A tactile sensor and a method for calibrating a tactile sensor

Abstract

The application provides a kind of tactile sensor and the calibration method of tactile sensor, belong to sensor technical field, the tactile sensor includes: the magnetic sensing layer, pressure sensing layer and flexible stress layer stacked in turn;The flexible stress layer is inlaid with the magnetic film of magnetic material composition, the position of magnetic film changes after flexible stress layer is subjected to three-dimensional force;The pressure sensing layer is used to measure the normal force of three-dimensional force;The magnetic sensing layer is used to detect the magnetic field data of magnetic film under different positions before and after stress, to solve three-dimensional force.The tactile sensor provided by the application, after the stress of flexible stress layer, the pressure is conducted to pressure sensing layer by deformation, and the detection of normal force is realized;At the same time, according to the magnetic field change of magnetic sensor before and after the stress of flexible stress layer, the displacement change of magnetic film is calculated, and finally decoupling is generated as three-dimensional force.

Description

Technical Field

[0001] This invention relates to the field of sensor technology, and in particular to a tactile sensor and a calibration method for the tactile sensor. Background Technology

[0002] Humanoid robots, as an important branch of the field of intelligent robots, are gradually entering various industries, especially showing broad application prospects in service, education, medical, and manufacturing sectors. Currently, the perception capabilities of humanoid robots are mainly concentrated in touch and vision, with tactile sensors, as a relatively new type of sensor, playing a crucial role in the field of humanoid robots.

[0003] Traditional tactile sensors (such as piezoresistive or capacitive sensors) can typically only measure normal pressure (one-dimensional information) and cannot measure tangential force. They also have high trigger forces and low sensitivity limits. To measure tangential or three-dimensional forces, complex sensor structures or cumbersome calibration methods for decoupling are required. While pure magnetic sensing schemes can measure three-dimensional forces, they suffer from low spatial resolution (due to simple magnetic sensing layouts) or difficulty in decoupling (due to complex magnetic sensing layouts). Summary of the Invention

[0004] This invention provides a tactile sensor and a calibration method for the tactile sensor, in order to solve at least one defect of existing tactile sensors.

[0005] In a first aspect, the present invention provides a tactile sensor, comprising: a magnetic sensing layer, a pressure sensing layer, and a flexible force-bearing layer stacked sequentially; the flexible force-bearing layer is embedded with a magnetic film composed of magnetic material, and the position of the magnetic film changes after the flexible force-bearing layer is subjected to a three-dimensional force; the pressure sensing layer is used to measure the normal force of the three-dimensional force; the magnetic sensing layer is used to detect and acquire magnetic field data of the magnetic film at different positions before and after the force is applied, so as to solve for the three-dimensional force.

[0006] According to the tactile sensor provided by the present invention, the pressure sensing layer includes a piezoresistive sensor array.

[0007] According to the tactile sensor provided by the present invention, the magnetic sensing layer adopts a single-point or array-type magnetic sensor design.

[0008] According to the tactile sensor provided by the present invention, the flexible force-bearing layer is integrally injection molded.

[0009] Secondly, the present invention also provides a calibration method for a tactile sensor, applied to any of the tactile sensors described above, comprising:

[0010] A three-dimensional calibration force is applied, and the first horizontal tangential force, the second horizontal tangential force, and the normal force of the three-dimensional calibration force are obtained. In addition, the first horizontal displacement and the second horizontal displacement of the magnetic film at the current position compared with the initial position before the force is applied are obtained. The first horizontal displacement corresponds to the first horizontal tangential force, and the second horizontal displacement corresponds to the second horizontal tangential force.

[0011] The first horizontal tangential force, the first horizontal displacement, and the normal force corresponding to each applied three-dimensional calibration force are used as the first calibration data, and the second horizontal tangential force, the second horizontal displacement, and the normal force are used as the second calibration data; wherein, the initial position is updated after the flexible stress layer is subjected to the three-dimensional calibration force each time;

[0012] Based on the first calibration data and the second calibration data, a first mapping function between the first horizontal tangential force and the first horizontal displacement and the normal force is constructed, and a second mapping function between the second horizontal tangential force and the second horizontal displacement and the normal force is constructed respectively.

[0013] The normal force measurement value output by the pressure sensing layer is calibrated based on the normal force of the three-dimensional calibration force to obtain the third mapping relationship function.

[0014] The calibration method for a tactile sensor provided by the present invention further includes: constructing a magnetic field mapping simulation model between the position of the magnetic film and the magnetic field data; determining the position of the magnetic film before and after being subjected to force using the magnetic field mapping simulation model based on the magnetic field data output by the magnetic sensing layer; and determining the displacement of the magnetic film in three-dimensional space based on the position of the magnetic film before and after being subjected to force.

[0015] According to the calibration method of the tactile sensor provided by the present invention, after calibration, the step of measuring the three-dimensional force to be measured includes: determining the first horizontal displacement and the second horizontal displacement of the magnetic membrane after the flexible force-bearing layer is subjected to force, relative to the initial position before the force is applied, based on the magnetic field mapping simulation model; after the pressure sensing layer detects the force, the following steps are performed: obtaining the normal force measurement value of the three-dimensional force to be measured, and determining the normal force of the three-dimensional force to be measured using a third mapping function based on the normal force measurement value; determining the first horizontal tangential force of the three-dimensional force to be measured using a first mapping function based on the first horizontal displacement and the normal force; and determining the second horizontal tangential force of the three-dimensional force to be measured using a second mapping function based on the second horizontal displacement and the normal force.

[0016] According to the calibration method for a tactile sensor provided by the present invention, before applying a three-dimensional calibration force, the method further includes: determining the number and layout of sensors in the pressure sensing layer and the magnetic sensing layer based on the size parameters of the product to which the tactile sensor is applied; determining the distance range between the magnetic film and the magnetic sensing layer, the deformation range of the elastic material of the flexible force-bearing layer, and the hardness range; obtaining multiple combinations of different parameters within the selectable range, measuring the different effects of each combination in turn, and determining the optimal parameter combination.

[0017] Thirdly, the present invention provides an electronic device including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steps of any of the above-described tactile sensor calibration methods.

[0018] Fourthly, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the calibration method for the tactile sensor as described above.

[0019] The tactile sensor and its calibration method provided by this invention have the following advantages compared with the prior art:

[0020] (1) The tactile sensor provided by the present invention transmits the pressure to the pressure sensing layer through deformation after the flexible force-bearing layer is subjected to force, thereby realizing the detection of normal force; at the same time, based on the magnetic field change of the magnetic sensor before and after the flexible force-bearing layer is subjected to force, the magnetic film displacement change is calculated, and finally decoupled to generate a three-dimensional force.

[0021] (2) The tactile sensor provided by the present invention realizes the joint calibration of multimodal data of pressure sensing and magnetic sensing. The normal force can be generated by the normal force measurement value directly output by the piezoresistive field, and the tangential force is obtained by decoupling through magnetic film displacement, thus solving the problems of missing dimensions and low spatial resolution of a single sensor.

[0022] (3) This invention establishes a nonlinear mapping model of elastic material deformation-magnetic field-force to achieve high-precision measurement of tangential force. Furthermore, it uses piezoresistive detection to determine whether the current elastic body is under stress. If the piezoresistive detection indicates that there is no current stress, it does not output three-dimensional force, thus preventing the output of three-dimensional force when there is external strong magnetic interference and improving the robustness of the tactile sensor. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 This is a flowchart illustrating the calibration method for the tactile sensor provided by the present invention;

[0025] Figure 2 This is a schematic diagram of the complete implementation process provided by the present invention;

[0026] Figure 3 This is a schematic diagram of the structure of the electronic device provided by the present invention. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0028] It should be noted that, in the description of the embodiments of the present invention, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0029] The terms "first," "second," etc., used in this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class, without limiting the number of objects; for example, a first object can be one or more. Furthermore, the character " / " generally indicates that the preceding and following objects have an "or" relationship.

[0030] The following is combined Figures 1-3 This invention describes the tactile sensor and its calibration method provided in the embodiments of the present invention.

[0031] This invention provides a tactile sensor, comprising: a magnetic sensing layer, a pressure sensing layer, and a flexible force-bearing layer stacked sequentially; the flexible force-bearing layer has an embedded magnetic film composed of magnetic material, and the position of the magnetic film changes after the flexible force-bearing layer is subjected to a three-dimensional force; the pressure sensing layer is used to measure the normal force of the three-dimensional force; the magnetic sensing layer is used to detect and acquire magnetic field data of the magnetic film at different positions before and after the force is applied, so as to solve for the three-dimensional force.

[0032] When the flexible support layer is subjected to an external force, the elastic displacement of the flexible support layer causes spatial displacement of the magnetic film and movement of the pressure sensing layer. The flexible support layer can be a silicone elastomer (formed from elastic material) with embedded micro-magnetic materials, in which the micro-magnetic materials form a magnetic film.

[0033] The size, material, and shape of the magnetic film can be set as needed, and the flexible force-bearing layer can be integrally injection molded.

[0034] The pressure sensing layer can be a piezoresistive sensor array, using a flexible piezoresistive array (such as carbon nanotube / PDMS composite material) to directly measure the normal force on the flexible force-bearing layer, with a spatial resolution of up to 0.1 mm.

[0035] The magnetic sensing layer can be designed with a single point or an array of magnetic sensors. The type of magnetic sensor can be a Hall sensor / TMR. By collecting magnetic field data before and after the force is applied, the displacement of the magnetic film after the force is applied can be calculated, thereby calculating the three-dimensional force.

[0036] Here is a brief explanation of how to calculate three-dimensional force using magnetic field data: First, a magnetic field mapping simulation model of the magnetic membrane position and magnetic field data (usually magnetic field strength data) is pre-constructed. Then, the change in the position of the magnetic membrane before and after being subjected to force can be determined using the pre-established magnetic field mapping simulation model. Further, the displacement of the magnetic membrane is determined based on the change in its position. Finally, the three-dimensional force can be calculated based on the pre-calibrated relationship between the displacement and the three-dimensional force.

[0037] The normal force measured using the pressure sensing layer is often more accurate than that measured using the magnetic sensing layer. This invention can use the normal force measured by the magnetic sensing layer as the normal force output of the tactile sensor and apply it to the process of decoupling the magnetic film displacement to generate the tangential force. Based on this, this invention proposes a calibration method for the tactile sensor.

[0038] Before formal calibration, the technical solution of the present invention also includes the following preparatory steps: determining the number and layout of sensors in the pressure sensing layer and the magnetic sensing layer according to the size parameters of the application product of the tactile sensor; determining the distance range between the magnetic film and the magnetic sensing layer, the deformation range of the elastic material of the flexible force-bearing layer, and the hardness range; obtaining multiple combinations of different parameters within the selectable range, measuring the different effects of each combination in turn, and determining the optimal parameter combination.

[0039] Figure 1 This is a flowchart illustrating the calibration method for the tactile sensor provided by the present invention, as shown below. Figure 1 As shown, including but not limited to the following steps:

[0040] Step 101: Apply a three-dimensional calibration force, obtain the first horizontal tangential force, the second horizontal tangential force, and the normal force of the three-dimensional calibration force, and obtain the first horizontal displacement and the second horizontal displacement of the magnetic film at the current position compared to the initial position before the force is applied.

[0041] Wherein, the first horizontal displacement corresponds to the first horizontal tangential force, and the second horizontal displacement corresponds to the second horizontal tangential force; the first horizontal tangential force can be the force Fx in the X-axis direction of the three-dimensional calibration force, the second horizontal tangential force can be the force Fy in the Y-axis direction of the three-dimensional calibration force, and the normal force can be the force Fz in the Z-axis direction of the three-dimensional calibration force; correspondingly, the first horizontal displacement and the second horizontal displacement are ΔD. x and ΔD y .

[0042] The three-dimensional calibration force can be applied through a mature calibration platform. The first horizontal tangential force, the second horizontal tangential force, and the normal force of the three-dimensional calibration force can be obtained based on the calibration platform.

[0043] The first and second horizontal displacements can be determined using magnetic field data before and after the force is applied. The calculation method for the displacements is explained below, including but not limited to the following steps:

[0044] (1) Construct a magnetic field mapping simulation model between the magnetic film position and magnetic field data;

[0045] (Dx, Dy, Dz) = g0 (Bx, By, Bz);

[0046] Where (Dx, Dy, Dz) are the positions of the magnetic film, and (Bx, By, Bz) are the magnetic field data (which can be magnetic field strength data).

[0047] (2) Based on the magnetic field data output by the magnetic sensing layer, the position of the magnetic film before and after being subjected to force is determined using the magnetic field mapping simulation model.

[0048] This step is to determine the current position after the force is applied and the initial position before the force is applied. Simply substitute the magnetic sensing data of each position into g0 to determine the position.

[0049] Understandably, the initial position is updated every time the flexible load-bearing layer is subjected to a three-dimensional calibration force in order to compensate for displacement drift.

[0050] (3) Determine the displacement of the magnetic membrane in three-dimensional space based on the position of the magnetic membrane before and after being subjected to force.

[0051] The first horizontal displacement ΔD can be determined based on the change in Dx before and after the force is applied. x The second horizontal displacement ΔD can be determined based on the change in Dy before and after the force is applied. y .

[0052] Step 102: Take the first horizontal tangential force, the first horizontal displacement, and the normal force corresponding to each applied three-dimensional calibration force as the first calibration data, and take the second horizontal tangential force, the second horizontal displacement, and the normal force as the second calibration data.

[0053] Step 103: Based on the first calibration data and the second calibration data, construct a first mapping function between the first horizontal tangential force and the first horizontal displacement and normal force, and a second mapping function between the second horizontal tangential force and the second horizontal displacement and normal force, respectively; specifically, the first mapping function is expressed as:

[0054] Fx=g1(ΔD x ,Fz);

[0055] The second mapping function is expressed as:

[0056] Fy=g2(ΔD y ,Fz).

[0057] Step 104: Calibrate the measured normal force output by the pressure sensing layer based on the normal force of the three-dimensional calibration force, and obtain the third mapping function; expressed as:

[0058] Fz = g3(Fz0);

[0059] Where Fz0 is the measured value of the normal force, and g1, g2, and g3 represent the mapping relationship functions, respectively.

[0060] Based on the above embodiments, as an optional embodiment, the step of measuring the three-dimensional force to be measured after calibration includes:

[0061] (1) Based on the magnetic field mapping simulation model, determine the first and second horizontal displacements of the magnetic membrane after the flexible force layer is subjected to force, relative to its initial position before being subjected to force.

[0062] (2) After the pressure sensing layer detects the force, perform the following steps:

[0063] Obtain the measured value of the normal force of the three-dimensional force to be measured, and determine the normal force of the three-dimensional force to be measured using the third mapping relationship function based on the measured value of the normal force;

[0064] Based on the first horizontal displacement and the normal force, the first horizontal tangential force of the three-dimensional force to be measured is determined using the first mapping relationship function.

[0065] Based on the second horizontal displacement and the normal force, the second horizontal tangential force of the three-dimensional force to be measured is determined using the second mapping relationship function.

[0066] To provide a clearer explanation of the technical solution of this invention, the following describes the process of preliminary preparation, data calibration, and the actual measurement of three-dimensional forces.

[0067] Figure 2 This is a schematic diagram of the complete implementation process provided by the present invention, such as... Figure 2 As shown, the present invention includes, but is not limited to, the following steps:

[0068] Step 1: Determine the composition and structure of the tactile sensor based on the product's shape; determine the PCB size based on dimensional parameters, which in turn determines the number and layout of sensors; determine the number and layout of measurement points for the piezoresistive mode based on spatial resolution.

[0069] Step 2: Determine the distance range between the magnetic film and the magnetic sensing layer based on the structural dimensional parameters (different silicone thicknesses, PCB board thicknesses); based on the three-dimensional force range index of the tactile sensor, the stress generated by the deformation of the silicone is fed back to the pressure sensing layer, which cannot exceed the measurement range of the pressure sensing layer. At the same time, the displacement of the magnetic film caused by the deformation of the silicone cannot cause the corresponding change in the magnetic field to exceed the measurement range of the magnetic sensing layer. Thus, the deformation range of the elastic material of the flexible force layer is determined. For the same force, elastic materials with different hardness produce different ranges of deformation, thus determining the hardness range of the elastic material. According to the resolution parameters of the tactile sensor, different hardness elastic materials, different distances, and different magnetic material parameters (material, size, quantity, and layout) affect the degree of magnetic field transformation. For example, the closer the magnetic film and the magnetic sensing layer are, the greater the change in magnetic field produced by the same deformation, which means it is easier to detect forces with small changes. Thus, various combinations of different parameters are obtained within the selectable range, and the different effects of each combination are measured in turn to determine the optimal parameter combination. For example, the elastic material hardness is 30, the distance between the magnetic film and the magnetic sensing layer is 5mm, the magnetic film thickness is 5mm, the PCB thickness is 2mm, the magnetic material is NdFeB, a 3x3 spherical magnet layout is used, and the center of the elastic material is aligned with the center of the magnetic sensing layer.

[0070] Step 3: Based on the obtained optimal combination, the accuracy of the completed tactile sensor is calibrated. A stable three-dimensional calibration force is generated by controlling a high-precision three-dimensional moving platform and designing a rigid pressing structure and fixture. The magnitude of the force is calculated by measuring the interaction force through a three-dimensional force sensor. The magnitude of the force is controlled by changing the moving step size. For example, pressing down 0.5mm will generate a normal force of 1N, and moving tangentially 0.5mm will generate a tangential force of 0.5N.

[0071] Step 4: Develop a force and magnetic data acquisition program for the control and automation of the 3D mobile platform based on the required calibration dataset. Fit the measured normal force value of the pressure sensing layer with the actual normal force value (normal force of the 3D calibration force) to obtain the magnitude Fz of the normal force at different measurement points.

[0072] Step 5: The calibration of the tactile sensor can be divided into two steps: First, through simulation modeling, the theoretical calculation of the relationship between the magnetic sensing layer's value and the magnetic membrane's position is obtained, thus obtaining the mapping relationship between the magnetic membrane's position and the magnetic field (Dx, Dy, Dz) = g0(Bx, By, Bz). The position of the magnetic membrane can be calculated in real time through the function g0. Second, before calibration, the initial position of the magnetic membrane is recorded, and a three-dimensional calibration force is applied to start calibration. The displacement / deformation of the magnetic membrane is obtained by calculating the current position of the magnetic membrane and subtracting the initial position. The normal force of the three-dimensional calibration force is used to calibrate the normal force measurement value output by the pressure sensing layer to obtain the mapping function g3. The normal force of the three-dimensional calibration force (i.e., Fz after calibration) and the actual tangential force Fx / Fy output by the three-dimensional force sensor (i.e., the tangential force of the three-dimensional calibration force) are combined for calibration to obtain the mapping relationship between the tangential force and the tangential deformation of the magnetic membrane (first horizontal displacement or second horizontal displacement) Fx = g1(ΔD x ,Fz),Fy=g2(ΔD y ,Fz).

[0073] Step 6: After calibration, the steps for measuring the three-dimensional force include: determining whether the flexible force-bearing layer is under stress through the piezoresistive layer (i.e., the pressure sensing layer). If the piezoresistive layer detects no current stress, it does not output the measurement result of the three-dimensional force (to prevent functions g1 and g2 from outputting the three-dimensional force when there is external strong magnetic interference). The position of the magnetic membrane before the piezoresistive force is applied is calculated using function g0 and recorded as the initial position. When the piezoresistive layer detects stress on the elastic body, the normal force of the three-dimensional force is determined using function g3. The current position of the magnetic membrane is calculated using the current magnetic field data through function g0. The true deformation ΔD of the magnetic membrane can be obtained by subtracting the initial position from the current position. x and ΔD y Furthermore, the tangential force is calculated using functions g1 and g2.

[0074] It should be noted that, since the elastomer cannot completely return to its original position after the force is removed (due to the different initial positions of the magnetic film), the magnetic field measured by the magnetic sensing layer in the two states without force is different, and the calculated three-dimensional force drifts. Therefore, it is necessary to update the initial position of the previous measurement before each application of the three-dimensional force.

[0075] In summary, the present invention has the following advantages compared with the prior art:

[0076] (1) The tactile sensor provided by the present invention transmits the pressure to the pressure sensing layer through deformation after the flexible force-bearing layer is subjected to force, thereby realizing the detection of normal force; at the same time, based on the magnetic field change of the magnetic sensor before and after the flexible force-bearing layer is subjected to force, the magnetic film displacement change is calculated, and finally decoupled to generate a three-dimensional force.

[0077] (2) The tactile sensor provided by the present invention realizes the joint calibration of multimodal data of pressure sensing and magnetic sensing. The normal force can be generated by the normal force measurement value directly output by the piezoresistive field, and the tangential force is obtained by decoupling through magnetic film displacement, thus solving the problems of missing dimensions and low spatial resolution of a single sensor.

[0078] (3) This invention establishes a nonlinear mapping model of elastic material deformation-magnetic field-force to achieve high-precision measurement of tangential force. Furthermore, it uses piezoresistive detection to determine whether the current elastic body is under stress. If the piezoresistive detection indicates that there is no current stress, it does not output three-dimensional force, thus preventing the output of three-dimensional force when there is external strong magnetic interference and improving the robustness of the tactile sensor.

[0079] Figure 3 This is a schematic diagram of the structure of the electronic device provided by the present invention, such as... Figure 3 As shown, the electronic device may include a processor 310, a communication interface 320, a memory 330, and a communication bus 340, wherein the processor 310, the communication interface 320, and the memory 330 communicate with each other via the communication bus 340. The processor 310 can call logical instructions in the memory 330 to execute a calibration method for the tactile sensor. This method includes: applying a three-dimensional calibration force; acquiring a first horizontal tangential force, a second horizontal tangential force, and a normal force of the three-dimensional calibration force; and acquiring a first horizontal displacement and a second horizontal displacement of the magnetic membrane at its current position relative to its initial position before the force is applied; wherein the first horizontal displacement corresponds to the first horizontal tangential force, and the second horizontal displacement corresponds to the second horizontal tangential force.

[0080] The first horizontal tangential force, the first horizontal displacement, and the normal force corresponding to each applied three-dimensional calibration force are used as the first calibration data, and the second horizontal tangential force, the second horizontal displacement, and the normal force are used as the second calibration data; wherein, the initial position is updated after the flexible stress layer is subjected to the three-dimensional calibration force each time;

[0081] Based on the first calibration data and the second calibration data, a first mapping function between the first horizontal tangential force and the first horizontal displacement and the normal force is constructed, and a second mapping function between the second horizontal tangential force and the second horizontal displacement and the normal force is constructed respectively.

[0082] The normal force measurement value output by the pressure sensing layer is calibrated based on the normal force of the three-dimensional calibration force to obtain the third mapping relationship function.

[0083] Furthermore, the logical instructions in the aforementioned memory 330 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0084] On the other hand, the present invention also provides a computer program product, the computer program product comprising a computer program stored on a non-transitory computer-readable storage medium, the computer program comprising program instructions, wherein when the program instructions are executed by a computer, the computer is able to execute the calibration method of the tactile sensor provided in the above embodiments, the method comprising:

[0085] A three-dimensional calibration force is applied, and the first horizontal tangential force, the second horizontal tangential force, and the normal force of the three-dimensional calibration force are obtained. In addition, the first horizontal displacement and the second horizontal displacement of the magnetic film at the current position compared with the initial position before the force is applied are obtained. The first horizontal displacement corresponds to the first horizontal tangential force, and the second horizontal displacement corresponds to the second horizontal tangential force.

[0086] The first horizontal tangential force, the first horizontal displacement, and the normal force corresponding to each applied three-dimensional calibration force are used as the first calibration data, and the second horizontal tangential force, the second horizontal displacement, and the normal force are used as the second calibration data; wherein, the initial position is updated after the flexible stress layer is subjected to the three-dimensional calibration force each time;

[0087] Based on the first calibration data and the second calibration data, a first mapping function between the first horizontal tangential force and the first horizontal displacement and the normal force is constructed, and a second mapping function between the second horizontal tangential force and the second horizontal displacement and the normal force is constructed respectively.

[0088] The normal force measurement value output by the pressure sensing layer is calibrated based on the normal force of the three-dimensional calibration force to obtain the third mapping relationship function.

[0089] In another aspect, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to perform the calibration method of the tactile sensor provided in the above embodiments, the method comprising:

[0090] A three-dimensional calibration force is applied, and the first horizontal tangential force, the second horizontal tangential force, and the normal force of the three-dimensional calibration force are obtained. In addition, the first horizontal displacement and the second horizontal displacement of the magnetic film at the current position compared with the initial position before the force is applied are obtained. The first horizontal displacement corresponds to the first horizontal tangential force, and the second horizontal displacement corresponds to the second horizontal tangential force.

[0091] The first horizontal tangential force, the first horizontal displacement, and the normal force corresponding to each applied three-dimensional calibration force are used as the first calibration data, and the second horizontal tangential force, the second horizontal displacement, and the normal force are used as the second calibration data; wherein, the initial position is updated after the flexible stress layer is subjected to the three-dimensional calibration force each time;

[0092] Based on the first calibration data and the second calibration data, a first mapping function between the first horizontal tangential force and the first horizontal displacement and the normal force is constructed, and a second mapping function between the second horizontal tangential force and the second horizontal displacement and the normal force is constructed respectively.

[0093] The normal force measurement value output by the pressure sensing layer is calibrated based on the normal force of the three-dimensional calibration force to obtain the third mapping relationship function.

[0094] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0095] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0096] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A calibration method for a tactile sensor, applied to a tactile sensor, characterized in that, The tactile sensor comprises a magnetic sensing layer, a pressure sensing layer, and a flexible force-bearing layer stacked sequentially; the flexible force-bearing layer has a magnetic film composed of magnetic material embedded in it, and the position of the magnetic film changes after the flexible force-bearing layer is subjected to a three-dimensional force; the pressure sensing layer is used to measure the normal force of the three-dimensional force. The magnetic sensing layer is used to detect and acquire magnetic field data of the magnetic film at different positions before and after being subjected to force, so as to solve for the three-dimensional force. The method includes: A three-dimensional calibration force is applied, and the first horizontal tangential force, the second horizontal tangential force, and the normal force of the three-dimensional calibration force are obtained. In addition, the first horizontal displacement and the second horizontal displacement of the magnetic film at the current position compared with the initial position before the force is applied are obtained. The first horizontal displacement corresponds to the first horizontal tangential force, and the second horizontal displacement corresponds to the second horizontal tangential force. The first horizontal tangential force, the first horizontal displacement, and the normal force corresponding to each applied three-dimensional calibration force are used as the first calibration data, and the second horizontal tangential force, the second horizontal displacement, and the normal force are used as the second calibration data; wherein, the initial position is updated after the flexible force-bearing layer is subjected to the three-dimensional calibration force each time, and the initial position is obtained by bringing its own magnetic sensing data into the magnetic field mapping simulation model; Based on the first calibration data and the second calibration data, a first mapping function between the first horizontal tangential force and the first horizontal displacement and the normal force is constructed, and a second mapping function between the second horizontal tangential force and the second horizontal displacement and the normal force is constructed respectively. The normal force measurement value output by the pressure sensing layer is calibrated based on the normal force of the three-dimensional calibration force to obtain the third mapping relationship function; After calibration is completed, the steps for measuring the three-dimensional force to be measured include: Based on the magnetic field mapping simulation model, the first and second horizontal displacements of the magnetic membrane after the flexible force-bearing layer is subjected to force are determined relative to its initial position before the force is applied. After the pressure sensing layer detects the force, the following steps are performed: Obtain the measured value of the normal force of the three-dimensional force to be measured, and determine the normal force of the three-dimensional force to be measured using the third mapping relationship function based on the measured value of the normal force; Based on the first horizontal displacement and the normal force, the first horizontal tangential force of the three-dimensional force to be measured is determined using the first mapping relationship function. Based on the second horizontal displacement and the normal force, the second horizontal tangential force of the three-dimensional force to be measured is determined using the second mapping relationship function.

2. The calibration method for a tactile sensor according to claim 1, characterized in that, Also includes: Construct a simulation model of magnetic field mapping between the magnetic membrane position and magnetic field data; Based on the magnetic field data output by the magnetic sensing layer, the position of the magnetic film before and after being subjected to force is determined using the magnetic field mapping simulation model. The displacement of the magnetic membrane in three-dimensional space is determined based on its position before and after the force is applied.

3. The calibration method for a tactile sensor according to claim 1, characterized in that, Before applying the three-dimensional calibration force, the following is also included: Based on the size parameters of the product for which the tactile sensor is applied, determine the number and layout of sensors in the pressure sensing layer and the magnetic sensing layer. Determine the distance range between the magnetic film and the magnetic sensing layer, and the deformation range and hardness range of the elastic material of the flexible force-bearing layer; Within the selectable range, various combinations of different parameters are obtained, and the effects of each combination are measured in turn to determine the optimal parameter combination.

4. The calibration method for a tactile sensor according to claim 1, characterized in that, The pressure sensing layer includes a piezoresistive sensor array.

5. The calibration method for a tactile sensor according to claim 1, characterized in that, The magnetic sensing layer employs a single-point or array-type magnetic sensor design.

6. The calibration method for a tactile sensor according to claim 1, characterized in that, The flexible load-bearing layer is integrally injection molded.

7. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the calibration method for the tactile sensor as described in any one of claims 1 to 6.

8. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the calibration method for the tactile sensor as described in any one of claims 1 to 6.

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