Three-dimensional coil combined excitation pose detection system and method for force tactile reproduction

Abstract

The application discloses a three-dimensional coil combination excitation pose detection system and method for force tactile reproduction, which comprises a three-dimensional background electromagnet module, a fingertip electromagnet module, a background electromagnet driving module, a fingertip voltage sensing module and a central control module. The three-dimensional background electromagnet is of an inner-outer layer nested type, the inner layer is a one-dimensional laminated coil electromagnet, and the outer layer is a two-dimensional array coil electromagnet. Some three-dimensional background electromagnet coils are selected to have electromagnetic pose detection and force tactile reproduction functions, so that electromagnetic pose detection based on three-dimensional coil combination excitation and position grid optimization is realized. A cost function is established according to the fingertip electromagnet module induction voltage theoretical value obtained through simulation and the actual measured value of the induction voltage obtained through the voltage sensing module, and the pose of the fingertip electromagnet, namely the position information and the rotation angle information, are solved and obtained. The interactive force that a virtual hand receives in a virtual interactive environment is calculated, and a control signal is output to the electromagnet driving module, so that force tactile reproduction is realized.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of pose detection in human-computer interaction, and particularly relates to a three-dimensional coil combined excitation pose detection system and method for force tactile reproduction. BACKGROUND

[0002] Nowadays, human-computer interaction presents diversified development, and the force tactile reproduction technology effectively improves the interaction quality due to its unique bidirectional information transmission characteristics, which enables people to better perceive the multi-dimensional information such as force, hardness and shape of objects in the interaction process. The pose input of human hand as the main part of interaction with objects is an important link in human-computer interaction. Through the pose detection of fingertips, the motion process of human hand is recorded, which can better realize the position interaction and force tactile reproduction between people and computers. Common pose detection methods of human hand include optical pose detection, inertial pose detection, ultrasonic pose detection and electromagnetic pose detection.

[0003] Among them, the electromagnetic pose detection method has unique advantages and application prospects in the field of force tactile human-computer interaction due to the freedom of activity range, the similarity with the physical law and the core element used in electromagnetic force tactile human-computer interaction, and the freedom from light obstruction. In 1979, Raab et al. proposed an early model of an electromagnetic pose detection system with three-axis orthogonal, and through mathematical analysis, it was pointed out that the three-axis excitation of the quasi-static magnetic dipole field and the induced information were sufficient to determine the position and attitude information of the sensor relative to the source, and the positioning accuracy of millimeter level could be achieved. Eugene et al. proposed a method of electromagnetic pose detection of a two-axis sensor based on three groups of three-axis excitation coils. Compared with the traditional three-axis sensor tracking method, it has better position resolution and update rate, but the number of excitation coils required is increased, and the detection accuracy will decrease with the increase of detection distance.

[0004] Berkelman et al. of the University of Hawaii developed an electromagnetic pose detection and force tactile reproduction multiplexing system, which consists of a bottom sensor array composed of 18 Hall sensors, a cylindrical permanent magnet and an electromagnetic coil for electromagnetic force generation, and the positioning error is 8mm. The Omni system developed by Langerak et al. takes into account the electromagnetic pose detection and force tactile reproduction. The system positions the permanent magnet at the end of the tool through the sensor array laid at the bottom, which is composed of 5 Hall sensors, and adjusts the excitation current of the spherical electromagnet according to the pose of the permanent magnet, realizing the multiplexing of pose detection and force tactile reproduction. The average positioning error of the Omni system is 5mm and the maximum electromagnetic force that can be generated on the permanent magnet is 2N. The above electromagnetic pose detection system for force tactile reproduction limits the free movement and natural interaction process of the operator's hand.

[0005] In the patent "Multi-point force tactile reproduction method and system based on Halbach array" (application publication number CN115904116A), a multi-point force tactile reproduction method and system based on Halbach array are proposed, which generates a three-dimensional controllable background electromagnetic field by exciting three-dimensional background electromagnets to regulate and control the electromagnetic force of fingertip electromagnets. However, the outer two-dimensional array type electromagnetic iron structure in the three-dimensional background electromagnet cannot fill all the space on the circumference of the one-dimensional electromagnet, leaving many gaps, which cannot produce a good magnetic field concentration effect inside the large coil, and the pose detection module uses an optical method, which has a light blocking problem. SUMMARY

[0006] To solve the above technical problems, the present application provides a three-dimensional coil combination excitation pose detection system and method for force tactile reproduction. The system uses a large number of three-dimensional array coils distributed on the periphery of the operating space, selects a group of three-dimensional orthogonal coil units closest to the fingertip sensing electromagnet as the excitation coil for pose detection, and realizes a more accurate and faster pose detection with natural, unobstructed and functional multiplexing in force tactile applications.

[0007] The three-dimensional coil combination excitation pose detection system for force tactile reproduction provided by the present application comprises a three-dimensional background electromagnet module, a fingertip electromagnet module, a background electromagnet driving module, a fingertip voltage sensing module and a central control module; wherein,

[0008] The three-dimensional background electromagnet module comprises an inner layer of stacked one-dimensional electromagnets, an outer layer of arrayed two-dimensional electromagnets and a support base. The stacked one-dimensional electromagnets and the outer layer of arrayed two-dimensional electromagnets are nested in a cylindrical structure supported by the support base, and the cylindrical structure is the operating space;

[0009] The fingertip electromagnet module comprises disc-shaped sensing coils for three orthogonal directions in pose detection mode and permanent magnets for three orthogonal directions in force tactile reproduction mode. The coils and permanent magnets corresponding to each direction are assembled together on the finger sleeve;

[0010] The background electromagnet driving module is used to receive control information from the central control module and drive the electromagnets in the three-dimensional background electromagnet module to generate corresponding magnetic fields;

[0011] The fingertip voltage sensing module obtains the induced voltage on the fingertip sensing coil and converts the analog voltage signal into a digital signal;

[0012] The central control module calculates the 6Dof position (x, y, z) and rotation angle (α, β, γ) information of the fingertips according to the induced voltage of the three-dimensional fingertip orthogonal electromagnet, calculates the interaction force of the fingertip agent point in the virtual environment, and outputs a driving signal to generate the required electromagnetic force on the fingertip electromagnet module to form force tactile reproduction.

[0013] Further, in the three-dimensional background electromagnet module, part of the three-dimensional background electromagnet coils have electromagnetic pose detection and force tactile reproduction functions, and a space coordinate system {G} is established with the center of the operation space as the origin O, the axial direction as the X-axis direction of the system, and the radial direction as the Y-axis direction.

[0014] The inner layer of the one-dimensional electromagnet includes a plurality of coaxial hollow disc-shaped stacked coil units, the inside of the coaxial hollow disc-shaped stacked coil unit is an internal cylindrical space, and K coils EM Xi As the excitation coil for generating the X-direction magnetic field, i=1, 2, …K, the K excitation coils divide the inner layer cylindrical operation space K+1 into equal parts;

[0015] The outer layer array two-dimensional electromagnet is uniformly distributed on the circumference of all one-dimensional stacked electromagnets and fills the outer space of the circumference, and the outer layer array two-dimensional electromagnet includes a two-dimensional array coil and a core that fills the inside of the two-dimensional array coil, forming a Halbach magnet array; a single two-dimensional coil unit in the two-dimensional array coil includes a tangential coil EM Tij and two radial coils EM R1ij , EM R2ij , and three coils are wrapped around the core unit;

[0016] During pose detection, K×N two-dimensional coil units distributed on the circumference of the selected K inner layer one-dimensional coils EM Xi are selected, where N two-dimensional radial coil units are in the radial cross section, and K two-dimensional radial coil units are in the axial cross section, as excitation coils for generating YZ-direction two-dimensional magnetic field, i=1, 2, …K, j=1, 2, …N, thereby the K inner layer one-dimensional coils and the K×N two-dimensional coil units on the circumference thereof form K three-dimensional orthogonal coil combined excitation units.

[0017] Further, in the fingertip electromagnet module, the corresponding sensing coil and the corresponding permanent magnet in each direction are assembled together on the finger sleeve, wherein the disc-shaped sensing coil serves as the sensing coil in the pose detection mode and receives the alternating magnetic field signal generated by the excitation coil in the three-dimensional background electromagnet module, and the permanent magnet is used to provide feedback force to the human finger in the force tactile reproduction mode.

[0018] The geometric center of the fingertip electromagnet module is taken as the origin, the central axis of any one of the sensing coils is set as the X axis, the central axis of any one of the other sensing coils in another direction is set as the Y axis, the Z axis is determined according to the right-hand rule, and a space coordinate system {S} is established; the 6Dof pose of the fingertip electromagnet module is (x, y, z, a, b, g), wherein (x, y, z) is the position coordinate of the fingertip electromagnet module in the space coordinate system {G}, and (a, b, g) are the angles of rotation of the fingertip electromagnet module around the X, Y and Z axes of the coordinate system {S} respectively; the fingertip electromagnet module EM FT The sensing coils in the x, y and z directions are respectively named EM FTx , EM FTy , EM FTz , and both ends of the three orthogonal sensing coils of the fingertip electromagnet module are connected with the voltage sensing module.

[0019] Further, the background electromagnet driving module superimposes the direct current voltage signal for force tactile reproduction and the sine wave signal for pose detection by using an operational amplifier addition circuit, and outputs the required electrical signal to all three-dimensional background electromagnet modules for force tactile reproduction and K three-dimensional orthogonal coil combined excitation units for pose detection under the control of the central control module.

[0020] Based on the above-mentioned three-dimensional coil combined excitation pose detection system for force tactile reproduction, the application also provides a detection method thereof, which comprises the following steps:

[0021] Step one, a virtual scene including a virtual hand and a virtual object model is established, and a space mapping relationship between the internal real operation space of the three-dimensional background electromagnet module and the virtual scene, and a three-dimensional position mapping relationship between the fingertip electromagnet module and the virtual hand are established;

[0022] Step two, according to the accuracy requirement, the internal operation space of the three-dimensional background electromagnet module is divided into grids to form discrete grid nodes in the three-dimensional space, and using the finite element method, the mapping relationship between the induced voltage, 6Dof pose of the fingertip electromagnet module at the discrete grid nodes and the driving current of the three-dimensional background electromagnet module on each magnetic moment component of the fingertip electromagnet module is simulated to obtain the off-line simulation data of the fingertip electromagnet module;

[0023] Step three, the three-dimensional background electromagnet module and the fingertip electromagnet module switch to the pose detection mode, and a set of K three-dimensional orthogonal coil combination excitation units are used to generate a pose detection excitation signal; the background electromagnet driving module applies excitation signals of different frequencies to each independent excitation coil in the three-dimensional orthogonal coil combination excitation unit, the voltage sensing module obtains the voltage across the fingertip sensing coil, and selects the sensing voltage with a larger voltage component corresponding to the frequency as the input; based on the obtained sensing voltage, the central control module establishes a cost function and uses an iterative method to solve, and finally obtains the 6Dof pose of the fingertip electromagnet;

[0024] Step four, the three-dimensional background electromagnet module and the fingertip electromagnet module switch to the force tactile reproduction mode, and based on a force tactile interaction model of a human fingertip and a virtual object in a virtual scene, a target three-dimensional feedback force of the fingertip electromagnet module at the current time is calculated;

[0025] Step five, the three-dimensional background electromagnet combination excitation method is used to generate electromagnetic force; according to the off-line simulation data and the given 6Dof pose and target three-dimensional feedback force of the fingertip electromagnet module, the central control module calculates the excitation signal value required by the three-dimensional background electromagnet module in the force tactile reproduction mode, controls the background electromagnet driving module to output excitation current to drive all three-dimensional background electromagnets, increases the magnetic field strength inside the operation space through the Hall effect, generates the required electromagnetic force on the fingertip electromagnet module, and forms the force tactile reproduction.

[0026] Further, the step three includes:

[0027] Step 3.1, the three-dimensional background electromagnet module and the fingertip electromagnet module switch to the pose detection mode, and a sinusoidal signal with an amplitude of U MAX is used to excite K three-dimensional orthogonal coil combination excitation units, K one-dimensional electromagnets EM Xi uniformly distributed in the inner layer are selected as excitation coils for generating an X-direction magnetic field, and N two-dimensional coil units uniformly distributed on the circumference of EM Xi are selected as excitation coils for generating YZ-direction two-dimensional magnetic fields;

[0028] Step 3.2, according to the Biot-Savart law, the magnetic induction intensity B i generated by the i th three-dimensional orthogonal coil combination excitation unit at the fingertip electromagnet module EM ET is represented as:

[0029] B i = f(x, y, z, w Xi , w Tij , w Rij );

[0030] Positioning EM ETAt that time, select one inner one-dimensional excitation coil with a larger magnetic field amplitude and phase component at the corresponding frequency, and one of the two-dimensional coil units on its circumference, and set it as EM. X1 EM T11 EM R11 , which serves as the input signal for the excitation coil in the pose detection algorithm;

[0031] Step 3.3, the voltage sensing module obtains the fingertip induction coil EM FTx EM FTy EM FTz The voltage U across the terminals x U y U z Based on the theoretical and measured values ​​of the induced voltage, a cost function is established:

[0032] E(x,y,z,α,β,γ)=(U′ x -U x ) 2 +(U′ y -U y ) 2 +(U′ z -U z ) 2 ;

[0033] Among them, U′ x ,U′ y ,U′ z This is the theoretical value of the induced voltage obtained from the simulation in step two.

[0034] In a preferred embodiment of this application, the number of two-dimensional coil units is set to N=3. The operating space of the three-dimensional background electromagnet is divided into K+1 equal parts by K inner one-dimensional excitation coils. One inner one-dimensional excitation coil and three two-dimensional coil units evenly distributed on its circumference form a three-dimensional orthogonal coil combination excitation unit. Excitation signals of different frequencies are applied to each three-dimensional orthogonal coil combination excitation unit and its excitation coils in each direction. The inner pose excitation coil EM... Xi Outer tangential pose excitation coil EM Tij and outer radial pose detection coil EM R1ij EM R2ij The applied excitation signal frequencies are w Xi w Tij w Rij .

[0035] Further, according to the established cost function, the Levenberg-Marquardt method is used to solve the 3 position information (x, y, z) and 3 rotation angle information (alpha, beta, gamma) of the fingertip electromagnet module relative to the spatial coordinate system, so as to obtain the numerical solution of the 6Dof pose of the fingertip electromagnet module.

[0036] Compared with the prior art, the above technical scheme has the following technical effects:

[0037] (1) The three-dimensional inner and outer layer nested background electromagnet is adopted, the inner layer is a one-dimensional stacked coil electromagnet, and the outer layer is a two-dimensional array coil electromagnet, an electromagnetic pose detection method based on three-dimensional coil combination excitation and position grid optimization is realized, and different accuracy requirements are met.

[0038] (2) The function multiplexing three-dimensional background electromagnet module and fingertip orthogonal electromagnet module make the structure of the force tactile human-computer interaction system more compact, expand the operation space, are not affected by light obstruction, and improve the pose detection accuracy. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 is a structural schematic diagram of a three-dimensional coil combination excitation pose detection system for force tactile reproduction.

[0040] Figure 2 is a radial section view of a three-dimensional inner and outer layer background electromagnet structure. DETAILED DESCRIPTION

[0041] In order to make the control method and control advantages of the present application clearer, the present application will be described clearly and completely below in combination with examples of the present application and drawings. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments.

[0042] Embodiment 1

[0043] The present embodiment provides a three-dimensional coil combination excitation pose detection system for force tactile reproduction, as shown in Figure 1 The three-dimensional coil combination excitation pose detection system for force tactile reproduction includes a three-dimensional background electromagnet module 1, a fingertip electromagnet module 2, a background electromagnet driving module 3, a fingertip voltage sensing module 4, and a central control module 5.

[0044] The three-dimensional background electromagnet module includes an inner layer stacked one-dimensional electromagnet, an outer layer array two-dimensional electromagnet, and a support base, the stacked one-dimensional electromagnet and the outer layer array two-dimensional electromagnet are nested into a cylindrical structure supported by the support base, and the operation space is in the cylindrical structure.

[0045] The fingertip electromagnet module includes disc-shaped induction coils for three orthogonal directions in the pose detection mode and permanent magnets for three orthogonal directions in the force tactile reproduction mode, and each direction corresponds to the combination of the coils and the permanent magnets assembled on the finger sleeve;

[0046] The background electromagnet driving module is used for receiving control information from the central control module to drive the electromagnets in the three-dimensional background electromagnet module to generate corresponding magnetic fields;

[0047] The fingertip voltage sensing module obtains the induced voltage on the fingertip induction coil and converts the analog voltage signal into a digital signal;

[0048] The central control module calculates the fingertip 6Dof position (x, y, z) and rotation angle (α, β, γ) information according to the induced voltage of the three-dimensional fingertip orthogonal electromagnet, calculates the interaction force of the fingertip agent point in the virtual environment, and outputs a driving signal to generate the required electromagnetic force on the fingertip electromagnet module to form force tactile reproduction.

[0049] Further, in the three-dimensional background electromagnet module, part of the three-dimensional background electromagnet coils have electromagnetic pose detection and force tactile reproduction functions, and a space coordinate system {G} is established with the center of the operation space as the origin O, the axial direction as the X-axis direction of the system, and the radial direction as the Y-axis direction, and the Z-axis is determined according to the right-hand rule.

[0050] The inner layer of the one-dimensional electromagnet includes a plurality of coaxial hollow disc-shaped stacked coil units, and the inside of the coaxial hollow disc-shaped stacked coil unit is an internal cylindrical space. During pose detection, K evenly distributed coils EM Xi As the excitation coil for generating an X-direction magnetic field, i=1, 2, …K, the K excitation coils divide the inner layer cylindrical operation space K+1 into equal parts;

[0051] The outer layer array two-dimensional electromagnet is evenly distributed on the circumference of all one-dimensional stacked electromagnets and fills the outer space of the circumference, and the outer layer array two-dimensional electromagnet includes a two-dimensional array coil and a core filling the inside of the two-dimensional array coil to form a Halbach magnet array; a single two-dimensional coil unit in the two-dimensional array coil includes a tangential coil EM Tij and two radial coils EM R1ij and EM R2ij The three coils are wrapped around the core unit;

[0052] During pose detection, select K inner layer one-dimensional coils EM XiK×N two-dimensional coil units on the circumference, wherein, N two-dimensional radial coil units in the radial section, K two-dimensional radial coil units in the axial section, as the excitation coil generating YZ direction two-dimensional magnetic field, i=1, 2, …K, j=1, 2, …N, thus, the K inner layer one-dimensional coil and K×N two-dimensional coil units on the circumference of the K three-dimensional orthogonal coil combination excitation unit.

[0053] Further, in the fingertip electromagnet module, the corresponding inductive coil and the corresponding permanent magnet in each direction are assembled together on the finger sleeve, wherein the disc-shaped inductive coil serves as the inductive coil in the pose detection mode, receives the alternating magnetic field signal generated by the excitation coil in the three-dimensional background electromagnet module, and the permanent magnet is used to provide feedback force to the human finger in the force tactile reproduction mode.

[0054] Taking the geometric center of the fingertip electromagnet module as the origin, setting the central axis of any one inductive coil as the X axis, setting the central axis of any one inductive coil in another direction as the Y axis, determining the Z axis according to the right-hand rule, and establishing a space coordinate system {S}; the 6Dof pose of the fingertip electromagnet module is (x, y, z, α, β, γ), wherein (x, y, z) is the position coordinate of the fingertip electromagnet module in the space coordinate system {G}, and (α, β, γ) are the angles of rotation of the fingertip electromagnet module around the X, Y and Z axes of the coordinate system {S} respectively; the fingertip electromagnet module EM FT The inductive coils in the x, y and z directions are respectively named EM FTx , EM FTy , EM FTz , and the two ends of the three orthogonal inductive coils of the fingertip electromagnet module are connected with the voltage sensing module.

[0055] Further, the background electromagnet driving module adopts an operational amplifier plus circuit to superimpose a direct current voltage signal for force tactile reproduction and a sine wave signal for pose detection, and a central control module controls the output of required electrical signals to all three-dimensional background electromagnet modules for force tactile reproduction and K three-dimensional orthogonal coil combination excitation units for pose detection.

[0056] Embodiment 2

[0057] Based on the above device, the application provides a detection method of a three-dimensional coil combination excitation pose detection system for force tactile reproduction, characterized in that the detection method comprises the following steps:

[0058] Step one, establishing a virtual scene including a virtual hand and a virtual object model, and establishing a spatial mapping relationship between a real operation space inside a three-dimensional background electromagnet module and the virtual scene, and a three-dimensional position mapping relationship between a fingertip electromagnet module and the virtual hand;

[0059] Step two, according to the accuracy requirements, the three-dimensional background electromagnet module internal operating space is meshed to form a discrete grid node in the three-dimensional space, using the finite element method, the mapping relationship of the induction voltage, 6Dof pose and three-dimensional background electromagnet module driving current on each magnetic moment component of the fingertip electromagnet module is simulated to obtain the offline simulation data thereof;

[0060] Step three, the three-dimensional background electromagnet module and the fingertip electromagnet module are switched to a pose detection mode, a specific K three-dimensional orthogonal coil combination excitation unit generates a pose detection excitation signal; the background electromagnet driving module applies an excitation signal of different frequencies to each independent excitation coil in the three-dimensional orthogonal coil combination excitation unit, the voltage sensing module obtains the voltage across the fingertip induction coil, and selects the induction voltage with a larger voltage component corresponding to the frequency as the input; based on the obtained induction voltage, the central control module establishes a cost function and uses an iterative method to solve, and finally obtains the 6Dof pose of the fingertip electromagnet.

[0061] Step four, the three-dimensional background electromagnet module and the fingertip electromagnet module are switched to a force tactile reproduction mode, based on a force tactile interaction model of a human fingertip and a virtual object in a virtual scene, a target three-dimensional feedback force of the fingertip electromagnet module at the current time is calculated.

[0062] Step five, a three-dimensional background electromagnet combination excitation method is used to generate electromagnetic force; according to the offline simulation data and the given 6Dof pose of the fingertip electromagnet module and the target three-dimensional feedback force, the central control module calculates the excitation signal value required by the three-dimensional background electromagnet module in the force tactile reproduction mode, controls the background electromagnet driving module to output the excitation current to drive all three-dimensional background electromagnets, increases the magnetic field strength inside the operating space through the Hall effect, generates the required electromagnetic force on the fingertip electromagnet module, and forms the force tactile reproduction.

[0063] Further, the step three includes:

[0064] Step 3.1, the three-dimensional background electromagnet module and the fingertip electromagnet module are switched to a pose detection mode, the pose detection mode refers to exciting a specific K three-dimensional orthogonal coil combination excitation unit with a sine wave signal with an amplitude of U MAX , selecting K one-dimensional electromagnets EM Xi uniformly distributed in the inner layer as excitation coils for generating X-direction magnetic field, and N two-dimensional coil units uniformly distributed on the circumference of EM Xi including one tangential coil EM Tij and two radial coils EM R1ij , EM R2ij as excitation coils for generating YZ-direction two-dimensional magnetic field.

[0065] The number of two-dimensional coil units N = 1, 2, 3, 4, …, n can be applied; N can be selected according to the different accuracy requirements of pose detection (pose detection excitation signal is applied), the greater N is, the higher the accuracy of pose detection is.

[0066] Taking N = 3 as an example, on the one hand, it is convenient to draw a graph, and on the other hand, the three two-dimensional units of the outer layer can better divide the circular operation space into three 120-degree regions, and the dead angle (weak signal) of pose detection is relatively less.

[0067] Taking the number of two-dimensional coil units N = 3 as an example, the operation space of the three-dimensional background electromagnet is divided into K+1 equal parts by K inner one-dimensional excitation coils, wherein one inner one-dimensional excitation coil and three two-dimensional coil units uniformly distributed on the circumference thereof form a three-dimensional orthogonal coil combined excitation unit. Different frequency excitation signals are applied to each three-dimensional orthogonal coil combined excitation unit and the excitation coils in each direction, and the inner pose excitation coil EM Xi , the outer tangential pose excitation coil EM Tij and the outer radial pose detection coil EM R1ij , EM R2ij The excitation signal frequencies are w Xi , w Tij , w Rij .

[0068] Step 3.2, according to the Biot-Savart law, the magnetic induction intensity B FT generated by the i-th three-dimensional orthogonal coil combined excitation unit at the fingertip electromagnet module EM i is represented as:

[0069] B i = f(x, y, z, w Xi , w Tij , w Rij )

[0070] When positioning EM FT , select an inner one-dimensional excitation coil with a larger magnetic field amplitude and phase component corresponding to the frequency and a certain one-dimensional coil unit on the circumference thereof, or say, the inner one-dimensional excitation coil with the largest corresponding component among all excitation coils and a certain one-dimensional coil unit on the circumference thereof. Assume that EM X1 , EM T11 , EM R11 are the excitation coil input signals of the pose detection algorithm.

[0071] Step 3.3, the voltage U obtained by the voltage sensing module at both ends of the fingertip sensing coil EM FTx , EM FTy , EM FTz ​x , U y , U z According to the inductive voltage theoretical value and the measured value, a cost function is established:

[0072] E(x, y, z, a, b, g) = (U' x - U x ) 2 + (U' y - U y ) 2 + (U' z - U z ) 2

[0073] Wherein, U' x , U' y , U' z are the inductive voltage theoretical values obtained by simulation in step two.

[0074] Further, according to the established cost function, the nonlinear least squares method, i.e. Levenberg-Marquardt method, is used to solve the 3 position information (x, y, z) and 3 rotation angle information (a, b, g) of the fingertip electromagnet module relative to the spatial coordinate system, so as to obtain the numerical solution of the 6Dof pose of the fingertip electromagnet module.

[0075] The direct current voltage signal of the force tactile reproduction of the present application is applied to all three-dimensional background electromagnets (all inner and outer coils), and the sine wave signal of the pose detection is applied to the selected K three-dimensional orthogonal coil combination excitation units in the three-dimensional background electromagnet.

[0076] Those skilled in the art in this technical field can understand that, unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meaning as generally understood by those of ordinary skill in the art to which the present application belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with those in the prior art, and unless defined as such, should not be interpreted with idealized or overly formal meanings.

[0077] The above specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present application. It should be understood that the above description is only a specific embodiment of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A three-dimensional coil combination excitation pose detection system for force tactile reproduction, characterized by, The detection system comprises a three-dimensional background electromagnet module, a fingertip electromagnet module, a background electromagnet driving module, a fingertip voltage sensing module and a central control module. The three-dimensional background electromagnet module comprises an inner layer stacked one-dimensional electromagnet, an outer layer arrayed two-dimensional electromagnet and a support base. The inner layer stacked one-dimensional electromagnet comprises a plurality of coaxial hollow disc-shaped stacked coil units, the coaxial hollow disc-shaped stacked coil units are internally provided with an internal cylindrical space, and K coils uniformly distributed in the internal cylindrical space are selected for pose detection Xi As the excitation coil for generating the X-direction magnetic field, i=1, 2, …K, the K excitation coils divide the cylinder operation space K+1 of the inner layer into equal parts; The outer layer array two-dimensional electromagnet is uniformly distributed on the circumference of all one-dimensional laminated electromagnets and fills the outer space of the circumference, the outer layer array two-dimensional electromagnet comprises a two-dimensional array coil and a core filling the inside of the two-dimensional array coil, and a Halbach magnet array is formed; a single two-dimensional coil unit in the two-dimensional array coil comprises a tangential coil EM Tij and inner and outer two radial coil EM R1ij , EM R2ij , and three coils are wrapped on the core unit; When the pose is detected, the K inner one-dimensional coil EMs distributed on the selected K one-dimensional coil EMs are selected Xi K×N two-dimensional coil units on the circumference, wherein, in the radial section, N two-dimensional radial coil units, in the axial section, K two-dimensional radial coil units, as the excitation coil generating the YZ direction two-dimensional magnetic field, j=1, 2, …N, j=1, 2, …N, thereby, the K inner one-dimensional coil and the K×N two-dimensional coil units on the circumference thereof form a K three-dimensional orthogonal coil combined excitation unit; The fingertip electromagnet module comprises three orthogonal direction disc-shaped sensing coils for pose detection mode and three orthogonal direction permanent magnets for force tactile reproduction mode. The background electromagnet driving module is used for receiving control information from the central control module and driving electromagnets in the three-dimensional background electromagnet module to generate corresponding magnetic fields. The fingertip voltage sensing module obtains sensing voltage on the fingertip sensing coil and converts analog voltage signals into digital signals. The central control module calculates fingertip 6Dof position (x, y, z) and rotation angle (α, β, γ) information according to sensing voltage of the three-dimensional fingertip orthogonal electromagnet, calculates interactive force of a fingertip proxy point in a virtual environment and outputs driving signals to generate required electromagnetic force on the fingertip electromagnet module to form force tactile reproduction. 2.The force haptics rendering oriented three-dimensional coil combination excitation pose detection system according to claim 1, wherein, The fingertip electromagnet module comprises three orthogonal direction disc-shaped sensing coils for pose detection mode and three orthogonal direction permanent magnets for force tactile reproduction mode. The geometric center of the fingertip electromagnet module is taken as the origin, the central axis of any one sensing coil is set as the X axis, the central axis of any one other direction sensing coil is set as the Y axis, the Z axis is determined according to the right-hand rule, and a space coordinate system {S} is established; the 6Dof pose of the fingertip electromagnet module is (x, y, z, α, β, γ), wherein (x, y, z) is the position coordinate of the fingertip electromagnet module in the space coordinate system {G}, and (α, β, γ) are the angles of rotation of the fingertip electromagnet module around the X, Y and Z axes of the coordinate system {S} respectively; the fingertip electromagnet module EM FT The sensing coils in the x, y and z directions are respectively named as EM FTx , EM FTy , EM FTz , and both ends of the three orthogonal sensing coils of the fingertip electromagnet module are connected with the voltage sensing module. 3.The force haptics rendering oriented three-dimensional coil combination excitation pose detection system according to claim 1, wherein, The background electromagnet driving module adopts an operational amplifier plus circuit to superimpose direct current voltage signals for force tactile reproduction and sine wave signals for pose detection. 4.The detection method of a three-dimensional coil combination excitation pose detection system for force tactile reproduction according to claim 1, wherein, The detection method comprises the following steps: Step one, a virtual scene comprising a virtual hand and a virtual object model is established, and a three-dimensional background electromagnet module internal real operation space and a virtual scene space mapping relationship and a fingertip electromagnet module and a virtual hand three-dimensional position mapping relationship are established. Step two, according to the accuracy requirements, the three-dimensional background electromagnet module internal operating space is meshed to form a discrete grid node in the three-dimensional space, using the finite element method, the simulation obtains the mapping relationship of the fingertip electromagnet module at the discrete grid node, the induced voltage, 6Dof pose and the three-dimensional background electromagnet module driving current on the force of each magnetic moment component of the fingertip electromagnet module, and obtains the fingertip electromagnet module offline simulation data; Step three, the three-dimensional background electromagnet module and the fingertip electromagnet module are switched to the pose detection mode, and a set of K three-dimensional orthogonal coil combination excitation units are used to generate a pose detection excitation signal; the background electromagnet driving module applies an excitation signal of different frequencies to each independent excitation coil in the three-dimensional orthogonal coil combination excitation unit, the voltage sensing module obtains the voltage across the fingertip sensing coil, and selects the larger sensing voltage as the input; based on the obtained sensing voltage, the central control module establishes a cost function and uses an iterative method to solve, and finally obtains the 6Dof pose of the fingertip electromagnet; The step three includes: Step 3.1, the three-dimensional background electromagnet module and the fingertip electromagnet module are switched to a pose detection mode, and a sinusoidal signal with an amplitude of U MAX excites the K three-dimensional orthogonal coil combination excitation unit, selects K one-dimensional electromagnets EM Xi as the excitation coil for generating the X direction magnetic field, and EM Xi N two-dimensional coil units uniformly distributed on the circumference as excitation coils for generating YZ direction two-dimensional magnetic field; Step 3.2, the magnetic induction B generated at the fingertip electromagnet module EMi of the ith three-dimensional orthogonal coil combination excitation unit is represented as: FT i is represented as:​ B i = f(x, y, z, w Xi ,w Tij ,w Rij ); w Xi , w Tij , w Rij are an inner layer position excitation coil EM Xi , an outer layer tangential position excitation coil EM Tij and an outer layer radial position detection coil EM R1ij , EM R2ij application excitation signal frequency; Positioning EM FT When the frequency is selected, one of the inner layer one-dimensional excitation coils with larger magnetic field amplitude and phase component and one of the two-dimensional coil units on the circumference thereof is selected and set as EM X1 , EM T11 , EM R11 , as the excitation coil input signal of the pose detection algorithm; Step 3.3, the voltage sensing module obtains the fingertip induction coil EM FTx EM FTy EM FTz The voltage U across the terminals x U y U z Based on the theoretical and measured values ​​of the induced voltage, a cost function is established: E(x,y,z,α,β,γ)=(U′ x -U x ) 2 +(U′ y -U2) 2 +(U′ z -U z ) 2 ; where U' = U - U0 x , U' = U - U0 y , U' = U - U0 z is the theoretical value of the induced voltage obtained by simulation in step two. Step four, the three-dimensional background electromagnet module and the fingertip electromagnet module are switched to the force tactile reproduction mode, and based on the force tactile interaction model of the human fingertip and the virtual object in the virtual scene, the target three-dimensional feedback force of the fingertip electromagnet module at the current time is calculated; Step five, the three-dimensional background electromagnet combination excitation method is used to generate electromagnetic force; according to the offline simulation data and the given 6Dof pose of the fingertip electromagnet module and the target three-dimensional feedback force, the central control module calculates the excitation signal value required by the three-dimensional background electromagnet module in the force tactile reproduction mode, controls the background electromagnet driving module to output the excitation current to drive all three-dimensional background electromagnets, increases the magnetic field strength inside the operating space through the Hall effect, generates the required electromagnetic force on the fingertip electromagnet module, and forms the force tactile reproduction.

5. The detection method according to claim 4, characterized in that, Set the number of two-dimensional coil units N = 3, the operating space of the three-dimensional background electromagnet is divided into K+1 equal parts by K inner one-dimensional excitation coils, wherein one inner one-dimensional excitation coil and three two-dimensional coil units uniformly distributed on its circumference form a three-dimensional orthogonal coil combined excitation unit; for each three-dimensional orthogonal coil combined excitation unit and its excitation coils in each direction, different frequency excitation signals are applied, the inner pose excitation coil EM Xi , the outer tangential pose excitation coil EM Tij and the outer radial pose detection coil EM R1ij , EM R2ij The excitation signal frequencies are w Xi , w Tij , w Rij .

6. The detection method according to claim 4, characterized in that, According to the established cost function, the Levenberg-Marquardt method is used to solve the 3 position information (x, y, z) and 3 rotation angle information (α, β, γ) of the fingertip electromagnet module relative to the spatial coordinate system, so as to obtain the numerical solution of the 6Dof pose of the fingertip electromagnet module.

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