High-thrust vibration table driving coil along-line temperature estimation method and system

Abstract

The invention discloses a method and a system for estimating the temperature along a line of a driving coil of a high-thrust vibrating table, which are suitable for a driving coil structure with water entering from two ends and water exiting from the middle for cooling, and are characterized in that temperature sensors are sequentially arranged on the upper layer from a water inlet to a middle water outlet along the winding direction of the driving coil at equal intervals; the temperature distribution condition of the upper layer is linearly fitted by monitoring the temperature value of the temperature sensor in real time, then the temperature distribution of the lower layer driving coil is symmetrically obtained, and the temperature rise condition of the driving coil is accurately evaluated by further utilizing the temperature value of the tail end of the driving coil and the slope increment ratio of the temperature fitting curve after a period of time. According to the invention, the comprehensive monitoring of the temperature distribution along the whole driving coil and the online accurate evaluation of the temperature rise condition are realized, and the support is provided for guaranteeing the use performance and the service life of the driving coil.

Description

Technical Field

[0001] The present invention relates to the technical field of vibration tables, and particularly relates to a method and system for estimating the temperature along the driving coil of a large-thrust vibration table. Background Art

[0002] In the field of modern engineering technology, a large-thrust vibration table is a vibration device that can generate a large thrust, and is widely used in fields such as aerospace, automotive, and electronics to simulate the vibration environment that a product experiences during actual use, in order to detect the reliability and durability of the product. The driving coil of a large-thrust vibration table, as the hub of its energy conversion, bears the important task of converting electrical energy into mechanical energy for driving the workbench to vibrate. During operation, in order to generate a sufficiently powerful electromagnetic force to achieve high-thrust output, a huge current needs to be passed through the driving coil, which will inevitably generate a large amount of heat inside the driving coil. If the accumulation of heat cannot be effectively controlled, it will affect its performance and lifespan.

[0003] In traditional technologies, the current measurement methods can be divided into two types: contact measurement and non-contact measurement. Contact measurement is generally achieved by embedding thermocouple measurement points on the driving coil, and non-contact measurement is generally achieved by installing a temperature sensor facing the driving coil inside the vibration table body. The existing measurement methods can only measure the temperature at the installation position of the sensor. This measurement method can only reflect the temperature at the measurement point. However, due to the relatively long driving coil in practice and the temperature differences at different positions, the existing measurement methods cannot comprehensively reflect the temperature distribution of the entire driving coil, and it is easy to miss local overheating points during the measurement process, affecting the accurate evaluation of the actual heating state of the driving coil of the large-thrust vibration table, and there are potential safety hazards in operation caused by inaccurate temperature monitoring. Summary of the Invention

[0004] In view of the above problems, the present invention provides a method for estimating the temperature along the driving coil of a large-thrust vibration table. The driving coil adopts a cooling structure with water inlet at both ends and water outlet in the middle, and specifically includes the following steps:

[0005] Step S1: Divide the driving coil of the vibration table into upper and lower layers from the middle water outlet. Along the winding direction of the driving coil, arrange n temperature sensors in sequence between the water inlet and the middle water outlet of the upper-layer driving coil. Denote the length of the position where the i-th temperature sensor is located from the water inlet of the upper-layer driving coil as L i , where: i = 1, 2, 3,..., n. The first temperature sensor is located at the water inlet of the upper-layer driving coil, and the n-th temperature sensor is located at the middle water outlet of the driving coil;

[0006] Step S2: Real-time monitor the temperature values of the n temperature sensors of the vibration table. Denote the value of the i-th temperature sensor as T i, the upper driving coil is divided into n - 1 segments from the water inlet to the middle water outlet according to the arranged temperature sensors, and the temperature distribution of the upper driving coil from the water inlet to the middle water outlet is obtained by linearly fitting the measured values of two temperature sensors in each segment. Among them, the temperature distribution along the driving coil in the j-th segment is obtained by linearly fitting the value T of the j-th temperature sensor j , the value T of the (j + 1)-th temperature sensor j+1 , and the expression is:

[0007]

[0008] Among them: T Lj represents the temperature of a point at a length of L from the water inlet of the upper driving coil in the j-th segment, j = 1, 2, 3, …, n - 1;

[0009] Step S3, according to the temperature distribution along the upper driving coil, symmetrically obtain the temperature distribution along the lower driving coil from the water inlet to the middle water outlet;

[0010] Step S4, preliminary determination of the cooling effect of the driving coil, determine whether the value T of the n-th temperature sensor n satisfies T n ≥ T max , among them: T max is the upper limit of the temperature threshold. If T n < T max , then execute Step S5; if T n satisfies T n ≥ T max , then it is determined that there is a problem of over-temperature of the vibration table driving coil and the cooling effect is poor;

[0011] Step S5, after an interval of Δt time, according to the operations in Steps S2 - S3, fit again to obtain the temperature distribution along the driving coil after Δt time. Among them, the expression of the temperature distribution along the driving coil in the j-th segment after Δt time is:

[0012]

[0013] Among them: T L ′ j represents the temperature of a point at a length of L from the water inlet of the upper driving coil in the j-th segment after Δt time, T j ′ represents the value of the j-th temperature sensor after Δt time, T j ′ +1 represents the (j + 1)-th temperature sensor after Δt time, j = 1, 2, 3, …, n - 1; continue to execute the next operation;

[0014] Step S6: Calculate the slope increment ratio Δk after a time interval of Δt. The calculation formula is as follows: Determine whether Δk satisfies Δk ≥ k max , where: k max is the upper limit of the slope increment ratio threshold. If Δk satisfies Δk ≥ k max , it is determined that there is a potential risk of excessive temperature rise in the driving coil of the vibration table and the cooling effect is poor; if Δk < k max , then perform the next operation;

[0015] Step S7: Determine whether Δk satisfies k min <Δk<k max , where: k min is the lower limit of the slope increment ratio threshold. If k min <Δk<k max , it is determined that the temperature rise of the driving coil of the vibration table is relatively gentle and the cooling effect is good; if Δk ≤ k min , it is determined that there is no risk of excessive temperature rise in the driving coil of the vibration table and the cooling effect is very good.

[0016] Preferably, the number n of the temperature sensors ranges from 5 to 10.

[0017] Preferably, the n temperature sensors are arranged at equal distances.

[0018] Preferably, the temperature sensor is a thermocouple temperature sensor.

[0019] Preferably, the upper limit T max of the temperature threshold ranges from 80°C to 120°C.

[0020] Preferably, the time interval Δt ranges from 60 s to 120 s.

[0021] Preferably, the upper limit k max of the slope increment ratio threshold ranges from 1.6 to 2.

[0022] Preferably, the lower limit k min of the slope increment ratio threshold ranges from 1.1 to 1.2.

[0023] The present invention further discloses a system for estimating the temperature along the driving coil of a large-thrust vibration table, including a driving coil, temperature sensors, and an external control module. The driving coil is wound with n temperature sensors arranged in sequence along the winding direction from the water inlet to the middle water outlet. The first temperature sensor is located at the water inlet of the upper-layer driving coil, and the nth temperature sensor is located at the middle water outlet of the driving coil. The plurality of temperature sensors are respectively electrically connected to the external control module through data lines, and the method for estimating the temperature along the driving coil of the large-thrust vibration table as described above is adopted.

[0024] Beneficial effects

[0025] 1. In the present invention, a plurality of thermocouple temperature sensors are arranged at equal intervals at specific positions on the upper layer of the driving coil, so as to obtain temperature data at different positions on the upper layer. By linearly fitting the temperature distribution on the upper layer and symmetrically obtaining the temperature distribution on the lower layer, the overall monitoring of the temperature distribution along the entire driving coil is realized, avoiding the problem of missing local overheating points due to limited measurement points, being able to more detailedly reflect the temperature conditions of each part of the coil, and greatly improving the comprehensiveness and accuracy of temperature monitoring.

[0026] 2. Based on the temperature - length function obtained by fitting, the present invention uses the comparison between the end temperature value and the set threshold for preliminary determination, can quickly screen out possible problems of abnormal temperature rise of the driving coil, and then gives a judgment on whether the cooling effect of the driving coil meets the standard.

[0027] 3. The present invention introduces the parameter of slope increment ratio, and deeply analyzes the temperature rise change of the driving coil from the perspective of the temperature change trend. By comparing the slope changes of the function at different times, not only can the temperature rise change of the driving coil be judged, but also the degree of temperature rise change can be more finely divided, which helps to timely discover potential abnormal temperature rises and take targeted measures. Description of the drawings

[0028] Figure 1 It is the overall schematic diagram of the temperature estimation along the driving coil of the invention.

[0029] Figure 2 It is the detailed flowchart of the temperature estimation method along the driving coil of the invention. Specific implementation manners

[0030] The present invention will be further described below in combination with the embodiments in the drawings:

[0031] The present invention provides a method for estimating the temperature along the driving coil of a large - thrust vibration table. The driving coil adopts a cooling structure with water inlet at both ends and water outlet in the middle, and specifically includes the following steps:

[0032] Step S1: Divide the driving coil of the vibration table into upper and lower layers from the middle water outlet. Along the winding direction of the driving coil, n temperature sensors are arranged in sequence between the water inlet and the middle water outlet of the upper - layer driving coil. The value range of n is 5 - 10. Denote the length from the position where the i - th temperature sensor is located to the water inlet of the upper - layer driving coil as L i , where: i = 1, 2, 3,..., n. The first temperature sensor is located at the water inlet of the upper - layer driving coil, the n - th temperature sensor is located at the middle water outlet of the driving coil, and the n temperature sensors are arranged at equal - distance intervals. The temperature sensors adopt thermocouple temperature sensors;

[0033] Step S2: Real-time monitor the temperature values of n temperature sensors on the shaking table, and record the value of the i-th temperature sensor as T i , divide the upper driving coil from the water inlet to the middle water outlet into n - 1 segments according to the arranged n temperature sensors, and linearly fit the measured values of two temperature sensors in each segment to obtain the temperature distribution of the upper driving coil from the water inlet to the middle water outlet. Among them: the temperature distribution along the driving coil in the j-th segment is linearly fitted by the value T j of the j-th temperature sensor and the value T j+1 of the (j + 1)-th temperature sensor, and the expression is:

[0034]

[0035] Among them: T Lj represents the temperature of the point at a length of L from the water inlet of the upper driving coil in the j-th segment, j = 1, 2, 3, L, n - 1;

[0036] Step S3: According to the temperature distribution along the upper driving coil, symmetrically obtain the temperature distribution along the lower driving coil from the water inlet to the middle water outlet;

[0037] Beneficial effect: The driving coil adopts a cooling structure with water inlet at both ends and water outlet in the middle. Therefore, there is no need to arrange a large number of additional sensors in the lower layer. Only according to the temperature distribution along the upper driving coil, the temperature distribution of the lower driving coil can be symmetrically obtained, reducing the cost and system complexity, and at the same time achieving a comprehensive acquisition of the temperature distribution of the entire driving coil;

[0038] Step S4: Preliminary determination of the cooling effect of the driving coil, judge whether the value T n of the n-th temperature sensor satisfies T n ≥T max . Among them: T max is the upper limit of the temperature threshold, and the value range of T max is 80°C to 120°C. If T n <T max , then execute Step S5; if T n satisfies T n ≥T max , then it is determined that there is a problem of over-temperature of the driving coil of the shaking table and the cooling effect is poor;

[0039] Beneficial effect: By judging whether the value of the n-th temperature sensor exceeds the upper limit of the temperature threshold, it is possible to quickly and preliminarily judge whether there is a problem of over-temperature of the driving coil and timely detect the situation of poor cooling effect;

[0040] Step S5: After an interval of Δt time, where the value range of Δt is 60s to 120s, perform the operations in steps S2 to S3 again to obtain the temperature distribution along the driving coil after Δt time. The expression for the temperature distribution along the driving coil at the j-th segment after Δt time is as follows:

[0041]

[0042] where: T L ′ j represents the temperature at a point with a length of L from the water inlet of the upper driving coil in the j-th segment after Δt time, and T j ′ represents the value of the j-th temperature sensor after Δt time, and T j ′ +1 represents the (j + 1)-th temperature sensor after Δt time, where j = 1, 2, 3, …, n - 1; continue to perform the next operation;

[0043] Step S6: Calculate the slope increment ratio Δk after Δt time. Its calculation formula is: Judge whether Δk satisfies Δk ≥ k max , where: k max is the upper limit of the slope increment ratio threshold, and the value range of k max is 1.6 to 2. If Δk satisfies Δk ≥ k max , it is determined that there is a hidden danger of too fast temperature rise and poor cooling effect in the driving coil of the vibration table; if Δk < k max , then perform the next operation;

[0044] Beneficial effect: After a certain interval of time, perform the operations of data acquisition and fitting again to obtain the temperature distribution along the driving coil after a certain time, which can track the change of the driving coil temperature over time in real time, discover the temperature change trend in time, and provide data support for accurately evaluating the cooling effect;

[0045] Step S7: Judge whether Δk satisfies k min < Δk < k max , where: k min is the lower limit of the slope increment ratio threshold, and the value range of k min is 1.1 to 1.2. If k min < Δk < k max , it is determined that the temperature rise of the driving coil of the vibration table is relatively gentle and the cooling effect is good; if Δk ≤ k min , it is determined that there is no hidden danger of too fast temperature rise in the driving coil of the vibration table and the cooling effect is very good.

[0046] Beneficial effects: By calculating and comparing the ratio of slope increments with the upper threshold, the cooling effect is deeply analyzed from the perspective of the temperature change trend. Compared with the traditional single-temperature comparison method, it can more accurately determine whether there is a hidden danger of excessive temperature rise in the driving coil, improving the accuracy of the cooling effect evaluation.

[0047] The present invention further discloses a system for estimating the temperature along the driving coil of a large-thrust vibration table, including a driving coil, temperature sensors, and an external control module. Along the winding direction of the driving coil from the water inlet to the middle water outlet, n temperature sensors are arranged in sequence. The first temperature sensor is located at the water inlet of the upper-layer driving coil, and the nth temperature sensor is located at the middle water outlet of the driving coil. The multiple temperature sensors are respectively electrically connected to the external control module through data lines, and the method for estimating the temperature along the driving coil of the large-thrust vibration table described above is adopted.

[0048] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited thereto. All changes that can be made within the knowledge of those skilled in the art without departing from the purpose of the present invention are within the protection scope of the claims of the present invention.

Claims

1. A method for estimating the temperature along the driving coil of a large-thrust vibration platform, wherein the driving coil adopts a cooling structure with water inlet at both ends and water outlet in the middle, characterized in that: The following steps are involved: S1. Divide the vibration table drive coil into two layers from the middle water outlet. Arrange n temperature sensors in sequence along the winding direction of the drive coil from the water inlet to the middle water outlet of the upper drive coil. The distance from the position of the i-th temperature sensor to the water inlet of the upper drive coil is L. i , where: i = 1, 2, 3, ..., n, the first temperature sensor is located at the water inlet of the upper drive coil, and the nth temperature sensor is located at the middle water outlet of the drive coil; S2, real-time monitoring of the temperature values ​​of n temperature sensors on the vibration platform, the value of the i-th temperature sensor is recorded as T i , the upper drive coil is divided into n-1 sections from the water inlet to the middle water outlet according to the arranged temperature sensors, and the temperature distribution of the upper drive coil from the water inlet to the middle water outlet is obtained by linear fitting using the measured values ​​of the two temperature sensors in each section, where: the temperature distribution along the j-th section of the drive coil is determined by the j-th temperature sensor value T j 、j+1th temperature sensor T j+1 The linear fitting expression is: Where: T Lj represents the temperature of the point in the jth segment that is L away from the water inlet of the upper driving coil, j = 1, 2, 3, L, n-1; S3. Based on the temperature distribution along the upper driving coil, the temperature distribution along the lower driving coil from the water inlet to the middle water outlet is symmetrically obtained; S4. Preliminary determination of the cooling effect of the drive coil and determination of the value T of the nth temperature sensor n Whether T is satisfied n ≥T max , where: T max is the upper temperature threshold, if T n <T max , then execute step S5; if T n Meet T n ≥T max , it is determined that the vibration table drive coil has an over-temperature problem and the cooling effect is poor; S5. After an interval of Δt, the temperature distribution along the driving coil after Δt is obtained by fitting again according to the operations of steps S2 to S3. The temperature distribution along the driving coil of the jth segment after Δt is expressed as follows: Where: T L ' j It represents the temperature of the point in the jth segment with a distance L from the water inlet of the upper driving coil after Δt time, T j ′ represents the value of the jth temperature sensor after Δt time, T j ' +1 It means that after Δt time, the j+1th temperature sensor, j=1,2,3,L,n-1; continue to the next step; S6. Calculate the slope increment ratio Δk after Δt time, and the calculation formula is: Determine whether Δk satisfies Δk≥k max , where: k max is the upper limit of the slope increment ratio threshold, if Δk satisfies Δk≥k max , it is determined that the vibration table drive coil has the risk of rapid temperature rise and poor cooling effect; if Δk<k max , then execute the next step; S7. Determine whether Δk satisfies k min <Δk<k max , where: k min is the lower limit of the slope increment ratio threshold, if k min <Δk<k max , it is determined that the temperature rise of the vibration table drive coil is relatively gentle and the cooling effect is good; if Δk≤k min , it is determined that the vibration table drive coil has no risk of rapid temperature rise and the cooling effect is very good.

2. The method for estimating the temperature along the driving coil of a high-thrust vibration table according to claim 1 is characterized in that: The number n of the temperature sensors ranges from 5 to 10.

3. The method for estimating the temperature along the driving coil of a high-thrust vibration table according to claim 1 is characterized in that: The n temperature sensors are arranged at equal distances from each other.

4. The method for estimating the temperature along the driving coil of a high-thrust vibration table according to claim 1 is characterized in that: The temperature sensor is a thermocouple temperature sensor.

5. The method for estimating the temperature along the driving coil of a high-thrust vibration table according to claim 1 is characterized in that: The upper temperature threshold T max The value range is 80℃~120℃.

6. The method for estimating the temperature along the driving coil of a high-thrust vibration table according to claim 1 is characterized in that: The interval time Δt ranges from 60s to 120s.

7. The method for estimating the temperature along the driving coil of a high-thrust vibration table according to claim 1 is characterized in that: The slope increment ratio upper threshold value k max The value range is 1.6 to 2.

8. The method for estimating the temperature along the driving coil of a high-thrust vibration table according to claim 1 is characterized in that: The slope increment ratio threshold lower limit k min The value range is 1.1 to 1.

2.

9. A temperature estimation system along the driving coil of a large thrust vibration table, comprising a driving coil, a temperature sensor and an external control module, wherein n temperature sensors are arranged in sequence along the winding direction of the driving coil from the water inlet to the middle water outlet of the driving coil, the first temperature sensor is located at the water inlet of the upper driving coil, and the nth temperature sensor is located at the middle water outlet of the driving coil, and the plurality of temperature sensors are electrically connected to the external control module via data lines, characterized in that: The external control module adopts a temperature estimation method along the driving coil of a large-thrust vibration table as described in any one of claims 1 to 8.

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