Resonant frequency temperature drift compensation method suitable for magnetoelectric sensor

Abstract

The invention discloses a resonant frequency temperature drift compensation method suitable for a magnetoelectric sensor, and belongs to the technical field of magnetoelectric sensors, and the method comprises the steps: obtaining the resonant frequencies of the magnetoelectric sensor at different temperatures; obtaining a function relationship between the resonant frequency and the temperature, and constructing a temperature compensation model based on the function relationship; and acquiring a sensing response of a sensor in real time, inputting the sensing response into the temperature compensation model, and generating compensated frequency output. Aiming at the problem that the resonant frequency of the magnetoelectric sensor changes along with the temperature, temperature compensation is carried out on the magnetoelectric sensor in a low-calculation-amount, low-cost and real-time mode.

Description

Technical Field

[0001] The invention belongs to the technical field of magnetoelectric sensors, and in particular relates to a resonant frequency temperature drift compensation method suitable for magnetoelectric sensors. Background Art

[0002] Magnetoelectric sensor is a sensitive device that can convert magnetic field signals into electrical signals. It is widely used in various magnetic field measurement and control systems. However, the performance of magnetoelectric sensor will be affected by the ambient temperature. The resonant frequency is an important performance indicator, and its value will change with the change of temperature. Therefore, studying the law of the change of the resonant frequency of magnetoelectric sensor with temperature is of great significance to improve its stability and reliability.

[0003] In the existing technology, hardware is usually used to achieve temperature compensation of the resonant frequency of the magnetoelectric sensor. This method mainly designs and manufactures a special temperature compensation circuit, and adjusts the resonant frequency of the magnetoelectric sensor in real time according to the actual measured temperature value to ensure its stability at different temperatures. In addition, some researchers have proposed a software-based temperature compensation method, which is to establish a mathematical model between temperature and resonant frequency, use a computer to calculate, and then compensate the resonant frequency.

[0004] However, there are still some problems with the existing temperature compensation technology. First, hardware-based temperature compensation requires additional circuit design and manufacturing, which not only increases the complexity and cost of the system, but also in some special environments (such as high temperature, high humidity, etc.), the stability and reliability of the hardware circuit may be affected. Secondly, although the software-based temperature compensation method can avoid the problems of hardware circuits, it requires a lot of calculations, which may cause certain troubles for applications with high real-time requirements. Summary of the invention

[0005] In order to solve the above technical problems, the present invention proposes a resonant frequency temperature drift compensation method applicable to a magnetoelectric sensor to solve the above problems existing in the prior art.

[0006] To achieve the above object, the present invention provides a method for compensating the resonant frequency temperature drift of a magnetoelectric sensor, comprising:

[0007] Obtain the resonant frequency of the magnetoelectric sensor at different temperatures;

[0008] Acquire a functional relationship between the resonant frequency and the temperature, and construct a temperature compensation model based on the functional relationship;

[0009] The sensor response of the sensor is acquired in real time, and the sensor response is input into the temperature compensation model to generate a compensated frequency output.

[0010] Preferably, the process of obtaining the resonant frequency of the magnetoelectric sensor at different temperatures includes:

[0011] By testing the frequency response of the magnetoelectric sensor at different temperatures, the frequency response data of the magnetoelectric sensor at different temperatures are obtained;

[0012] The resonant frequency of the magnetoelectric sensor at different temperatures is obtained based on the frequency response data.

[0013] Preferably, the process of obtaining the functional relationship between the resonant frequency and the temperature comprises: performing polynomial fitting on the relationship between the resonant frequency and the temperature to obtain the functional relationship between the resonant frequency and the temperature.

[0014] Preferably, the process of generating the compensated frequency output comprises:

[0015] Receive the sensor output frequency of the sensor under a certain temperature data;

[0016] The temperature data and the sensor output frequency are input into the temperature compensation model for calculation to obtain a compensated frequency output.

[0017] Preferably, the process of inputting the temperature data and the sensor output frequency into the temperature compensation model for calculation includes:

[0018] Acquire a temperature change based on the temperature data, and acquire a frequency offset of the temperature data;

[0019] The temperature compensation model calculates the frequency offset and the sensor output frequency to generate a calibrated resonant frequency at a compensated temperature.

[0020] Preferably, the expression for obtaining the temperature change based on the temperature data is:

[0021] ΔT=TT nominal ;

[0022] Among them, T is other temperature points, T nominal is the reference temperature, ΔT is the temperature change;

[0023] The expression of the frequency offset of the temperature data is:

[0024]

[0025] Among them, f T is the predicted frequency calculated by the sensor based on the functional relationship between the resonant frequency and temperature when the temperature is T; is the resonant frequency of the sensor at the reference temperature, and Δf is the frequency offset of the temperature data.

[0026] Preferably, the expression for the calibration resonant frequency when generating the compensated temperature is:

[0027] f calibration =f-Δf;

[0028] Among them, f calibration is the calibration resonant frequency at the compensated temperature, and f is the resonant frequency at the measured temperature point.

[0029] Preferably, after generating the compensated frequency output, the method further comprises: after compensating each temperature point, fitting again to observe whether the fitting straight line is a straight line parallel to the temperature axis.

[0030] Compared with the prior art, the present invention has the following advantages and technical effects:

[0031] The present invention obtains the resonant frequency of a magnetoelectric sensor at different temperatures; obtains the functional relationship between the resonant frequency and the temperature, and constructs a temperature compensation model based on the functional relationship; obtains the sensor response of the sensor in real time, and inputs the sensor response into the temperature compensation model to generate a compensated frequency output. The present invention addresses the problem that the resonant frequency of a magnetoelectric sensor changes with temperature, and performs temperature compensation on the magnetoelectric sensor in a low-computation, low-cost, and real-time manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0033] Figure 1 A schematic diagram of a temperature compensation prediction model according to an embodiment of the present invention;

[0034] Figure 2 A flow chart of frequency compensation for sensor output according to an embodiment of the present invention;

[0035] Figure 3 A schematic diagram showing a comparison of frequency response curves of a sensor before and after compensation according to an embodiment of the present invention;

[0036] Figure 4 It is a schematic diagram of a resonant frequency-temperature fitting curve of an embodiment of the present invention;

[0037] Figure 5 Schematic diagram of the relationship between the resonant frequency and temperature before and after compensation according to an embodiment of the present invention. DETAILED DESCRIPTION

[0038] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0039] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0040] Embodiment 1

[0041] This embodiment provides a method for compensating the resonant frequency temperature drift of a magnetoelectric sensor, including:

[0042] Obtain the resonant frequency of the magnetoelectric sensor at different temperatures;

[0043] Acquire a functional relationship between the resonant frequency and the temperature, and construct a temperature compensation model based on the functional relationship;

[0044] The sensor response of the sensor is acquired in real time, and the sensor response is input into the temperature compensation model to generate a compensated frequency output.

[0045] By testing the frequency response of the magnetoelectric sensor at different temperatures, the frequency response data of the magnetoelectric sensor at different temperatures are obtained, and the resonant frequency is obtained. By fitting the relationship between the resonant frequency and temperature with a polynomial, the functional relationship between the two is obtained, thereby establishing a frequency temperature prediction compensation model for the magnetoelectric sensor, such as Figure 1 shown.

[0046] After receiving the sensor response at a certain temperature, the temperature data and the output frequency of the sensor are passed into the compensation model. The compensation model calculates the frequency offset of the sensor at the temperature according to the temperature and frequency. The compensated frequency output is obtained by subtracting the frequency offset from the output frequency, such as Figure 2 shown.

[0047] The method of the present invention is used to perform temperature compensation on the frequency response of the magnetoelectric sensor at different temperatures. The frequency response curves before and after compensation are as follows: Figure 3 shown.

[0048] Figure 4 The resonant frequency-temperature diagram composed of the resonant frequency and the temperature is extracted from the frequency response curve of the magnetoelectric sensor provided by the present invention at different temperatures.

[0049] Figure 5 The invention provides the resonant frequency of the magnetoelectric sensor after fitting by a first-order polynomial.

[0050] Further optimizing the scheme, the process of obtaining the resonant frequency of the magnetoelectric sensor at different temperatures includes:

[0051] By testing the frequency response of the magnetoelectric sensor at different temperatures, the frequency response data of the magnetoelectric sensor at different temperatures are obtained;

[0052] The resonant frequency of the magnetoelectric sensor at different temperatures is obtained based on the frequency response data.

[0053] According to a further optimization scheme, the process of obtaining the functional relationship between the resonant frequency and the temperature includes: performing polynomial fitting on the relationship between the resonant frequency and the temperature to obtain the functional relationship between the resonant frequency and the temperature.

[0054] Further optimizing the solution, the process of generating the compensated frequency output includes:

[0055] Receive the sensor output frequency of the sensor under a certain temperature data;

[0056] The temperature data and the sensor output frequency are input into the temperature compensation model for calculation to obtain a compensated frequency output.

[0057] Further optimizing the scheme, the process of inputting the temperature data and the sensor output frequency into the temperature compensation model for calculation includes:

[0058] Acquire a temperature change based on the temperature data, and acquire a frequency offset of the temperature data;

[0059] The temperature compensation model calculates the frequency offset and the sensor output frequency to generate a calibrated resonant frequency at a compensated temperature.

[0060] Further optimizing the solution, the expression for obtaining the temperature change based on the temperature data is:

[0061] ΔT=TT nominal ;

[0062] Among them, T is other temperature points, T nominal is the reference temperature, ΔT is the temperature change;

[0063] The expression of the frequency offset of the temperature data is:

[0064]

[0065] Among them, f T is the predicted frequency calculated by the sensor based on the functional relationship between the resonant frequency and temperature when the temperature is T; is the resonant frequency of the sensor at the reference temperature, and Δf is the frequency offset of the temperature data.

[0066] Further optimizing the solution, the expression of the calibration resonant frequency when generating the compensated temperature is:

[0067] f calibration =f-Δf;

[0068] Among them, f calibration is the calibration resonant frequency at the compensated temperature, and f is the resonant frequency at the measured temperature point.

[0069] A further optimization scheme, after generating the compensated frequency output, further includes: after compensating each temperature point, fitting again to observe whether the fitting straight line presents a straight line parallel to the temperature axis.

[0070] Embodiment 2

[0071] This embodiment provides a method for compensating the resonant frequency temperature drift of a magnetoelectric sensor, including:

[0072] The sensor is subjected to frequency sweep tests at different temperatures to obtain the curve of the sensor's resonant frequency changing with temperature. The sensor's resonant frequency shifts with temperature, showing an obvious linear trend. The fitting curve is obtained by fitting, such as Figure 4 shown.

[0073] It can be seen from the fitting parameters that the resonant frequency and temperature change show a strong negative correlation. The resonant frequency at different temperatures is compensated by the slope of the fitting straight line. Taking 20℃ as the reference temperature point, the compensation method is as follows:

[0074] First, calculate the equation of the fitting line, except for the reference temperature (T nominal ), the temperature changes of other temperature points (T) are:

[0075] ΔT=TT nominal ;

[0076] The predicted frequency offset is:

[0077]

[0078] In the formula, f T is the predicted frequency calculated by the sensor based on the functional relationship between the resonant frequency and temperature when the temperature is T; is the resonant frequency of the sensor at the reference temperature.

[0079] Subtract the predicted offset Δf from the measured resonant frequency f at the temperature point to obtain the calibrated resonant frequency f at the compensated temperature T. calibration for:

[0080] f calibration=f-Δf;

[0081] Since thermal expansion is the main cause of the frequency offset of the magnetoelectric sensor, the offset law of each frequency point is basically the same. Therefore, this compensation method is used to compensate each temperature point and then fit again.

[0082] Observe whether the fitting straight line is parallel to the temperature axis to judge the quality of the compensation performance.

[0083] From the fitting curve parameters, we can see that the slope of the fitting curve of the compensated data is in the micron level, that is, the resonant frequency basically does not change with temperature. Therefore, this compensation method is applied to the test frequency range, and the results are as follows: Figure 3 shown.

[0084] The above are only preferred specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for compensating the resonant frequency temperature drift of a magnetoelectric sensor, characterized in that: The following steps are involved: Obtain the resonant frequency of the magnetoelectric sensor at different temperatures; Acquire a functional relationship between the resonant frequency and the temperature, and construct a temperature compensation model based on the functional relationship; The sensor response of the sensor is acquired in real time, and the sensor response is input into the temperature compensation model to generate a compensated frequency output.

2. The resonant frequency temperature drift compensation method for a magnetoelectric sensor according to claim 1, characterized in that: The process of obtaining the resonant frequency of the magnetoelectric sensor at different temperatures includes: By testing the frequency response of the magnetoelectric sensor at different temperatures, the frequency response data of the magnetoelectric sensor at different temperatures are obtained; The resonant frequency of the magnetoelectric sensor at different temperatures is obtained based on the frequency response data.

3. The resonant frequency temperature drift compensation method for a magnetoelectric sensor according to claim 1, characterized in that: The process of obtaining the functional relationship between the resonant frequency and the temperature includes: performing polynomial fitting on the relationship between the resonant frequency and the temperature to obtain the functional relationship between the resonant frequency and the temperature.

4. The resonant frequency temperature drift compensation method for a magnetoelectric sensor according to claim 1, characterized in that: The process of generating the compensated frequency output includes: Receive the sensor output frequency of the sensor under a certain temperature data; The temperature data and the sensor output frequency are input into the temperature compensation model for calculation to obtain a compensated frequency output.

5. The resonant frequency temperature drift compensation method applicable to a magnetoelectric sensor according to claim 4, characterized in that: The process of inputting the temperature data and the sensor output frequency into the temperature compensation model for calculation includes: Acquire a temperature change based on the temperature data, and acquire a frequency offset of the temperature data; The temperature compensation model calculates the frequency offset and the sensor output frequency to generate a calibrated resonant frequency at a compensated temperature.

6. The resonant frequency temperature drift compensation method for a magnetoelectric sensor according to claim 5, characterized in that: The expression for obtaining the temperature change based on the temperature data is: ΔT=T-T nominal ; Among them, T is other temperature points, T nominal is the reference temperature, ΔT is the temperature change; The expression of the frequency offset of the temperature data is: Among them, f T is the predicted frequency calculated by the sensor based on the functional relationship between the resonant frequency and temperature when the temperature is T; is the resonant frequency of the sensor at the reference temperature, and Δf is the frequency offset of the temperature data.

7. The resonant frequency temperature drift compensation method for a magnetoelectric sensor according to claim 5, characterized in that: The expression for generating the calibrated resonant frequency at the compensated temperature is: f calibration =f-Δf; Among them, f calibration is the calibration resonant frequency at the compensated temperature, and f is the resonant frequency at the measured temperature point.

8. The resonant frequency temperature drift compensation method for a magnetoelectric sensor according to claim 1, characterized in that: After generating the compensated frequency output, the method further includes: performing compensation on each temperature point, fitting again, and observing whether the fitting straight line is a straight line parallel to the temperature axis.

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