A method for measuring the temperature of a solenoid valve control coil

Abstract

The present invention discloses a method for measuring the temperature of a solenoid valve control coil, comprising: S1: judging whether the operating conditions of the control coil temperature measurement method are met, and if so, executing S2; S2: calculating the theoretical temperature of the current control coil and the deviation self-learning value of the control coil temperature; S3: storing the calculated deviation self-learning value of the control coil temperature in the area corresponding to the theoretical temperature of the control coil in the constructed self-learning value table; S4: obtaining the characteristic value of the deviation self-learning model according to the self-learning value table; S5: calculating the deviation self-learning correction value according to the characteristic value of the deviation self-learning model and the theoretical temperature of the current control coil; S6: using the deviation self-learning correction value under the current working condition to correct the theoretical temperature of the control coil. The present invention utilizes the existing temperature sensor, and through the control coil theoretical temperature and the deviation self-learning model, it can not only reflect the average temperature of the coil, but also meet the requirements of the solenoid valve control coil temperature detection accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of engines, and more specifically, to a method for measuring the temperature of a solenoid valve control coil. Background Art

[0002] Solenoid valves have high performance and low prices. They are widely used in various actuators such as automobiles and engineering machinery, and are an important part of them. The coil is an important component of the solenoid valve, which generates magnetic potential and magnetic flux to make the solenoid valve work. The linear control of the solenoid valve realizes the continuity of the coil control current, and also increases the conduction time of the coil. When the coil is powered on, if the heat generated by the resistance loss (and other losses) cannot be dissipated, the temperature of the coil will rise (referred to as temperature rise). During the solenoid valve power-on process, the high heat generation of the coil and poor heat dissipation conditions are a prominent problem, which results in reduced control performance of the solenoid valve and temperature resistance of the coil, thereby affecting the performance of the solenoid valve. If the temperature rise of the coil exceeds the maximum allowable temperature rise, its insulation will be reduced. In severe cases, it will cause breakdown and short circuit between the coil turns, and even damage the solenoid valve. Therefore, the linear control of the solenoid valve must monitor the temperature rise of the control coil in real time, which plays a very important role in ensuring the temperature resistance of the coil and the control performance of the solenoid valve.

[0003] In the existing technical solution, the temperature of the solenoid valve coil is directly detected by a temperature sensor: a thermal resistor or other temperature sensor is installed on the surface of the coil to directly collect the temperature. Although it has a high temperature detection accuracy, it has the following disadvantages:

[0004] 1. The temperature collection point has high requirements. Due to the limitation of the solenoid valve structure, the temperature of the collection point cannot reflect the average temperature of the coil.

[0005] 2. The temperature sensor installed inside the solenoid valve cannot be measured, and third-party testing agencies cannot use this method to detect the temperature of the coil.

[0006] 3. Since the internal gap of the coil winding is very narrow, the installation of the temperature sensor leads to a complex structure of the solenoid valve, high manufacturing cost and high failure rate.

[0007] The measurement method for indirectly detecting the temperature of the solenoid valve coil is as shown in patent CN101558221B: "The internal resistance of the coil is determined based on this current and voltage. The temperature of the coil is calculated based on the internal resistance and the known internal resistance at room temperature. For this purpose, a family of characteristic curves can be specified, for example. The relationship between the coil temperature and the internal resistance is stored in the family of characteristic curves. Alternatively, it is specified that the temperature is calculated based on the detected parameters." Although it can theoretically reflect the average temperature of the coil, due to the material, manufacturing process, structure and other reasons, the nominal resistance and resistance temperature coefficient of the product coil are different from the theoretical values. The error caused by the difference in nominal resistance does not change with temperature, and the error caused by the difference in resistance temperature coefficient increases as the temperature changes and deviates from the base point; and the deviation caused by aging and sample distribution, the error of the resistance of the internal connecting wire and the external wire changing with temperature, etc., cannot be completely eliminated by only using the preset family of characteristic curves, which in turn affects the temperature measurement accuracy. The present invention will be carried out to address the above problems. Summary of the invention

[0008] In order to solve the above technical problems, an object of the present invention is to provide a method for measuring the temperature of a solenoid valve control coil.

[0009] In order to achieve the above object, the present invention provides a method for measuring the temperature of a solenoid valve control coil, comprising the following steps:

[0010] S1: Determine whether the operating conditions of the control coil temperature measurement method are met. If so, execute S2;

[0011] S2: Calculate the current theoretical temperature of the control coil and the deviation self-learning value of the control coil temperature;

[0012] S3: storing the control coil temperature deviation self-learning value calculated in step S2 into a region corresponding to the theoretical temperature of the control coil in a constructed self-learning value table, wherein the self-learning value table is a table of corresponding relationships between the theoretical temperature of the control coil and the calculated control coil temperature deviation self-learning value;

[0013] S4: Obtaining characteristic values ​​of the deviation self-learning model according to the self-learning value table;

[0014] S5: Calculate the deviation self-learning correction value according to the characteristic value of the deviation self-learning model and the theoretical temperature of the current control coil;

[0015] S6: Use the deviation self-learning correction value under the current working condition to correct the theoretical temperature of the control coil.

[0016] Optionally, in the method for measuring the temperature of the control coil, the process of executing step S2 is as follows:

[0017] Determine the internal resistance of the control coil through current and voltage;

[0018] The theoretical temperature of the control coil is calculated based on the internal resistance and the known internal resistance at room temperature;

[0019] The deviation between the current measured temperature of the sensor and the theoretical temperature of the control coil is integrated, and the result of the integration is used as the deviation self-learning value of the control coil temperature.

[0020] Optionally, in the method for measuring the temperature of the control coil, in step S2, the method for calculating the theoretical temperature of the control coil is as follows:

[0021] The theoretical temperature of the control coil is calculated using the following formula:

[0022]

[0023] In the above formula:

[0024] R = internal resistance of the coil;

[0025] α = Temperature coefficient of resistance (standard value of copper at room temperature 20°C = 0.0039300 1 / K);

[0026] R20 = nominal resistance of the coil at room temperature 20°C;

[0027] T = theoretical temperature of the control coil.

[0028] Optionally, in the control coil temperature measurement method, after executing step S2, the following steps are further included:

[0029] The peripheral area of ​​the current control coil temperature in the self-learning value table is smoothly modified according to the deviation self-learning value at the current control coil temperature.

[0030] Optionally, in the control coil temperature measurement method, the process of smoothly modifying the surrounding area of ​​the current control coil temperature in the self-learning value table according to the deviation self-learning value at the current control coil temperature is as follows:

[0031] If the current control coil temperature is room temperature, the difference between the deviation self-learning value at the current control coil temperature and the deviation self-learning value at the last control coil temperature in the self-learning value table is calculated, and the deviation self-learning value at the control coil temperature in the surrounding area of ​​the current control coil temperature in the self-learning value table is modified.

[0032] If the current control coil temperature is not room temperature, the proportional relationship between the deviation self-learning value at the current control coil temperature in the self-learning value table and the deviation self-learning value at the control coil temperature in its peripheral table is analyzed; the deviation self-learning value at the control coil temperature in the peripheral area of ​​the current control coil temperature in the self-learning value table is modified according to the proportional relationship and the deviation self-learning value after correction of the current control coil temperature.

[0033] Optionally, in the method for measuring the temperature of the control coil, in step S3, the following steps are also included:

[0034] Real-time monitoring is performed on whether there is any unreasonable situation in the deviation self-learning value of the control coil temperature under each working condition in the self-learning value table; if so, after further judgment and confirmation based on the judgment conditions, a deviation self-learning value fault of the control coil temperature will be reported.

[0035] Optionally, in the control coil temperature measurement method, after enabling the operating conditions of the control coil temperature self-learning method (i.e., the operating conditions of the control coil temperature measurement method in step S1), the number of storage times of the deviation self-learning value under the control coil temperature is accumulated.

[0036] Optionally, in the control coil temperature measurement method, in step S4 and step S5, the deviation self-learning model is as follows:

[0037] C=a+bt

[0038] C is the deviation self-learning correction value, a and b are characteristic values, and t is temperature.

[0039] Optionally, in the control coil temperature measurement method, in step S4, the method for obtaining the characteristic value of the deviation self-learning model according to the self-learning value table includes but is not limited to: least squares method, stochastic gradient descent method, etc.

[0040] Optionally, in the method for measuring the temperature of the control coil, the self-learning value table and the characteristic values ​​of the deviation self-learning model are stored in a memory to support power-off retention.

[0041] Optionally, in the control coil temperature measurement method, in step S1, the operating conditions of the control coil temperature measurement method include:

[0042] Conditions for the establishment of steady-state thermal equilibrium of the engine;

[0043] The engine power-on time meets a certain threshold; and

[0044] The engine operating condition is stable.

[0045] Optionally, in the control coil temperature measurement method, the condition for the engine steady-state thermal equilibrium to be established includes:

[0046] The engine shutdown time is greater than a certain threshold;

[0047] The ambient temperature is within certain thresholds; and

[0048] The difference between the maximum and minimum values ​​of the solenoid valve control medium temperature, ambient temperature and engine temperature is within a certain threshold.

[0049] Optionally, in the method for measuring the control coil temperature, when the engine operating condition is stable, the engine speed and load are within a certain threshold.

[0050] Due to the adoption of the above technical scheme, in the control coil temperature measurement method provided by the present invention, the control coil temperature measurement method is to calculate the theoretical temperature and the deviation self-learning value of the current control coil under the operating conditions; store the calculated deviation self-learning value of the control coil temperature in the area corresponding to the control coil temperature in the constructed self-learning value table, and the self-learning value table is a table of the correspondence between the control coil temperature and the deviation self-learning value; obtain the characteristic value of the deviation self-learning model according to the self-learning value table; then, calculate the deviation self-learning correction value according to the characteristic value of the deviation self-learning model and the current control coil temperature, and use the deviation self-learning correction value under the current operating condition to correct the theoretical temperature of the control coil.

[0051] In the method of the present invention, the existing temperature sensor is utilized, and by controlling the coil theoretical temperature and the deviation self-learning model, it can not only reflect the average temperature of the coil, but also solve the problems such as the difference between the nominal resistance and resistance temperature coefficient of the product coil and the theoretical value, the deviation caused by aging and sample distribution, and the error of the resistance of the internal connecting wire and the external wire changing with the temperature, thereby meeting the requirements of the temperature detection accuracy of the solenoid valve control coil. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 The figure is a flow chart of a method for measuring the temperature of a solenoid valve control coil according to an embodiment of the present invention.

[0053] Figure 2 It is a schematic diagram of a method for measuring the temperature of a solenoid valve control coil according to an embodiment of the present invention.

[0054] Figure 3 It is a schematic diagram of smooth modification of the self-learning value table according to an embodiment of the present invention. DETAILED DESCRIPTION

[0055] The following is a further detailed description of the method for measuring the temperature of the solenoid valve control coil proposed by the present invention in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present invention will become clearer according to the following description and claims. It should be noted that the accompanying drawings are in a very simplified form and are not in precise proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0056] like Figure 1 As shown, the implementation process of a method for measuring the temperature of a solenoid valve control coil provided in this embodiment includes:

[0057] First, step S1 is executed to determine whether the operating conditions of the control coil temperature measurement method are met. If so, step S2 is executed.

[0058] Next, step S2 is executed to calculate the current theoretical temperature of the control coil and the deviation self-learning value under the control coil temperature.

[0059] Next, execute step S3 to store the calculated deviation self-learning value of the control coil temperature into the area corresponding to the control coil temperature in the constructed self-learning value table, wherein the self-learning value table is a table of the correspondence between the theoretical temperature of the control coil and the calculated deviation self-learning value of the control coil temperature.

[0060] Next, executing step S4, obtaining the characteristic value of the deviation self-learning model according to the self-learning value table;

[0061] Next, step S5 is executed to calculate the deviation self-learning correction value according to the characteristic value of the deviation self-learning model and the current control coil temperature.

[0062] Next, step S6 is executed to correct the control coil theoretical temperature using the deviation self-learning correction value under the current working condition.

[0063] In step S1, the operating conditions of the control coil temperature measurement method include:

[0064] 1. The engine steady-state thermal balance is established, including:

[0065] 1.1 The engine shutdown time is greater than a certain threshold value, which can be set according to the experience of those skilled in the art and will not be elaborated here.

[0066] 1.2 The ambient temperature is within a certain threshold.

[0067] 1.3 The difference between the maximum and minimum values ​​of the solenoid valve control medium temperature, ambient temperature and engine temperature is within a certain threshold value, which can be set according to the experience of technicians in this field and will not be elaborated here.

[0068] 2. The engine power-on time is within a certain threshold, which can be set based on the experience of technicians in this field and will not be elaborated here.

[0069] 3. The engine operating condition is stable, which is manifested as: the engine speed and load are within a certain threshold. The threshold can be set according to the experience of technicians in this field and will not be elaborated here.

[0070] The specific scheme for executing step S2 is as follows:

[0071] like Figure 2 As shown, step S2 includes the following steps:

[0072] S20: Determine the internal resistance of the control coil through the current and voltage;

[0073] S21: Calculating the theoretical temperature of the control coil according to the internal resistance and the known internal resistance at room temperature;

[0074] S22: Integrate the deviation between the current measured temperature of the sensor and the theoretical temperature of the control coil, and use the result of the integration as the deviation self-learning value of the control coil temperature.

[0075] Specifically, in step S21, the formula ① for calculating the theoretical temperature of the control coil is as follows:

[0076]

[0077] In formula ①:

[0078] R is the internal resistance of the coil;

[0079] α is the temperature coefficient of resistance (standard value of copper at room temperature 20°C = 0.0039300 1 / K);

[0080] R20 is the nominal resistance of the coil at room temperature of 20°C;

[0081] T is the theoretical temperature of the control coil;

[0082] Specifically, after executing S2, the following steps are also included:

[0083] According to the deviation self-learning value at the current control coil temperature, the surrounding area of ​​the current control coil temperature in the self-learning value table is smoothly modified to obtain the deviation self-learning value of the surrounding area; in other words, when a deviation is learned to modify the deviation self-learning value of a certain temperature, the corresponding surrounding area needs to be numerically adjusted according to a certain offset or ratio, and the offset and ratio can match.

[0084] In this embodiment, Figure 3As shown, the specific process of smoothly modifying the surrounding area of ​​the current control coil temperature in the self-learning value table according to the deviation self-learning value at the current control coil temperature is as follows:

[0085] S230: Determine whether the current control coil temperature is room temperature, if so, execute S231, otherwise execute S232.

[0086] S231: Calculate the difference between the deviation self-learning value at the current control coil temperature and the deviation self-learning value at the last control coil temperature in the self-learning value table, and modify the deviation self-learning value in the surrounding area of ​​the current control coil temperature in the self-learning value table.

[0087] S232: Analyze the proportional relationship between the deviation self-learning value at the current control coil temperature in the self-learning value table and the deviation self-learning value at the control coil temperature in its surrounding table; execute S233.

[0088] S233: modifying the deviation self-learning value in the peripheral area of ​​the current control coil temperature in the self-learning value table according to the proportional relationship and the deviation self-learning value corrected by the current control coil temperature.

[0089] Take the simple self-learning value table shown in Table 1 as an example. In the table, A represents the area where the current working condition is located, B is the first circle expanding around A, and C is the second circle expanding around A. The number of expanded circles can match, and the locations of the expanded circles are all in the area around A.

[0090] Table 1: Simple self-learning value table

[0091] D C B A B C D

[0092] The self-learning value table in this embodiment is stored in the memory to support power-off retention and avoid the problem of data loss due to power-off.

[0093] Preferably, in the present embodiment, the memory is divided into a matrix of 1 row and 7 columns; accordingly, please refer to Table 2, which is a table for dividing the deviation self-learning working conditions of the control coil temperature, and the solenoid valve control coil temperature self-learning working conditions are divided into a matrix of 1 row and 7 columns, and the self-learning value of the current temperature working condition is stored in the grid in the self-learning value table corresponding to the matrix, that is, each temperature working condition performs the deviation self-learning of the control coil temperature separately, obtains the deviation self-learning value corresponding to the working condition, and stores it in the corresponding cell; when the expansion condition is met, the self-learning value of the surrounding working condition is modified, and the modified self-learning value is also saved in the matrix, and the matrix is ​​not lost when the power is off. The self-learning value table constructed by the control coil temperature measurement method of the present invention is not limited to 1 row and 7 columns, and can be specifically matched according to the solenoid valve control coil temperature working condition division situation.

[0094] Table 2: Measurement method of control coil temperature Self-learning working condition division table

[0095] temperature -20 -10 0 10 20 30 40 Deviation self-learning value

[0096] Please continue to refer to Figure 2 , in S3, the following steps are also included:

[0097] Real-time monitoring of whether there is any unreasonable situation in the deviation self-learning value of the control coil temperature under each working condition in the self-learning value table; if so, after further judgment and confirmation based on the judgment condition, a control coil temperature deviation self-learning value fault will be reported;

[0098] And / or, after enabling the operating conditions of the control coil temperature self-learning method, the number of storage times of the deviation self-learning value of the control coil temperature is accumulated. When the number of storage times is less than the threshold, when the surrounding area currently disclosed in the self-learning value table is smoothly modified, different proportions can be selected according to the matching.

[0099] In this embodiment, the unreasonable situation includes but is not limited to: the temperature deviation self-learning value under a certain steady-state thermal equilibrium condition exceeds the threshold range, and the value is clearly incorrect; in this case, the judgment condition is that the temperature deviation self-learning value exceeds the threshold range. The specific unreasonable situation can also be set according to actual experience.

[0100] In this embodiment, in S4 and S5, the formula ② of the deviation self-learning model is as follows:

[0101] C=a+bt②

[0102] in

[0103] C is the deviation self-learning correction value;

[0104] a and b are eigenvalues;

[0105] t is temperature.

[0106] Preferably, in this embodiment, in S4, the method for obtaining the characteristic value of the deviation self-learning model according to the self-learning value table adopts the least squares method.

[0107] Finally, the theoretical temperature of the control coil is corrected using the deviation self-learning correction value under the current working conditions.

[0108] In summary, in the control coil temperature measurement method provided by the present invention, the control coil temperature measurement method is to calculate the theoretical temperature and deviation self-learning value of the current control coil under the operating conditions; store the calculated control coil temperature deviation self-learning value in the area corresponding to the control coil temperature in the constructed self-learning value table, and the self-learning value table is a table about the corresponding relationship between the control coil temperature and the deviation self-learning value; obtain the characteristic value of the deviation self-learning model according to the self-learning value table; then, according to the characteristic value of the deviation self-learning model and the current control coil temperature, calculate the deviation self-learning correction value, and use the deviation self-learning correction value under the current working condition to correct the control coil theoretical temperature. In the method of the present invention, by using the existing temperature sensor, through the control coil theoretical temperature and the deviation self-learning model, it can not only reflect the average temperature of the coil, but also solve the problems such as the difference between the nominal resistance and resistance temperature coefficient of the product coil and the theoretical value, the deviation caused by aging and sample distribution, and the resistance error of the internal connecting wire and the external wire with the temperature change, so as to meet the requirements of the temperature detection accuracy of the solenoid valve control coil.

[0109] The above description is only a description of the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention. Any changes or modifications made by a person skilled in the art in the field of the present invention based on the above disclosure shall fall within the scope of protection of the claims.

Claims

1. A method for measuring the temperature of a solenoid valve control coil, characterized in that: The steps include: S1: Determine whether the operating conditions of the control coil temperature measurement method are met. If so, execute S2; S2: Calculate the current theoretical temperature of the control coil and the deviation self-learning value of the control coil temperature, integrate the deviation between the current sensor measured temperature and the theoretical temperature of the control coil, and use the result of the integration as the deviation self-learning value of the control coil temperature; S3: storing the control coil temperature deviation self-learning value calculated in step S2 into a region corresponding to the theoretical temperature of the control coil in a constructed self-learning value table, wherein the self-learning value table is a table of corresponding relationships between the theoretical temperature of the control coil and the calculated control coil temperature deviation self-learning value; S4: Acquire characteristic values ​​of the deviation self-learning model according to the self-learning value table, wherein a method for acquiring characteristic values ​​of the deviation self-learning model according to the self-learning value table is a least squares method or a stochastic gradient descent method; S5: Calculate the deviation self-learning correction value according to the characteristic value of the deviation self-learning model and the theoretical temperature of the current control coil. The deviation self-learning model is as follows: C=a+bt C is the deviation self-learning correction value, a and b are characteristic values, and t is the theoretical temperature; S6: Use the deviation self-learning correction value under the current working condition to correct the theoretical temperature of the control coil.

2. The method for measuring the temperature of a control coil according to claim 1, characterized in that: The process of executing step S2 is as follows: The internal resistance of the control coil is determined by the current and the voltage; the setpoint temperature of the control coil is determined from this internal resistance and the known internal resistance at room temperature.

3. The method for measuring the temperature of a control coil according to claim 1, characterized in that: In step S2, the method for calculating the theoretical temperature of the control coil is as follows: The theoretical temperature of the control coil is calculated using the following formula: In the above formula: R = internal resistance of the coil; α = Temperature coefficient of resistance, standard value of copper at room temperature 20°C = 0.0039300 1 / K; R20 = nominal resistance of the coil at room temperature 20°C; T = theoretical temperature of the control coil.

4. The method for measuring the temperature of a control coil according to claim 1, characterized in that: After executing step S2, the following steps are also included: The peripheral area of ​​the current control coil temperature in the self-learning value table is smoothly modified according to the deviation self-learning value at the current control coil temperature.

5. The method for measuring the temperature of a control coil according to claim 4, characterized in that: In the control coil temperature measurement method, the process of smoothly modifying the surrounding area of ​​the current control coil temperature in the self-learning value table according to the deviation self-learning value at the current control coil temperature is as follows: If the current control coil temperature is room temperature, the difference between the deviation self-learning value at the current control coil temperature and the deviation self-learning value at the last control coil temperature in the self-learning value table is calculated, and the deviation self-learning value at the control coil temperature in the surrounding area of ​​the current control coil temperature in the self-learning value table is modified; If the current control coil temperature is not room temperature, the proportional relationship between the deviation self-learning value at the current control coil temperature in the self-learning value table and the deviation self-learning value at the control coil temperature in its peripheral table is analyzed; the deviation self-learning value at the control coil temperature in the peripheral area of ​​the current control coil temperature in the self-learning value table is modified according to the proportional relationship and the deviation self-learning value after correction of the current control coil temperature.

6. The method for measuring the temperature of a control coil according to claim 1, characterized in that: In step S3, the following steps are also included: Real-time monitoring is performed on whether there is any unreasonable situation in the deviation self-learning value of the control coil temperature under each working condition in the self-learning value table; if so, after further judgment and confirmation based on the judgment conditions, a deviation self-learning value fault of the control coil temperature will be reported.

7. The method for measuring the temperature of a control coil according to claim 1, characterized in that: After the operating conditions of the control coil temperature self-learning method are enabled, that is, after the operating conditions of the control coil temperature measurement method in step S1, the number of storage times of the deviation self-learning value under the control coil temperature is accumulated.

8. The method for measuring the temperature of a control coil according to claim 1, characterized in that: The self-learning value table and the characteristic values ​​of the deviation self-learning model are stored in the memory to support power-off retention.

9. The method for measuring the temperature of a control coil according to claim 1, characterized in that: In step S1, the operating conditions of the control coil temperature measurement method include: Conditions for the establishment of steady-state thermal equilibrium of the engine; The engine power-on time meets a certain threshold; and The engine operating condition is stable.

10. The method for measuring the temperature of a control coil according to claim 9, characterized in that: The conditions for the steady-state thermal balance of the engine to be established include: The engine shutdown time is greater than a certain threshold; The ambient temperature is within certain thresholds; and The difference between the maximum and minimum values ​​of the solenoid valve control medium temperature, ambient temperature and engine temperature is within a certain threshold.

11. The method for measuring the temperature of a control coil according to claim 9, characterized in that: When the engine operating condition is stable, the engine speed and load are within a certain threshold.

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