Tactile sensor and calibration method of tactile sensor

Abstract

The invention provides a tactile sensor and a calibration method of the tactile sensor, and belongs to the technical field of sensors, the tactile sensor comprises a magnetic sensing layer, a pressure sensing layer and a flexible stress layer which are stacked in sequence; a magnetic film made of a magnetic material is embedded in the flexible stress layer, and after the flexible stress layer is subjected to three-dimensional force, the position of the magnetic film is changed; the pressure sensing layer is used for measuring a normal force of a three-dimensional force; and the magnetic sensing layer is used for detecting and acquiring magnetic field data of the magnetic film at different positions before and after the magnetic film is stressed so as to solve a three-dimensional force. According to the touch sensor provided by the invention, after the flexible stress layer is stressed, the pressure is transmitted to the pressure sensing layer through deformation, so that normal force detection is realized; meanwhile, according to the magnetic field change of the magnetic sensor before and after the flexible stress layer is stressed, the displacement change of the magnetic film is calculated, and finally the three-dimensional force is generated through decoupling.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sensors, in particular to a tactile sensor and a calibration method of the tactile sensor. BACKGROUND

[0002] As an important branch of the field of intelligent robots, humanoid robots have gradually entered various industries and shown broad application prospects in fields such as service, education, medical treatment and manufacturing. At present, the sensing ability of humanoid robots mainly focuses on touch and vision. As a relatively new sensor, the tactile sensor plays a crucial role in the field of humanoid robots.

[0003] Traditional tactile sensors (such as pressure resistance or capacitance-based sensors) can usually only measure normal pressure (one-dimensional information) and cannot measure tangential force, have large triggering force and low upper limit of sensitivity; if the tangential force or three-dimensional force is measured, complex sensor structures must be relied on or cumbersome calibration methods must be used for decoupling. Although the pure magnetic sensing scheme can measure three-dimensional force, it has the problems of low spatial resolution (simple magnetic sensing layout) or difficult decoupling (complex magnetic sensing layout). SUMMARY

[0004] The present application provides a tactile sensor and a calibration method of the tactile sensor to solve at least one defect of the existing tactile sensor.

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

[0006] According to the tactile sensor provided by the present application, the pressure sensing layer comprises a pressure resistance sensor array.

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

[0008] According to the tactile sensor provided by the present application, the flexible force receiving layer adopts one-piece injection molding.

[0009] In a second aspect, the present application further provides a calibration method of a tactile sensor, applied to the tactile sensor as described above, comprising:

[0010] The three-dimensional calibration force is applied, a first horizontal tangential force, a second horizontal tangential force and a normal force of the three-dimensional calibration force are obtained, and a first horizontal displacement amount and a second horizontal displacement amount of the magnetic film at the current position compared with an initial position before force is obtained; wherein the first horizontal displacement amount corresponds to the first horizontal tangential force, and the second horizontal displacement amount corresponds to the second horizontal tangential force;

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

[0012] Based on the first calibration data and the second calibration data, a first mapping relationship function of the first horizontal tangential force and the first horizontal displacement amount and the normal force, and a second mapping relationship function of the second horizontal tangential force and the second horizontal displacement amount and the normal force are constructed respectively;

[0013] The normal force measurement value output by the pressure sensing layer is calibrated according to the normal force of the three-dimensional calibration force, and a third mapping relationship function is obtained.

[0014] The calibration method of the tactile sensor provided by the application further comprises: constructing a magnetic field mapping simulation model between the magnetic film position and the magnetic field data; determining the positions of the magnetic film before and after force according to the magnetic field data output by the magnetic sensing layer by using the magnetic field mapping simulation model; and determining the displacement amount of the magnetic film in the three-dimensional space according to the positions of the magnetic film before and after force.

[0015] After the calibration is completed, the step of measuring the three-dimensional force to be measured according to the calibration method of the tactile sensor provided by the application comprises: determining the first horizontal displacement amount and the second horizontal displacement amount of the magnetic film after the flexible force layer is subjected to force compared with the initial position before force according to the magnetic field mapping simulation model; and after the pressure sensing layer detects force, the following steps are performed: obtaining a 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 by using the third mapping relationship function according to the normal force measurement value; determining the first horizontal tangential force of the three-dimensional force to be measured by using the first mapping relationship function according to the first horizontal displacement amount and the normal force; and determining the second horizontal tangential force of the three-dimensional force to be measured by using the second mapping relationship function according to the second horizontal displacement amount and the normal force.

[0016] Before the three-dimensional calibration force is applied, the calibration method of the tactile sensor provided by the application further comprises: 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 of the magnetic film and the magnetic sensing layer, the deformation range and the hardness range of the elastic material of the flexible force layer; obtaining a plurality of combinations of different parameters in the optional range, sequentially measuring the different effects of each combination, and determining the optimal parameter combination.

[0017] In a third aspect, the present application provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the calibration method of the tactile sensor according to any one of the above aspects when executing the program.

[0018] In a fourth aspect, the present application further provides a non-transitory computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the calibration method of the tactile sensor according to any one of the above aspects.

[0019] The tactile sensor and the calibration method of the tactile sensor provided by the present application have the following beneficial effects compared with the prior art:

[0020] (1) The tactile sensor provided by the present application can transmit the pressure to the pressure sensing layer through deformation after the flexible force layer is subjected to force, so as to realize the detection of the normal force; at the same time, the magnetic film displacement change is calculated according to the magnetic field change of the magnetic sensor before and after the flexible force layer is subjected to force, and finally decoupled into three-dimensional force.

[0021] (2) The tactile sensor provided by the present application realizes the joint calibration of pressure sensing and magnetic sensing multi-modal data, the normal force can be generated from the normal force measurement value directly output by the piezoresistance, and the tangential force is obtained by magnetic film displacement decoupling, so as to solve the problems of single sensor dimension loss and low spatial resolution.

[0022] (3) The present application establishes a nonlinear mapping model of elastic material deformation-magnetic field-force, realizes high-precision measurement of tangential force, and judges whether the current elastic body is in a force state through piezoresistance, if the piezoresistance detects that there is no force at present, the three-dimensional force is not output, so as to prevent the output of three-dimensional force when there is external strong magnetic interference, and improve the robustness of the tactile sensor. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0024] Figure 1 is a flowchart of the calibration method of the tactile sensor provided by the present application;

[0025] Figure 2 is a complete implementation flowchart provided by the present application;

[0026] Figure 3 is a structure diagram of the electronic device provided by the present application. DETAILED DESCRIPTION

[0027] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below with reference to the drawings in the present application. Obviously, the described embodiments are only some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall into the protection scope of the present application.

[0028] It should be noted that, in the description of the embodiments of the present application, the terms "comprise", "contain" or any other variants thereof are intended to cover the non-exclusive inclusion, so that the process, method, article or equipment comprising a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment. Without more limitation, the element defined by the statement "comprising a" does not exclude the presence of another identical element in the process, method, article or equipment comprising the element. The above terms can be understood according to the specific meaning of the terms in the present application by those of ordinary skill in the art according to the specific circumstances.

[0029] The terms "first", "second", and the like in the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the terms thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than that illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally a category and do not limit the number of objects, for example, the first object can be one or more. In addition, the character " / ", generally indicates that the associated objects before and after are in an "or" relationship.

[0030] The embodiments of the present application will be described below in conjunction with Figures 1-3 The present application provides a tactile sensor and a calibration method of the tactile sensor.

[0031] The present application provides a tactile sensor, comprising: a magnetic sensing layer, a pressure sensing layer and a flexible force receiving layer stacked in sequence; the flexible force receiving layer is embedded with a magnetic film composed of magnetic material, and the position of the magnetic film changes after the flexible force receiving layer is subjected to three-dimensional force; the pressure sensing layer is used to measure the normal force of the three-dimensional force; and the magnetic sensing layer is used to detect and obtain the magnetic field data of the magnetic film at different positions before and after being subjected to force, so as to solve the three-dimensional force.

[0032] When the flexible stress layer is subjected to external force, the flexible stress layer is elastically displaced to cause the magnetic film to be spatially displaced and the pressure sensing layer to act.

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

[0034] The pressure sensing layer can be a piezoresistive sensor array, which uses a flexible piezoresistive array (such as a carbon nanotube / PDMS composite material) to directly measure the normal force received by the flexible stress layer, and the spatial resolution can reach 0.1 mm.

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

[0036] The way of calculating the three-dimensional force using the magnetic field data is briefly described as follows: first, a magnetic field mapping simulation model of the magnetic film position and the magnetic field data (generally the magnetic field strength data) is constructed in advance, and then the pre-established magnetic field mapping simulation model is used to determine the position change of the magnetic film before and after the force is applied; further, the displacement of the magnetic film is determined according to the position change of the magnetic film before and after the force is applied; further, the three-dimensional force can be calculated according to the pre-calibrated relationship between the displacement and the three-dimensional force.

[0037] The normal force measured by the pressure sensing layer is often more accurate than the normal force measured by the magnetic sensing layer. The present application 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, the present application proposes a calibration method for the tactile sensor.

[0038] Before formal calibration, the technical solution of the present application further includes the following preparation steps: determining the number and layout of the 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 of the magnetic film and the magnetic sensing layer, the deformation range and the hardness range of the elastic material of the flexible stress layer; obtaining a plurality of combinations of different parameters within the optional range, and sequentially measuring the different effects of each combination to determine the optimal parameter combination.

[0039] Figure 1 is a flowchart of the calibration method of the tactile sensor provided by the present application, as shown in Figure 1 the following steps are included but not limited to:

[0040] Step 101: applying a three-dimensional calibration force, obtaining a first horizontal tangential force, a second horizontal tangential force and a normal force of the three-dimensional calibration force, and obtaining a first horizontal displacement amount and a second horizontal displacement amount of the magnetic film at a current position compared with an initial position before being subjected to force.

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

[0042] The three-dimensional calibration force can be applied by a mature calibration platform, and 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 horizontal displacement amount and the second horizontal displacement amount can be determined by magnetic field data before and after being subjected to force. The calculation method of the displacement amount is described below, including but not limited to the following steps:

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

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

[0046] wherein (Dx, Dy, Dz) is the magnetic film position, and (Bx, By, Bz) is the magnetic field data (which can be magnetic field intensity data).

[0047] (2) determining the positions of the magnetic film before and after being subjected to force by using the magnetic field mapping simulation model according to the magnetic field data output by the magnetic sensing layer.

[0048] This step is to obtain the current position after being subjected to force and the initial position before being subjected to force. Only by substituting the magnetic sensing data of the respective positions into g0, the respective positions can be determined.

[0049] It can be understood that the initial position is updated after the flexible force-receiving layer is subjected to the three-dimensional calibration force each time, so as to compensate for displacement drift.

[0050] (3) determining the displacement amount of the magnetic film in the three-dimensional space according to the positions of the magnetic film before and after being subjected to force.

[0051] wherein the first horizontal displacement amount ΔD x can be determined according to the change amount of Dx before and after being subjected to force, and the second horizontal displacement amount ΔD y can be determined according to the change amount of Dy before and after being subjected to force.

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

[0053] Step 103: based on the first calibration data and the second calibration data, constructing a first mapping relationship function of the first horizontal tangential force and the first horizontal displacement amount and the normal force, and a second mapping relationship function of the second horizontal tangential force and the second horizontal displacement amount and the normal force; specifically, the first mapping relationship function is expressed as:

[0054] Fx=g1(ΔD x ,Fz);

[0055] The second mapping relationship function is expressed as:

[0056] Fy=g2(ΔD y ,Fz)。

[0057] Step 104: calibrating the normal force measurement value output by the pressure sensing layer according to the normal force of the three-dimensional calibration force, and obtaining a third mapping relationship function; which is expressed as:

[0058] Fz=g3(Fz0);

[0059] Wherein, Fz0 is the normal force measurement value, and g1, g2 and g3 represent the mapping relationship function respectively.

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

[0061] (1) determining the first horizontal displacement amount and the second horizontal displacement amount of the magnetic film after the flexible force layer is stressed compared with the initial position before the stress according to the magnetic field mapping simulation model;

[0062] (2) after the pressure sensing layer detects the stress, the following steps are executed:

[0063] 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 by using the third mapping relationship function according to the normal force measurement value;

[0064] Determining the first horizontal tangential force of the three-dimensional force to be measured by using the first mapping relationship function according to the first horizontal displacement amount and the normal force;

[0065] Determining the second horizontal tangential force of the three-dimensional force to be measured by using the second mapping relationship function according to the second horizontal displacement amount and the normal force.

[0066] In order to make the technical solutions of the present application clearer, the present application is described below from the preparation, data calibration and the arrangement process of the actual measurement of three-dimensional force.

[0067] Figure 2 The complete implementation process schematic diagram provided by the present application is shown in Figure 2 The present application includes but is not limited to the following steps:

[0068] Step 1: Determine the composition structure of the tactile sensor according to the morphology of the product, determine the number and layout of the sensors according to the size parameter to determine the size of the PCB, and determine the number and layout of the measurement points of the piezoresistive module according to the spatial resolution;

[0069] Step 2: Determine the distance range of the magnetic film and the magnetic sensing layer according to the size parameter of the structure (different thicknesses of silica gel and PCB thicknesses); according to the three-dimensional force range index of the tactile sensor, the stress generated by the deformation of the silica gel is fed back to the pressure sensing layer, which cannot exceed the measurement range of the pressure sensing layer, and the displacement of the magnetic film caused by the deformation of the silica gel cannot cause the corresponding change of the magnetic field to exceed the measurement range of the magnetic sensing layer in the magnetic sensing layer, thereby determining the deformation range of the elastic material of the flexible force layer. For the same force, the deformation range of the elastic material with different hardnesses is different, thereby determining the hardness range of the elastic material; according to the resolution parameter of the tactile sensor, different hardnesses of the elastic material, different distances, and different magnetic material parameters (material, size, number and layout) affect the degree of change of the magnetic field, for example, the closer the distance between the magnetic film and the magnetic sensing layer, the greater the amount of change of the magnetic field generated by the same amount of deformation, that is, it is easier to detect smaller forces, thereby obtaining a plurality of combinations of different parameters within the selectable range, and measuring the different effects of each combination in turn, thereby determining the optimal parameter combination; for example, the hardness of the elastic material is 30, the distance between the magnetic film and the magnetic sensing layer is 5mm, the thickness of the magnetic film is 5mm, the thickness of the PCB is 2mm, the magnetic material is selected to be NdFeB, and the layout of the 3x3 spherical magnet is used, and the center of the elastic material is aligned with the center of the magnetic sensing layer.

[0070] Step 3: According to the obtained optimal combination, calibrate the precision of the completed tactile sensor, generate a stable three-dimensional calibration force by controlling the high-precision three-dimensional moving platform and designing the rigid pressing structure and jig, measure the interaction force by the three-dimensional force sensor to calculate the size of the force, and realize the size control of the force by changing the moving step length, for example, pressing 0.5mm will generate 1N of normal force, and tangential movement of 0.5mm will generate 0.5N of tangential force.

[0071] Step 4: Develop a force and magnetic data acquisition program for three-dimensional mobile platform control and automation according to the required calibration data set. The normal force measurement value of the pressure sensing layer is fitted and calibrated with the actual normal force value (the normal force of the three-dimensional calibration force), so that the size of the normal force at different measurement points is obtained Fz.

[0072] Step 5: The calibration of the tactile sensor can be divided into two steps: the first step is to obtain the theoretical calculation of the position relationship of the magnetic sensing layer and the magnetic film through simulation modeling, so as to obtain the mapping relationship of the magnetic film position and the magnetic field (Dx, Dy, Dz) = g0(Bx, By, Bz), and the position of the magnetic film can be calculated in real time through the function g0; the second step is to record the initial position of the magnetic film before calibration, and to apply a three-dimensional calibration force to start calibration, and to obtain the displacement amount / deformation amount of the magnetic film by calculating the current position of the magnetic film and subtracting the initial position, and to obtain the mapping function g3 by calibrating the normal force measurement value output by the pressure sensing layer with the normal force of the three-dimensional calibration force (i.e. Fz after calibration), and to calibrate the true tangential force Fx / Fy (i.e. the tangential force of the three-dimensional calibration force) output by the three-dimensional force sensor to obtain the mapping relationship of the tangential force and the tangential deformation of the magnetic film (the first horizontal displacement amount or the second horizontal displacement amount) Fx = g1(ΔD x ,Fz)、Fy = g2(ΔD y ,Fz)。

[0073] Step 6: After calibration, the steps of measuring three-dimensional force include: judging whether the flexible force receiving layer is in a force receiving state through the piezoresistive layer (i.e. the pressure sensing layer), if the piezoresistive layer detects that there is no force at present, the three-dimensional force measurement result is not output (to prevent the functions g1 and g2 from outputting three-dimensional force when there is external strong magnetic interference), and the position of the magnetic film before the piezoresistive layer is stressed is calculated through the function g0, and is recorded as the initial position. When the piezoresistive layer detects that the elastomer is stressed, the normal force of the three-dimensional force is determined by using the function g3, and the current position of the magnetic film is calculated by using the current magnetic field data through the function g0; the real deformation of the magnetic film ΔD x and ΔD y is obtained by calculating the current position minus the initial position, and further, the tangential force is calculated through the functions g1 and g2.

[0074] It should be noted that since the elastomer cannot completely return to the original position (the initial position of the magnetic film is different) after the stress is removed, the magnetic field measured by the magnetic sensing layer in the two previous non-stressed states is different, and the calculated three-dimensional force drifts, so the initial position measured last time needs to be updated before each three-dimensional force is applied.

[0075] In summary, the present application has the following beneficial effects compared with the prior art:

[0076] (1) The tactile sensor provided by the application can realize the detection of normal force by conducting the pressure to the pressure sensing layer through deformation after the flexible force receiving layer is subjected to force; meanwhile, the magnetic film displacement change is calculated according to the magnetic field change of the magnetic sensor before and after the flexible force receiving layer is subjected to force, and finally decoupled into three-dimensional force.

[0077] (2) The tactile sensor provided by the application realizes the joint calibration of pressure sensing and magnetic sensing multi-modal data, the normal force can be generated from the normal force measurement value directly output by the piezoresistance, and the tangential force is obtained by magnetic film displacement decoupling, solving the problems of single sensor dimension loss and low spatial resolution.

[0078] (3) The application establishes an elastic material deformation-magnetic field-force nonlinear mapping model, realizes high-precision measurement of tangential force, and judges whether the current elastic body is in a force state through piezoresistance, if the piezoresistance detects that there is no force at present, the three-dimensional force is not output, 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 is a structural schematic diagram of an electronic device provided by the application, as Figure 3 shown, the electronic device can include: a processor 310, a communications interface 320, a memory 330 and a communications bus 340, wherein the processor 310, the communications interface 320, the memory 330 complete mutual communication through the communications bus 340. The processor 310 can call the logic instructions in the memory 330 to execute the calibration method of the tactile sensor, the method comprising: applying a three-dimensional calibration force, obtaining a first horizontal tangential force, a second horizontal tangential force and a normal force of the three-dimensional calibration force, and obtaining a first horizontal displacement amount and a second horizontal displacement amount of the magnetic film at the current position compared with the initial position before being subjected to force; wherein the first horizontal displacement amount corresponds to the first horizontal tangential force, and the second horizontal displacement amount corresponds to the second horizontal tangential force;

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

[0081] Based on the first calibration data and the second calibration data, a first mapping relationship function of the first horizontal tangential force and the first horizontal displacement amount and the normal force is constructed, and a second mapping relationship function of the second horizontal tangential force and the second horizontal displacement amount and the normal force is constructed;

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

[0083] In addition, the logical instructions in the memory 330 described above can be implemented in the form of a software function unit and sold or used as an independent product, and can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application essentially or the part that contributes to the prior art or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, including a plurality of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the method described in various embodiments of the present application. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various media that can store program codes.

[0084] On the other hand, the present application also provides a computer program product, which comprises a computer program stored on a non-transitory computer readable storage medium, and the computer program comprises program instructions, when the program instructions are executed by a computer, the computer can execute the calibration method of the tactile sensor provided by the above-mentioned embodiments, and the method comprises:

[0085] applying a three-dimensional calibration force, obtaining a first horizontal tangential force, a second horizontal tangential force and a normal force of the three-dimensional calibration force, and obtaining a first horizontal displacement and a second horizontal displacement of the magnetic film at the current position compared with the initial position before being stressed; wherein 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 taken as first calibration data, and the second horizontal tangential force, the second horizontal displacement and the normal force are taken as 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 relationship function of the first horizontal tangential force and the first horizontal displacement and the normal force, and a second mapping relationship function of the second horizontal tangential force and the second horizontal displacement and the normal force are constructed respectively;

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

[0089] In yet another aspect, the present application also provides a non-transitory computer readable storage medium having stored thereon a computer program, which, when executed by a processor, implements the method for calibrating a tactile sensor provided by any of the above embodiments, the method comprising:

[0090] applying a three-dimensional calibration force, obtaining a first horizontal tangential force, a second horizontal tangential force and a normal force of the three-dimensional calibration force, and obtaining a first horizontal displacement and a second horizontal displacement of the magnetic film at the current position compared with the initial position before being subjected to the force; wherein the first horizontal displacement corresponds to the first horizontal tangential force, and the second horizontal displacement corresponds to the second horizontal tangential force;

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

[0092] based on the first calibration data and the second calibration data, respectively constructing a first mapping relationship function of the first horizontal tangential force and the first horizontal displacement and the normal force, and a second mapping relationship function of the second horizontal tangential force and the second horizontal displacement and the normal force;

[0093] calibrating the normal force measurement value output by the pressure sensing layer according to the normal force of the three-dimensional calibration force, and obtaining a third mapping relationship function.

[0094] The device embodiments described above are only schematic, wherein the units shown as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, i.e., can be located in one place, or can be distributed on multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the present embodiment. Those skilled in the art can understand and implement without creative labor.

[0095] From the above description of the embodiments, those skilled in the art can clearly understand that the embodiments can be realized by means of software plus necessary general hardware platforms, and of course can also be realized by hardware. Based on such understanding, the above technical solutions essentially or in other words the part that contributes to the prior art can be embodied in the form of a software product, which can be stored in a computer readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes a plurality of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute the methods described in each embodiment or some parts of the embodiments.

[0096] It should be pointed out finally that the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit the same; and although the present application has been described in detail with reference to the foregoing embodiments, it should be appreciated by those skilled in the art that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features thereof can be replaced equivalently; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A tactile sensor characterized by, include: A magnetic sensing layer, a pressure sensing layer, and a flexible force-bearing layer are stacked sequentially. The flexible force-bearing layer is embedded with a magnetic film composed of magnetic material. When the flexible force-bearing layer is subjected to three-dimensional force, the position of the magnetic film changes. The pressure sensing layer is used to measure the normal force of a 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 the three-dimensional force.

2. The tactile sensor according to claim 1, characterized by, The pressure sensing layer includes a piezoresistive sensor array.

3. The tactile sensor according to claim 1, wherein The magnetic sensing layer employs a single-point or array-type magnetic sensor design.

4. The tactile sensor according to claim 1, characterized by, The flexible load-bearing layer is integrally injection molded.

5. A method of calibrating a tactile sensor, applied to the tactile sensor according to any one of claims 1 to 4, characterized by, include: 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 stress layer is subjected to the three-dimensional calibration force each time; 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 normal force is constructed, and a second mapping function between the second horizontal tangential force and the second horizontal displacement and 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.

6. The method of calibrating a tactile sensor according to claim 5, wherein, 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.

7. The method of calibrating a tactile sensor according to claim 5, wherein, 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.

8. The method of calibrating a tactile sensor according to claim 5, wherein, 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.

9. An electronic device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, The computer program is executed by the processor to implement the steps of the method for calibrating the tactile sensor according to any one of claims 5 to 8.

10. A non-transitory computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to implement the steps of the method for calibrating the tactile sensor according to any one of claims 5 to 8.

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