Air pressure equalization control system and method for multi-integrated vibration test system

Abstract

Disclosed in the present invention are an air pressure equalization control system and method for a multi-integrated vibration test system. The air pressure equalization control system comprises: an intake valve, a vacuum pump, a pipe, a lower switch valve, an upper switch valve, a vibration table, a test chamber, a sensor system, and a control unit. The sensor system comprises a temperature sensor, upper air pressure sensors, and a lower air pressure sensor, wherein the upper air pressure sensors are evenly distributed in a sealed cavity of the test chamber. The control unit collects state information of each sensor, and by incorporating the temperature change pattern in a test process, performs control operations on the intake value, the vacuum pump, the lower switch valve, and the upper switch valve, respectively, so as to dynamically compensate for an air pressure change caused by a temperature change, thereby achieving equalization control of the air pressure inside a sealed cavity of the vibration table and the air pressure inside the sealed cavity of the test chamber.

Description

A pressure equalization control system and method for a multi-integrated vibration test system Technical Field

[0001] This invention relates to the field of vibration table technology, specifically to a pressure equalization control system and method for a multi-integrated vibration test system. Background Technology

[0002] Currently, electric vibration tables are widely used in reliability research and testing of complete products and components in sectors such as aviation, aerospace, weaponry, electronics, shipbuilding, machinery, energy, chemical industry, and instrumentation. However, the experimental environment for some products is limited by environmental factors such as temperature, humidity, and air pressure, making it impossible to conduct vibration tests under special working conditions. Using an electric vibration table in conjunction with a comprehensive test chamber (used to simulate temperature, humidity, air pressure, and vibration environments) is the main method to solve this problem. A crucial aspect of using a multi-comprehensive vibration test system is achieving automatic pressure equalization between the vibration table and the comprehensive test chamber. However, current multi-comprehensive vibration test systems have the following shortcomings in terms of air pressure equalization:

[0003] 1. Existing multi-integrated vibration test systems typically achieve air pressure equalization by connecting the inside of the vibration table with the inside of the integrated test chamber, and then using a vacuum pump to simultaneously evacuate air from both the connected vibration table and the integrated test chamber to simulate low-pressure conditions. The vacuum pump usually operates at a fixed speed. If the vacuum pump speed is too slow, it will take a long time to reach the desired air pressure. If the vacuum pump speed is too fast, it will easily cause over-adjustment of the air pressure inside the integrated test chamber, resulting in poor air pressure equalization.

[0004] 2. Existing multi-integrated vibration test systems generally ignore the changes in air pressure in the integrated test chamber caused by the temperature rise during the heating test in a low-pressure environment, and do not take corresponding measures to dynamically compensate for the air pressure changes, resulting in poor air pressure equalization during the heating test.

[0005] 3. In existing low-pressure environment vibration tests, when collecting the air pressure of the integrated test chamber, a single air pressure sensor is usually used to measure the air pressure of the integrated test chamber. The air pressure measurement inside the integrated test chamber is not comprehensive and cannot accurately reflect the global air pressure value inside the integrated test chamber. Air pressure equalization control based on this pressure value often causes a certain air pressure equalization error. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a pressure equalization control system and method for a multi-integrated vibration test system that is simple in structure, low in cost, and has good performance.

[0007] This invention provides a pressure equalization control system for a multi-integrated vibration test system, including an inlet valve, a vacuum pump, pipelines, a lower switch valve, an upper switch valve, a vibration table, a test chamber, a sensor system, and a control unit. The vibration table includes a transition platform, a moving coil, and a housing. The transition platform is connected to the moving coil by screws, and the moving coil and housing are connected by a seal, forming a sealed cavity within the vibration table. The test chamber is located above the transition platform and is connected to it by a seal. The test chamber contains a sealed cavity. The inlet of the lower switch valve is connected to the sealed cavity of the vibration table. The inlet of the upper switch valve is connected to the sealed cavity of the test chamber. The inlet valve is an electromagnetic proportional directional valve, with the valve opening positively correlated with the current magnitude. The vacuum pump is equipped with... It has two speed settings: high speed and low speed. The pipeline has an upper port, a lower port, a left port, and a right port. The upper port is connected to the outlet of the upper switch valve, the lower port is connected to the vacuum pump, the left port is connected to the outlet of the air inlet valve, and the right port is connected to the outlet of the lower switch valve. The sensor system includes a temperature sensor, an upper air pressure sensor, and a lower air pressure sensor. The upper air pressure sensors are evenly distributed within the sealed cavity of the test chamber. The lower air pressure sensors are arranged within the sealed cavity of the vibration table support. The temperature sensor is arranged within the sealed cavity of the test chamber. The control unit is used to collect signals from the upper air pressure sensor, the lower air pressure sensor, and the temperature sensor, and to run the multi-integrated vibration test system air pressure equalization control method provided by this invention.

[0008] This invention also provides a method for air pressure equalization control of a multi-integrated vibration test system, comprising the following steps:

[0009] Step S1: Before the vibration test begins, the air pressure of the vibration test system is initially set, and the value of the i-th upper air pressure sensor is recorded as P. i Where: i = 1, 2, 3...m, m is the number of upper air pressure sensors, and the air pressure sensor closest to the upper switch valve is denoted as the first upper air pressure sensor; calculate the average value P of the m upper air pressure sensor values. 上 P 上 The calculation formula is P 上 = (P1+P2+P3+...+P) m ) / m; Let the rated speed of the vacuum pump be n. 额 High speed is n 高 Low speed is n 低 , where: n 高 and n 低 The expressions are n 高 =η 高 n 额 and n 低 =η 低 n 额 η 高 and η低 These are the high-speed coefficient and the low-speed coefficient, respectively.

[0010] Step S2: Set the vacuum pump to high speed to evacuate the sealed cavity of the test chamber and the sealed cavity of the vibration table. Record the desired air pressure required for the vibration test as P. Close the inlet valve and open the upper and lower switch valves. Record δ. P上 The allowable error value for air pressure in the sealed cavity of the test chamber is given by α, where α is the air pressure coefficient and α > 1. The value P1 of the first upper air pressure sensor is collected in real time, and the condition |P1 - αP| ≤ δ is determined in real time. P上 Whether it holds true, if |P1-αP|≤δ P上 If this condition is not met, the vacuum pump will continue to operate at high speed; if |P1-αP|≤δ P上 If successful, proceed to the next step.

[0011] Step S3: The vacuum pump is used at low speed to regulate the air pressure in the sealed cavity of the test chamber and the sealed cavity of the vibration table. Once the desired air pressure is reached in both cavities, proceed to the next step. The specific steps for regulating the air pressure in the sealed cavity of the test chamber and the sealed cavity of the vibration table using the vacuum pump at low speed are as follows:

[0012] Step S31: Set the vacuum pump to low speed operation and record δ. P下 To determine the allowable error value of the air pressure in the sealed cavity of the vibration table, the values ​​of m upper air pressure sensors are collected in real time, and P is calculated according to the formula for calculating the average value of the m upper air pressure sensor values ​​in step S1. 上 Real-time acquisition of barometric pressure sensor values ​​P 下 ;

[0013] Step S32: Based on the value P calculated in real time by the upper air pressure sensor 上 The value P collected in real time by the barometric pressure sensor 下 Compare and judge, if |PP 上 |>δ P上 And |PP 下 |>δ P下 If the upper and lower switching valves remain open, the vacuum pump continues to run at a low speed, and then proceed to the next step; if |PP 上 |≤δ P上 And |PP 下 |>δ P下 If the upper switch valve is closed, the lower switch valve remains open, the vacuum pump continues to run at a low speed, and then proceed to the next step; if |PP 上 |>δ P上 And |PP 下 |≤δ P下 If the lower switch valve is closed, the upper switch valve remains open, the vacuum pump continues to run at a low speed, and then proceed to the next step; if |PP上 |≤δ P上 And |PP 下 |≤δ P下 Proceed directly to the next step;

[0014] Step S33, Judgment Condition | PP 上 |≤δ P上 and |PP 下 |≤δ P下 Do they satisfy the conditions simultaneously? If so, |PP 上 |≤δ P上 And |PP 下 |≤δ P下 This indicates that the sealed cavity of the test chamber and the sealed cavity of the vibration table have reached the desired air pressure. Close the upper and lower switch valves and the vacuum pump. If the pressure is not met, |PP 上 |≤δ P上 And |PP 下 |≤δ P下 Then return to step S32;

[0015] Step S4: When conducting the temperature rise test under low pressure, pressure compensation for the temperature rise test should be performed simultaneously. First, calculate the temperature difference ΔT based on the temperature curve given in the temperature rise test. 升 Let the initial temperature of the temperature curve be T. 初 The temperature curve ends at temperature T. 末 ΔT 升 The calculation formula is ΔT 升 =T 末 -T 初 ;

[0016] Step S5: Determine ΔT 升 Does ΔT satisfy? 升 <λ 下 , where: λ 下 The lower limit of the temperature difference threshold is ΔT. 升 ≥λ 下 If ΔT 升 <λ 下 To perform air pressure compensation in the sealed cavity of the test chamber under small temperature differences, execute steps S51 to S52, as follows:

[0017] Step S51: Real-time acquisition of temperature sensor value T, and determination of T≥T 初 +β 小 ΔT 升 Whether it is true or not, where: β 小 For a small temperature rise coefficient, if T ≥ T 初 +β 小 ΔT 升If this is not true, continue the heating experiment and repeat step S51; if T≥T 初 +β 小 ΔT 升 If successful, the upper switch valve will open, the vacuum pump will run at low speed, and the next step will be executed.

[0018] Step S52: Real-time acquisition of values ​​from m upper barometric pressure sensors and calculation of P based on the average value calculation formula of the m upper barometric pressure sensor values ​​in step S1. 上 And judge in real time |PP 上 |≤δ P上 Whether it is true or not, if |PP 上 |≤δ P上 If this is not the case, keep the upper switch valve open, the vacuum pump continues to run at low speed, and repeat step S52; if |PP 上 |≤δ P上 Establishment, closing the upper switch valve and vacuum pump, ending the temperature rise test pressure compensation;

[0019] Step S6: Determine ΔT 升 Does it satisfy λ? 下 ≤ΔT 升 <λ 上 , where: λ 上 The upper limit of the temperature difference threshold is ΔT. 升 ≥λ 上 If λ 下 ≤ΔT 升 <λ 上 To perform air pressure compensation in the sealed cavity of the test chamber under medium temperature difference, proceed with steps S61 to S63, as follows:

[0020] Step S61: Real-time acquisition of the temperature sensor value T, and record β. 中 Given a medium temperature rise coefficient, determine if T ≥ T 初 +β 中 ΔT 升 Whether it holds true, if T≥T 初 +β 中 ΔT 升 If this is not true, continue the heating experiment and repeat step S61; if T≥T 初 +β 中 ΔT 升 If successful, the upper switch valve will open, the vacuum pump will run at high speed, and the next step will be executed.

[0021] Step S62: Real-time acquisition of values ​​from m upper barometric pressure sensors and calculation of P based on the average value calculation formula of the m upper barometric pressure sensor values ​​in step S1. 上 , denote δ P δ represents the error value in converting vacuum pump speed to air pressure.P The value is greater than δ P上 Real-time judgment | PP 上 |≤δ P Whether it is true or not, if |PP 上 |≤δ P If this is not the case, keep the upper switch valve open, run the vacuum pump at high speed, and repeat step S62; if |PP 上 |≤δ P If successful, the upper switch valve remains open, the vacuum pump runs at low speed, and the next step is executed.

[0022] Step S63: Real-time acquisition of values ​​from m upper barometric pressure sensors and calculation of P based on the average value calculation formula of the m upper barometric pressure sensor values ​​in step S1. 上 And judge in real time |PP 上 |≤δ P上 Whether it is true or not, if |PP 上 |≤δ P上 If this is not the case, keep the upper switch valve open, the vacuum pump continues to run at low speed, and repeat step S63; if |PP 上 |≤δ P上 Establishment, closing the upper switch valve and vacuum pump, ending the temperature rise test pressure compensation;

[0023] Step S7: Perform air pressure compensation in the sealed cavity of the test chamber under large temperature difference, including the following steps:

[0024] Step S71: Real-time acquisition of the temperature sensor value T, and recording β 高 For a high temperature rise coefficient, determine if T ≥ T 初 +β 高 ΔT 升 Whether it holds true, if T≥T 初 +β 高 ΔT 升 If this is not true, continue the heating experiment and repeat step S71; if T≥T 初 +β 高 ΔT 升 If successful, proceed to the next step;

[0025] Step S72: Real-time acquisition of values ​​from m upper barometric pressure sensors and calculation of P based on the average value calculation formula of the m upper barometric pressure sensor values ​​in step S1. 上 And judge in real time |PP 上 |≤δ P Whether it is true or not, if |PP 上 |≤δ P If this is not the case, keep the upper switch valve open, run the vacuum pump at high speed, and repeat step S72; if |PP 上 |≤δP If successful, the upper switch valve remains open, the vacuum pump runs at low speed, and the next step is executed.

[0026] Step S73: Real-time acquisition of values ​​from m upper barometer sensors and calculation of P based on the average value calculation formula of the m upper barometer sensor values ​​in step S1. 上 And judge in real time |PP 上 |≤δ P上 Whether it is true or not, if |PP 上 |≤δ P上 If this is not the case, keep the upper switch valve open, the vacuum pump continues to run at low speed, and repeat step S73; if |PP 上 |≤δ P上 Once established, close the upper switch valve and vacuum pump, and end the temperature rise test pressure compensation.

[0027] Preferably, the upper air pressure sensors are evenly distributed at the same height within the sealed cavity of the test chamber.

[0028] Preferably, there are two or four air pressure sensors.

[0029] Preferably, the high-speed coefficient η 高 The value range is 0.7 to 0.8, and the low-gear speed coefficient η 低 The value range is 0.5 to 0.6.

[0030] Preferably, the pressure coefficient α ranges from 1.5 to 1.9.

[0031] Preferably, the allowable error value δ of the air pressure in the sealed cavity of the test chamber is... P上 The value range is 0.1 Pa to 0.3 Pa, and the allowable error value δ for the air pressure in the sealed cavity of the vibration table is... P下 The value range is 0.1 Pa to 0.3 Pa, and the error value δ for converting vacuum pump speed to air pressure is... P The value range is 1 Pa to 1.5 Pa.

[0032] Preferably, the lower limit of the temperature difference threshold λ 下 The value range is 100℃~200℃, and the upper limit of the temperature difference threshold λ 上 The value range is 500℃~600℃.

[0033] Preferably, a low temperature rise coefficient β 小 The value ranges from 0.6 to 0.65, and the medium temperature rise coefficient β 中 The value ranges from 0.4 to 0.45, indicating a high temperature rise coefficient β. 高 The value range is 0.3 to 0.35.

[0034] Beneficial effects:

[0035] 1. The air pressure equalization control method of the multi-integrated vibration test system proposed in this invention uses a vacuum pump that operates at high speed and low speed according to different air pressure values ​​during the evacuation process of the sealed cavity of the vibration table test chamber and the sealed cavity of the vibration table. This shortens the time required for the air pressure in the sealed cavity of the vibration table test chamber and the sealed cavity of the vibration table to reach the desired air pressure, and improves the stability accuracy of the air pressure in the sealed cavity of the vibration table test chamber and the sealed cavity of the vibration table.

[0036] 2. The air pressure equalization control method of the multi-integrated vibration test system proposed in this invention adopts different air pressure equalization control methods according to the different temperature differences between the initial temperature and the final temperature of the temperature curve during the heating test. When the temperature difference is large or medium, the vacuum pump is operated at high speed and low speed in combination to achieve air pressure equalization. When the temperature difference is small, the vacuum pump is operated at low speed to achieve air pressure equalization, thereby effectively ensuring the degree of air pressure equalization during the heating test.

[0037] 3. The present invention arranges multiple air pressure sensors at the same height in the sealed cavity of the vibration table test chamber, and calculates their average value as the air pressure value in the sealed cavity of the vibration table test chamber, thereby improving the accuracy of air pressure detection.

[0038] 4. In the process of air pressure equalization control of the multi-integrated vibration test system, the vacuum pump only needs to be set to high and low speeds. There is no need to continuously adjust the speed of the vacuum pump steplessly. The system is simple, easy to build, low in cost, easy to install, simple and reliable, highly adaptable, and has good performance. It has wide applicability. Attached Figure Description

[0039] Figure 1 is a schematic diagram of the structure of the present invention.

[0040] Figure 2 shows the sensor arrangement inside the test chamber of the present invention.

[0041] Figure 3. Initial air pressure setting control flowchart.

[0042] Figure 4. Flowchart of pressure compensation control for the heating test.

[0043] 1. Inlet valve; 2. Vacuum pump; 3. Pipeline; 4. Lower switch valve; 5. Upper switch valve; 6. Transition platform; 7. Sealed cavity of the test chamber; 8. Lower air pressure sensor; 9. Temperature sensor; 10. Upper air pressure sensor; 11. Test chamber; 12. Vibration table cover; 13. Sealed cavity of the vibration table; 14. Moving coil; 15. Control unit. Detailed Implementation

[0044] The present invention will be further described below with reference to the embodiments shown in the accompanying drawings:

[0045] This invention provides a pressure equalization control system for a multi-integrated vibration test system, including an inlet valve, a vacuum pump, pipelines, a lower switch valve, an upper switch valve, a vibration table, a test chamber, a sensor system, and a control unit. The vibration table includes a transition platform, a moving coil, and a housing. The transition platform is connected to the moving coil by screws, and the moving coil and housing are connected by a seal, forming a sealed cavity within the vibration table. The test chamber is located above the transition platform and is connected to it by a seal. The test chamber contains a sealed cavity. The inlet of the lower switch valve is connected to the sealed cavity of the vibration table. The inlet of the upper switch valve is connected to the sealed cavity of the test chamber. The inlet valve is an electromagnetic proportional directional valve, with the valve opening positively correlated with the current. The vacuum pump is equipped with both high-speed and low-speed operation modes. The system includes a control unit; the pipeline has an upper port, a lower port, a left port, and a right port. The upper port is connected to the outlet of the upper switch valve, the lower port is connected to the vacuum pump, the left port is connected to the outlet of the air inlet valve, and the right port is connected to the outlet of the lower switch valve. The sensor system includes a temperature sensor, an upper air pressure sensor, and a lower air pressure sensor. The upper air pressure sensors are evenly distributed within the sealed cavity of the test chamber at the same height, and a total of four upper air pressure sensors are provided. The lower air pressure sensors are arranged within the sealed cavity of the vibration table support. The temperature sensor is arranged within the sealed cavity of the test chamber. The control unit is used to collect signals from the upper air pressure sensor, the lower air pressure sensor, and the temperature sensor, and to run the multi-integrated vibration test system air pressure equalization control method provided by this invention.

[0046] This invention also provides a method for air pressure equalization control of a multi-integrated vibration test system, comprising the following steps:

[0047] Step S1: Before the vibration test begins, the air pressure of the vibration test system is initially set, and the value of the i-th upper air pressure sensor is recorded as P. i Where: i = 1, 2, 3...m, m is the number of upper air pressure sensors, and the air pressure sensor closest to the upper switch valve is denoted as the first upper air pressure sensor; calculate the average value P of the m upper air pressure sensor values. 上 P 上 The calculation formula is P 上 = (P1+P2+P3+...+P) m ) / m; Let the rated speed of the vacuum pump be n. 额 High speed is n 高 Low speed is n 低 , where: n 高 and n 低 The expressions are n 高 =η 高 n 额 and n 低 =η 低 n 额η 高 and η 低 These are the high-speed coefficient and the low-speed coefficient, respectively, η 高 The value range is 0.7 to 0.8, η 低 The value range is 0.5 to 0.6;

[0048] Step S2: Set the vacuum pump to high speed to evacuate the sealed cavity of the test chamber and the sealed cavity of the vibration table. Record the desired air pressure required for the vibration test as P. Close the inlet valve and open the upper and lower switch valves. Record δ. P上 δ represents the allowable error value of the air pressure in the sealed cavity of the test chamber. P上 The value range is 0.1 Pa to 0.3 Pa, α is the pressure coefficient and α > 1, with a value range of 1.5 to 1.9. The value P1 of the first upper pressure sensor is collected in real time and the condition |P1 - αP| ≤ δ is determined in real time. P上 Whether it holds true, if |P1-αP|≤δ P上 If this condition is not met, the vacuum pump will continue to operate at high speed; if |P1-αP|≤δ P上 If successful, proceed to the next step.

[0049] Step S3: The vacuum pump is used at low speed to regulate the air pressure in the sealed cavity of the test chamber and the sealed cavity of the vibration table. Once the desired air pressure is reached in both cavities, proceed to the next step. The specific steps for regulating the air pressure in the sealed cavity of the test chamber and the sealed cavity of the vibration table using the vacuum pump at low speed are as follows:

[0050] Step S31: Set the vacuum pump to low speed operation and record δ. P下 δ represents the allowable error value of the air pressure in the sealed cavity of the vibration table. P下 The value range is 0.1 Pa to 0.3 Pa. The values ​​from m upper barometer sensors are collected in real time, and P is calculated based on the average value of the m upper barometer sensor values ​​obtained in step S1. 上 Real-time acquisition of barometric pressure sensor values ​​P 下 ;

[0051] Step S32: Based on the value P calculated in real time by the upper air pressure sensor 上 The value P collected in real time by the barometric pressure sensor 下 Compare and judge, if |PP 上 |>δ P上 And |PP 下 |>δ P下 If the upper and lower switching valves remain open, the vacuum pump continues to run at a low speed, and then proceed to the next step; if |PP 上 |≤δ P上 And |PP 下 |>δ P下If the upper switch valve is closed, the lower switch valve remains open, the vacuum pump continues to run at a low speed, and then proceed to the next step; if |PP 上 |>δ P上 And |PP 下 |≤δ P下 If the lower switch valve is closed, the upper switch valve remains open, the vacuum pump continues to run at a low speed, and then proceed to the next step; if |PP 上 |≤δ P上 And |PP 下 |≤δ P下 Proceed directly to the next step;

[0052] Step S33, Judgment Condition | PP 上 |≤δ P上 and |PP 下 |≤δ P下 Do they satisfy the conditions simultaneously? If so, |PP 上 |≤δ P上 And |PP 下 |≤δ P下 This indicates that the sealed cavity of the test chamber and the sealed cavity of the vibration table have reached the desired air pressure. Close the upper and lower switch valves and the vacuum pump. If the pressure is not met, |PP 上 |≤δ P上 And |PP 下 |≤δ P下 Then return to step S32;

[0053] Step S4: When conducting the temperature rise test under low pressure, pressure compensation for the temperature rise test should be performed simultaneously. First, calculate the temperature difference ΔT based on the temperature curve given in the temperature rise test. 升 Let the initial temperature of the temperature curve be T. 初 The temperature curve ends at temperature T. 末 ΔT 升 The calculation formula is ΔT 升 =T 末 -T 初 ;

[0054] Step S5: Determine ΔT 升 Does ΔT satisfy? 升 <λ 下 , where: λ 下 λ is the lower limit of the temperature difference threshold. 下 The value range is 100℃~200℃, if ΔT 升 ≥λ 下 If ΔT 升 <λ 下 To perform air pressure compensation in the sealed cavity of the test chamber under small temperature differences, execute steps S51 to S52, as follows:

[0055] Step S51: Real-time acquisition of temperature sensor value T, and determination of T≥T 初 +β 小 ΔT 升 Whether it is true or not, where: β 小 For a small temperature rise coefficient, β 小 The value ranges from 0.6 to 0.65. If T ≥ T 初 +β 小 ΔT 升 If this is not true, continue the heating experiment and repeat step S51; if T≥T 初 +β 小 ΔT 升 If successful, the upper switch valve will open, the vacuum pump will run at low speed, and the next step will be executed.

[0056] Step S52: Real-time acquisition of values ​​from m upper barometric pressure sensors and calculation of P based on the average value calculation formula of the m upper barometric pressure sensor values ​​in step S1. 上 And judge in real time |PP 上 |≤δ P上 Whether it is true or not, if |PP 上 |≤δ P上 If this is not the case, keep the upper switch valve open, the vacuum pump continues to run at low speed, and repeat step S52; if |PP 上 |≤δ P上 Establishment, closing the upper switch valve and vacuum pump, ending the temperature rise test pressure compensation;

[0057] Step S6: Determine ΔT 升 Does it satisfy λ? 下 ≤ΔT 升 <λ 上 , where: λ 上 λ represents the upper limit of the temperature difference threshold. 上 The value range is 500℃~600℃, if ΔT 升 ≥λ 上 If λ 下 ≤ΔT 升 <λ 上 To perform air pressure compensation in the sealed cavity of the test chamber under medium temperature difference, proceed with steps S61 to S63, as follows:

[0058] Step S61: Real-time acquisition of the temperature sensor value T, and record β. 中 For medium temperature rise coefficient, β 中 The value ranges from 0.4 to 0.45. Determine if T ≥ T. 初 +β 中 ΔT 升 Whether it holds true, if T≥T 初 +β 中ΔT 升 If this is not true, continue the heating experiment and repeat step S61; if T≥T 初 +β 中 ΔT 升 If successful, the upper switch valve will open, the vacuum pump will run at high speed, and the next step will be executed.

[0059] Step S62: Real-time acquisition of values ​​from m upper barometric pressure sensors and calculation of P based on the average value calculation formula of the m upper barometric pressure sensor values ​​in step S1. 上 , denote δ P δ represents the error value in converting vacuum pump speed to air pressure. P The value is greater than δ P上 δ P The value range is 1 Pa to 1.5 Pa, and it is judged in real time | PP 上 |≤δ P Whether it is true or not, if |PP 上 v≤δ P If this is not the case, keep the upper switch valve open, run the vacuum pump at high speed, and repeat step S62; if |PP 上 |≤δ P If successful, the upper switch valve remains open, the vacuum pump runs at low speed, and the next step is executed.

[0060] Step S63: Real-time acquisition of values ​​from m upper barometric pressure sensors and calculation of P based on the average value calculation formula of the m upper barometric pressure sensor values ​​in step S1. 上 And judge in real time |PP 上 |≤δ P上 Whether it is true or not, if |PP 上 |≤δ P上 If this is not the case, keep the upper switch valve open, the vacuum pump continues to run at low speed, and repeat step S63; if |PP 上 |≤δ P上 Establishment, closing the upper switch valve and vacuum pump, ending the temperature rise test pressure compensation;

[0061] Step S7: Perform air pressure compensation in the sealed cavity of the test chamber under large temperature difference, including the following steps:

[0062] Step S71: Real-time acquisition of the temperature sensor value T, and recording β 高 For a high temperature rise coefficient, β 高 The value ranges from 0.3 to 0.35. Determine if T ≥ T. 初 +β 高 ΔT 升 Whether it holds true, if T≥T 初 +β 高 ΔT 升If this is not true, continue the heating experiment and repeat step S71; if T≥T 初 +β 高 ΔT 升 If successful, proceed to the next step;

[0063] Step S72: Real-time acquisition of values ​​from m upper barometric pressure sensors and calculation of P based on the average value calculation formula of the m upper barometric pressure sensor values ​​in step S1. 上 And judge in real time |PP 上 v≤δ P Whether it is true or not, if |PP 上 |≤δ P If this is not the case, keep the upper switch valve open, run the vacuum pump at high speed, and repeat step S72; if |PP 上 v≤δ P If successful, the upper switch valve remains open, the vacuum pump runs at low speed, and the next step is executed.

[0064] Step S73: Real-time acquisition of values ​​from m upper barometer sensors and calculation of P based on the average value calculation formula of the m upper barometer sensor values ​​in step S1. 上 And judge in real time |PP 上 |≤δ P上 Whether it is true or not, if |PP 上 |≤δ P上 If this is not the case, keep the upper switch valve open, the vacuum pump continues to run at low speed, and repeat step S73; if |PP 上 |≤δ P上 Once established, close the upper switch valve and vacuum pump, and end the temperature rise test pressure compensation.

[0065] 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. Various changes that can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention are all within the protection scope of the claims of the present invention.

Claims

1. A multi-comprehensive vibration test system air pressure equalization control system, characterized in that, The utility model relates to a multi-comprehensive vibration test system, which comprises: a gas valve, a vacuum pump, a pipeline, a lower on-off valve, an upper on-off valve, a vibration table, a test box, a sensor system and a control unit; the vibration table comprises a transition table, a moving coil and a cover, the transition table is connected with the moving coil through screws, the moving coil and the cover are connected through a sealing element, and a closed cavity of the vibration table is formed between the moving coil and the cover through the sealing element; the test box is arranged above the transition table and is connected with the transition table through a sealing element, and a closed cavity is arranged in the test box; the inlet end of the lower on-off valve is connected with the closed cavity of the vibration table; the inlet end of the upper on-off valve is connected with the closed cavity of the test box; the gas valve is an electromagnetic proportional reversing valve, and the valve opening degree is positively correlated with the current size; the vacuum pump is provided with two gears of high speed and low speed; the pipeline is provided with an upper port, a lower port, a left side port and a right side port, the upper port is connected with the outlet end of the upper on-off valve, the lower port is connected with the vacuum pump, the left side port is connected with the outlet end of the gas valve, and the right side port is connected with the outlet end of the lower on-off valve; the sensor system comprises temperature sensors, upper air pressure sensors and lower air pressure sensors, the upper air pressure sensors are uniformly distributed in the closed cavity of the test box; the lower air pressure sensors are arranged in the closed cavity of the support part of the vibration table; and the temperature sensors are arranged in the closed cavity of the test box; the control unit is used for collecting signals of the upper air pressure sensors, the lower air pressure sensors and the temperature sensors and running a multi-comprehensive vibration test system air pressure balance control method.

2. The air pressure equalization control system for a multi-integrated vibration test system according to claim 1, characterized in that, The upper air pressure sensors are uniformly distributed at the same height in the closed cavity of the test box.

3. The air pressure equalization control system of a multi-comprehensive vibration test system according to claim 1, wherein, The number of the upper air pressure sensors is two or four.

4. The air pressure equalization control system of a multi-comprehensive vibration test system according to claim 1, wherein, The multi-comprehensive vibration test system air pressure balance control method comprises the following steps: Step S1: Before the vibration test begins, the air pressure of the vibration test system is initially set, and the value of the i-th upper air pressure sensor is recorded as P. i Where: i = 1, 2, 3...m, m is the number of upper air pressure sensors, and the air pressure sensor closest to the upper switch valve is denoted as the first upper air pressure sensor; calculate the average value P of the m upper air pressure sensor values. 上 P 上 The calculation formula is P 上 = (P1+P2+P3+...+P) m ) / m; Let the rated speed of the vacuum pump be n. 额 High speed is n 高 Low speed is n 低 , where: n 高 and n 低 The expressions are n 高 =η 高 n 额 and n 低 =η 低 n 额 η 高 and η 低 These are the high-speed coefficient and the low-speed coefficient, respectively. Step S2, set the vacuum pump to high speed operation to pump the test chamber and the vibration table closed cavity, record the desired pressure P required for the vibration test, close the inlet valve, open the upper and lower switch valve, record δ P上 P1-αP|≤δ P上 is not established, the vacuum pump continues to run at high speed; if |P1-αP|≤δ P上 is established, the next step is executed. P上 is established, the next step is executed. in step S3, the vacuum pump uses low speed to adjust the air pressure of the closed cavities of the test box and the vibration table, and when the closed cavities reach the expected air pressure, the next operation is performed; Step S4, when the temperature rising test under low pressure is performed, the temperature rising test pressure compensation is simultaneously performed, first, according to the given temperature curve of the temperature rising test, the temperature difference ΔT of the temperature curve is calculated 升 , the initial temperature of the temperature curve is T 初 , the end temperature of the temperature curve is T 末 , and the calculation formula of ΔT 升 is ΔT 升 =T 末 -T 初 ; Step S5, judging ΔT 升 whether ΔT is satisfied 升 <λ 下 wherein: λ 下 is the lower limit of temperature difference threshold, if ΔT 升 ≥ λ 下 , then step S6 is executed; if ΔT 升 < λ 下 , the test chamber closed cavity air pressure compensation under small temperature difference is carried out, and steps S51-S52 are executed, the specific steps are as follows: Step S51, collect temperature sensor value T in real time, and judge whether T≥T 初 +β 小 ΔT 升 is true, wherein:β 小 is a small temperature coefficient, if T≥T 初 +β 小 ΔT 升 is not true, continue to carry out the temperature rise experiment, and repeat step S51; if T≥T 初 +β 小 ΔT 升 is true, then open the upper switch valve, the vacuum pump runs at low speed, and the next step is executed. Step S52, real-time collection of m upper air pressure sensor values and calculation of P according to the average value calculation formula of m upper air pressure sensor values in step S1 上 , and real-time judgment of whether |P-P 上 |≤δ P上 is established, if |P-P 上 |≤δ P上 is not established, the upper switch valve is kept open, the vacuum pump continues to run at low speed, and step S52 is repeatedly executed; if |P-P 上 |≤δ P上 is established, the upper switch valve and the vacuum pump are closed, and the temperature rising test pressure compensation is ended. Step S6, judging ΔT 升 whether λ 下 ≤ ΔT 升 < λ 上 , wherein: λ 上 is the upper limit of temperature difference threshold, if ΔT 升 ≥ λ 上 , then execute step S7; if λ 下 ≤ ΔT 升 < λ 上 , proceed to the test chamber closed cavity pressure compensation under the medium temperature difference, then execute steps S61-S63, the specific steps are as follows: Step S61, collect the value T of the temperature sensor in real time, and record β 中 is the medium temperature coefficient, and T≥T 初 +β 中 ΔT 升 is established, if T≥T 初 +β 中 ΔT 升 is not established, continue to perform the temperature rising experiment, and repeat step S61; if T≥T 初 +β 中 ΔT 升 is established, open the upper on-off valve, the vacuum pump runs at high speed, and the next step is performed. Step S62, real-time acquisition of m upper air pressure sensor values and calculation of P according to the average value calculation formula of m upper air pressure sensor values in step S1 上 , record δ P as the vacuum pump speed conversion air pressure error value, the value of δ P is greater than δ P上 , real-time judgment whether |P-P 上 |≤δ P , if |P-P 上 |≤δ P is not established, the upper on-off valve is kept open, the vacuum pump is operated at high speed, and step S62 is repeatedly executed; if |P-P 上 |≤δ P is established, the upper on-off valve is kept open, the vacuum pump is operated at low speed, and the next step is executed; Step S63, real-time acquisition of m upper air pressure sensor values and calculation of P according to the average value calculation formula of m upper air pressure sensor values in step S1 上 , and real-time judgment of whether |P-P 上 |≤δ P上 is established, if |P-P 上 |≤δ P上 is not established, the upper on-off valve is kept open, the vacuum pump continues to run at low speed, and step S63 is repeatedly executed; if |P-P 上 |≤δ P上 is established, the upper on-off valve and the vacuum pump are closed, and the temperature rising test pressure compensation is ended. in step S7, the air pressure of the closed cavity of the test box under a large temperature difference is compensated, and the steps include: Step S71, collect the value T of the temperature sensor in real time, and record β 高 For high temperature coefficient, judge whether T≥T 初 +β 高 ΔT 升 is true, if T≥T 初 +β 高 ΔT 升 is not true, continue to carry out the temperature rising experiment, and repeat step S71; if T≥T 初 +β 高 ΔT 升 is true, then execute the next step; Step S72, real-time acquisition of m upper air pressure sensor values and calculation of P according to the average value calculation formula of m upper air pressure sensor values in step S1 上 , and real-time judgment of whether |P-P 上 |≤δ P is established, if |P-P 上 |≤δ P is not established, keep the upper switch valve open, the vacuum pump runs at high speed, and step S72 is repeatedly executed; if |P-P 上 |≤δ P is established, keep the upper switch valve open, the vacuum pump runs at low speed, and the next step is executed. Step S73, real-time acquisition of m upper air pressure sensor values and calculation of P according to the average value calculation formula of m upper air pressure sensor values in step S1 上 , and real-time judgment of whether |P-P 上 |≤δ P上 is established, if |P-P 上 |≤δ P上 is not established, the upper on-off valve is kept open, the vacuum pump continues to run at a low speed, and step S73 is repeatedly executed; if |P-P 上 |≤δ P上 is established, the upper on-off valve and the vacuum pump are closed, and the temperature rising test pressure compensation is ended.

5. The method of claim 4, wherein, in step S3, the specific steps that the vacuum pump uses low speed to adjust the air pressure of the closed cavities of the test box and the vibration table are as follows: Step S31, set the vacuum pump to low speed operation, record δ P下 The vibration table closed cavity gas pressure allowable error value, real-time acquisition of m upper air pressure sensor values and according to the average value of m upper air pressure sensor values in step S1 calculation formula calculation P 上 , real-time acquisition of lower air pressure sensor values P 下 ; Step S32: Based on the value P calculated in real time by the upper air pressure sensor 上 The value P collected in real time by the barometric pressure sensor 下 Compare and judge, if |PP 上 |>δ P上 And |PP 下 |>δ P下 If the upper and lower switching valves remain open, the vacuum pump continues to run at a low speed, and then proceed to the next step; if |PP 上 |≤δ P上 And |PP 下 |>δ P下 If the upper switch valve is closed, the lower switch valve remains open, the vacuum pump continues to run at a low speed, and then proceed to the next step; if |PP 上 |>δ P上 And |PP 下 |≤δ P下 If the lower switch valve is closed, the upper switch valve remains open, the vacuum pump continues to run at a low speed, and then proceed to the next step; if |PP 上 |≤δ P上 And |PP 下 |≤δ P下 Proceed directly to the next step; Step S33, judging condition |P-P 上 |≤δ P上 and |P-P 下 |≤δ P下 are satisfied, if |P-P 上 |≤δ P上 and |P-P 下 |≤δ P下 , it indicates that the test chamber closed cavity and the vibration table closed cavity reach the expected pressure, and the upper switch valve, the lower switch valve and the vacuum pump are closed; if |P-P 上 |≤δ P上 and |P-P 下 |≤δ P下 are not satisfied, return to step S32.

6. The method of claim 4, wherein the pressure equalization control is performed by a plurality of pressure equalization valves. High gear speed coefficient η 高 The value range is 0.7-0.8, low gear speed coefficient η 低 The value range is 0.5-0.6, and the air pressure coefficient α value range is 1.5-1.

9.

7. The method of claim 4, wherein the pressure equalization control is performed by a plurality of pressure equalization valves. The allowable error value δ of the air pressure in the closed cavity of the test chamber P上 The value range is 0.1 Pa-0.3 Pa, and the error value δ of the air pressure converted by the rotation speed of the vacuum pump P The value range is 1 Pa-1.5 Pa.

8. The method of claim 4, wherein, Temperature difference threshold lower limit λ 下 Temperature difference threshold upper limit λ 上 Temperature difference threshold upper limit λ 9. The method of claim 4, wherein the pressure equalization control is performed by a plurality of pressure equalization valves. Low temperature coefficient β 小 Medium temperature coefficient β 中 High temperature coefficient β 高 Medium temperature coefficient β 10. The method of claim 5, wherein, The allowable error value δ of the air pressure in the sealed cavity of the vibration table P下 The value range is 0.1 Pa-0.3 Pa.

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