An FBG-based helical beam high-sensitivity parallel six-axis force sensor

Abstract

The present invention discloses an FBG-based spiral beam high-sensitivity parallel six-axis force sensor, comprising: a fixed platform, a measurement platform, and a plurality of elastic connecting beams; both the fixed platform and the measurement platform are hollow cylinders, and the measurement platform is concentrically arranged inside the fixed platform; the distal ends of the plurality of elastic connecting beams are evenly distributed and fixed on the central ring on the outer side surface of the measurement platform; the proximal ends of the plurality of elastic connecting beams are fixedly arranged at intervals on the upper and lower end surfaces of the inner side surface of the fixed platform; an optical fiber is arranged inside each elastic connecting beam, and both ends of each optical fiber are respectively fixed on the corresponding side surfaces of the measurement platform and the fixed platform, and each optical fiber is led out from the outer side surface of the fixed platform; when a force / moment acts on the measurement platform, it is transmitted to the elastic connecting beam, and the deformation of the elastic connecting beam causes the grating center wavelength of the internal optical fiber to drift, so that the six-axis force value can be obtained from the drift of the center wavelength. The present invention can obtain higher sensitivity and higher resolution.

Description

Technical Field

[0001] The present invention relates to the field of measurement technology, and particularly relates to an FBG-type spiral beam high-sensitivity parallel six-dimensional force sensor. Background Art

[0002] As a core component for a robot to achieve safe and efficient operation, a six-dimensional force sensor provides force and torque information in three directions when the robot performs task operations, and has been widely used in fields such as collision testing, aerospace, medical rehabilitation, and industrial manufacturing.

[0003] The basic principle of a six-dimensional force sensor is to transfer the deformation generated by an external load to a detection element through an elastic element, and measure the magnitude of the applied force and torque. Among them, the design of the elastic element is the core issue, and the shape and size of the elastic element determine the performance of the sensor such as sensitivity, stiffness, and reliability. The existing force sensor structure designs mainly include cross beams and derivative structures, Y-shaped beam structures, T-shaped beams, and parallel structures, etc. Chinese Patent ZL201811367523.4 discloses a six-dimensional force sensor that uses a cross beam and a T-shaped beam and applies strain gauges as detection elements to achieve decoupling structurally. Chinese Patent ZL202210280781.1 discloses a six-dimensional force sensor that uses a derivative structure of a cross beam as an elastic element and adopts a capacitance detection method to achieve a compact structure of the six-dimensional force sensor. Chinese Patent ZL202010411837.0 discloses a spherical six-dimensional force sensor that uses six Y-shaped beams combined with strain gauges to achieve the detection of six-dimensional force. Chinese Patent 201610534836.9 discloses a shunt-type three-plane branch parallel six-dimensional force sensor, which has the advantage of large-range measurement. The above structures have problems such as different degrees of anisotropy difference or large inter-dimensional coupling. Their detection elements are strain gauges, capacitors, etc. These elements are vulnerable to electromagnetic interference, have poor linearity, and have serious zero-point drift and other problems, and it is difficult to be applicable to industrial or medical scenarios requiring high precision and high sensitivity. Summary of the Invention

[0004] The present invention provides an FBG-type spiral beam high-sensitivity parallel six-dimensional force sensor, which adopts a parallel distribution of FBG-type spiral beams, has high measurement sensitivity, small size, light weight, and is not affected by electromagnetic interference.

[0005] To achieve the above technical objectives, the present invention adopts the following technical solutions:

[0006] An FBG-type spiral beam high-sensitivity parallel six-dimensional force sensor, comprising: a fixed platform, a measurement platform, and a plurality of elastic connecting beams, and the number of elastic connecting beams is an even number;

[0007] The fixed platform is a hollow cylinder;

[0008] The measurement platform is a cylinder, and the diameter of the measurement platform is smaller than the inner diameter of the fixed platform. The measurement platform is concentrically arranged inside the fixed platform;

[0009] The distal ends of the plurality of elastic connecting beams are evenly distributed and fixed on the central ring on the outer side of the measurement platform;

[0010] The proximal ends of the plurality of elastic connecting beams are fixedly arranged at the upper and lower end faces of the inner side of the fixed platform at intervals; the plurality of elastic connecting beams are spirally distributed between the inner side of the fixed platform and the outer side of the measurement platform;

[0011] For the elastic connecting beam, the connecting parts at both ends are hollow cylinders, and the middle section is a hollow spiral beam, and the cross section of the spiral beam is rectangular;

[0012] Optical fibers are arranged inside each elastic connecting beam. The two ends of each optical fiber are respectively fixed to the outer side of the measurement platform and the inner side of the fixed platform, and each optical fiber is led out from the outer side of the fixed platform;

[0013] When the measurement platform is subjected to force / moment, it deforms and transmits to the elastic connecting beam. The deformation of the elastic connecting beam causes the grating center wavelength of the internal optical fiber to drift, so that the six-dimensional force value is obtained from the drift of the center wavelength.

[0014] Furthermore, the number of the plurality of elastic connecting beams is set to 6; the distal positions of all the elastic connecting beams are sequentially set as b1~b6 in the counterclockwise order, and the corresponding proximal positions are a1~a6 respectively, and a1~a6 are distributed in the counterclockwise order. The positions of a1~a6 projected on the plane of the distal central ring are A1~A6 respectively. Then, a1, a3, and a5 are spaced 120° from each other, and a2, a4, and a6 are spaced 120° from each other;

[0015] Taking the center of the distal central ring as the origin to establish a three-dimensional Cartesian coordinate system, the distal and proximal positions of all the elastic connecting beams satisfy the conditions:

[0016] ;

[0017] ;

[0018] ;

[0019] ;

[0020] ;

[0021] Among them, is the Jacobian matrix of the six-dimensional force, , , , , , , , are all intermediate variables; is the projection point is the angle of the line connecting the projection point to the origin of the coordinate system with respect to the x-axis, is the projection point is the angle of the line connecting the point to the origin of the coordinate system with respect to the x-axis, is the point is the angle of the line connecting the point to the origin of the coordinate system with respect to the x-axis, is the length of the elastic connecting beam, is the height of the proximal end relative to the plane of the distal center ring, is the outer side diameter of the measurement platform,

[0022] is the inner side diameter of the fixed platform.

[0023] Furthermore, optical fiber arrangement grooves are provided on both end faces of the fixed platform, and an optical fiber centralized outlet is provided on the side face of the fixed platform; at the position of the optical fiber centralized outlet of both end faces, an optical fiber guiding outlet communicating with the optical fiber centralized outlet is provided; the optical fiber arrangement grooves are used to place the optical fibers led out from the inner side face of the fixed platform, and the optical fibers in the optical fiber arrangement grooves are led out of the sensor through the optical fiber guiding outlet and the optical fiber centralized outlet.

[0024] Furthermore, the sensor further includes an upper cover located on the first end face of the fixed platform and a base located on the side of the second end face;

[0025] The upper cover is fixedly connected to the measurement platform and there is a gap with a first preset distance between the upper cover and the fixed platform;

[0026] The base is fixedly connected to the fixed platform and there is a gap with a second preset distance between the base and the measurement platform.

[0027] Furthermore, the measurement platform is a hollow cylinder.

[0028] Furthermore, all optical fibers adopt Bragg gratings.

[0029] Furthermore, the sensor further includes a data decoupling module, and the data decoupling module adopts the KAN model; the KAN model outputs the six-dimensional force applied to the measurement platform according to the center wavelength drift values obtained by each optical fiber of the sensor.

[0030] Furthermore, the KAN model includes an input layer, a single hidden layer, and an output layer. The learning method for the model parameters is as follows: Apply a known six-dimensional force to the sensor and collect the central wavelengths obtained by each optical fiber of the sensor to construct training samples; then train the parameters in the KAN model based on the training samples.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0032] A kind of FBG-based spiral beam high-sensitivity parallel six-dimensional force sensor of the present invention uses a spiral structure with high sensitivity as the elastic beam of the sensor, combines the advantages of FBG's anti-electromagnetic interference, sensitive response, and small volume, and can quickly sense the force change received by the measurement platform. The change in force causes the elastic beam to deform, thereby generating a corresponding FBG wavelength drift. Through the KAN model for six-dimensional force decoupling processing, the force components in each direction can be accurately measured, improving the accuracy and stability of six-dimensional force measurement. In addition, the sensor is manufactured by metal 3D printing, and the main body structure of the sensor is integrally formed, enhancing the compactness of the structure, reducing the assembly error of the sensor at the same time, and improving the reliability and measurement accuracy of the sensor. The comprehensive application of these technologies enables the sensor to obtain higher sensitivity and resolution, and expands its application scope to industrial and medical scenarios with higher precision and safety requirements. Description of the Drawings

[0033] Figure 1 It is a schematic diagram of the overall exploded structure of a kind of FBG-based spiral beam high-sensitivity parallel six-dimensional force sensor according to an embodiment of the present invention.

[0034] Figure 2 It is a schematic diagram of the structure of a kind of FBG-based spiral beam high-sensitivity parallel six-dimensional force sensor according to an embodiment of the present invention.

[0035] Figure 3 It is a schematic diagram of the top view and optical fiber distribution of a kind of FBG-based spiral beam high-sensitivity parallel six-dimensional force sensor according to an embodiment of the present invention; wherein (a) is the top view and (b) is the optical fiber distribution schematic diagram.

[0036] Figure 4 It is a schematic diagram of the spiral beam of a kind of FBG-based spiral beam high-sensitivity parallel six-dimensional force sensor according to an embodiment of the present invention; wherein (a) is the detailed schematic diagram and (b) is the cross-sectional view.

[0037] Figure 5 It is a schematic diagram of the structure diagram of the spiral beam and the coordinate diagram of the spiral beam endpoints of a kind of FBG-based spiral beam high-sensitivity parallel six-dimensional force sensor according to an embodiment of the present invention; wherein (a) is the beam structure diagram and (b) is the coordinate diagram of the spiral beam endpoints.

[0038] Description of reference numerals in the figure: 1 is the upper cover, 2 is the sensor body, 3 is the base, 201 is the fixed platform, 202 is the fiber optic centralized outlet, 203 is the fiber optic guiding outlet, 204 is the fiber optic limiting beam, 205 is the fiber optic layout groove, 206 is the fiber optic distal glue groove, 207 is the fixed platform nut hole, 208 is the measurement platform, 209 is the fiber optic proximal glue groove, 210 is the measurement platform nut hole, 211 is the elastic connection beam, 211-1 is the first spiral beam, 211-2 is the second spiral beam, 211-3 is the third spiral beam, 211-4 is the fourth spiral beam, 211-5 is the fifth spiral beam, 211-6 is the sixth spiral beam, 212-1 is the first optical fiber, 212-2 is the second optical fiber, 212-3 is the third optical fiber, 212-4 is the fourth optical fiber, 212-5 is the fifth optical fiber, 212-6 is the sixth optical fiber. Specific implementation mode

[0039] The embodiments of the present invention will be described in detail below. Based on the technical solutions of the present invention, detailed implementation modes and specific operation processes are given, and the technical solutions of the present invention are further explained and illustrated.

[0040] This embodiment provides an FBG-type spiral beam high-sensitivity parallel six-dimensional force sensor, as Figure 1 shown, including an upper cover 1, a base 3 and a sensor body 2. The upper cover 1 is located at the first end face of the sensor body 2, and the base 3 is located at the second end face of the sensor body 2. As Figure 2 shown, the sensor body 2 includes a fixed platform 201, a measurement platform 208, a plurality of elastic connection beams 211 and a data decoupling module. The number of elastic connection beams 211 is an even number.

[0041] The fixed platform 201 is a hollow cylinder, the measurement platform 208 is a hollow cylinder, the diameter of the measurement platform 208 is smaller than the inner side diameter of the fixed platform 201, the height of the measurement platform 208 is smaller than the height of the fixed platform 201, and the measurement platform 208 is concentrically arranged inside the fixed platform 201.

[0042] As Figure 3 shown, the distal ends of the plurality of elastic connection beams 211 are evenly distributed and fixed on the central ring on the outer side face of the measurement platform 208; the proximal ends of the plurality of elastic connection beams 211 are fixed at intervals on the upper and lower end faces of the inner side face of the fixed platform 201; the plurality of elastic connection beams 211 are spirally distributed between the inner side face of the fixed platform 201 and the outer side face of the measurement platform 208.

[0043] As Figure 4As shown, for the elastic connection beam 211, the connecting parts at both ends are hollow cylindrical, and the middle section is a hollow spiral beam. The cross-section of the spiral beam is rectangular. At the connection with the measurement platform 208, each elastic connection beam 211 is provided with a fiber optic distal glue groove 206, and at the connection with the fixed platform 201, each elastic connection beam 211 is provided with a fiber optic proximal glue groove 209. A fiber optic is arranged inside each elastic connection beam 211, and both ends of each fiber optic are fixed in the glue grooves on the outer side of the measurement platform 208 and the inner side of the fixed platform 201 respectively by glue. In this embodiment, all fiber optics adopt Bragg gratings.

[0044] On both end faces of the fixed platform 201, identical circular fiber optic arrangement grooves 205 are provided. On the top surface of the fiber optic arrangement groove 205 (between the top circles of the inner and outer sides of the fixed platform 201), several fiber optic limiting beams 204 are evenly arranged. A fiber optic centralized outlet 202 is provided on the outer side of the fixed platform 201. At the position of the fiber optic centralized outlet 202 on the fiber optic arrangement grooves 205 on both end faces of the fixed platform 201, a fiber optic guiding outlet 203 communicating with the fiber optic centralized outlet 202 is provided. The fiber optic arrangement groove 205 is used to place the fiber optic led out from the inner side of the fixed platform 201, and the fiber optic in the fiber optic arrangement groove 205 is limited within the fiber optic arrangement groove 205 and finally led out of the sensor through the fiber optic guiding outlet 203 and the fiber optic centralized outlet 202.

[0045] In this embodiment, the number of elastic connection beams 211 is set to 6. The 6 elastic connection beams are numbered 211-1 to 211-6 on each side, as Figure 4 shown. The corresponding fiber optics inside are numbered 212-1 to 212-6; the distal positions of all elastic connection beams 211 are set as b1~b6 in counterclockwise order, and the corresponding proximal positions are a1~a6 respectively. And a1~a6 are distributed in counterclockwise order. The positions of a1~a6 in the plane projection of the distal center circle are A1~A6 respectively. Then, a1, a3, and a5 are spaced 120° from each other, and a2, a4, and a6 are spaced 120° from each other. Taking the center of the distal center circle as the origin to establish a three-dimensional Cartesian coordinate system, the distal and proximal positions of all elastic connection beams 211 satisfy the conditions:

[0046] ;

[0047] ;

[0048] ;

[0049] ;

[0050] ;

[0051] Among them, is the Jacobian matrix of the six - dimensional force, , , , , , , , are all intermediate variables; is the angle of the line connecting the projection point and the origin of the coordinate system with respect to the x - axis, is the angle of the line connecting the projection point and the origin of the coordinate system with respect to the x - axis, is the angle of the line connecting the point and the origin of the coordinate system with respect to the x - axis, is the angle of the line connecting the point and the origin of the coordinate system with respect to the x - axis, is the length of the elastic connection beam 211, is the height of the proximal end with respect to the plane of the distal center ring, is the outer - side diameter of the measurement platform 208, is the inner - side diameter of the fixed platform 201.

[0052] The upper cover 1 is fixedly connected to the measurement platform 208 and there is a gap with a first preset distance between the upper cover 1 and the fixed platform 201; the base 3 is fixedly connected to the fixed platform 201 and there is a gap with a second preset distance between the base 3 and the measurement platform 208. When the measurement platform 208 receives the force / moment transmitted by the upper cover 1, it can prevent the measurement platform 208 from contacting the base 3 and affecting the measurement accuracy, and prevent the upper cover 1 from contacting the fixed platform 201 and affecting the measurement accuracy.

[0053] In this embodiment, on the connection surface between the fixed platform 201 and the base 3, fixing - platform nut holes 207 are provided at the position where the limiting beam 204 extends inwardly to fixedly connect the fixed platform 201 and the base 3. On the connection surface between the measurement platform 208 and the upper cover 1, a plurality of measurement - platform nut holes 210 are uniformly provided to fixedly connect the measurement platform 208 and the upper cover 1.

[0054] The data decoupling module adopts the KAN model and outputs the six - dimensional force applied to the measurement platform 208 according to the central - wavelength drift values obtained from each optical fiber of the sensor. Specifically, the KAN model includes an input layer, a single hidden layer, and an output layer. The learning method of the model parameters is: applying a known six - dimensional force to the sensor and collecting the central wavelengths obtained from each optical fiber of the sensor to construct a training sample; then training the parameters in the KAN model based on the training sample.

[0055] When the measurement platform 208 is subjected to force / moment, it deforms and transfers the deformation to the elastic connecting beam 211. The deformation of the elastic connecting beam 211 causes the grating center wavelength of the internal optical fiber to drift. Thus, the six-dimensional force value is output according to the drift amount of the center wavelength of the optical fiber by the KAN model adopted by the data decoupling module.

[0056] The structural layout principle of the FBG type spiral beam high-sensitivity parallel six-dimensional force sensor in this embodiment is as follows:

[0057] According to the screw theory, establish the force balance equation:

[0058] ;

[0059] where is the axial force on the th elastic beam; represents the unit line vector of the th elastic beam relative to the reference coordinate system; and respectively represent the force and moment applied to the measurement platform; is the dual symbol.

[0060] The above equation can be rewritten in matrix form:

[0061] ;

[0062] where is the force Jacobian matrix, which can be expressed as:

[0063] ;

[0064] is a matrix, the first three rows are the force vectors, and the last three rows are the moment vectors. For clarity of expression, the matrix can be expressed as:

[0065] ;

[0066] where, is the force vector mapping matrix, is the moment vector mapping matrix.

[0067] When studying the isotropy of the sensor, the matrix is usually expressed in the form of the force vector mapping matrix and the moment vector mapping matrix as shown in the following formula:

[0068] ;

[0069] In the sensor structure design, it is generally considered When both and and are zero matrices, it indicates that the sensor meets the decoupling performance. Further, when

[0070] is a diagonal matrix, the sensor is considered to be isotropic in force and moment.

[0071] ;

[0072] ;

[0073] where, as Figure 5 shown, is the coordinate of the connection point between the elastic connection beam of the sensor and the inner side of the fixed platform, is the coordinate of the connection point between the elastic connection beam of the sensor and the outer side of the measurement platform, is the connecting point interval angle with the center of the sensor as the coordinate origin, is the connecting point interval angle with the center of the sensor as the coordinate origin, is the length of the elastic connection beam, and the lengths of the elastic connection beams in the present invention are the same.

[0074] The expression of can be obtained as:

[0075] ;

[0076] .

[0077] Therefore, the FBG spiral beam high-sensitivity parallel six-dimensional force sensor in this embodiment meets the decoupling performance and isotropy. Therefore, the sensor structure design satisfies the following formula:

[0078] .

[0079] In addition, the data decoupling module in this embodiment adopts the KAN model, which specifically includes:

[0080] (1) Apply a given numerical six-dimensional force to the measurement platform to obtain the central wavelength drift amounts of optical fiber 1 to optical fiber 6, and construct training samples and prediction samples respectively.

[0081] (2) Construct a KAN model containing an input layer, a single hidden layer, and an output layer; where the input signal is the central wavelength drift amounts of 6 optical fibers , and the output is the given numerical six-dimensional force (three-dimensional force and three-dimensional moment) , and the elements of its hidden layer can be expressed as:

[0082] ;

[0083] Among them, is the activation function from the -th node of the input layer to the -th node of the hidden layer, represents the number of nodes in the input layer, represents the number of nodes in the hidden layer.

[0084] Then, each node in its output layer can be expressed as:

[0085] ;

[0086] Among them, is the activation function from the nodes of the hidden layer to the -th node of the output layer, is the number of nodes in the output layer.

[0087] (3) Use the training samples to optimize and learn the parameters of the KAN model, and obtain the data decoupling module of the six-axis force sensor based on the KAN model, which is expressed as: . Among them, , .

[0088] (4) Input the center wavelength drift amounts output by all the newly obtained 6 optical fibers into the data decoupling module , and output the corresponding six-axis force.

[0089] The above embodiments are the preferred embodiments of the present application. Those of ordinary skill in the art can also make various transformations or improvements on this basis. Without departing from the general concept of the present application, these transformations or improvements should all fall within the scope required to be protected by the present application.

Claims

1. A FBG type spiral beam high sensitivity parallel six-dimensional force sensor, characterized in that: include: A fixed platform, a measuring platform and a plurality of elastic connecting beams, wherein the number of the elastic connecting beams is an even number; The fixed platform is a hollow cylinder; The measuring platform is a cylinder, the diameter of the measuring platform is smaller than the inner diameter of the fixed platform, and the measuring platform is concentrically arranged inside the fixed platform; The distal ends of the plurality of elastic connecting beams are evenly distributed and fixed on the central circular ring on the outer side of the measuring platform; The proximal ends of the plurality of elastic connection beams are fixed at intervals on the upper and lower end surfaces of the inner side surface of the fixed platform; the plurality of elastic connection beams are distributed in a spiral shape between the inner side surface of the fixed platform and the outer side surface of the measuring platform; The elastic connecting beam has two end connecting parts which are hollow cylindrical, and the middle section is a hollow spiral beam, and the cross section of the spiral beam is rectangular; An optical fiber is arranged inside each elastic connecting beam, and two ends of each optical fiber are respectively fixed to the outer side surface of the measuring platform and the inner side surface of the fixed platform, and each optical fiber is led out from the outer side surface of the fixed platform; The measuring platform is deformed when subjected to force / torque and the deformation is transmitted to the elastic connecting beam. The deformation of the elastic connecting beam causes the central wavelength of the grating of the internal optical fiber to drift, thereby obtaining a six-dimensional force value from the drift of the central wavelength. The number of the plurality of elastic connecting beams is set to 6; the distal positions of all the elastic connecting beams are set to b1 to b6 in counterclockwise order, and the corresponding proximal positions are a1 to a6, and a1 to a6 are distributed in counterclockwise order, and the positions of a1 to a6 projected on the distal center circular ring plane are A1 to A6, then a1, a3, a5 are spaced 120° apart in pairs, and a2, a4, a6 are spaced 120° apart in pairs; A three-dimensional Cartesian coordinate system is established with the center of the far-end central ring as the origin, and the far-end and near-end positions of all elastic connecting beams meet the conditions: ； ； ； ； ； in, is the Jacobian matrix of the six-dimensional force, , , , , , , , are all intermediate variables; The projection point The angle of the line connecting the origin of the coordinate system with respect to the x-axis, The projection point The angle of the line connecting the origin of the coordinate system with respect to the x-axis, For point The angle of the line connecting the origin of the coordinate system with respect to the x-axis, For point The angle of the line connecting the origin of the coordinate system with respect to the x-axis, is the length of the elastic connecting beam, is the height of the proximal end relative to the plane of the distal central ring, To measure the outer diameter of the platform, is the inner diameter of the fixed platform.

2. The FBG type spiral beam high-sensitivity parallel six-dimensional force sensor according to claim 1 is characterized in that: Optical fiber arrangement grooves are arranged on both end surfaces of the fixed platform, and optical fiber concentrated outlets are arranged on the side of the fixed platform; optical fiber arrangement grooves on both end surfaces are arranged at the positions of the optical fiber concentrated outlets, and optical fiber guide outlets connected to the optical fiber concentrated outlets are arranged; The optical fiber arrangement groove is used to place the optical fiber led out from the inner side of the fixed platform, and the optical fiber in the optical fiber arrangement groove is led out of the sensor through the optical fiber guide outlet and the optical fiber concentration outlet.

3. The FBG type spiral beam high-sensitivity parallel six-dimensional force sensor according to claim 2 is characterized in that: A plurality of optical fiber limiting beams are evenly arranged on the top surface of the optical fiber arrangement groove.

4. The FBG type spiral beam high-sensitivity parallel six-dimensional force sensor according to claim 1 is characterized in that: The sensor also includes an upper cover located on the first end surface of the fixed platform and a base located on the second end surface side; The upper cover is fixedly connected to the measuring platform, and there is a gap of a first preset distance between the upper cover and the fixed platform; The base is fixedly connected to the fixed platform, and there is a gap of a second preset distance between the base and the measuring platform.

5. The FBG type spiral beam high-sensitivity parallel six-dimensional force sensor according to claim 1 is characterized in that: The measuring platform is a hollow cylinder.

6. The FBG type spiral beam high-sensitivity parallel six-dimensional force sensor according to claim 1 is characterized in that: All optical fibers use Bragg gratings.

7. The FBG type spiral beam high-sensitivity parallel six-dimensional force sensor according to claim 1 is characterized in that: The sensor also includes a data decoupling module, which adopts a KAN model; the KAN model outputs the six-dimensional force applied to the measurement platform according to the central wavelength drift value obtained by each optical fiber of the sensor.

8. The FBG type spiral beam high-sensitivity parallel six-dimensional force sensor according to claim 7 is characterized in that: The KAN model includes an input layer, a single hidden layer and an output layer. The method for learning the model parameters is: applying a known six-dimensional force on the sensor, collecting the central wavelength obtained by each optical fiber of the sensor, and constructing a training sample; then training the parameters in the KAN model based on the training sample.

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