Displacement determination method and device for magnetostrictive actuator, equipment, medium and product

Abstract

The invention discloses a magnetostrictive actuator displacement determination method, device and equipment, a medium and a product, and relates to the field of magnetostrictive actuators, and the method comprises the steps: determining the output displacement of a magnetostrictive actuator through an output displacement model according to an input current, a GMM rod parameter and a coil parameter; the determination method of the output displacement model specifically comprises the following steps: acquiring a test input current, a test GMM rod parameter and a test coil parameter of the magnetostrictive actuator; determining the magnetization intensity of the GMM rod based on a spatial non-uniform magnetic field model according to the test input current and the test GMM rod parameters; determining temperature distribution by using an equivalent thermal network model based on an equivalent thermal resistance principle according to the test GMM rod parameters and the test coil parameters; and constructing an output displacement model according to the magnetization intensity and temperature distribution of the GMM rod based on the influence of the temperature on the magnetostrictive effect and the thermal expansion displacement. According to the invention, the calculation precision of the output displacement of the magnetostrictive actuator can be improved.

Description

Technical Field

[0001] The present application relates to the field of magnetostrictive actuators, and particularly to a method, device, equipment, medium and product for determining the displacement of a magnetostrictive actuator. Background Art

[0002] Magnetostrictive actuators have the advantages of high energy density, fast response speed, high Curie temperature, etc., and are widely used in fields such as precision manufacturing, ultrasonic testing, sonar systems, etc. With the upgrading of the industry, magnetostrictive actuators are responsible for high-precision displacement output, and accurate modeling can accurately predict key parameters such as the stroke and output force of the actuator, ensuring precise control during the processing. Therefore, a method for improving the output displacement accuracy of magnetostrictive actuators is needed. Summary of the Invention

[0003] The purpose of the present application is to provide a method, device, equipment, medium and product for determining the displacement of a magnetostrictive actuator, which can improve the calculation accuracy of the output displacement of the magnetostrictive actuator.

[0004] To achieve the above purpose, the present application provides the following solutions:

[0005] In a first aspect, the present application provides a method for determining the displacement of a magnetostrictive actuator, including:

[0006] Obtain the actual input current, actual GMM rod parameters and actual coil parameters of the magnetostrictive actuator;

[0007] Determine the output displacement of the magnetostrictive actuator using the output displacement model based on the actual input current, the actual GMM rod parameters and the actual coil parameters;

[0008] The specific method for determining the output displacement model includes:

[0009] Obtain the test input current, test GMM rod parameters and test coil parameters of the magnetostrictive actuator;

[0010] Determine the magnetization intensity of the GMM rod based on the test input current and the test GMM rod parameters using the spatially non-uniform magnetic field model;

[0011] Determine the temperature distribution using the equivalent thermal network model based on the test GMM rod parameters and the test coil parameters according to the principle of equivalent thermal resistance;

[0012] Construct an output displacement model based on the magnetization intensity of the GMM rod and the temperature distribution according to the influence of temperature on the magnetostrictive effect and thermal expansion displacement.

[0013] Optionally, the magnetostrictive intensity of the GMM rod is determined based on the space non-uniform magnetic field model according to the test input current and the test GMM rod parameters, specifically including:

[0014] Determine the magnetic induction intensity equation in the GMM rod according to the permeability of the test GMM rod parameters;

[0015] Determine the radial magnetic field equation generated by eddy current in the GMM rod according to the test input current based on Maxwell's equations;

[0016] Determine the intensity equation of the excitation magnetic field in the GMM rod according to the magnetic induction intensity equation in the GMM rod and the radial magnetic field equation;

[0017] Determine the magnetostrictive intensity of the GMM rod by using the J-A model according to the intensity equation of the excitation magnetic field in the GMM rod.

[0018] Optionally, the temperature distribution is determined based on the equivalent thermal resistance principle according to the test GMM rod parameters and the test coil parameters by using an equivalent thermal network model, specifically including:

[0019] Construct an equivalent thermal network model based on the equivalent thermal resistance principle according to the test GMM rod parameters and the test coil parameters;

[0020] Determine the turbine loss power of the GMM rod and the hysteresis loss power of the GMM rod by using the equivalent thermal network model based on the equivalent thermal resistance principle according to the test GMM rod parameters;

[0021] Calculate the loss power of the GMM rod according to the turbine loss power of the GMM rod and the hysteresis loss power of the GMM rod;

[0022] Calculate the temperature distribution of the GMM rod according to the loss power of the GMM rod and the test GMM rod parameters.

[0023] Optionally, an output displacement model is constructed based on the influence of temperature on the magnetostrictive effect and thermal expansion displacement according to the magnetostrictive intensity of the GMM rod and the temperature distribution, specifically including:

[0024] Establish a model of the influence of temperature on the magnetostrictive effect and thermal expansion displacement according to the test GMM rod parameters, the magnetostrictive intensity of the GMM rod, and the temperature distribution;

[0025] Construct an output displacement model by using an equivalent second-order mass-spring-damper system and Laplace transform according to the model of the influence of temperature on the magnetostrictive effect and thermal expansion displacement.

[0026] Optionally, the expression of the model of the influence of temperature on the magnetostrictive effect and thermal expansion displacement is:

[0027]

[0028] Among them, λ S , M S , M(T G(Z) ), σ, E G , α T and T c are respectively the saturation magnetostrictive coefficient, saturation magnetization intensity, magnetization intensity at temperature T G(Z) , pre-pressure, Young's modulus, thermal expansion coefficient and Curie temperature of the GMM rod; T1 is the temperature before thermal expansion, T2 is the temperature after thermal expansion; β is the correction coefficient, ε G is the strain of the GMA, T G is the specific temperature value on the GMM rod, and T0 is the temperature when correcting the β parameter. z represents the axial direction of the GMM rod, and l G is the effective length of the GMM rod.

[0029] Optionally, the expression of the output displacement model is:

[0030]

[0031] Among them, y is the output displacement; Me, Cm and k are respectively the equivalent mass, equivalent damping and equivalent stiffness of the GMA; A G is the cross-sectional area of the GMM rod, E G is Young's modulus, ε G is the strain of the GMM rod, and s is the Laplace operator.

[0032] In a second aspect, the present application provides a device for determining the displacement of a magnetostrictive actuator, including:

[0033] An actual data acquisition module, configured to acquire the actual input current, actual GMM rod parameters and actual coil parameters of the magnetostrictive actuator;

[0034] An output displacement determination module, configured to determine the output displacement of the magnetostrictive actuator according to the actual input current, the actual GMM rod parameters and the actual coil parameters by using the output displacement model;

[0035] The method for determining the output displacement model specifically includes:

[0036] Acquire the test input current, test GMM rod parameters and test coil parameters of the magnetostrictive actuator;

[0037] Determine the magnetization intensity of the GMM rod according to the test input current and the test GMM rod parameters based on the spatially non-uniform magnetic field model;

[0038] Determine the temperature distribution according to the test GMM rod parameters and the test coil parameters based on the principle of equivalent thermal resistance by using the equivalent thermal network model;

[0039] Based on the influence of temperature on the magnetostrictive effect and thermal expansion displacement, an output displacement model is constructed according to the magnetization intensity of the GMM rod and the temperature distribution.

[0040] In a third aspect, the present application provides a computer device, including: a memory, a processor, and a computer program stored on the memory and executable on the processor, where the processor executes the computer program to implement the magnetostrictive actuator displacement determination method described in any one of the above.

[0041] In a fourth aspect, the present application provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, it implements the magnetostrictive actuator displacement determination method described in any one of the above.

[0042] In a fifth aspect, the present application provides a computer program product, including a computer program, and when the computer program is executed by a processor, it implements the magnetostrictive actuator displacement determination method described in any one of the above.

[0043] According to the specific embodiments provided by the present application, the present application has the following technical effects:

[0044] The present application provides a method, device, equipment, medium, and product for determining the displacement of a magnetostrictive actuator. The final output displacement is calculated using an output displacement model based on the actual input current, actual magnetostrictive (Giantmagnetostrictive material, GMM) rod parameters, and actual coil parameters. In the process of determining the output displacement model, the magnetization intensity of the GMM rod is determined based on a spatially non-uniform magnetic field model, the temperature distribution is determined using an equivalent thermal resistance principle and an equivalent thermal network model, and by considering the influence of temperature on the magnetization of the GMM rod and the thermal expansion displacement, finally, constructing the output displacement model based on the magnetization intensity and temperature distribution can reduce the influence of thermal expansion displacement caused by temperature, thereby improving the accuracy of the final output displacement calculation. Description of the Drawings

[0045] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0046] Figure 1 It is a flowchart of the output displacement model calculation method;

[0047] Figure 2 It is a working principle diagram of the magnetostrictive actuator;

[0048] Figure 3 It is a heat transfer mode diagram of a magnetostrictive actuator;

[0049] Figure 4 It is a structural diagram of a magnetostrictive actuator;

[0050] Figure 5 It is a heat transfer path diagram of a magnetostrictive actuator;

[0051] Figure 6 It is an equivalent thermal network model diagram of a magnetostrictive actuator;

[0052] Figure 7 It is a radial magnetic field distribution diagram inside the GMM rod;

[0053] Figure 8 It is an axial magnetic field distribution and temperature distribution diagram inside the GMM rod under different currents;

[0054] Figure 9 It is a GMA output displacement characteristic diagram under different currents;

[0055] Figure 10 It is a GMA output displacement characteristic diagram under different frequencies;

[0056] Figure 11 It is a flow chart of a method for determining the displacement of a magnetostrictive actuator provided in an embodiment of the present application. Detailed implementation manners

[0057] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0058] To make the above objects, features, and advantages of the present application more obvious and understandable, the present application will be further described in detail below with reference to the accompanying drawings and specific implementation manners.

[0059] The working process of a magnetostrictive actuator is to convert an electric field into a magnetic field. The magnetostrictive material elongates under the action of the magnetic field, and heat is generated. Therefore, the operation of a magnetostrictive actuator involves the coupling among electromagnetic, thermal, and mechanical energies. Due to the low magnetic permeability of the magnetostrictive rod and the influence of eddy currents, the magnetic field distribution in the material is non-uniform. In addition, the non-uniform electromagnetic loss causes the temperature of the magnetostrictive actuator to increase and shows a non-uniform distribution. Since the magnetization characteristics of the magnetostrictive rod are significantly affected by temperature, an increase in temperature will greatly reduce the magneto-mechanical conversion efficiency and increase the thermal expansion displacement, resulting in a large variation in the output displacement of the magnetostrictive actuator over time. Therefore, it is necessary to analyze the magnetic field and temperature distributions under different working conditions. This application considers the magnetic field and temperature distributions under different working conditions through a spatially non-uniform magnetic field model and an equivalent thermal network model, thereby improving the accuracy of calculating the final output displacement of the magnetostrictive actuator.

[0060] During the operation of a magnetostrictive actuator, it is jointly affected by electromagnetic, thermal, and mechanical fields, and their distributions in the actuator are non-uniform. Through the analysis and modeling of the non-uniform magnetic field inside the GMM rod, this application constructs a spatial thermal network model of the magnetostrictive actuator (Giantmagnetostrictive actuator, GMA), establishes a mechanical output model of the GMA, solves the output displacement of the GMA through the Simlink / Matlab simulation software, analyzes the influence law of different working conditions on the output displacement of the GMA, and based on the Simlink / Matlab simulation software, improves the output accuracy, has a wide range of applications, and can accurately grasp the operating characteristics of the GMA.

[0061] As Figure 11 shown, a method for determining the displacement of a magnetostrictive actuator provided by this application includes:

[0062] Step 1101: Obtain the actual input current, actual GMM rod parameters, and actual coil parameters of the magnetostrictive actuator. Among them, both the actual GMM rod parameters and the test GMM rod parameters include the magnetic permeability, electrical conductivity, thermal conductivity, charge density, radius, and effective length of the GMM rod. Both the actual coil parameters and the test coil parameters include the total number of turns of the coil, the inner and outer diameters of the coil, the effective radius of the enameled wire, magnetic permeability, and electrical conductivity.

[0063] Step 1102: Determine the output displacement of the magnetostrictive actuator according to the actual input current, the actual GMM rod parameters, and the actual coil parameters using the output displacement model.

[0064] The specific method for determining the output displacement model includes:

[0065] Obtain the test input current, test GMM rod parameters, and test coil parameters of the magnetostrictive actuator.

[0066] Determine the magnetization intensity of the GMM rod based on the spatial inhomogeneous magnetic field model according to the test input current and the test GMM rod parameters.

[0067] Determine the temperature distribution based on the equivalent thermal resistance principle using the equivalent thermal network model according to the test GMM rod parameters and the test coil parameters.

[0068] Construct an output displacement model based on the magnetization intensity of the GMM rod and the temperature distribution according to the influence of temperature on the magnetostrictive effect and thermal expansion displacement.

[0069] In an exemplary embodiment, determining the magnetization intensity of the GMM rod based on the spatial inhomogeneous magnetic field model according to the test input current and the test GMM rod parameters specifically includes:

[0070] Determine the magnetic induction intensity equation in the GMM rod according to the magnetic permeability of the test GMM rod parameters.

[0071] Determine the radial magnetic field equation generated by eddy currents in the GMM rod based on the test input current according to Maxwell's equations.

[0072] Determine the intensity equation of the excitation magnetic field in the GMM rod according to the magnetic induction intensity equation in the GMM rod and the radial magnetic field equation.

[0073] Determine the magnetization intensity of the GMM rod using the J-A model according to the intensity equation of the excitation magnetic field in the GMM rod.

[0074] In an exemplary embodiment, determining the temperature distribution based on the equivalent thermal resistance principle using the equivalent thermal network model according to the test GMM rod parameters and the test coil parameters specifically includes:

[0075] Construct an equivalent thermal network model based on the equivalent thermal resistance principle according to the test GMM rod parameters and the test coil parameters; determine the eddy current loss power of the GMM rod and the hysteresis loss power of the GMM rod using the equivalent thermal network model according to the test GMM rod parameters based on the equivalent thermal resistance principle; calculate the loss power of the GMM rod according to the eddy current loss power of the GMM rod and the hysteresis loss power of the GMM rod; calculate the temperature distribution of the GMM rod according to the loss power of the GMM rod and the test GMM rod parameters.

[0076] Analyze the main heat transfer methods and heat transfer paths encountered during the operation of the GMA, determine the loss heat sources of the material according to the magnetic circuit model, calculate the thermal resistance, heat capacity and thermal power in the thermal circuit based on the equivalent thermal resistance principle, and finally establish an equivalent thermal network model of the GMA. Specifically, the excitation coil and the GMM rod.

[0077] The exciting coil and the GMM rod are the two main heat sources for the operation of the GMA. Heat conduction and heat convection are the two heat transfer methods. The exciting coil will generate a large amount of heat due to ohmic loss under high-frequency current, and transfer the heat to the yoke and permanent magnet through convection with the internal air. Subsequently, the heat will dissipate outward through the shell by heat conduction. The GMM rod will generate eddy current loss and hysteresis loss under an alternating magnetic field, and the heat will dissipate outward through heat convection with the internal air and heat conduction between the yoke, permanent magnet and shell.

[0078] a. Equivalent thermal network model of the coil.

[0079] The loss power P of the coil C can be expressed as:

[0080]

[0081] The heat capacity C of the coil C can be solved according to the heat capacity formula C = cρV, where c, ρ, and V represent the specific heat capacity, density, and volume of the material respectively. This formula is also applicable to the solution of the heat capacity of the GMM rod. I is the input current, and R C is the total resistance of the coil, and R Cd is the DC resistance, and R Cs is the AC resistance.

[0082] The thermal resistances in the equivalent network model of the coil are as follows:

[0083]

[0084]

[0085] R CA1 ,R CA2 ,R CA3 are the first equivalent axial thermal resistance, the second equivalent axial thermal resistance, and the third equivalent axial thermal resistance of the coil respectively. l c is the length of the coil, λ C is the thermal conductivity of the coil, r1 is the inner diameter of the coil, and r2 is the outer diameter of the coil.

[0086] b. Thermal network model of the GMM rod.

[0087] The temperature of the GMM rod is mainly generated by eddy current loss and hysteresis loss.

[0088] The eddy current loss power P eddy , and the hysteresis loss power Ph of the GMM rod.

[0089]

[0090] Where: N is the total number of turns of the coil; R1 and R2 are the inner and outer radii of the coil; rC 、 μ C and ρ C are respectively the effective radius, permeability and resistivity of the enameled wire; ρ, r G and l G are respectively the charge density, radius and effective length of the GMM rod; μ I is the real part of the complex permeability.

[0091] The heat capacity C of the coil C can be solved according to the heat capacity formula C = cρV, where c, ρ, and V respectively represent the specific heat capacity, density and volume of the material. This formula is also applicable to the solution of the heat capacity of the GMM rod.

[0092] c. Other regional thermal network models.

[0093] Other regions of the GMA include permanent magnets, upper and lower magnetic conduction blocks, the housing, and the output rod. Since these regions are not heat sources and have little influence on the heat conduction process, they can be represented by single nodes and can be ignored. These regions can be regarded as composed of cylindrical components, and the heat capacity can be solved according to the heat capacity formula C = cρV.

[0094] When the GMA works, heat will be transferred from the heat source component to other components through the internal air, and heat will also be transferred between the housing and the external air through heat convection. The heat transfer thermal resistance corresponding to the air can be calculated.

[0095] d. GMA thermal network model.

[0096] Build a thermal network model of the GMA for thermal analysis. Connect the regions with similar temperatures in the heat transfer relationship with nodes, separate them with corresponding thermal barriers in the middle, and connect the heat capacities in parallel between the nodes and zero points in each region. Calculate the parameters of each region in the model, including heat source power, thermal resistance, heat capacity, etc., and use a computer to solve the GMA thermal network model to obtain the temperature distribution on the GMM rod.

[0097] In an exemplary embodiment, an output displacement model is constructed based on the influence of temperature on the magnetostrictive effect and thermal expansion displacement according to the magnetization intensity of the GMM rod and the temperature distribution, specifically including: establishing a temperature model for the magnetostrictive effect and thermal expansion displacement according to the measured GMM rod parameters, the magnetization intensity of the GMM rod and the temperature distribution; constructing an output displacement model according to the temperature model for the magnetostrictive effect and thermal expansion displacement using an equivalent second-order mass-spring-damping system and Laplace transform.

[0098] In practical applications, the expression of the temperature model for the magnetostrictive effect and thermal expansion displacement is:

[0099]

[0100] Among them, λS , M S , M(T G(Z) ), σ, E G , α T and T c are respectively the saturation magnetostrictive coefficient, saturation magnetization intensity, magnetization intensity at temperature T G(Z) of the GMM rod, pre-pressure, Young's modulus, coefficient of thermal expansion and Curie temperature; T1 is the temperature before thermal expansion, T2 is the temperature after thermal expansion; β is the correction coefficient, and ε G is the strain of the GMA, T G is the specific temperature value on the GMM rod, and T0 is the temperature when correcting the β parameter. z represents the axial direction of the GMM rod, and l G is the effective length of the GMM rod.

[0101] In practical applications, the expression of the output displacement model is:

[0102]

[0103] where y is the output displacement; M e , C m and k are respectively the equivalent mass, equivalent damping and equivalent stiffness of the GMA; A G is the cross-sectional area of the GMM rod, E G is Young's modulus, ε G is the strain of the GMM rod, and s is the Laplace operator.

[0104] In practical applications, after constructing the output displacement model based on the influence of temperature on the magnetostrictive effect and thermal expansion displacement according to the magnetization intensity of the GMM rod and the temperature distribution, it further includes: using Simlink / Matlab simulation software to solve the output displacement model of the GMA, and analyzing the influence law on the output displacement of the GMA under different working conditions.

[0105] This application is based on the physical model of the actual magnetostrictive actuator, and can analyze the output displacement characteristics of the actuator in real time. This application is based on the magnetic field inhomogeneity, fully considering its influence on the temperature distribution, and then affecting the output displacement of the GMA. The proposed calculation method can more accurately describe the output characteristics of the GMA under different working conditions compared with the current lumped parameter model.

[0106] As Figure 1 shown, this application also provides the calculation process of the output displacement model in practical applications, mainly including the following steps:

[0107] Step 1: According to the working principle of the magnetostrictive actuator, considering the reverse magnetic field generated by eddy currents in the GMM rod, establish a spatially inhomogeneous magnetic field model.

[0108] Step 1.1: The working principle of the magnetostrictive actuator is as follows Figure 2 As shown; when an alternating current is passed through the coil of the magnetostrictive actuator, the magnetic induction intensity equation in the GMM rod can be derived:

[0109]

[0110]

[0111] where: r and z are the radial and axial directions of the GMM rod respectively; B z0 is the magnetic induction intensity at the center of the GMM rod; μ G is the magnetic permeability of the GMM rod, n is the mathematical symbol of the summation formula and has no practical meaning, B z (r,z) is the axial magnetic induction intensity on the GMM rod, B r (r,z) is the radial magnetic induction intensity on the GMM rod. r d is the radius of the point on the GMM rod.

[0112] Step 1.2: Based on Maxwell's equations, the radial magnetic field equation generated by eddy currents in the GMM rod is derived:

[0113]

[0114] where: ζ 2 =jwμ G σ G ; ζ is a simplified formula symbol, w is the frequency of the input current, σ G is the conductivity of the GMM rod, is the radial magnetic field equation of eddy currents in the GMM rod, H(r) is the radial magnetic field on the GMM rod considering eddy currents, and j is the imaginary unit in mathematics.

[0115] Step 1.3: The intensity equation of the excitation magnetic field in the GMM rod:

[0116]

[0117] Through the J-A model, the relationship between the magnetization intensity M and the magnetic field intensity H can be obtained:

[0118]

[0119] H e =H + αM an

[0120] M irr =(M - cM an ) / (1 - c)

[0121]

[0122] where: k is the irreversible loss coefficient, δ is the direction coefficient, c is the reversible loss coefficient, H e is the effective magnetic field, α is the mean field parameter of the internal coupling of magnetic domains, a is the shape parameter of the anhysteretic magnetization, M irr is the reversible magnetization, M an is the anhysteretic magnetization, M s is the saturation magnetization. H0 is the magnetic field strength at the center of the GMM rod; is the phase angle of the hysteresis effect; μ0 is the magnetic permeability of air, t is time, a is the first parameter which has no practical meaning and is used to simplify the formula, b is the second parameter which has no practical meaning and is used to simplify the formula, γ′ is the third parameter which has no practical meaning and is used to simplify the formula, r G is the radius of the GMM rod, M is the total magnetization, H e is the effective magnetic field inside the GMM rod, H is the magnetic field generated by the excitation coil. k1 is the eddy current loss factor, k2 is the anomalous loss factor.

[0123] Step 2: By analyzing the heat transfer mode and heat transfer path, establish a spatial thermal network model of GMA based on the principle of equivalent thermal resistance.

[0124] Step 2.1: Through the heat source analysis of the coil and the GMM rod, confirm that heat conduction and heat convection are the main heat transfer modes during the operation of GMA, as Figure 3 shown; deduce the power equation of the main heat source:

[0125]

[0126] where: N is the total number of turns of the coil; R1 and R2 are the inner and outer radii of the coil; r C , μ C and ρ C are the effective radius, magnetic permeability and resistivity of the enameled wire respectively; ρ, r G and l G are the charge density, radius and effective length of the GMM rod respectively; μ I is the real part of the complex magnetic permeability, P C is the loss power of the coil, I is the input current, f is the input frequency, P eddy is the eddy current loss power of the GMM rod, P h is the hysteresis loss power of the GMM rod.

[0127] Step 2.2: Considering the material properties and positions of the components in the GMA actuator, the results are as Figure 4 shown; confirm its specific heat transfer path, as Figure 5 shown; deduce the heat transfer equation of the GMM rod:

[0128]

[0129] In the formula: P G = P eddy + p h ; T G(Z) is the temperature distribution on the GMM rod; λ G is the thermal conductivity on the GMM rod.

[0130] Among them, P G(r，z，t) is the loss power of the GMM rod.

[0131] Step 2.3: According to the principle of equivalent thermal resistance, combined with the analysis of the heat sources and heat transfer paths of each component, establish an equivalent thermal network model of the GMA, as Figure 6 shown. R GR1 , R GR2 and R GR3 are the equivalent radial thermal resistances of the GMM rod, R GA(Z) is the equivalent axial thermal resistance of the GMM rod, R PmA , R YouA , R YodA and R PmR , R YouR , R YodR are the equivalent thermal resistances of the permanent magnet, upper yoke, and lower yoke in the axial and radial directions respectively. R ShuA and R ShdA are the equivalent radial thermal resistances of the upper and lower outer housings respectively, R ShdR is the equivalent axial thermal resistance of the housing, R um R Base and R out are the thermal resistances of the upper magnetic guide block, lower magnetic guide base, and output rod respectively. R CA1 , R CA2 , R CA3 are the equivalent axial thermal resistances of the coil respectively, R CR1 , R CR2 , R CR3 are the equivalent radial thermal resistances of the coil respectively, R airi is the equivalent thermal resistance of air. T Ci is the temperature of the inner wall of the coil in the radial direction, T Co is the temperature of the outer wall of the coil in the radial direction, T Cu is the temperature of the top of the coil in the axial direction, T C is the average temperature of the coil, C C is the heat capacity of the GMM rod, C G is the heat capacity of the GMM rod, C Pm is the heat capacity of the permanent magnet, C Yo is the heat capacity of the yoke, C um is the heat capacity of the upper magnetic guide block, C Base is the heat capacity of the lower magnetic guide base, CSh , C Shu and C Shd is the heat capacity of the housing, C out is the heat capacity of the output rod, C air is the heat capacity of the air.

[0132] The specific structure of the equivalent thermal network model is as follows:

[0133] The equivalent model of the GMM rod is respectively connected to the upper magnetic conduction equivalent model, the lower magnetic conduction block equivalent model and the third air equivalent model; the third air equivalent model is also connected to the equivalent model of the excitation coil; the equivalent model of the excitation coil is also respectively connected to the first air equivalent model, the second air equivalent model and the fourth air equivalent model; the first air equivalent model is also connected to the first upper yoke equivalent model; the connection of the first upper yoke equivalent model is respectively connected to the output rod equivalent model and a first housing equivalent model; the output rod equivalent model is also connected to the second upper yoke equivalent model and the upper magnetic conduction block equivalent model; the second upper yoke equivalent model and the upper magnetic conduction block equivalent model are connected; the first housing equivalent model, the first upper yoke equivalent model, the lower yoke equivalent model, the first permanent magnet equivalent model, the second first housing equivalent model, the second housing equivalent model and the second permanent magnet equivalent model are all connected; the second air equivalent model is connected to the first lower yoke equivalent model; the first lower yoke equivalent model is respectively connected to another first housing equivalent model, the lower magnetic conduction base equivalent model and the second lower yoke equivalent model; the second lower yoke equivalent model, another first housing equivalent model and the first permanent magnet equivalent model are connected to each other; the fourth air equivalent model is also connected to the second permanent magnet equivalent model. Among them, the two first housing equivalent models, the second housing equivalent model, the first permanent magnet equivalent model, the second permanent magnet equivalent model, the first lower yoke equivalent model, the second lower yoke equivalent model, the first upper yoke equivalent model, the second upper yoke equivalent model, the upper magnetic conduction block equivalent model and the lower magnetic conduction base equivalent model are all connected equivalent thermal resistances and equivalent heat capacities, the other end of the equivalent heat capacity is grounded, and the other end of the equivalent thermal resistance is the external port of the model.

[0134] The equivalent model of the GMM rod specifically includes: R GA(Z) is respectively connected to the upper magnetic conduction block equivalent model, C G , P G , R GR3 , and the lower magnetic conduction base equivalent model; the other ends of C G , P G are all grounded, and R GR3 is respectively connected to R GR1 , R GR2 ; R GR1 , R GR2 are respectively connected to R air5 , R air6 ; R air5 , Rair6 The other ends are all grounded.

[0135] The equivalent model of the excitation coil specifically includes: R CA1 Connected to the first upper yoke equivalent model and R CA2 , R CA3 Connected; R CA2 Connected to the second air equivalent model; R CA3 Connected to C C , P C , R CR3 Connected, R CR3 Connected to R CR1 , R CR2 Connected; R CR1 Also connected to the fourth air equivalent model; R CR2 Also connected to the third air equivalent model. C C , P C The other ends are all grounded.

[0136] The thermal resistance of the coil can be calculated by the following formula:

[0137]

[0138]

[0139] Among them, R CA1 , R CA2 , R CA3 Are the first equivalent axial thermal resistance, the second equivalent axial thermal resistance and the third equivalent axial thermal resistance of the coil respectively, l c Is the length of the coil, λ C Is the thermal conductivity of the coil, r1 is the inner diameter of the coil, and r2 is the outer diameter of the coil.

[0140] The axial equivalent thermal resistance of the permanent magnet, upper yoke, lower yoke and housing and the radial equivalent thermal resistance of the GMM rod, permanent magnet, upper yoke, lower yoke and housing can be calculated by the following formula:

[0141]

[0142] R Rheat , R Aheat , l heat , λ heat , r Rheat1 , r Rheat2 Are the radial thermal resistance, axial thermal resistance, heat transfer length, thermal conductivity, inner and outer radii of the heat transfer element respectively.

[0143] The equivalent thermal resistance of air can be calculated by the following formula

[0144]

[0145] A air is the area of the contact surface, h air is the convective heat transfer coefficient of the surface.

[0146] According to the definition of equivalent thermal resistance: the ratio of the length of the heat transfer element to the product of its heat transfer cross-sectional area and thermal conductivity, the equivalent thermal resistances of the upper magnetic conduction block, the lower magnetic conduction base, and the output rod can be calculated.

[0147] T G o and T Gi are the temperatures of the inner and outer surfaces of the GMM rod respectively, T C ′ u , T C ′ d and T C ′ o are the temperatures transferred from the top, bottom, and outer wall of the coil to the upper yoke, lower yoke, and permanent magnet through internal air heat convection respectively, T G ′ o is the temperature transferred from the outer wall of the GMM radial direction to the coil through internal air heat convection, T Gu and T Gd are the temperatures of the axial top and bottom of the GMM rod respectively, T um is the temperature of the upper magnetic conduction block, T Base is the temperature of the base yoke, T YouR is the temperature near the permanent magnet at the axial end of the upper yoke, T YodR is the temperature near the permanent magnet at the axial end of the lower yoke, T YouA and T YodA are the temperatures near the housing at the axial ends of the upper and lower yokes respectively, T out output rod temperature, T ShuA and T ShdA are the temperatures of the upper and lower housing bodies respectively, T ShR is the temperature of the side housing, T PmA and T PmR are the axial and radial temperatures of the permanent magnet respectively.

[0148] Step 3: Considering the influence of temperature on the magnetostrictive effect and thermal expansion displacement, establish a GMA mechanical output model.

[0149] Step 3.1: According to the material properties of the GMM rod, establish a model of the influence of temperature on the magnetostrictive effect and thermal expansion displacement:

[0150]

[0151] In the formula: λ S , M S , M(T G(Z) ), σ, E G , α T and T cThey are the saturation magnetostrictive coefficient, saturation magnetization, magnetization at temperature T, pre-pressure, Young's modulus, coefficient of thermal expansion, and Curie temperature of the GMM rod, respectively; T1 and T2 are the temperatures before and after thermal expansion; β is the correction coefficient. G(Z) The magnetization, pre-pressure, Young's modulus, coefficient of thermal expansion, and Curie temperature at G(Z) ; T1 and T2 are the temperatures before and after thermal expansion; β is the correction coefficient.

[0152] Step 3.2: Based on the working principle of the GMA, equivalent it to a second-order mass-spring-damping system, and use Laplace transform. Its output displacement model:

[0153]

[0154] In the formula: y is the output displacement; M e , C m and k are the equivalent mass, equivalent damping, and equivalent stiffness of the GMA, respectively.

[0155] Step 4: Use Simlink / Matlab simulation software to test the characteristics of the GMA under different input current amplitudes and frequencies, and accurately obtain the input-output relationship of the GMA under different working conditions.

[0156] Step 4.1: Set the input current to 6A and 100Hz, and obtain the internal radial magnetic field distribution of the GMM rod, as Figure 7 shown.

[0157] Step 4.2: Set the frequency to 100Hz, and the input currents to 2A, 4A, and 6A respectively, and obtain the internal axial magnetic field distribution and temperature distribution of the GMM rod, as Figure 8 shown.

[0158] Step 4.3: Set the frequency to 100Hz, and the input currents to 2A, 4A, 6A, and 8A respectively, and obtain the output displacement characteristics of the GMA under different currents, as Figure 9 shown.

[0159] Step 4.4: Set the current to 6A, and the input currents to 20Hz, 50Hz, 100Hz, and 200Hz respectively, and obtain the output displacement characteristics of the GMA under different frequencies, as Figure 10 shown.

[0160] Based on the same inventive concept, the embodiment of the present application also provides a magnetostrictive actuator displacement determination device for implementing the magnetostrictive actuator displacement determination method involved above. The solution provided by this device to solve the problem is similar to the solution described in the above method. Therefore, the specific limitations in one or more embodiments of the magnetostrictive actuator displacement determination device provided below can refer to the limitations on the magnetostrictive actuator displacement determination method in the above text, and will not be repeated here.

[0161] In an exemplary embodiment, a device for determining the displacement of a magnetostrictive actuator is provided, including:

[0162] An actual data acquisition module, configured to acquire the actual input current, actual GMM rod parameters, and actual coil parameters of the magnetostrictive actuator;

[0163] An output displacement determination module, configured to determine the output displacement of the magnetostrictive actuator according to the actual input current, the actual GMM rod parameters, and the actual coil parameters by using an output displacement model;

[0164] The method for determining the output displacement model specifically includes:

[0165] Acquire the test input current, test GMM rod parameters, and test coil parameters of the magnetostrictive actuator;

[0166] Determine the magnetization intensity of the GMM rod based on the test input current and the test GMM rod parameters according to the spatially non-uniform magnetic field model;

[0167] Determine the temperature distribution according to the test GMM rod parameters and the test coil parameters by using an equivalent thermal network model based on the principle of equivalent thermal resistance;

[0168] Construct an output displacement model based on the magnetization intensity of the GMM rod and the temperature distribution according to the influence of temperature on the magnetostrictive effect and thermal expansion displacement.

[0169] In an exemplary embodiment, a computer device is provided. The computer device can be a server or a terminal. The computer device includes a processor, a memory, an input / output interface (Input / Output, abbreviated as I / O), and a communication interface. Among them, the processor, the memory, and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store data for determining the displacement of the magnetostrictive actuator. The input / output interface of the computer device is used to exchange information between the processor and external devices. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, it implements a method for determining the displacement of a magnetostrictive actuator.

[0170] Those skilled in the art can understand that the structure of this application is merely a block diagram of some structures related to the solution of this application, and does not constitute a limitation on the computer device to which the solution of this application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine some components, or have different component arrangements. In an exemplary embodiment, a computer device is provided, including a memory and a processor. A computer program is stored in the memory, and when the processor executes the computer program, the above-mentioned method embodiments are implemented.

[0171] In an exemplary embodiment, a computer-readable storage medium is provided, storing a computer program, and when the computer program is executed by a processor, the above-mentioned method embodiments are implemented.

[0172] In an exemplary embodiment, a computer program product is provided, including a computer program, and when the computer program is executed by a processor, the above-mentioned method embodiments are implemented.

[0173] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use, and processing of relevant data need to comply with relevant regulations.

[0174] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, database, or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memories. Non-volatile memories can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memories can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0175] The databases involved in the embodiments provided in the present application can include at least one of relational databases and non-relational databases. Non-relational databases can include distributed databases based on blockchain, etc., without limitation. The processors involved in the embodiments provided in the present application can be general-purpose processors, central processors, graphics processors, digital signal processors, programmable logics, data processing logics based on quantum computing, etc., without limitation.

[0176] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope described in this specification.

[0177] Specific examples are used in this article to elaborate on the principles and implementation manners of the present application. The descriptions of the above embodiments are only used to help understand the methods and core ideas of the present application; at the same time, for those of ordinary skill in the art, according to the ideas of the present application, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. A method for determining the displacement of a magnetostrictive actuator, characterized in that The method for determining the displacement of the magnetostrictive actuator includes: Obtaining the actual input current, actual GMM rod parameters, and actual coil parameters of the magnetostrictive actuator; Determining the output displacement of the magnetostrictive actuator by using the output displacement model according to the actual input current, the actual GMM rod parameters, and the actual coil parameters; The specific method for determining the output displacement model includes: Obtaining the test input current, test GMM rod parameters, and test coil parameters of the magnetostrictive actuator; Determining the magnetization intensity of the GMM rod based on the spatial non-uniform magnetic field model according to the test input current and the test GMM rod parameters; Determining the temperature distribution by using the equivalent thermal network model based on the equivalent thermal resistance principle according to the test GMM rod parameters and the test coil parameters; Constructing an output displacement model based on the magnetization intensity of the GMM rod and the temperature distribution according to the influence of temperature on the magnetostrictive effect and thermal expansion displacement.

2. The method for determining the displacement of the magnetostrictive actuator according to claim 1, wherein Determining the magnetization intensity of the GMM rod based on the spatial non-uniform magnetic field model according to the test input current and the test GMM rod parameters, specifically including: Determining the magnetic induction intensity equation in the GMM rod according to the magnetic permeability of the test GMM rod parameters; Determining the radial magnetic field equation generated by eddy currents in the GMM rod based on Maxwell's equations according to the test input current; Determining the intensity equation of the excitation magnetic field in the GMM rod according to the magnetic induction intensity equation in the GMM rod and the radial magnetic field equation; Determining the magnetization intensity of the GMM rod by using the J-A model according to the intensity equation of the excitation magnetic field in the GMM rod.

3. The method for determining the displacement of the magnetostrictive actuator according to claim 1, characterized in that, Determining the temperature distribution by using the equivalent thermal network model based on the equivalent thermal resistance principle according to the test GMM rod parameters and the test coil parameters, specifically including: Constructing an equivalent thermal network model based on the equivalent thermal resistance principle according to the test GMM rod parameters and the test coil parameters; Determining the turbine loss power of the GMM rod and the hysteresis loss power of the GMM rod by using the equivalent thermal network model based on the equivalent thermal resistance principle according to the test GMM rod parameters; Calculating the loss power of the GMM rod according to the turbine loss power of the GMM rod and the hysteresis loss power of the GMM rod; Calculating the temperature distribution of the GMM rod according to the loss power of the GMM rod and the test GMM rod parameters.

4. The method for determining the displacement of the magnetostrictive actuator according to claim 1, wherein Constructing an output displacement model based on the magnetization intensity of the GMM rod and the temperature distribution according to the influence of temperature on the magnetostrictive effect and thermal expansion displacement, specifically including: Establishing a model of the influence of temperature on the magnetostrictive effect and thermal expansion displacement according to the test GMM rod parameters, the magnetization intensity of the GMM rod, and the temperature distribution; Constructing an output displacement model by using the equivalent second-order mass-spring-damper system and Laplace transform according to the model of the influence of temperature on the magnetostrictive effect and thermal expansion displacement.

5. The method for determining the displacement of the magnetostrictive actuator according to claim 4, characterized in that The expression of the model of the influence of temperature on the magnetostrictive effect and thermal expansion displacement is: Among them, λ S , M S , σ, E G , α T and T c are respectively the saturation magnetostrictive coefficient, saturation magnetization intensity, magnetization intensity at temperature T G(Z) , pre-pressure, Young's modulus, thermal expansion coefficient and Curie temperature of the GMM rod; T1 is the temperature before thermal expansion, T2 is the temperature after thermal expansion; β is the correction coefficient, ε G is the strain of the GMA, T G is the specific temperature value on the GMM rod, and T0 is the temperature when correcting the β parameter. z represents the axial direction of the GMM rod, and l G is the effective length of the GMM rod.

6. The method for determining the displacement of the magnetostrictive actuator according to claim 1, characterized in that, The expression of the output displacement model is: where y is the output displacement; M e , C m and k are the equivalent mass, equivalent damping and equivalent stiffness of the GMA, respectively; A G is the cross-sectional area of the GMM rod, E G is Young's modulus, ε G is the strain of the GMM rod, and s is the Laplace operator.

7. A displacement determination device for a magnetostrictive actuator, characterized in that, The device for determining the displacement of the magnetostrictive actuator includes: An actual data acquisition module for obtaining the actual input current, actual GMM rod parameters, and actual coil parameters of the magnetostrictive actuator; An output displacement determination module, configured to determine the output displacement of the magnetostrictive actuator by using an output displacement model according to the actual input current, the actual GMM rod parameters, and the actual coil parameters; The specific method for determining the output displacement model includes: Obtaining the test input current, test GMM rod parameters, and test coil parameters of the magnetostrictive actuator; Determining the magnetization intensity of the GMM rod based on the test input current and the test GMM rod parameters according to the spatially non-uniform magnetic field model; Determining the temperature distribution by using an equivalent thermal network model based on the equivalent thermal resistance principle according to the test GMM rod parameters and the test coil parameters; Constructing an output displacement model based on the magnetization intensity of the GMM rod and the temperature distribution according to the influence of temperature on the magnetostrictive effect and the thermal expansion displacement.

8. A computer device, comprising: A memory, a processor, and a computer program stored on the memory and executable on the processor, wherein the processor executes the computer program to implement the magnetostrictive actuator displacement determination method according to any one of claims 1-6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the magnetostrictive actuator displacement determination method according to any one of claims 1-6.

10. A computer program product comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the magnetostrictive actuator displacement determination method according to any one of claims 1-6.

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