Method and system for determining icing state of aircraft surface
By combining a complex impedance sensing mechanism with relaxation polarization and thermodynamic models, a quantitative analysis model for ice bonding state is constructed, which solves the problem that existing technologies cannot effectively determine the ice bonding state on the surface of aircraft wings, and realizes low-cost, non-invasive ice bonding state determination.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HUAZHONG UNIV OF SCI & TECH
- Filing Date
- 2024-01-09
- Publication Date
- 2026-05-19
AI Technical Summary
Existing technologies cannot effectively and quantitatively analyze the ice-binding state on the surface of aircraft wings, and traditional methods are costly, complex to install, and cannot achieve non-invasive measurements.
Data was collected using a complex impedance sensing mechanism. Combined with the relaxation polarization model, the DLP dispersion model, and the thermodynamic inversion model, a neural network model was used to perform quantitative analysis of the ice-binding state, and a complex impedance quantification model of the ice-binding state was constructed.
It achieves non-invasive, low-cost identification of ice-binding states, enables quantitative analysis of ice-binding states, and provides theoretical guidance.
Smart Images
Figure CN117825456B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of aerial detection technology, specifically relating to a method and system for determining the ice-binding state on the surface of an aircraft. Background Technology
[0002] Icing poses a serious threat to aviation safety, necessitating the exploration of efficient detection, prevention, and de-icing strategies. Current de-icing methods are energy-intensive due to a lack of effective perception and assessment of de-icing time and effectiveness. Therefore, an effective method for determining the bonding state between the icing layer and the skin is urgently needed.
[0003] Current methods for measuring ice bonding state and bonding strength mainly fall into two categories: one is to assess the shear and peel stress at the ice-substrate interface using mechanical measuring devices; the other is to indirectly reflect the bonding state between the ice layer and the substrate by observing the ice-water transition at the substrate location. The problem with mechanical assessment methods is their reliance on large-scale mechanical measuring devices. Detecting icing locations is an irreversible, destructive, and invasive measurement, limiting their application to laboratory-based principle verification. The problem with interface observation methods is their reliance on high-resolution microscopes or X-ray scanning imaging devices. Deploying these on wings presents drawbacks such as high cost, limited installation space, and lack of flush conformal protection.
[0004] In summary, the two methods mentioned above rely on mechanical measurement devices and high-precision imaging devices, which have high installation costs and cannot quantitatively analyze the ice-bonding state of the wing surface. They also lack theoretical guidance for judging the ice-bonding state of the wing surface. Summary of the Invention
[0005] To overcome the shortcomings of existing technologies that cannot quantitatively analyze the ice-bonding state of wing surfaces, this invention provides a method for determining the ice-bonding state of aircraft surfaces, comprising the following steps:
[0006] Collect complex impedance data at the location of icing on the wing skin;
[0007] The complex impedance data is input into the relaxation polarization model, and the dielectric parameter spectrum characteristic data is output; the dielectric parameter spectrum characteristic data is input into the DLP dispersion model to calculate the interfacial free energy of the ice-bonded interface.
[0008] Input the complex impedance data, relaxation time and dielectric constant in the relaxation polarization model into the thermodynamic inversion model to calculate the temperature at the ice junction.
[0009] Thickness calibration was performed on the complex impedance data to obtain the water film thickness at the freezing location;
[0010] Substituting the water film thickness and the temperature at the ice junction into the calculation formula for the interfacial free energy, a complex impedance quantization model of the ice junction state is constructed.
[0011] The complex impedance data, the temperature at the ice-bond junction, and the water film thickness are input into a neural network model for feature extraction. Based on the extraction results, the ice-bond state is classified to obtain the ice-bond state type.
[0012] The ice-binding state complex impedance quantification model is used to quantitatively analyze the ice-binding state types, and the ice-binding state is determined based on the quantitative analysis results.
[0013] Preferably, the complex impedance data includes capacitance spectrum characteristic data and loss tangent frequency characteristic data, and the dielectric parameter spectrum characteristic data is obtained based on the capacitance spectrum characteristic data and the relaxation polarization model; the temperature is inverted based on the thermodynamic inversion model, capacitance spectrum characteristic data, loss tangent data, and the relationship between relaxation time and the real and imaginary parts of the dielectric constant in the relaxation polarization model; the thickness of the water film at the freezing location is obtained by calibrating the capacitance spectrum characteristic data in the complex impedance measurement data.
[0014] Preferably, the relaxation polarization model is:
[0015]
[0016] In the formula, These are the static dielectric constant and optical frequency dielectric constant of ice, respectively, τ. ice denoted as the relaxation time constant of ice, k and b are the fitting coefficients of the complex permittivity and the parallel equivalent capacitance, respectively, ω is the angular frequency, ω = 2πf, and the sweep frequency range includes 1kHz to 10GHz.
[0017] Preferably, the DLP dispersion model is:
[0018]
[0019] In the formula, F(L) represents the influence of van der Waals forces on the interfacial free energy, L represents the water film thickness, K is a constant, T is the surface temperature, r(i) is the lower limit of the integration level, and K s This is a constant used to convert to the static frequency.
[0020] The preferred thermodynamic inversion model is:
[0021]
[0022] In the formula, ε'(ω) and ε'(ω) are the real and imaginary parts of the dielectric constant, respectively. ∞ E is the optical frequency dielectric constant. τ As the activation energy, k B C is the Boltzmann constant. τ ω is a constant coefficient, and ω is the angular frequency.
[0023] Preferably, the complex impedance quantization model for the ice-bound state is as follows:
[0024]
[0025] In the formula, ε'(ω) and ε'(ω) are the real and imaginary parts of the dielectric constant, respectively. ∞ E is the optical frequency dielectric constant. τ As the activation energy, k B C is the Boltzmann constant. τ K is a constant coefficient, k1 and k2 are the fitting weight coefficients for simulation and experimental data, respectively, and C is a constant coefficient. middle1 C high1 These represent the intermediate frequency and high frequency capacitors in the simulation, respectively; C middle2 C high2 denoted as the intermediate frequency and high frequency capacitors in the experiment, respectively, and r(i) is the lower limit of the integration stage.
[0026] Preferably, the ice-binding state includes:
[0027]
[0028] In the formula, t is time, and L th The threshold for distinguishing the thickness of the water film in the pre-melted state and the solid-liquid state, where T is the surface temperature and L is the thickness of the water film. water L represents the thickness of the water film. mix The combined thickness of the ice layer and the water film.
[0029] This invention also provides a system for determining the ice-bonding state of an aircraft surface, comprising:
[0030] Complex impedance sensing mechanism, used to collect complex impedance data of the icing location on the wing skin;
[0031] The interface free energy acquisition module is used to input the complex impedance data into the relaxation polarization model and output the dielectric parameter spectrum characteristic data; input the dielectric parameter spectrum characteristic data into the DLP dispersion model to calculate the interface free energy of the ice-bonded interface.
[0032] The temperature calculation module is used to input complex impedance data, relaxation time and dielectric constant from the relaxation polarization model into the thermodynamic inversion model to calculate the temperature at the ice junction.
[0033] The water film thickness determination module is used to calibrate the thickness of the complex impedance data to obtain the water film thickness at the freezing location.
[0034] The quantitative model building module is used to substitute the water film thickness and the temperature at the ice junction into the calculation formula of the interfacial free energy to build a complex impedance quantitative model of the ice junction state.
[0035] The combined state classification module is used to input complex impedance data, temperature at the ice-bond junction, and water film thickness into the neural network model for feature extraction, and to classify the ice-bond state based on the extraction results to obtain the ice-bond state type.
[0036] The combined state discrimination module is used to quantitatively analyze the ice binding state type using the ice binding state complex impedance quantification model, and to discriminate the ice binding state based on the quantitative analysis results, and then transmit the discrimination results to the host computer.
[0037] Preferably, the complex impedance sensing mechanism is a thin-film interdigital electrode sensor. The upper and lower surfaces of the thin-film interdigital electrode sensor are made of polyimide insulating flexible material, the middle electrode is made of copper foil material, and the upper and lower surfaces and the middle electrode are bonded and laminated with adhesive.
[0038] Preferably, the thin-film interdigital electrode sensor is a pair of interdigital electrodes with multiple spatial wavelengths.
[0039] The method and system for determining the ice-bonding state on the surface of an aircraft provided by this invention have the following beneficial effects:
[0040] This invention, at the microscopic level of intermolecular forces, combines Debye relaxation polarization, DLP dispersion, and the principles of molecular thermal motion to obtain the temperature and water film thickness of the ice-binding state. A complex impedance quantification model of the ice-binding state can be constructed using these parameters. Furthermore, by using a neural network model to extract features from the multidimensional feature data—complex impedance spectrum, water film thickness, and temperature—the ice-binding state can be classified. The quantitative analysis model and the classification results of the ice-binding state allow for quantitative analysis of the ice-binding state, thus providing theoretical guidance for its identification.
[0041] The ice-binding state detection method proposed in this invention does not rely on mechanical measurement devices and high-precision imaging devices, and realizes non-invasive measurement. At the same time, the thin-film sensing mechanism meets the requirements for flush and conformal installation, and has a low cost. Attached Figure Description
[0042] To more clearly illustrate the embodiments and design schemes of the present invention, the accompanying drawings required for this embodiment will be briefly described below. The drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0043] Figure 1 This is a flowchart of a method for determining the ice-binding state on the surface of an aircraft according to an embodiment of the present invention;
[0044] Figure 2 A microscopic schematic diagram for detecting the ice-bound state; Detailed Implementation
[0045] To enable those skilled in the art to better understand and implement the technical solutions of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and should not be construed as limiting the scope of protection of the present invention.
[0046] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the technical solution of this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.
[0047] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In the description of this invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "connected" or "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances. In the description of this invention, unless otherwise stated, "a plurality of" means two or more, which will not be elaborated further here.
[0048] Example
[0049] This invention provides a method for determining the ice-bonding state on the surface of an aircraft, specifically as follows: Figure 1 As shown, it includes the following steps:
[0050] Step 1: Use a complex impedance sensor to collect complex impedance data at the location of icing on the wing skin.
[0051] Specifically, this invention uses an edge electric field sensing mechanism to collect complex impedance data at the location of icing on the wing skin.
[0052] Step 2: Input the complex impedance data into the relaxation polarization model and output the dielectric parameter spectrum characteristic data; input the dielectric parameter spectrum characteristic data into the DLP dispersion model and calculate the interfacial free energy of the ice-bonded interface; input the complex impedance data, relaxation time and dielectric constant in the relaxation polarization model into the thermodynamic inversion model and invert the temperature at the ice-bonded area; perform thickness calibration on the complex impedance data to obtain the water film thickness at the freezing location.
[0053] This invention treats the complex impedance electrode sensing mechanism and the ice as a non-ideal capacitor, equivalent to an RC parallel network. Based on Debye relaxation theory (i.e., the relaxation polarization model), the calculation formulas for the real part of the complex permittivity (energy storage capacitance term) ε'(ω), the imaginary part of the complex permittivity (dielectric loss term) ε'(ω), and the loss tangent tanδ are obtained. The energy storage capacitance term ε'(ω) will directly reflect the capacitance data C of the RC parallel network obtained after electrode frequency sweep. p (ω), as shown below:
[0054]
[0055] In the formula, These are the static and optical frequency dielectric constants of ice, τ. ice denoted as the relaxation time constant of ice, and k and b are the fitting coefficients for the complex permittivity and parallel equivalent capacitance, respectively. These coefficients are related to the electrode structure and the materials of the sensing mechanism and can be fitted experimentally. ω is the angular frequency, ω = 2πf. The frequency sweep range covers 1kHz to 10GHz, encompassing the diffusion range of ice and water as much as possible, and the measurement results are selected from 1kHz to 2MHz to reduce measurement complexity.
[0056] The water film thickness at the ice junction is measured without relying on optical calibration equipment; thickness calibration is performed using the capacitance parameter from complex impedance measurement data. Low-frequency capacitance C low Characterizing ice thickness L ice Intermediate frequency capacitor C middle The mixed thickness L characterizes the ice layer and water film. mix High-frequency capacitor C high Used to characterize the thickness L of the water film water Water film thickness L water It can be determined by the mixed thickness L mix Subtract ice thickness L ice Verification was performed. The calibration curves for ice thickness, water film thickness, and capacitance were fitted using finite element simulation and icing test data, as shown below:
[0057] L water =k1f(C middle1 C high1 )+k2f(C middle2 C high2 )
[0058] In the formula, k1 and k2 are the fitting weight coefficients for simulation and experimental data, respectively, and C middle1 C high1 These represent the intermediate frequency and high frequency capacitors in the simulation, respectively; C middle2 C high2 These represent the intermediate frequency and high frequency capacitors used in the test, respectively. Specifically, low-frequency data are selected from 100Hz to 1kHz, intermediate-frequency data from 10kHz to 10MHz, and high-frequency data from above 10MHz.
[0059] The experimental apparatus of this invention includes a complex impedance measurement module consisting of an edge electric field sensing mechanism and an LCR meter, an ice-binding state observation module consisting of an X-ray diffractometer, a temperature measurement module consisting of a temperature-sensing resistor, and a heating device simulating thermal de-icing at the bottom of the sensing mechanism. The main experimental procedure involves heating from -15°C in a 5mm thick ice layer. The complex impedance measurement module is excited at a frequency ranging from 100Hz to 2MHz, measuring data such as capacitance and loss angle. Simultaneously, the temperature measurement module records real-time temperature changes, and the ice-binding state observation device records changes in the water film. The experiment continues until the ice layer completely melts.
[0060] The simulation platform of this invention is based on COMSOL multiphysics finite element software. The simulation process is basically the same as the experiment, except that the influence relationship between various parameters can be simulated through the parameter scanning function. The complex impedance data is measured by changing the water film thickness at the interface; and by fixing the water film thickness and changing the temperature.
[0061] A simplified DLP dispersion model is introduced, and the interface free energy is characterized by van der Waals forces to represent the ice binding state, as shown below:
[0062]
[0063] In the formula, F(L,ω) represents the influence of van der Waals forces on the interfacial free energy, L and ω represent the water film thickness and angular frequency, respectively, K is a constant, T is the surface temperature, and ε' ice (ω) and ε' water (ω) represents the real part of the complex permittivity of ice and water, respectively, and r(i) is the lower bound integration series, which is also an increasing function of L. It should be noted that the determination of the ice binding state should not be related to the measurement frequency; therefore, it needs to be fixed at a certain frequency, preferably using the static permittivity of ice and water. The simplified version is shown below:
[0064]
[0065] In the formula, F(L) represents the influence of van der Waals forces on the interfacial free energy, L represents the water film thickness, K is a constant, T is the surface temperature, r(i) is the lower limit of the integration level, and K s This is a constant used to convert to the static frequency.
[0066] By introducing interfacial free energy, the measurement of the ice-bonded state is transformed into the detection of the ice-bonded temperature T and the water film thickness L. A microscopic schematic diagram of the ice-bonded state is shown below. Figure 2 As shown:
[0067] Among them, L th The threshold for distinguishing the thickness of the pre-melted water film is on the order of nm, L. ice L represents the thickness of the ice layer. wat This indicates the overall thickness of the water film, on the order of millimeters.
[0068] Temperature measurement at the ice junction does not rely on a temperature sensor, but is based on a relaxation polarization and thermodynamic inversion model. A correlation mechanism between temperature and complex impedance spectrum is established through relaxation time, as shown below:
[0069]
[0070] In the formula, E τ As the activation energy, k B C is the Boltzmann constant. τ The constant is used. Substituting the above equation into the Debye relaxation formula, the temperature at the ice-ice junction is inverted from the complex impedance measurement data, as shown below:
[0071]
[0072] In the formula, ε'(ω) and ε'(ω) are the real and imaginary parts of the dielectric constant, respectively. ∞ E is the optical frequency dielectric constant. τ As the activation energy, k B C is the Boltzmann constant. τ It is a constant coefficient.
[0073] The overall process for calculating temperature and water film thickness is as follows:
[0074] (1) Based on the loss tangent tanδ and the real part of capacitance C in the complex impedance measurement data P Calculate the imaginary part C of the capacitor. I C I =C P tanδ;
[0075] (2) Search for C within the dispersion interval I The minimum absolute value of the partial derivative of the frequency f is used to calculate the relaxation time τ.
[0076] (3) Calculate the inversion temperature T. For actual sensor measurements, this temperature represents the relaxation time and the theoretical temperature model; the mapping relationship is obtained through parameter fitting. A and B are both fitting coefficients; calculate the partial derivatives with respect to time t. This temperature is a data fitting result of relaxation time and temperature calculated based on temperature and complex impedance data collected during the actual experiment.
[0077] (5) Thickness calibration was performed using capacitance parameters from finite element simulation and complex impedance measurement data. Low-frequency capacitance C low Mapped to ice thickness L ice Intermediate frequency capacitor C middle The mixed thickness L characterizes the ice layer and water film. mix High-frequency capacitor C high Used to characterize the thickness L of the water film water .
[0078] Step 3: Substitute the water film thickness and the temperature at the ice junction into the formula for calculating the interfacial free energy to construct a complex impedance quantization model of the ice junction state.
[0079] The constructed quantitative model of the ice-bound state and complex impedance spectrum is shown below:
[0080]
[0081] In the formula, ε'(ω) and v'(ω) are the real and imaginary parts of the dielectric constant, respectively. ∞ E is the optical frequency dielectric constant. τ As the activation energy, k B C is the Boltzmann constant. τ K is a constant coefficient, k1 and k2 are the fitting weight coefficients for simulation and experimental data, respectively, and C is a constant coefficient. middle1 C high1 These represent the intermediate frequency and high frequency capacitors in the simulation, respectively; C middle2 C high2 denoted as the intermediate frequency and high frequency capacitors in the experiment, respectively, and r(i) is the lower limit of the integration stage.
[0082] Step 4: Input the complex impedance data, temperature at the ice-bond junction, and water film thickness into the neural network model for feature extraction, and classify the ice-bond state according to the extraction results to obtain the ice-bond state type; use the ice-bond state complex impedance quantification model to perform quantitative analysis on the ice-bond state type, and determine the ice-bond state according to the quantitative analysis results.
[0083] Data features such as complex impedance spectrum, temperature, and water film thickness are combined into a multi-dimensional feature vector, and a neural network model is used for feature extraction and classification to distinguish different ice-binding states. Based on the water film state at the ice-binding point, four state categories are preset, as shown below:
[0084]
[0085] In the formula, t is time, and L th The threshold for distinguishing the thickness of the water film in the pre-melted state and the solid-liquid state, where T is the surface temperature and L is the thickness of the water film. water L represents the thickness of the water film. mix The combined thickness of the ice layer and the water film.
[0086] This invention also provides a system for determining the ice-bonding state of an aircraft surface, comprising a complex impedance sensing mechanism, an interface free energy acquisition module, a temperature calculation module, a water film thickness determination module, a quantization model construction module, a bonding state classification module, and a bonding state discrimination module. The complex impedance sensing mechanism is used to collect complex impedance data at the icing location on the wing skin; the interface free energy acquisition module is used to input the complex impedance data into a relaxation polarization model and output dielectric parameter spectral characteristic data; the dielectric parameter spectral characteristic data is input into a DLP dispersion model to calculate the interface free energy of the ice-bonding interface; the temperature calculation module is used to input the complex impedance data, relaxation time, and dielectric constant from the relaxation polarization model into a thermodynamic inversion model to invert and calculate the temperature at the ice-bonding location; the water film thickness determination module is used to calibrate the thickness of the complex impedance data to obtain the water film thickness at the icing location. The quantification model construction module is used to substitute the water film thickness and the temperature at the ice-bond junction into the calculation formula of the interfacial free energy to construct a complex impedance quantification model for the ice-bond state. The bonding state classification module is used to input the complex impedance data, the temperature at the ice-bond junction, and the water film thickness into the neural network model for feature extraction, and classify the ice-bond state according to the extraction results to obtain the ice-bond state type. The bonding state discrimination module is used to quantitatively analyze the ice-bond state type using the complex impedance quantification model for the ice-bond state, and discriminate the ice-bond state according to the quantitative analysis results, and transmit the discrimination results to the host computer.
[0087] Specifically, the complex impedance sensing mechanism is a thin-film interdigital electrode sensor. The upper and lower surfaces of the thin-film interdigital electrode sensor are made of polyimide insulating flexible material. The thin-film interdigital electrode sensor is a pair of interdigital electrodes with multiple spatial wavelengths. The middle electrode is made of copper foil material, and the upper and lower surfaces are bonded and laminated with the middle electrode by adhesive.
[0088] In summary, this invention, by combining the principles of Debye relaxation polarization, DLP dispersion, and molecular thermal motion at the microscopic level of intermolecular forces, can obtain the ice-binding temperature and water film thickness. A quantitative analysis model for the ice-binding state can be constructed using these parameters. Furthermore, by using a neural network model to extract features from multidimensional characteristic data such as complex impedance spectroscopy, water film thickness, and temperature, the ice-binding state can be classified. The quantitative analysis model and the classification results of the ice-binding state allow for quantitative analysis of the ice-binding state, thus providing theoretical guidance for its identification.
[0089] The ice-binding state detection method proposed in this invention does not rely on mechanical measurement devices and high-precision imaging devices, and realizes non-invasive measurement. At the same time, the thin-film sensing mechanism meets the requirements for flush and conformal installation, and has a low cost.
[0090] The above-described embodiments are merely preferred embodiments of the present invention, and the scope of protection of the present invention is not limited thereto. Any simple changes or equivalent substitutions of the technical solutions that can be obviously obtained by those skilled in the art within the scope of the technology disclosed in the present invention shall fall within the scope of protection of the present invention.
Claims
1. A method for determining the ice-bonding state on the surface of an aircraft, characterized in that, Includes the following steps: Collect complex impedance data at the location of icing on the wing skin; The complex impedance data is input into the relaxation polarization model, and the dielectric parameter spectrum characteristic data is output; the dielectric parameter spectrum characteristic data is input into the DLP dispersion model to calculate the interfacial free energy of the ice-bonded interface. Input the complex impedance data, relaxation time and dielectric constant in the relaxation polarization model into the thermodynamic inversion model to calculate the temperature at the ice junction. Thickness calibration was performed on the complex impedance data to obtain the water film thickness at the freezing location; Substituting the water film thickness and the temperature at the ice junction into the calculation formula for the interfacial free energy, a complex impedance quantization model of the ice junction state is constructed. The complex impedance data, the temperature at the ice-bond junction, and the water film thickness are input into a neural network model for feature extraction. Based on the extraction results, the ice-bond state is classified to obtain the ice-bond state type. The ice-binding state complex impedance quantification model is used to quantitatively analyze the ice-binding state types, and the ice-binding state is determined based on the quantitative analysis results.
2. The method for determining the ice-bonding state on the surface of an aircraft according to claim 1, characterized in that, The complex impedance data includes capacitance spectrum characteristic data and loss tangent frequency characteristic data. The dielectric parameter spectrum characteristic data is obtained by inputting the capacitance spectrum characteristic data into the relaxation polarization model. The temperature at the ice junction is obtained by inputting the capacitance spectrum characteristic data, loss tangent frequency characteristic data, relaxation time and dielectric constant in the relaxation polarization model into the thermodynamic inversion model. The thickness of the water film at the freezing location is obtained by performing thickness calibration on the capacitance spectrum characteristic data.
3. The method for determining the ice-bonding state on the surface of an aircraft according to claim 1, characterized in that, The relaxation polarization model is as follows: In the formula, , These are the static dielectric constant and the optical frequency dielectric constant of ice, respectively. Let be the relaxation time constant of ice. k and b These are the fitting coefficients for the complex permittivity and the parallel equivalent capacitance, respectively. Angular frequency, The frequency sweep range includes 1kHz to 10GHz.
4. The method for determining the ice-bonding state on the surface of an aircraft according to claim 1, characterized in that, The DLP dispersion model is as follows: In the formula, This indicates the magnitude of the effect of van der Waals forces on the interface free energy. Indicates the thickness of the water film. Surface temperature, The lower limit of the integration level, This is a constant used to convert to the static frequency.
5. The method for determining the ice-bonding state on the surface of an aircraft according to claim 1, characterized in that, The thermodynamic inversion model is as follows: In the formula, and These are the real and imaginary parts of the dielectric constant, respectively. The dielectric constant of optical frequency, For activation energy, Boltzmann's constant, It is a constant coefficient.
6. The method for determining the ice-bonding state on the surface of an aircraft according to claim 1, characterized in that, The complex impedance quantization model for the ice-binding state is as follows: In the formula, and These are the real and imaginary parts of the dielectric constant, respectively. The dielectric constant of optical frequency, For activation energy, Boltzmann's constant, The constant coefficient, and These are the fitting weight coefficients for simulation and experimental data, respectively. These represent the intermediate frequency and high frequency capacitors in the simulation, respectively. These represent the medium-frequency and high-frequency capacitors in the test, respectively. This represents the lower limit of the integration level.
7. The method for determining the ice-bonding state on the surface of an aircraft according to claim 1, characterized in that, The ice-binding state includes: In the formula, For time, The threshold for distinguishing the thickness of the water film in the pre-melted state and the solid-liquid state. Surface temperature, For water film thickness, The combined thickness of the ice layer and the water film.
8. A system for determining the ice-bonding state on the surface of an aircraft, characterized in that, include: Complex impedance sensing mechanism, used to collect complex impedance data of the icing location on the wing skin; The interface free energy acquisition module is used to input the complex impedance data into the relaxation polarization model and output the dielectric parameter spectrum characteristic data; input the dielectric parameter spectrum characteristic data into the DLP dispersion model to calculate the interface free energy of the ice-bonded interface. The temperature calculation module is used to input complex impedance data, relaxation time and dielectric constant from the relaxation polarization model into the thermodynamic inversion model to calculate the temperature at the ice junction. The water film thickness determination module is used to calibrate the thickness of the complex impedance data to obtain the water film thickness at the freezing location. The quantitative model building module is used to substitute the water film thickness and the temperature at the ice junction into the calculation formula of the interfacial free energy to build a complex impedance quantitative model of the ice junction state. The combined state classification module is used to input complex impedance data, temperature at the ice-bond junction, and water film thickness into the neural network model for feature extraction, and to classify the ice-bond state based on the extraction results to obtain the ice-bond state type. The combined state discrimination module is used to quantitatively analyze the ice binding state type using the ice binding state complex impedance quantification model, and to discriminate the ice binding state based on the quantitative analysis results, and then transmit the discrimination results to the host computer.
9. The system for determining the ice-bonding state on the surface of an aircraft according to claim 8, characterized in that, The complex impedance sensing mechanism is a thin-film interdigital electrode sensor. The upper and lower surfaces of the thin-film interdigital electrode sensor are made of polyimide insulating flexible material, the middle electrode is made of copper foil material, and the upper and lower surfaces and the middle electrode are bonded and laminated with adhesive.
10. The system for determining the ice-bonding state on the surface of an aircraft according to claim 9, characterized in that, The thin-film interdigital electrode sensor is a pair of interdigital electrodes with multiple spatial wavelengths.