digital conversion circuit, which couples the first electrode at each point through a switch array to acquire the self-capacitance of the first electrode and / or the mutual capacitance between two mutually insulated first electrodes when an object approaches, and the first electrode serves as a proximity detection electrode.
[0016] An electronic skin is also provided, comprising the aforementioned curved electromagnetic tactile sensor.
[0017] A robot is also provided, which includes the aforementioned electronic skin.
[0018] Compared with existing technologies, the sensor structure of this invention has advantages such as fast response speed, high signal-to-noise ratio, good force detection sensitivity, and stable and accurate measurement. Attached Figure Description
[0019] Figure 1a Provide a stereoscopic view of the Hall effect 3D sensor; Figure 1b A schematic diagram of the internal structure of a Hall effect 3D sensor is provided.
[0020] Figure 2 A schematic diagram of the convex surface of a Hall effect 3D sensor is given.
[0021] Figure 3a A schematic diagram of a capacitor array is given, showing the upper and lower electrodes arranged in rows and columns to form a matrix. Figure 3b Figure 1 shows a schematic diagram of the piezoelectric array with point electrodes for the upper and lower electrodes; Figure 2 shows a schematic diagram of the piezoresistive array with the upper and lower electrodes for the upper and lower electrodes. Figure 3d A schematic diagram of the structure of the left and right electrodes on the top surface of the piezoresistive array is given. Detailed Implementation
[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.
[0023] See Figure 1a , Figure 1b The curved electromagnetic tactile sensor includes a measurement branch, a processing module, and at least one sensing unit. Each sensing unit has a flexible body 100 for contacting external objects, and a force detection component is disposed within a region of the flexible body 100.
[0024] The flexible body 100 has a downwardly protruding flexible structure 110, the surface of which deforms in contact with the underlying surface. The force detection assembly includes a magnetic source 130 for actively generating a magnetic field and magnetic field measurement electronics 140. The magnetic source 130 is embedded in the flexible structure 110, and the magnetic field measurement electronics 140, such as a Hall effect sensor, is positioned below the flexible structure 110. At least one magnetic field measurement electronics 140 is present, forming a one-dimensional normal sensor. At least three magnetic field measurement electronics 140 can be provided, distributed around the periphery of the flexible structure 110, forming a three-dimensional force detection. The magnetic field measurement electronics 140 is in direct or indirect contact with the curved surface of the flexible structure 110. The deformation of the flexible body 100 under external force causes the curved surface of the flexible structure 110 to change the direct or indirect contact area with the magnetic field measurement electronics 140. The measurement branch includes an analog-to-digital converter circuit. The processing module is coupled to each magnetic field measuring electronic component 140 via the analog-to-digital converter circuit. It is used to output an electrical signal characterizing the contact force based on the magnetic flux of the magnetic field measuring electronic component 140 changed by the deformation of the flexible structure 110.
[0025] When the upper part of the flexible hemispherical pressure sensing structure is subjected to pressure of different magnitudes and directions, the area and orientation of the part of the hemisphere in contact with the Hall effect sensor change accordingly. This causes the distance and orientation between the internal permanent magnet and the Hall effect sensor to change in the same direction, thus altering the magnetic flux of the Hall effect sensor. By detecting the output of the Hall effect sensor, the magnitude and direction of the pressure can be decoupled. The Hall effect sensor has a fast response speed and a high signal-to-noise ratio. Through direct or indirect contact between the convex curved surface and the magnetic field measuring electronic component 140, high force detection sensitivity is achieved through surface deformation and rolling contact. Direct or indirect contact ensures stable and accurate detection.
[0026] As an improvement, the lower surface of the flexible structure 110 is axially symmetric, and all magnetic field measuring electronic components 140 are located in the same plane and are evenly distributed around the circumference of the axial symmetry line of the lower surface of the flexible structure 110, which facilitates mechanical decoupling.
[0027] As another improvement, see Figure 2 The flexible body 100 is a cover with its surface converging upwards, and the flexible structure 110 is fixed to the inner surface of the cover, while its outer surface is convex and easily subjected to force. In the sensor structure of this invention, the flexible body 100 and the flexible structure 110 are integrally formed or separately arranged. The curved surface of the flexible structure 110 of this invention is preferably a spherical or ellipsoidal surface to form multi-directional conformal contact and reduce frictional resistance.
[0028] As an alternative implementation of proximity sensing, the flexible body 100 is made of a non-ferromagnetic conductive material and reused as a proximity detection electrode. The measurement branch includes a capacitance-to-digital converter (CDC) circuit. The CDC circuit is coupled to the flexible body 100 to obtain the capacitance change generated as an external object approaches. The processing module is coupled to the CDC circuit to output a proximity sensing signal based on the capacitance change.
[0029] As another improvement, see Figure 1a , Figure 1b The flexible body 100 has at least two measurement points 200. Each measurement point 200 is arranged at a different position on the flexible body 100 to form a sensing array 300 of sensing units. Each measurement point 200 in the sensing array 300 is used to detect the spatial position of the force application point of the corresponding sensing unit flexible body 100. The measurement branch is coupled with a force detection component to obtain a first type of detection data, and each measurement point 200 is coupled with a switch array to obtain a second type of detection data. The processing module is coupled with the measurement branch to output a three-dimensional force signal based on the first type of detection data and a spatially resolved signal based on the second type of detection data. For machine surface tactile sensing, pursuing high spatial resolution in the normal direction is of great significance, such as allowing mechanical fingers to respond to the force position of sharp objects or needle pricks. However, pursuing high spatial resolution in the tangential direction is not very meaningful. Even the human hand, which has evolved biologically, does not need to have excessively high requirements for spatial recognition of friction or shear effects. Blindly pursuing high spatial resolution in all three directions will only lead to a more complex sensing array structure, and at the same time, it will be difficult to overcome the spatial resolution problem of the already sufficiently miniaturized three-dimensional force-sensitive unit array. In the sensor structure of this utility model, the three-dimensional force detection component, as the smallest unit, realizes independent measurement of three-dimensional force. By means of multi-point measurement distributed on its flexible body 100, an array for sensing the position of the force is formed, which makes up for the spatial resolution of the normal direction. The sensing array 300 takes into account both the sensitivity of three-dimensional force detection and a high level of spatial resolution.
[0030] See Figure 3aAs a realization of the sensing array 300 on the flexible body 100, the first electrode 210 and the second electrode 220 are strip electrodes, separated and supported by a dielectric film 410. The projection of the first electrode 210 relative to the second electrode 220 at least covers a portion of the area of the second electrode 220. The measurement branch includes a capacitance-to-digital converter (CDC) circuit, which uses Δ-Σ modulation to convert the measured capacitance value into a digital value by repeatedly charging and discharging the measured capacitance and comparing it with a reference capacitance, thereby improving the capacitance measurement sensitivity to the 1ff level. The capacitance-to-digital converter circuit couples the first electrode 210 and the second electrode 220 at each point through a switch array to obtain the parallel plate mutual capacitance between the first electrode 210 and the second electrode 220 at each point. The first electrode 210 and the second electrode 220 serve as capacitance sensing electrodes. When the measurement point 200 is subjected to force, changes in the distance between the first electrode 210 and the second electrode 220 directly cause changes in capacitance, exhibiting good linear response and insensitivity to temperature and humidity.
[0031] See Figure 3b As a second optional implementation of the sensing array 300, and as a preferred embodiment, each measurement point 200 is provided with a piezoelectric material and a first electrode 210 and a second electrode 220 respectively disposed on the upper and lower surfaces of the piezoelectric material. The first electrode 210 and the second electrode 220 are point electrodes, and the piezoelectric material between each measurement point 200 can be integrally formed into a thin film 420 for convenient engineering manufacturing. The first electrode 210 and the second electrode 220 serve as signal output electrodes of the piezoelectric material at the corresponding point. The measurement branch includes a piezoelectric measurement circuit, which couples the first electrode 210 and the second electrode 220 at each point through a switch array to acquire the electrical signal between the first electrode 210 and the second electrode 220 at each point. The piezoelectric measurement circuit includes a charge amplifier to amplify the electrical signal. The piezoelectric material is sensitive to vibration, has a fast response speed, a thickness of 7-110 micrometers, and can be divided into 1mm segments. 2 Piezoelectric materials offer significant advantages for achieving higher spatial resolution, but are susceptible to temperature interference and are not well-suited for detecting static forces. They possess high insulation strength and a relative permittivity of 10⁻⁶. -15Suitable for use as a dielectric, the signal output electrodes can be reused to form a capacitive sensor. Capacitors have good detection of static forces, forming a complementary relationship. Specifically, in the piezoelectric method, the projection of the first electrode 210 relative to the second electrode 220 at each measurement point 200 is set to at least cover a portion of the area of the second electrode 220. The capacitance digital conversion circuit of the measurement branch is coupled to the first electrode 210 and the second electrode 220 at each point through a switch array to obtain the parallel plate mutual capacitance between the first electrode 210 and the second electrode 220 at each point. The first electrode 210 and the second electrode 220 serve as reused electrodes for both the capacitive sensing electrode and the signal output electrode of the piezoelectric material. During dynamic pressure application, the spatial position of the force point is sensed based on the change in the piezoelectric signal. When the system is statically stable, the system switches to parallel plate capacitance for force sensing.
[0032] When using the aforementioned capacitive sensing array 300 or piezoelectric sensing array 300 to detect spatial position, each measurement point 200 has at least a first electrode 210, which serves as a proximity detection electrode. A capacitance-to-digital conversion circuit couples the first electrode 210 at each point via a switch array to acquire the self-capacitance of the first electrode 210 and / or the mutual capacitance between the first electrodes 210 at two points. When the three-dimensional force detection component does not detect pressure, the first electrode 210 is configured for non-contact capacitive sensing. Multiple first electrodes 210 can be combined into one self-capacitance electrode or two mutual-capacitance electrodes, increasing the electrode area for capacitive proximity detection, thus achieving non-contact object detection. When using mutual capacitance, different objects have different dielectric constants, resulting in different capacitance changes when entering a planar mutual capacitance electric field, which can further achieve material identification. When an object is sensed approaching, the first electrode 210 switches to capacitive contact detection. Each measurement point 200 collects the self-capacitance of the first electrode 210 at the point or the mutual capacitance of the first electrode 210 between two points. The contact of the object causes a sudden change in the self-capacitance of the first electrode 210 and / or the mutual capacitance of the first electrode 210 between two points, thereby realizing the measurement of the contact position and sensing the point of force application.
[0033] Piezoelectric materials such as PVDF exhibit strong pyroelectric and dielectric effects, enabling them to sense temperature changes. Based on the aforementioned piezoelectric array in the sensing array 300, upon detecting object contact, the piezoelectric signals from adjacent non-pressurized points or the mutual capacitance signals of the parallel plates are acquired. If there is a temperature difference between the contacting object and the sensor, the piezoelectric materials at adjacent non-pressurized points generate charge due to radiation and conduction effects, or their dielectric constant changes with temperature. The object temperature is inferred from the charge changes or mutual capacitance changes at adjacent non-pressurized points. Further, the piezoelectric signal at the pressurized point can be acquired to determine the pressure at that point. The pressure at the pressurized point is then corrected based on the inferred object temperature, such as by using a mapping relationship to determine a correction coefficient based on stability. Alternatively, in a simpler case, given the piezoelectric signals from the pressurized point and adjacent non-pressurized points, the difference between the piezoelectric signals from the pressurized point and the adjacent non-pressurized points can be used to characterize the normal pressure. The normal force measured based on the piezoelectric material can be used as a verification of the normal force of the three-dimensional force detection component.
[0034] The combination of PVDF pressure, capacitance, and flexible hemispherical Hall pressure sensors can compensate for the shortcomings of each individual sensor.
[0035] See Figure 3c , Figure 3d As a third optional implementation of the sensing array 300, each measurement point 200 is provided with a piezoresistive material 430, and the layer containing the piezoresistive material 430 is called a piezoresistive layer 440. A first electrode 210 and a second electrode 220 are correspondingly provided on the piezoresistive material 430 at each measurement point 200. For the piezoresistive material 430, the first electrode 210 can be provided on the top surface and the second electrode 220 on the bottom surface, such as... Figure 3c Alternatively, the first electrode 210 and the second electrode 220 can also be coplanarly disposed on the piezoresistive material 430, such as... Figure 3d The first electrode 210 and the second electrode 220 serve as signal output electrodes for the corresponding points of the piezoresistive material 430. The measurement branch includes a piezoresistive measurement circuit, which couples the first electrode 210 and the second electrode 220 at each point via a switch array. This circuit acquires the electrical signal between the first electrode 210 and the second electrode 220 at each point when an object comes into contact with it. The piezoresistive material 430 can sense the contact pressure and position of the object, exhibiting high spatial resolution.
[0036] Furthermore, the piezoresistive material 430 forms insulating gaps between each measurement point 200 or between the aggregated areas formed by several measurement points 200. The capacitance-to-digital conversion circuit is coupled to the first electrode 210 of each point through a switch array. This is used to acquire the self-capacitance of the first electrode 210 and / or the mutual capacitance between two mutually insulated first electrodes 210 when an object approaches. The first electrode 210 serves as a proximity detection electrode. Similarly, when the three-dimensional force detection component does not detect pressure, it acts as a non-contact capacitance sensor. When an object approaches, the first electrode 210 is converted to a contact position measurement. Since the piezoresistive detection principle requires grounding, the second electrode 220 serves as the near-ground terminal of the measurement point 200. It is connected in series with the ground as a selector switch. It is grounded during piezoresistive acquisition and disconnected during capacitance acquisition to prevent the capacitance from being grounded through the piezoresistive field.
[0037] When the piezoresistive material 430 is a pressure- and temperature-sensitive polymer material, similar to the temperature measurement method of piezoelectric materials, temperature measurement and pressure verification can be achieved based on the piezoresistive signals of the pressure point and adjacent non-pressure points.
[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit the scope of protection of this utility model. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this utility model without departing from the essence and scope of the technical solutions of this utility model.
Claims
1. A curved electromagnetic tactile sensor, characterized in that: The curved electromagnetic three-dimensional force sensor includes a measurement branch, a processing module and at least one sensing unit. Each sensing unit is provided with a flexible body for contacting external objects. A force detection component is provided inside the area contained in the flexible body. The flexible body has a downwardly protruding flexible structure, and the surface of the flexible structure is curved. The force detection component includes a magnetic source for actively generating a magnetic field and at least one magnetic field measuring electronic element. The magnetic source is embedded in a flexible structure, and the magnetic field measuring electronic element is located below the flexible structure. The magnetic field measuring electronic element is in direct or indirect contact with the curved surface of the flexible structure. When the flexible body is deformed by external force, the curved surface of the flexible structure changes the direct or indirect contact area with the magnetic field measuring electronic element. The measurement branch includes an analog-to-digital converter circuit. The processing module is coupled to each magnetic field measurement electronic component via the analog-to-digital converter circuit, and is used to output an electrical signal characterizing the contact force based on the magnetic flux of the magnetic field measurement electronic component changed by the deformation of the flexible structure.
2. The curved electromagnetic tactile sensor according to claim 1, characterized in that: The magnetic field measuring electronic element has at least three components, and each magnetic field measuring electronic element is distributed around the periphery of the flexible structure.
3. The curved electromagnetic tactile sensor according to claim 2, characterized in that: The lower surface of the flexible structure is axially symmetric, and all the magnetic field measuring electronic components are located in the same plane and are uniformly distributed around the axis of symmetry of the lower surface of the flexible structure.
4. The curved electromagnetic tactile sensor according to claim 1, characterized in that: The flexible body is a cover with its surface facing upwards, and the flexible structure is fixed to the inner surface of the cover. And / or, the flexible body and flexible structure are integrally formed or separately set.
5. The curved electromagnetic tactile sensor according to claim 1, characterized in that: The surface of the flexible structure is spherical or ellipsoidal.
6. The curved electromagnetic tactile sensor according to claim 1, characterized in that: The flexible body is made of a non-ferromagnetic conductive material and serves as a proximity detection electrode. The measurement branch includes a capacitance-to-digital conversion circuit, which is coupled to a flexible body to obtain the capacitance change caused by the approach of an external object. The processing module is coupled to the capacitance-to-digital conversion circuit and is used to output a proximity sensing signal based on the capacitance change.
7. The curved electromagnetic tactile sensor according to claim 2, characterized in that: The flexible body has at least two measurement points distributed on it. Each measurement point is arranged at a different position on the corresponding flexible body to form a sensing array of sensing units. Each measurement point in the sensing array is used to detect the spatial position of the force application point of the corresponding sensing unit flexible body. The measuring branch coupling force detection component obtains a first type of detection data, and the switch array couples each measuring point to obtain a second type of detection data; The processing module is coupled to the measurement branch and is used to output a three-dimensional force signal based on the first type of detection data and a spatially resolved signal based on the second type of detection data.
8. The curved electromagnetic tactile sensor according to claim 7, characterized in that: Each measurement point includes a first electrode and a second electrode stacked one on top of the other, and the projection of the first electrode relative to the second electrode covers at least a portion of the area of the second electrode. The measurement branch includes a capacitance-to-digital converter circuit. The capacitance-to-digital converter circuit couples the first electrode and the second electrode at each point through a switch array to obtain the mutual capacitance between the first electrode and the second electrode at each point. The first electrode and the second electrode serve as capacitance sensing electrodes.
9. The curved electromagnetic tactile sensor according to claim 7, characterized in that: Each measurement point is equipped with a piezoelectric material, a first electrode and a second electrode respectively set on the upper and lower surfaces of the piezoelectric material. The piezoelectric material between each measurement point is either integrated or separate. The first electrode and the second electrode serve as signal output electrodes of the piezoelectric material at the corresponding point. The measurement branch includes a piezoelectric measurement circuit. The piezoelectric measurement circuit couples the first electrode and the second electrode at each point through a switch array to acquire the electrical signal between the first electrode and the second electrode at each point. The piezoelectric measurement circuit includes a charge amplifier to amplify the electrical signal.
10. The curved electromagnetic tactile sensor according to claim 9, characterized in that: The projection of the first electrode relative to the second electrode at least covers a portion of the area of the second electrode; The measurement branch includes a capacitance-to-digital conversion circuit. The capacitance-to-digital conversion circuit couples the first electrode and the second electrode at each point through a switch array to obtain the mutual capacitance between the first electrode and the second electrode at each point. The first electrode and the second electrode serve as multiplexed electrodes for the capacitance sensing electrode and the signal output electrode of the piezoelectric material.
11. The curved electromagnetic tactile sensor according to any one of claims 7-10, characterized in that: Each measurement point includes at least a first electrode, and the measurement branch includes a capacitance-to-digital converter circuit. The capacitance-to-digital converter circuit is coupled to the first electrode of each point through a switch array to obtain the self-capacitance of the first electrode and / or the mutual capacitance between the first electrodes of two points. The first electrode serves as at least a proximity detection electrode.
12. The curved electromagnetic tactile sensor according to claim 7, characterized in that: Each measurement point is equipped with a piezoresistive material, and the piezoresistive material at each measurement point is equipped with a first electrode and a second electrode. The first electrode and the second electrode are respectively disposed on the upper and lower surfaces of the piezoresistive material or coplanarly disposed on the piezoresistive material. The first electrode and the second electrode serve as signal output electrodes of the piezoresistive material at the corresponding point. The measurement branch includes a piezoresistive measurement circuit, which couples the first electrode and the second electrode at each point through a switch array to acquire the electrical signal between the first electrode and the second electrode at each point when the object is in contact.
13. The curved electromagnetic tactile sensor according to claim 12, characterized in that: Piezoresistive materials are used to form insulating gaps between individual measurement points or between aggregated areas formed by several measurement points; The second electrode serves as the near-ground end of the measurement point, and a selector switch is connected in series between the second electrode and the ground. The measurement branch includes a capacitance-to-digital conversion circuit, which is coupled to the first electrode at each point through a switch array. This circuit is used to acquire the self-capacitance of the first electrode and / or the mutual capacitance between two mutually insulated first electrodes when an object approaches. The first electrode serves as the proximity detection electrode.
14. An electronic skin, characterized in that, Including the curved electromagnetic tactile sensor as described in any one of claims 1-13.
15. A robot, characterized in that, Including the electronic skin as described in claim 14.