Moving-coil equilibrium control method for low-pressure horizontal vibration test, and apparatus

Abstract

Disclosed in the present invention are a moving-coil equilibrium control method for a low-pressure horizontal vibration test, and an apparatus. The method comprises: detecting the displacement of a moving coil to obtain the velocity of a moving coil; and on the basis of the magnitude of the velocity of the moving coil, using a corresponding linear control function to adjust the opening degree of a vacuum solenoid valve or an air-source solenoid valve, such that when the moving coil reaches an equilibrium position, the velocity of the moving coil is zero, thereby enabling the moving coil to quickly and smoothly return to the equilibrium position after exceeding an equilibrium position threshold. The moving-coil equilibrium control method for a low-pressure horizontal vibration test in the present invention solves the problem of it being difficult for a moving coil to accurately reach an equilibrium position, enables the moving coil to quickly and smoothly return to the equilibrium position after exceeding an equilibrium position threshold, and effectively ensures the control accuracy during the adjustment of the position of the moving coil.

Description

A method and apparatus for controlling the dynamic coil balance in a horizontal low-pressure vibration test Technical Field

[0001] This invention relates to the field of vibration table technology, specifically to a method and device for controlling the dynamic coil balance in a horizontal low-pressure vibration test. Background Technology

[0002] Vibration tables are common vibration testing devices, widely used in aviation, aerospace, power supply batteries, electrical engineering, electronics, instrumentation, medical and other fields. Most existing vibration tables are used in normal pressure environments. However, vibration tests sometimes need to simulate actual working conditions, so a low-pressure environment is created in a sealed chamber to conduct the vibration test in a low-pressure environment.

[0003] Currently, there are several patents in China describing methods for controlling horizontal low-pressure vibration. Existing methods control one or both of the vacuum solenoid valve and the gas source solenoid valve to open or close, maintaining the balance of the moving coil by adjusting the opening time ratio of the vacuum solenoid valve and the gas source solenoid valve. However, the following problems still exist in this control method:

[0004] 1. Existing horizontal low-pressure vibration control methods use one of the vacuum solenoid valves or the gas source solenoid valve to open and release gas on the vacuum test vibration table during the process of maintaining the balance of the moving coil, so that the air pressure of the negative pressure test chamber and the vacuum test vibration table can be restored to the balance point. However, before the moving coil is balanced, the air pressure difference caused by the vibration test causes the moving coil to exceed the balance position threshold. When the air pressure of the vacuum test vibration table and the negative pressure test chamber is balanced, the moving coil is difficult to return to the balance position.

[0005] 2. In the existing horizontal low-pressure vibration control method, the vacuum solenoid valve and the gas source solenoid valve are charged and discharged at a fixed degree during the process of maintaining the balance of the moving coil, and the opening time always starts from the shortest opening time setting. The moving coil moves slowly, resulting in the moving coil taking too long to return to the balance position.

[0006] 3. The existing horizontal low-pressure vibration control method always uses the method of increasing the opening time of the solenoid valve every second during each adjustment to control the gas source solenoid valve and the vacuum solenoid valve in order to maintain the balance of the moving coil. It does not adjust the solenoid valve control strategy according to the position of the moving coil, resulting in poor test control accuracy. Summary of the Invention

[0007] To address the aforementioned technical problems, this invention proposes a method and apparatus for controlling the dynamic coil balance in a horizontal low-pressure vibration test, thereby solving the problem that existing low-pressure vibration test apparatuses struggle to maintain the dynamic coil's positional balance and that their control methods are relatively simple.

[0008] A method for controlling the dynamic coil balance in a horizontal low-pressure vibration test includes the following steps:

[0009] Step S1: Place the specimen on the specimen mounting platform, detect the initial position of the moving coil using a displacement sensor, create negative pressure inside the negative pressure test chamber and the vibration table to stabilize the position of the moving coil; start the vacuum vibration test table to drive the specimen to vibrate on the specimen mounting platform.

[0010] Step S2: Determine whether the moving coil exceeds the moving coil equilibrium position threshold. The specific steps are as follows: Let the displacement of the moving coil before adjusting its position be Δd. Δd is positive when the moving coil moves towards the negative pressure test chamber, and negative when it moves towards the vibration table. The displacement sensor detects the moving coil displacement Δd in real time and determines whether |Δd|≤δ D , where: δ D The threshold for the equilibrium position of the moving coil; if |Δd|≤δ is not satisfied. D Then proceed to step S3; if |Δd|≤δ D If so, then repeat step S2;

[0011] Step S3: The moving coil velocity is calculated by detecting the moving coil displacement during the adjustment process using a displacement sensor. A linear control function is then used to adjust the opening of the vacuum solenoid valve connecting the second vacuum pump and the vibration table, or to adjust the opening of the gas source solenoid valve connecting the high-pressure gas source and the vibration table, so that the moving coil velocity is zero when it reaches the equilibrium position. The specific steps are as follows:

[0012] If Δd>δ D This indicates that the moving coil moves towards the negative pressure test chamber, thus opening the vacuum solenoid valve. The initial opening degree of the vacuum solenoid valve is K. z Then, based on the speed of the moving coil, the opening of the vacuum solenoid valve is adjusted using a corresponding linear control function to make the moving coil quickly approach the equilibrium position.

[0013] If Δd < -δ D This indicates that the moving coil moves towards the vibrating table body, thus opening the air source solenoid valve. The initial opening degree of the air source solenoid valve is K. q Then, based on the speed of the moving coil, the opening of the air source solenoid valve is adjusted using a corresponding linear control function to make the moving coil quickly approach the equilibrium position.

[0014] Step S4: Complete the test and remove the specimen.

[0015] Beneficial effects: The moving coil balance control method for horizontal low-pressure vibration test proposed in this invention obtains the moving coil velocity by detecting the moving coil displacement, and adjusts the opening of the vacuum solenoid valve or the air source solenoid valve so that the moving coil velocity is zero when it reaches the equilibrium position, so that the moving coil can quickly and smoothly return to the equilibrium position after exceeding the equilibrium position threshold.

[0016] In one optional implementation, step S3 adjusts the opening of the vacuum solenoid valve or the gas source solenoid valve according to the position of the moving coil, and different control methods are adopted according to the different distances of the moving coil from the equilibrium position, specifically:

[0017] When 0≤d i When <μ1D, the opening of the vacuum solenoid valve or the gas source solenoid valve is adjusted according to the speed of the moving coil using a linear control function with the first slope, so that the moving coil quickly approaches the equilibrium position.

[0018] When μ1D≤d i When the speed is <μ2D, the opening of the vacuum solenoid valve or the gas source solenoid valve is adjusted according to the speed of the moving coil using a linear control function with the second slope, so that the moving coil moves smoothly.

[0019] In satisfying d i When =μ2D, the opening degree-displacement control function is used to adjust the opening degree of the vacuum solenoid valve or the gas source solenoid valve, wherein the first slope is greater than the second slope;

[0020] d i For the tth i The displacement of the moving coil at any given time is given by μ1, which is the first distance coefficient, ranging from 0.5 to 0.6; and μ2, which is the second distance coefficient, ranging from 0.8 to 0.9.

[0021] D is the distance between the initial adjustment position and the initial position of the moving coil;

[0022] i = 1, 2, 3…n, where n is the number of samples; the position where the moving coil is furthest from the initial position is the initial adjustment position, at which point d i =0.

[0023] Beneficial effects: The moving coil balance control method for horizontal low-pressure vibration tests proposed in this invention employs different control methods depending on the distance between the moving coil and the equilibrium position during the adjustment process. When the distance is relatively far, a linear control function with a large slope is used to adjust the opening of the vacuum solenoid valve or the air source solenoid valve to make the moving coil quickly approach the equilibrium position. When the distance is moderate, a linear control function with a small slope is used to adjust the opening of the vacuum solenoid valve or the air source solenoid valve to make the moving coil move smoothly. When the distance is relatively close, a displacement-related control function is used to adjust the opening of the vacuum solenoid valve or the air source solenoid valve, thereby effectively ensuring the control accuracy during the adjustment process of the moving coil position.

[0024] In one alternative implementation, if 0 ≤ d i <μ1D, i.e., the tth i Displacement d of the moving coil at any moment i When the distance is the first distance, execute steps S31 to S32 to calculate the moving circle speed;

[0025] Step S31: The displacement sensor collects data in real time at time t.i Displacement d of the moving coil at any moment i The velocity v of the moving coil is calculated. i And determine in real time whether λ is satisfied. vx ≤v i ≤λ vs , where: λ vx λ is the lower limit of the first distance moving coil velocity threshold; vs The upper limit of the first distance moving coil speed threshold; if λ is not satisfied vx ≤v i ≤λ vs Then adjust the opening of the vacuum solenoid valve or the gas source solenoid valve, specifically:

[0026] When adjusting the opening of the vacuum solenoid valve

[0027] When adjusting the opening of the air source solenoid valve And repeat step S31, where: K z K represents the initial opening degree of the vacuum solenoid valve. q ε represents the initial opening degree of the air source solenoid valve. K1 This is the control coefficient for the opening degree of the first distance solenoid valve; The average value of the first distance speed threshold. The calculation formula is (λ) vx +λ vs ) / 2; if λ is satisfied vs ≤v i ≤λ vs If the opening of the solenoid valve remains unchanged, then step S32 is executed.

[0028] Step S32: The displacement sensor collects data in real time at time t. i Displacement d of the moving coil at any moment i And determine whether μ1D≤d is satisfied. i <μ2D, if μ1D≤d i If μ<2D, then return to step S31; if μ<1D≤d i If <μ2D, then proceed to step S33;

[0029] Step S33: If μ1D≤d i <μ2D, i.e., the t-th i Displacement d of the moving coil at any moment i When the distance is the second distance, the control steps are as follows: The displacement sensor collects the data at the t-th distance in real time. i Displacement d of the moving coil at any moment i The velocity v of the moving coil is calculated. i And determine in real time whether κ is satisfied. vx ≤v i ≤κ vs , where: κvx This is the lower limit of the second distance moving coil speed threshold;

[0030] κ vs The upper limit of the second distance moving coil speed threshold; κ vs <λ vs If v i Not satisfied with κ vx ≤v i ≤κ vs Then adjust the opening of the vacuum solenoid valve or the gas source solenoid valve. And repeat step S5, where: K2 is the opening degree of the vacuum solenoid valve or the gas source solenoid valve when the moving coil just enters the second distance stage; ε K2 ε is the control coefficient for the opening degree of the second distance vacuum solenoid valve or gas source solenoid valve. K2 <ε K1 ; The average value of the second distance speed threshold. The calculation formula is (κ) vx +κ vs ) / 2; if κ is satisfied vx ≤v i ≤κ vs If the vacuum solenoid valve or the gas source solenoid valve remains open, then proceed to step S34.

[0031] Step S34: The displacement sensor collects data in real time at time t. i Displacement d of the moving coil at any moment i And determine whether μ2D≤d is satisfied. i ≤D; if μ2D≤d is not satisfied i If μ2D ≤ d, then return to step S33; if μ2D ≤ d, then return to step S33. i If ≤D, then proceed to step S35;

[0032] Step S35, when d is satisfied i =μ2D, that is, the t-th i Displacement d of the moving coil at any moment i For the third distance, the specific control steps are as follows: close the vacuum solenoid valve or the gas source solenoid valve, and the displacement sensor collects the data at the t-th distance in real time. i Displacement d of the moving coil at any moment i The velocity v of the moving coil is calculated. i When v i When = 0, determine whether d is satisfied. i =D, if d is not satisfied i =D, then execute step S36; if d is satisfied i =D, then the vibration test ends;

[0033] Step S36, if d is satisfied i If >D, then the air source solenoid valve is opened, and the opening degree of the air source solenoid valve is K = Kq [d i -(d0+D) / 2], where: d0 is the moving coil velocity v in step S35 i =0 when the moving coil displacement is reached; when K = 0, return to step S35; if d is satisfied i If <D, then the vacuum solenoid valve is opened, and the opening degree of the vacuum solenoid valve is K = K z [(d0+D) / 2-d i When K = 0, return to step S35.

[0034] Beneficial effects: By further subdividing the moving coil displacement stages and specifically adjusting the opening of the vacuum solenoid valve or air source solenoid valve and the moving coil speed, and setting corresponding thresholds and control coefficients at different distance stages, the motion state of the moving coil at each stage during its return to the equilibrium position is more controllable. Dynamically adjusting the opening of the vacuum solenoid valve or air source solenoid valve based on the moving coil speed and displacement prevents the moving coil from overshooting the equilibrium position or experiencing large fluctuations due to excessive speed or improper control when approaching it. This effectively improves the accuracy and stability of the moving coil's return to the equilibrium position, thereby enhancing the reliability of the entire horizontal low-pressure vibration test device.

[0035] In one alternative implementation, formula v is used. i =(d i -d i-1 ) / (t i -t i-1 Calculate the velocity of the moving coil, where: v i For the t-th moving circle i Moment velocity, d i For the tth i The displacement of the moving coil at any given time, d i-1 For the tth i-1 Displacement d of the moving coil at any moment i-1 Let v1 = 0 at time t1.

[0036] In one optional implementation, the moving coil balance position threshold δ D The value range is 0.5mm to 1.0mm.

[0037] Beneficial effects: A moving coil balance position threshold of 0.5mm to 1.0mm can effectively reduce the frequent triggering of the adjustment mechanism due to small displacement fluctuations caused by moving coil vibration, while ensuring the balance accuracy of the moving coil. This avoids over-adjustment of the system, reduces system energy consumption and equipment wear, and ensures timely and effective control when the moving coil displacement exceeds the reasonable range, thus maintaining the stable operation of the test device.

[0038] In one optional implementation, the initial opening degree K of the gas source solenoid valve is... q The value range is 0.4 to 0.6, and the initial opening degree K of the vacuum solenoid valve is...z The value range is 0.4 to 0.6.

[0039] Beneficial effects: The initial opening of the gas source solenoid valve and the vacuum solenoid valve within this range can avoid the drastic changes in air pressure caused by excessively large initial openings, which would make the moving coil unstable, and can also prevent the moving coil from adjusting too slowly by excessively small initial openings. This helps to accelerate the movement of the moving coil towards the equilibrium position while ensuring the smooth movement of the moving coil, thereby improving the adjustment efficiency and system response performance.

[0040] In one optional implementation, the first distance to the lower limit of the moving coil speed threshold λ vx The value range is 8mm / s to 9mm / s; the upper limit of the first distance moving coil speed threshold λ vs The value range is 10 mm / s to 11 mm / s;

[0041] The second distance to the lower limit of the moving coil speed threshold κ vx The value range is 7mm / s to 8mm / s; the upper limit of the second distance moving coil speed threshold κ vs The value range is 8 mm / s to 9 mm / s.

[0042] Beneficial effects: These threshold ranges are set based on the motion characteristics and control requirements of the moving coil at different displacement stages, accurately defining the reasonable range of the moving coil speed. Timely adjustment of the solenoid valve opening when the moving coil speed exceeds the corresponding threshold effectively prevents the moving coil from deviating from the expected trajectory due to excessive speed or slowness, ensuring the motion stability and adjustment accuracy of the moving coil at different stages, and guaranteeing the reliability of the entire test process.

[0043] In one optional implementation, the opening control coefficient ε of the first distance solenoid valve K1 The value range is 0.06 to 0.07; the second distance solenoid valve opening control coefficient ε K2 The value range is 0.03 to 0.04.

[0044] Beneficial effects: When the distance is far, using a larger control coefficient can make the solenoid valve opening have a more obvious regulating effect on the displacement change of the moving coil, and quickly close the distance between the moving coil and the equilibrium position; when the distance is close, using a smaller control coefficient can achieve fine adjustment of the solenoid valve opening, avoiding overshoot or instability of the moving coil due to excessive adjustment range, thereby improving the control accuracy and stability of the entire moving coil position adjustment process.

[0045] This invention further discloses a horizontal low-pressure vibration test device, using the aforementioned horizontal low-pressure vibration test moving coil balance control method, including a negative pressure test chamber, a vacuum vibration test bench, and a control unit. The negative pressure test chamber includes a negative pressure chamber body, a first vacuum pump for generating negative pressure in the negative pressure chamber body, a support platform protruding from the bottom wall into the negative pressure chamber body, a specimen mounting surface slidably disposed on the support platform, and a connecting member connecting the specimen mounting surface and the moving coil.

[0046] The vacuum vibration test bench includes a vibration table body, a moving coil connected to the vibration table body to output vibration, a second vacuum pump connected to the vibration table body, a high-pressure gas source connected to the vibration table body, and a displacement sensor for detecting the position of the moving coil.

[0047] It also includes a vacuum solenoid valve connecting the second vacuum pump to the vibration table body, a gas source solenoid valve connecting the high-pressure gas source to the vibration table body, a back pressure solenoid valve for connecting the negative pressure box body and the outside air, and a negative pressure solenoid valve for controlling the on / off state of the first vacuum pump.

[0048] The signal input terminal of the control unit is connected to the displacement sensor, and the signal output terminal is connected to the vacuum solenoid valve, the gas source solenoid valve, the back pressure solenoid valve, and the negative pressure solenoid valve.

[0049] In one optional embodiment, both the vacuum solenoid valve and the gas source solenoid valve are proportional solenoid valves.

[0050] In summary, the moving coil balance control method for horizontal low-pressure vibration tests proposed in this invention solves the problem that the moving coil is difficult to accurately reach the equilibrium position, allowing the moving coil to quickly and smoothly return to the equilibrium position after exceeding the equilibrium position threshold, effectively ensuring the control accuracy during the adjustment of the moving coil position. Attached Figure Description

[0051] Figure 1 is a schematic diagram of the structural principle of the present invention;

[0052] Figure 2 is a control flowchart of the present invention;

[0053] Figure 3 is a flowchart of the moving coil position adjustment control.

[0054] Explanation of reference numerals in the attached figures:

[0055] 1. Second vacuum pump; 2. Vibration table body; 3. Vacuum solenoid valve; 4. First vacuum pump; 5. Negative pressure solenoid valve; 6. Negative pressure test chamber; 7. High-pressure gas source; 8. Gas source solenoid valve; 9. Moving coil; 10. Connecting parts; 11. Specimen mounting platform; 12. Support table. Detailed Implementation

[0056] The present invention will be further described below with reference to the embodiments in the accompanying drawings, so that those skilled in the art can better understand and implement the present invention, but the embodiments are not intended to limit the present invention.

[0057] As shown in Figure 2, the present invention provides a method for controlling the dynamic coil balance in a horizontal low-pressure vibration test, comprising the following steps:

[0058] Step S1: Place the specimen on the specimen mounting platform, detect the initial position of the moving coil using a displacement sensor, create negative pressure inside the negative pressure test chamber and the vibration table to stabilize the position of the moving coil; start the vacuum vibration test table to drive the specimen to vibrate on the specimen mounting platform.

[0059] Step S2: Determine whether the moving coil exceeds the moving coil equilibrium position threshold. The specific steps are as follows: Let the displacement of the moving coil before adjusting its position be Δd. Δd is positive when the moving coil moves towards the negative pressure test chamber, and negative when it moves towards the vibration table. The displacement sensor detects the moving coil displacement Δd in real time and determines whether |Δd|≤δ D , where: δ D The threshold for the equilibrium position of the moving coil; if |Δd|≤δ is not satisfied. D Then proceed to step S3; if |Δd|≤δ D If so, then repeat step S2;

[0060] Step S3: The moving coil velocity is calculated by detecting the moving coil displacement during the adjustment process using a displacement sensor. A linear control function is then used to adjust the opening of the vacuum solenoid valve 3 connecting the second vacuum pump 1 and the vibration table 2, or to adjust the opening of the gas source solenoid valve 8 connecting the high-pressure gas source 7 and the vibration table 2, so that the moving coil velocity is zero when it reaches the equilibrium position. The specific steps are as follows:

[0061] If Δd>δ D This indicates that the moving coil moves towards the negative pressure test chamber, thus opening the vacuum solenoid valve. The initial opening degree of the vacuum solenoid valve is K. z Then, based on the speed of the moving coil, the opening of the vacuum solenoid valve is adjusted using a corresponding linear control function to make the moving coil quickly approach the equilibrium position.

[0062] If Δd < -δ D This indicates that the moving coil moves towards the vibrating table body, thus opening the air source solenoid valve. The initial opening degree of the air source solenoid valve is K. q Then, based on the speed of the moving coil, the opening of the air source solenoid valve is adjusted using a corresponding linear control function to make the moving coil quickly approach the equilibrium position.

[0063] Step S4: Complete the test and remove the specimen.

[0064] This invention discloses a method for controlling the dynamic coil balance in a horizontal low-pressure vibration test. The method obtains the dynamic coil velocity by detecting the dynamic coil displacement, and adjusts the opening of the vacuum solenoid valve or the gas source solenoid valve so that the dynamic coil velocity is zero when it reaches the equilibrium position, allowing the dynamic coil to quickly and smoothly return to the equilibrium position after exceeding the equilibrium position threshold.

[0065] In one optional implementation, step S3 adjusts the opening of the vacuum solenoid valve or the gas source solenoid valve according to the position of the moving coil, and different control methods are adopted according to the different distances of the moving coil from the equilibrium position, specifically:

[0066] When 0≤d i <μ1 D At that time, the opening of the vacuum solenoid valve or the gas source solenoid valve is adjusted according to the speed of the moving coil using a linear control function with the first slope, so that the moving coil quickly approaches the equilibrium position.

[0067] When μ1D≤d i <μ2 D At the same time, the opening of the vacuum solenoid valve or the gas source solenoid valve is adjusted according to the speed of the moving coil using a linear control function with the second slope, so that the moving coil moves smoothly.

[0068] In satisfying d i When =μ2D, the opening degree-displacement control function is used to adjust the opening degree of the vacuum solenoid valve or the gas source solenoid valve, wherein the first slope is greater than the second slope;

[0069] d i For the tth i The displacement of the moving coil at any given time is given by μ1, which is the first distance coefficient, ranging from 0.5 to 0.6; and μ2, which is the second distance coefficient, ranging from 0.8 to 0.9.

[0070] D is the distance between the initial adjustment position and the initial position of the moving coil;

[0071] i = 1, 2, 3…n, where n is the number of samples; the position where the moving coil is furthest from the initial position is the initial adjustment position, at which point d i =0.

[0072] The proposed method for controlling the dynamic coil balance in horizontal low-pressure vibration tests employs different control methods depending on the distance between the dynamic coil and the equilibrium position during the adjustment process. When the distance is relatively far, a linear control function with a large slope is used to adjust the opening of the vacuum solenoid valve or the air source solenoid valve to make the dynamic coil quickly approach the equilibrium position. When the distance is moderate, a linear control function with a small slope is used to adjust the opening of the vacuum solenoid valve or the air source solenoid valve to make the dynamic coil move smoothly. When the distance is relatively close, a displacement-related control function is used to adjust the opening of the vacuum solenoid valve or the air source solenoid valve, thereby effectively ensuring the control accuracy during the adjustment process of the dynamic coil position.

[0073] In one alternative implementation, if 0 ≤ d i <μ1D, i.e., the tth i Displacement d of the moving coil at any moment i When the distance is the first distance, execute steps S31 to S32 to calculate the moving circle speed;

[0074] Step S31: The displacement sensor collects data in real time at time t. i Displacement d of the moving coil at any moment i The velocity v of the moving coil is calculated. i And determine in real time whether λ is satisfied. vx ≤v i ≤λ vs , where: λ vx λ is the lower limit of the first distance moving coil velocity threshold; vs The upper limit of the first distance moving coil speed threshold; if λ is not satisfied vx ≤v i ≤λ vs Then adjust the opening of the vacuum solenoid valve or the gas source solenoid valve, specifically:

[0075] When adjusting the opening of the vacuum solenoid valve

[0076] When adjusting the opening of the air source solenoid valve And repeat step S31, where: K z K represents the initial opening degree of the vacuum solenoid valve. q ε represents the initial opening degree of the air source solenoid valve. K1 This is the control coefficient for the opening degree of the first distance solenoid valve; The average value of the first distance speed threshold. The calculation formula is (λ) vx +λ vs ) / 2; if λ is satisfied vx ≤v i ≤λ vs If the opening of the solenoid valve remains unchanged, then step S32 is executed.

[0077] Step S32: The displacement sensor collects data in real time at time t. i Displacement d of the moving coil at any moment i And determine whether μ1D≤d is satisfied. i <μ2D, if μ1D≤d i If μ<2D, then return to step S31; if μ<1D≤d i If <μ2D, then proceed to step S33;

[0078] Step S33: If μ1D≤d i <μ2D, i.e., the t-th i Displacement d of the moving coil at any moment iWhen the distance is the second distance, the control steps are as follows: The displacement sensor collects the data at the t-th distance in real time. i Displacement d of the moving coil at any moment i The velocity v of the moving coil is calculated. i And determine in real time whether κ is satisfied. vx ≤v i ≤κ vs , where: κ vx This is the lower limit of the second distance moving coil speed threshold;

[0079] κ vs The upper limit of the second distance moving coil speed threshold; κ vs <λ vs If v i Not satisfied with κ vx ≤v i ≤κ vs Then adjust the opening of the vacuum solenoid valve or the gas source solenoid valve. And repeat step S5, where: K2 is the opening degree of the vacuum solenoid valve or the gas source solenoid valve when the moving coil just enters the second distance stage; ε K2 ε is the control coefficient for the opening degree of the second distance vacuum solenoid valve or gas source solenoid valve. K2 <ε K1 ; The average value of the second distance speed threshold. The calculation formula is (κ) vx +κ vs ) / 2; if κ is satisfied vx ≤v i ≤κ vs If the vacuum solenoid valve or the gas source solenoid valve remains open, then proceed to step S34.

[0080] Step S34: The displacement sensor collects data in real time at time t. i Displacement d of the moving coil at any moment i And determine whether μ2D≤d is satisfied. i ≤D; if μ2D≤d is not satisfied i If μ2D ≤ d, then return to step S33; if μ2D ≤ d, then return to step S33. i If ≤D, then proceed to step S35;

[0081] Step S35, when d is satisfied i =μ2D, that is, the t-th i Displacement d of the moving coil at any moment i For the third distance, the specific control steps are as follows: close the vacuum solenoid valve or the gas source solenoid valve, and the displacement sensor collects the data at the t-th distance in real time. i Displacement d of the moving coil at any moment i The velocity v of the moving coil is calculated. i When v i When = 0, determine whether d is satisfied.i =D, if d is not satisfied i =D, then execute step S36; if d is satisfied i =D, then the vibration test ends;

[0082] Step S36, if d is satisfied i If >D, then the air source solenoid valve is opened, and the opening degree of the air source solenoid valve is K = K q [d i -(d0+D) / 2], where: d0 is the moving coil velocity v in step S35 i =0 when the moving coil displacement is reached; when K = 0, return to step S35; if d is satisfied i If <D, then the vacuum solenoid valve is opened, and the opening degree of the vacuum solenoid valve is K = K z [(d0+D) / 2-d i When K = 0, return to step S35.

[0083] This invention further subdivides the moving coil displacement stages and adjusts the opening degree of the vacuum solenoid valve or the air source solenoid valve and the moving coil speed accordingly. Corresponding thresholds and control coefficients are set for different distance stages, making the motion state of the moving coil more controllable at each stage during its return to the equilibrium position. By dynamically adjusting the opening degree of the vacuum solenoid valve or the air source solenoid valve based on the moving coil speed and displacement, the invention avoids the moving coil from overshooting the equilibrium position or experiencing large fluctuations due to excessive speed or improper control when approaching the equilibrium position. This effectively improves the accuracy and stability of the moving coil's return to the equilibrium position, thereby enhancing the reliability of the entire horizontal low-pressure vibration test device.

[0084] In one alternative implementation, formula v is used. i =(d1-d i-1 ) / (t i -t i-1 Calculate the velocity of the moving coil, where: v i For the t-th moving circle i Moment velocity, d i For the tth i The displacement of the moving coil at any given time, d i-1 For the tth i-1 Displacement d of the moving coil at any moment i-1 Let v1 = 0 at time t1.

[0085] In one optional implementation, the moving coil balance position threshold δ D The value range is 0.5mm to 1.0mm.

[0086] A moving coil balance position threshold of 0.5mm to 1.0mm can effectively reduce the frequent triggering of the adjustment mechanism due to small displacement fluctuations caused by moving coil vibration, while ensuring the balance accuracy of the moving coil. This avoids over-adjustment of the system, reduces system energy consumption and equipment wear, and ensures timely and effective control when the moving coil displacement exceeds the reasonable range, thus maintaining the stable operation of the test device.

[0087] In one optional implementation, the initial opening degree K of the gas source solenoid valve is... q The value range is 0.4 to 0.6, and the initial opening degree K of the vacuum solenoid valve is... z The value range is 0.4 to 0.6.

[0088] Understandably, the initial opening of the gas source solenoid valve and the vacuum solenoid valve within this range can both prevent the initial opening from being too large, which would cause drastic changes in air pressure and make the moving coil unstable, and prevent the initial opening from being too small, which would make the moving coil adjustment speed too slow. This helps to accelerate the speed at which the moving coil moves to the equilibrium position while ensuring the smooth movement of the moving coil, thereby improving the adjustment efficiency and system response performance.

[0089] In one optional implementation, the first distance to the lower limit of the moving coil speed threshold λ vx The value range is 8mm / s to 9mm / s; the upper limit of the first distance moving coil speed threshold λ vs The value range is 10 mm / s to 11 mm / s;

[0090] The second distance to the lower limit of the moving coil speed threshold κ vx The value range is 7mm / s to 8mm / s; the upper limit of the second distance moving coil speed threshold κ vs The value range is 8 mm / s to 9 mm / s.

[0091] These threshold ranges are set based on the motion characteristics and control requirements of the moving coil at different displacement stages, accurately defining the reasonable range of the moving coil speed. Timely adjustment of the solenoid valve opening when the moving coil speed exceeds the corresponding threshold effectively prevents the moving coil from deviating from the expected trajectory due to excessive speed or slowness, ensuring the motion stability and adjustment accuracy of the moving coil at different stages, and guaranteeing the reliability of the entire test process.

[0092] In one optional implementation, the opening control coefficient ε of the first distance solenoid valve K1 The value range is 0.06 to 0.07; the second distance solenoid valve opening control coefficient ε K2 The value range is 0.03 to 0.04.

[0093] Using a larger control coefficient when the distance is greater allows the solenoid valve opening to have a more significant regulating effect on the displacement change of the moving coil, quickly closing the distance between the moving coil and the equilibrium position; using a smaller control coefficient when the distance is less allows for fine adjustment of the solenoid valve opening, avoiding overshoot or instability of the moving coil due to excessive adjustment, thereby improving the control accuracy and stability of the entire moving coil position adjustment process.

[0094] As shown in Figure 1, the present invention further discloses a horizontal low-pressure vibration test device, using the aforementioned horizontal low-pressure vibration test moving coil balance control method, including a negative pressure test chamber, a vacuum vibration test bench, and a control unit. The negative pressure test chamber includes a negative pressure chamber body, a first vacuum pump for generating negative pressure in the negative pressure chamber body, a support platform protruding from the bottom wall into the negative pressure chamber body, a specimen mounting surface slidably disposed on the support platform, and a connector connecting the specimen mounting surface and the moving coil.

[0095] The vacuum vibration test bench includes a vibration table body, a moving coil connected to the vibration table body to output vibration, a second vacuum pump connected to the vibration table body, a high-pressure gas source connected to the vibration table body, and a displacement sensor for detecting the position of the moving coil.

[0096] It also includes a vacuum solenoid valve connecting the second vacuum pump to the vibration table body, a gas source solenoid valve connecting the high-pressure gas source to the vibration table body, a back pressure solenoid valve for connecting the negative pressure box body and the outside air, and a negative pressure solenoid valve for controlling the on / off state of the first vacuum pump.

[0097] The signal input terminal of the control unit is connected to the displacement sensor, and the signal output terminal is connected to the vacuum solenoid valve, the gas source solenoid valve, the back pressure solenoid valve, and the negative pressure solenoid valve.

[0098] In one optional embodiment, both the vacuum solenoid valve and the gas source solenoid valve are proportional solenoid valves.

[0099] In summary, the moving coil balance control method for horizontal low-pressure vibration tests proposed in this invention solves the problem that the moving coil is difficult to accurately reach the equilibrium position, allowing the moving coil to quickly and smoothly return to the equilibrium position after exceeding the equilibrium position threshold, effectively ensuring the control accuracy during the adjustment of the moving coil position.

Claims

1. A horizontal low air pressure vibration test moving coil balance control method, characterized by, Includes the following steps: Step S1: Place the specimen on the specimen mounting platform, detect the initial position of the moving coil using a displacement sensor, create a negative pressure inside the negative pressure test chamber and the vibration table to stabilize the position of the moving coil; start the vacuum vibration test table to drive the specimen to vibrate on the specimen mounting platform. Step S2, judging whether the moving coil exceeds the moving coil balance position threshold value, the specific steps are as follows: record the moving coil displacement as Δd before adjusting the moving coil position, the moving coil moves Δd to the negative test box direction, and the moving coil moves Δd to the vibration table body direction; the displacement sensor detects the moving coil displacement Δd in real time, and judges whether it satisfies |Δd|≤δ D , wherein: δ D is the moving coil balance position threshold value; if it does not satisfy |Δd|≤δ D , step S3 is executed; if it satisfies |Δd|≤δ D , step S2 is repeatedly executed; Step S3: Detect the displacement of the moving coil during the adjustment process using a displacement sensor and calculate the moving coil speed. Use a linear control function to adjust the opening of the vacuum solenoid valve (3) connecting the second vacuum pump (1) and the vibration table (2) or to adjust the opening of the gas source solenoid valve (8) connecting the high-pressure gas source (7) and the vibration table (2) so that the moving coil speed is zero when it reaches the equilibrium position. The specific steps are as follows: If Δd > δ D , it indicates that the moving coil moves to the negative pressure test chamber direction, then the vacuum electromagnetic valve is opened, and then the opening degree of the vacuum electromagnetic valve is adjusted according to the corresponding linear control function according to the speed of the moving coil. If Δd < -δ D , it indicates that the moving coil moves to the direction of the vibration table body, the air source electromagnetic valve is opened, and then the opening of the air source electromagnetic valve is adjusted according to the corresponding linear control function according to the speed of the moving coil. Step S4: Complete the test and remove the specimen.

2. The horizontal low-pressure vibration test moving coil balance control method according to claim 1, characterized by, Step S3 adjusts the opening of the vacuum solenoid valve or the gas source solenoid valve according to the position of the moving coil. Different control methods are used depending on the distance of the moving coil from the equilibrium position. Specifically: When 0≤d i When μ1D, the vacuum solenoid opening or the air source solenoid opening is adjusted according to the moving coil speed using the linear control function with the first slope. When μ1D≤d i When μ2D, the vacuum solenoid opening or air supply solenoid opening is adjusted according to the linear control function with the second slope according to the moving coil speed. When d i When μ2D is met, the opening-displacement control function is adopted to adjust the opening of the vacuum electromagnetic valve or the opening of the air source electromagnetic valve, wherein the first slope > the second slope. d i For t i The moment of the moving coil displacement, μ1 is the first distance coefficient, the value range is 0.5~0.6;μ2 is the second distance coefficient, the value range is 0.8~0.9; D is the distance between the initial adjustment position and the initial position of the moving coil; i = 1, 2, 3…n, n is the sampling times; the farthest position from the initial position of the moving coil is the initial adjustment position, at this time d i = 0.

3. The horizontal low-pressure vibration test moving coil balance control method according to claim 2, characterized by, if 0≤d i < μ1D, i.e. t i the moment the moving coil displacement d i is the first distance, steps S31-S32 are executed to calculate the moving coil speed; Step S31, calculate t i Instantaneous voice coil velocity v i And real-time judge whether to meet λ vx ≤v i ≤λ vs , wherein: λ vx The first distance voice coil velocity threshold lower limit; λ vs The first distance voice coil velocity threshold upper limit; if not meet λ vx ≤v i ≤λ vs , adjust the vacuum electromagnetic valve opening or air source electromagnetic valve opening, specifically: When adjusting the vacuum solenoid valve opening degree, When the air source solenoid valve opening is adjusted, And repeat step S31, where: K z K represents the initial opening degree of the vacuum solenoid valve. q ε represents the initial opening degree of the air source solenoid valve. K1 This is the control coefficient for the opening degree of the first distance solenoid valve; for the first distance speed threshold mean, = (λ vx + λ vs ) / 2; if λ vx ≤ v i ≤ λ vs , the electromagnetic valve opening is kept unchanged, and then step S32 is executed; Step S32, the displacement sensor collects t i the moment moving coil displacement d i and judges whether it satisfies μ1D≤d i <μ2D, if it does not satisfy μ1D≤d i <μ2D, then returns to step S31; if it satisfies μ1D≤d i <μ2D, then executes step S33; Step S33: If μ1D≤d i <μ2D, i.e., t i Displacement d of the moving coil at any moment i For the second distance, the control steps are as follows: Calculate t i Constant moving coil speed v i And determine in real time whether κ is satisfied. vx ≤v i ≤κ vs , where: κ vx The lower limit of the second distance moving coil velocity threshold; κ vs The upper limit of the second distance moving coil speed threshold; κ vs <λ vs ; If v i Not satisfied with κ vx ≤v i ≤κ vs Then adjust the opening of the vacuum solenoid valve or the gas source solenoid valve. And repeat step S5, where: K2 is the opening degree of the vacuum solenoid valve or the gas source solenoid valve when the moving coil just enters the second distance stage; ε K2 ε is the control coefficient for the opening degree of the second distance vacuum solenoid valve or gas source solenoid valve. K2 <ε K1 ; for the second distance speed threshold mean, The calculation formula is (κ vx +κ vs ) / 2; if κ vx ≤v i ≤κ vs , the vacuum solenoid or the air source solenoid is kept unchanged, and then step S34 is executed; Step S34: The displacement sensor collects data in real time at time t. i Displacement d of the moving coil at any moment i And determine whether μ2D≤d is satisfied. i ≤D; if μ2D≤d is not satisfied i If μ2D ≤ d, then return to step S33; if μ2D ≤ d, then return to step S33. i If ≤D, then proceed to step S35; Step S35, when d is satisfied i =μ2D, i.e., t i Displacement d of the moving coil at any moment i For the third distance, the specific control steps are as follows: Close the vacuum solenoid valve or the gas source solenoid valve, and calculate t. i Constant moving coil speed v i When v i When = 0, determine whether d is satisfied. i =D, if d is not satisfied i =D, then execute step S36; if d is satisfied i =D, then the vibration test ends; Step S36, if d is satisfied i If >D, then the air source solenoid valve is opened, and the opening degree of the air source solenoid valve is K = K q [d i -(d0+D) / 2], where: d0 is the moving coil velocity v in step S35 i =0 when the moving coil displacement is reached; when K=0, return to step S35; if d is satisfied i If <D, then the vacuum solenoid valve is opened, and the opening degree of the vacuum solenoid valve is K = K z [(d0+D) / 2-d i When K = 0, return to step S35.

4. The horizontal low-pressure vibration test moving coil balance control method according to claim 2, characterized by, Using formula v i =(d i -d i-1 ) / (t i -t i-1 Calculate the velocity of the moving coil, where: v i For dynamic coil t i Moment velocity, d i For t i The displacement of the moving coil at any given time, d i-1 For t i-1 Displacement d of the moving coil at any moment i-1 Let v1 = 0 at time t1.

5. The horizontal low pressure vibration test moving coil balance control method according to claim 1, characterized by, The moving coil balance position threshold δ D The value range is 0.5mm-1.0mm.

6. The method for controlling the dynamic coil balance in a horizontal low-pressure vibration test according to claim 3, characterized in that, The initial opening degree K of the gas source solenoid valve q The value range is 0.4 to 0.6, and the initial opening degree K of the vacuum solenoid valve is... z The value range is 0.4 to 0.

6.

7. The method for controlling the dynamic coil balance in a horizontal low-pressure vibration test according to claim 3, characterized in that, The first distance to the lower limit of the moving coil speed threshold λ vx The value range is 8mm / s to 9mm / s; the upper limit of the first distance moving coil speed threshold λ vs The value range is 10 mm / s to 11 mm / s; Second distance moving coil speed threshold lower limit K vx The value range is 7mm / s~8mm / s; second distance moving coil speed threshold upper limit K vs The value range is 8mm / s~9mm / s.

8. The horizontal low-pressure vibration test moving coil balance control method according to claim 3, characterized by, The first distance solenoid valve opening degree control coefficient ε K1 The second distance solenoid valve opening degree control coefficient ε K2 The second distance solenoid valve opening degree control coefficient ε 9. A horizontal low-pressure vibration testing apparatus, using the horizontal low-pressure vibration testing moving coil balance control method as described in any one of claims 1 to 8, characterized in that, Includes a negative pressure test chamber (6), a vacuum vibration test bench, and a control unit, among which, The negative pressure test chamber includes a negative pressure chamber body, a first vacuum pump (4) for generating negative pressure in the negative pressure chamber body, a support platform (12) protruding from the bottom wall into the negative pressure chamber body, a specimen mounting surface (11) slidably disposed on the support platform, and a connector (10) connecting the specimen mounting surface and the moving coil (9). The vacuum vibration test bench includes a vibration table body (2), a moving coil (9) connected to the vibration table body (2) to output vibration, a second vacuum pump (1) connected to the vibration table body (2), a high-pressure gas source (7) connected to the vibration table body (2), and a displacement sensor for detecting the position of the moving coil (9). It also includes a vacuum solenoid valve (3) connecting the second vacuum pump (1) and the vibration table body (2), a gas source solenoid valve (8) connecting the high pressure gas source (7) and the vibration table body (2), a back pressure solenoid valve for connecting the negative pressure box and the outside air, and a negative pressure solenoid valve (5) for controlling the on and off of the first vacuum pump (4). The signal input terminal of the control unit is connected to the displacement sensor, and the signal output terminal is connected to the vacuum solenoid valve (3), the gas source solenoid valve (8), the back pressure solenoid valve, and the negative pressure solenoid valve (5).

10. The horizontal low-pressure vibration testing device according to claim 9, characterized in that, Both the vacuum solenoid valve (3) and the gas source solenoid valve (8) are proportional solenoid valves.

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