Method for controlling the balance of a moving coil in a low-pressure horizontal vibration test and related device

Abstract

FIELD: vibration benches.SUBSTANCE: invention discloses a method for controlling the balance of a moving coil in a low-pressure horizontal vibration test and a related device. The speed of the moving coil is obtained by determining the displacement of the moving coil. The opening degree of the solenoid valve for vacuum or the opening degree of the solenoid valve for the air source is adjusted using an appropriate linear control function according to the speed of the moving coil so as to ensure that the speed of the moving coil is zero when the moving coil reaches the equilibrium position, and to ensure that the moving coil can return to the equilibrium position quickly and smoothly after exceeding the equilibrium position threshold.EFFECT: control accuracy during adjustment of the position of the moving coil.9 cl, 3 dwg

Description

[0001] FIELD OF TECHNOLOGY

[0002] The present invention relates to the technical field of vibration test machines, and in particular relates to a method for controlling the balance of a moving coil in a low-pressure horizontal vibration test and a related device.

[0003] BACKGROUND OF THE INVENTION

[0004] Shake stands are common vibration testing equipment widely used in industries such as aviation, aerospace, batteries, electrical engineering, electronics, instrumentation, and medicine. Most existing shake stands are used in normal-pressure environments. Sometimes, vibration testing requires simulating real operating conditions, so a low-pressure environment is created in a sealed enclosure to allow vibration testing in a low-pressure environment.

[0005] Currently, there are many patents in China describing methods for controlling low-pressure horizontal vibration. In existing low-pressure horizontal vibration control methods, one of the vacuum solenoid valve and the air source solenoid valve is controlled to open, or both are controlled to close, by adjusting the opening timing of the vacuum solenoid valve and the air source solenoid valve to maintain the balance of the moving coil. However, these control methods still have the following drawbacks.

[0006] 1. In the existing method for controlling horizontal low-pressure vibration, the air pressure of the negative pressure test box and the vacuum test shaker is restored to the equilibrium point by using a method in which the vacuum test shaker is inflated and deflated by controlling one of the vacuum solenoid valve and the air source solenoid valve to be open while maintaining the balance of the moving coil. However, before the moving coil is balanced, since the pressure difference caused by the vibration test results exceeds the equilibrium position threshold, when the air pressure of the vacuum test shaker and the negative pressure test box are balanced with each other, it is difficult to return the moving coil to the equilibrium position.

[0007] 2. In the existing low-pressure horizontal vibration control method, the vacuum solenoid valve and the air source solenoid valve are inflated and deflated at a fixed opening degree while maintaining the balance of the moving coil. The opening time of the solenoid valve and the air source solenoid valve starts from the gear with the shortest opening time each time, and the moving coil moves at a relatively low speed, resulting in the time required for the moving coil to return to the equilibrium position being too long.

[0008] 3. In the existing low-pressure horizontal vibration control method, the method of continuously increasing the opening time of the solenoid valve every second during each adjustment to maintain the balance of the moving coils is constantly used to control the solenoid valve for the gas source and the solenoid valve for the vacuum, and the solenoid valve control strategy is not adjusted based on the position of the moving coil, resulting in relatively poor test control accuracy.

[0009] SUMMARY OF THE INVENTION

[0010] In view of the above technical problems, the present invention provides a method for controlling the balance of a moving coil in a low-pressure horizontal vibration test and a related device, which solves the problems that the existing low-pressure vibration test device is difficult to maintain the balance of the position of the moving coil, and the control methods are simple.

[0011] A method for controlling the balance of a moving coil in a low-pressure horizontal vibration test is provided, which comprises the following steps.

[0012] In step S1, the test specimen is placed on the test specimen positioning table, the initial position of the moving coil is detected by the displacement sensor, a negative pressure is generated inside the negative pressure test box and the vibration test bench body to stabilize the position of the moving coil, and the vacuum vibration test bench is started to vibrate the test specimen on the test specimen positioning table.

[0013] In step S2, it is determined whether the moving coil exceeds the equilibrium position threshold of the moving coil. The specific steps are as follows. The displacement of the moving coil before adjusting the position of the moving coil is recorded as , when the moving coil moves to the negative pressure test box, is positive, and when the moving coil moves towards the body of the vibration stand, is negative, the offset the moving coil is determined by means of a displacement sensor in real time, and it is determined whether the inequality is satisfied , Where denotes the threshold of the equilibrium position of the moving coil, and when the inequality is not satisfied, then step S3 is performed, and when the inequality is satisfied, then step S2 is performed again.

[0014] In step S3, the displacement of the moving coil is detected by means of a displacement sensor, the speed of the moving coil is calculated and obtained during the adjustment, the opening degree of the solenoid valve for the vacuum connecting the second vacuum pump and the shaker body, or the opening degree of the solenoid valve for the air source connecting the high-pressure air source and the shaker body is adjusted using a linear control function so as to ensure that the speed of the moving coil is zero when the moving coil reaches the equilibrium position, the specific steps are as follows.

[0015] When , the solenoid valve for vacuum is opened, and means that the moving coil moves to the negative pressure test box, and the initial opening degree of the solenoid valve for vacuum is , and then the opening degree of the solenoid valve for vacuum is adjusted using an appropriate linear control function according to the speed of the moving coil so as to ensure that the moving coil can be quickly brought to the equilibrium position.

[0016] When , the solenoid valve for the air source is opened, and means that the moving coil moves toward the vibration table body; and then the opening degree of the solenoid valve for the air source is adjusted using the corresponding linear control function according to the speed of the moving coil, so as to ensure that the moving coil can quickly move to the equilibrium position.

[0017] At step S4, the test is completed and the test specimen is taken out.

[0018] Advantageous effects: in the method for controlling the balance of a moving coil in a low-pressure horizontal vibration test provided in the present invention, the speed of the moving coil is obtained by detecting the displacement of the moving coil, and the opening degree of the solenoid valve for the vacuum or the opening degree of the solenoid valve for the air source is adjusted so as to ensure that the speed of the moving coil is zero when the moving coil reaches the equilibrium position, so that the moving coil can be quickly and smoothly returned to the equilibrium position when the moving coil exceeds the equilibrium position threshold.

[0019] In an optimal embodiment, in step 3, the vacuum solenoid valve or the air source solenoid valve is adjusted to open according to the position of the moving coil, and different control methods are applied according to different distances between the moving coil and the equilibrium position, which specifically includes the following steps.

[0020] When the inequality is satisfied , the opening degree of the solenoid valve for the vacuum or the opening degree of the solenoid valve for the air source is adjusted using a linear control function with the first slope according to the speed of the moving coil, so as to ensure that the moving coil can be quickly brought to the equilibrium position.

[0021] When the inequality is satisfied , the opening degree of the solenoid valve for the vacuum or the opening degree of the solenoid valve for the air source is adjusted using a linear control function with a second slope according to the speed of the moving coil, so as to ensure that the moving coil can move smoothly.

[0022] When equality is satisfied , the opening degree of the solenoid valve for the vacuum or the opening degree of the solenoid valve for the air source is adjusted using a control function with the opening degree dependent on the offset, wherein the former slope is greater than the latter.

[0023] Here denotes the displacement of the moving coil at a given moment in time , denotes the coefficient for the first distance and is in the range from 0.5 to 0.6, denotes the coefficient for the second distance and ranges from 0.8 to 0.9.

[0024] denotes the distance between the initial position of the moving coil adjustment and the initial position of the moving coil.

[0025] , denotes the moments of time when the measurement is taken, and the position at which the moving coil is most distant from the initial position of the moving coil is the initial position of the regulation, and at this moment in time .

[0026] Advantageous Effects. In the method for controlling the balance of a moving coil in a low-pressure horizontal vibration test provided by the present invention, different control methods are adopted according to different distances between the moving coil and the equilibrium position during adjustment of the position of the moving coil. When the moving coil is relatively far from the equilibrium position, the opening degree of the solenoid valve for the vacuum or the opening degree of the solenoid valve for the air source are adjusted using a linear control function with a large slope, so as to ensure that the moving coil can quickly approach the equilibrium position;and when the moving coil is at a middle distance from the equilibrium position, the opening degree of the solenoid valve for the vacuum or the opening degree of the solenoid valve for the air source is adjusted using a small-slope linear control function to ensure that the moving coil can move smoothly; and when the moving coil is relatively close to the equilibrium position, the opening degree of the solenoid valve for the vacuum or the opening degree of the solenoid valve for the air source is adjusted using a displacement-dependent control function, which ensures the control accuracy during the adjustment of the position of the moving coil.

[0027] In the optimal implementation, when the inequality is satisfied , that is, displacement moving coil at the moment of time is the first distance, then steps S31 to S32 are performed to calculate the speed of the moving coil.

[0028] At step S31, the offset moving coil at the moment of time obtained by means of a displacement sensor to calculate and obtain the speed moving coil at the moment of time , and determine in real time whether the speed is satisfactory inequality , Where denotes the lower limit of the speed threshold of the moving coil at the first distance, denotes the upper limit of the speed threshold of the moving coil at the first distance when the inequality is not satisfied, the opening degree of the solenoid valve for vacuum or the opening degree of the solenoid valve for air source is regulated, which specifically has the following form.

[0029] When adjusting the opening degree of the solenoid valve for vacuum, .

[0030] When adjusting the opening degree of the solenoid valve for the air source, , and step S31 is performed again, where denotes the initial degree of opening of the solenoid valve for vacuum, denotes the initial degree of opening of the solenoid valve for the air source, denotes the control coefficient for the opening degree of the solenoid valve at the first distance, denotes the average value for the speed thresholds at the first distance, where calculated using the formula , and when the inequality is satisfied , the opening degree of the solenoid valve is kept unchanged, then step S32 is performed.

[0031] At step S32, the offset moving coil at the moment of time obtained by means of a displacement sensor in real time, it is determined whether the displacement satisfies moving coil inequality , when inequality is not satisfied, return to step S31; and when the inequality is satisfied, step S33 is performed.

[0032] At step S33, when the inequality is satisfied, that is, the displacement moving coil at the moment of time is the second distance, the control stages are as follows. Speed moving coil at the moment of time are calculated and obtained, and in real time it is determined whether it satisfies inequality , Where denotes the lower limit of the moving coil speed threshold at the second distance.

[0033] denotes the upper limit of the speed threshold of the moving coil at the second distance, and , When does not satisfy the inequality , the opening degree of the solenoid valve for vacuum or the opening degree of the solenoid valve for air source is adjusted as , and repeat step S5, where denotes the opening degree of the solenoid valve for vacuum or the opening degree of the solenoid valve for air source when the moving coil just enters the second distance stage, denotes the control coefficient for the opening degree of the solenoid valve for vacuum or the opening degree of the solenoid valve for the air source at the second distance, and , denotes the average value for the speed thresholds at the second distance, and calculated using the formula , when the inequality is satisfied , the opening degree of the vacuum valve or the opening degree of the air source solenoid valve is kept unchanged, then step S34 is performed.

[0034] At step S34, the offset moving coil at the moment of time are obtained by means of a displacement sensor in real time and it is determined whether the displacement satisfies moving coil inequality , when inequality is not satisfied, return to step S33, and when the inequality is satisfied, step S35 is performed.

[0035] At step S35, when equality is satisfied , that is, displacement moving coil at the moment of time is the third distance, the specific control steps are as follows. The solenoid valve for vacuum or solenoid valve for air closes, the displacement moving coil at the moment of time obtained through a displacement sensor in real time to calculate and obtain the speed moving coil at the moment of time , When , determine whether the equality is satisfied , and when equality is not satisfied, perform step S36, and when equality is satisfied, the vibration test is completed.

[0036] At step S36, when the inequality is satisfied , the solenoid valve for the air source is opened, the opening degree of the solenoid valve for the air source is , Where denotes the displacement of the moving coil when the speed of the moving coil is at step S35, when , return to step S35 when the inequality is satisfied , the solenoid valve for vacuum is opened, the degree of opening of the valve for vacuum is , and when , return to the execution of step S35.

[0037] Advantageous effects. The moving coil displacement stage is further subdivided. The opening degree of the solenoid valve for vacuum or the opening degree of the solenoid valve for air source are specifically adjusted. The corresponding thresholds and control coefficients are set at different stages of the distance, so that the moving state of the moving coil at each stage is more controllable when returning to the equilibrium position.The opening degree of the solenoid valve for the vacuum or the opening degree of the solenoid valve for the air source is dynamically adjusted by the speed of the moving coil and the displacement of the moving coil, which prevents the moving coil from passing the equilibrium position or generating relatively large fluctuations due to excessive speed or improper control when approaching the equilibrium position, and also effectively improves the accuracy and stability of returning the moving coil to the equilibrium position, so that the reliability of the entire low-pressure horizontal vibration testing apparatus is improved.

[0038] In the optimal embodiment, the speed of the moving coil is calculated using the formula , Where denotes the speed of the moving coil at a given moment in time , denotes the displacement of the moving coil at a given moment in time , denotes displacement moving coil at the moment of time , and the speed of the moving coil at the moment of time write it down as .

[0039] In the optimal implementation, the threshold The equilibrium position of the moving coil is in the range from 0.5 mm to 1.0 mm.

[0040] Advantageous effects: The equilibrium position threshold of the moving coil is in the range of 0.5mm to 1.0mm, which can effectively reduce the situation in which the adjusting mechanism is often triggered due to minor displacement fluctuations caused by the vibration of the moving coil, avoid over-regulation of the system, reduce the energy consumption of the system and the wear and tear of the equipment, ensure that effective control can be performed in time when the displacement of the moving coil exceeds a reasonable range, and maintain the stable operation of the testing device with the precondition of ensuring the balance accuracy of the moving coil.

[0041] In the optimal embodiment, the initial opening degree solenoid for the air source is in the range of 0.4 to 0.6, and the initial opening degree The solenoid valve for vacuum is in the range from 0.4 to 0.6.

[0042] Beneficial effects: The initial opening degree of the air source solenoid valve and the vacuum solenoid valve within this range can not only eliminate the unstable movement of the moving coil due to sudden changes in air pressure caused by an excessively large initial opening degree, but also prevent the moving coil from adjusting too slowly due to an excessively small initial opening degree, which is beneficial to accelerating the speed of the moving coil moving to the equilibrium position on the basis of ensuring the smooth movement of the moving coil, and improves the regulation efficiency and response performance of the system.

[0043] In the optimal implementation, the lower limit The speed threshold of the moving coil at the first distance is in the range from 8 mm / s to 9 mm / s, and the upper limit The speed threshold of the moving coil at the first distance is in the range from 10 mm / s to 11 mm / s.

[0044] Lower Limit The speed threshold of the moving coil at the second distance is in the range from 7 mm / s to 8 mm / s, and the upper limit The speed threshold of the moving coil at the second distance is in the range from 8 mm / s to 9 mm / s.

[0045] The beneficial effects are as follows. These thresholds are set based on the motion characteristics and control requirements of the moving coil at different displacement stages, and can accurately determine the reasonable range of the moving coil speed. When the moving coil speed exceeds the corresponding threshold, the opening degree of the solenoid valve is adjusted in a timely manner, effectively preventing the moving coil from deviating from the expected trajectory due to excessively fast or slow speed. This ensures the stability of the moving coil's motion and control accuracy at different stages, and guarantees the reliability of the entire testing process.

[0046] In the optimal implementation, the control coefficient the opening degree of the solenoid valve at the first distance is in the range from 0.06 to 0.07, and the control coefficient The opening degree of the solenoid valve at the second distance is in the range from 0.03 to 0.04.

[0047] The beneficial effects are as follows. When the moving coil is relatively far from the equilibrium position, a relatively large control gain is adopted, which can give the solenoid valve opening degree a more pronounced regulating effect on the change in the displacement of the moving coil and quickly reduce the distance between the dynamic coil and the equilibrium position. When the moving coil is relatively close to the equilibrium position, a relatively small control gain is adopted, which can realize precise adjustment of the solenoid valve opening degree and eliminate the possibility of moving coil overshoot or instability due to excessive control range. Thus, control accuracy and stability are improved throughout the entire process of adjusting the position of the moving coil.

[0048] Furthermore, the present invention provides a low-pressure vibration testing device that uses a method for controlling the balance of a moving coil in a low-pressure horizontal vibration test. The device comprises a negative pressure test box, a vacuum vibration test rig, and a control unit. The negative pressure test box comprises a negative pressure box housing, a first vacuum pump configured to create a negative pressure in the negative pressure box housing, a supporting table protruding from the bottom wall of the negative pressure box housing into the negative pressure box housing, a mounting table for test specimens slidably located on the supporting table, and a connector connecting the mounting table for test specimens and the moving coil.

[0049] The vacuum vibration test bench comprises a vibration bench body, a moving coil connected to the vibration bench body to provide vibration, a second vacuum pump connected to the vibration bench body, a high-pressure air source connected to the vibration bench body, and a displacement sensor configured to detect the position of the moving coil.

[0050] The device further comprises a solenoid valve for vacuum connecting the second vacuum pump and the vibration stand body, a solenoid valve for air source connecting the high-pressure air source and the vibration stand body, a check solenoid valve configured to connect the negative pressure box and external air, and a solenoid valve for negative pressure configured to control the opening and closing of the first vacuum pump.

[0051] The control unit signal input terminal is in connection with the displacement sensor, and the control unit signal output terminal is in connection with the vacuum solenoid valve, the air source solenoid valve, the check solenoid valve, and the negative pressure solenoid valve.

[0052] In an optimal embodiment, the vacuum solenoid valve and the air source solenoid valve are both proportional solenoid valves.

[0053] In summary, the method for controlling the balance of a moving coil in a low-pressure horizontal vibration test proposed in the present invention solves the problem that it is difficult for the moving coil to accurately reach the equilibrium position, and can ensure that the moving coil can return to the equilibrium position quickly and smoothly after exceeding the equilibrium position threshold, which effectively guarantees the control accuracy in the process of adjusting the position of the moving coil.

[0054] BRIEF DESCRIPTION OF GRAPHIC MATERIALS

[0055] Fig. 1 illustrates a schematic diagram of the structure of the present invention.

[0056] Fig. 2 illustrates a control block diagram of the present invention.

[0057] Fig. 3 illustrates a block diagram of the regulation and control of the position of the moving coil.

[0058] Description of reference numbers

[0059] 1. The second vacuum pump, 2. Shaker body, 3. Solenoid valve for vacuum, 4. The first vacuum pump, 5. Negative pressure solenoid valve, 6. Negative pressure test box, 7. High pressure air source, 8. Solenoid valve for air source, 9. Moving coil, 10. Connectors, 11. Test specimen installation table, 12. Support table.

[0060] DETAILED DESCRIPTION OF IMPLEMENTATION OPTIONS

[0061] The present invention will be further described below with reference to the embodiments shown in the accompanying drawings so that those skilled in the art can better understand and implement the present invention, but these embodiments are not intended to limit the present invention.

[0062] As shown in Fig. 2, the present invention provides a method for controlling the balance of a moving coil in a low-pressure horizontal vibration test, which includes the following steps.

[0063] In step S1, the test specimen is placed on the test specimen positioning table, the initial position of the moving coil is detected by the displacement sensor, a negative pressure is generated inside the negative pressure test box and the vibration test bench body to stabilize the position of the moving coil, and the vacuum vibration test bench is started to vibrate the test specimen on the test specimen positioning table.

[0064] In step S2, it is determined whether the moving coil exceeds the equilibrium position threshold of the moving coil. The specific steps are as follows. The displacement of the moving coil before adjusting the position of the moving coil is recorded as , when the moving coil moves to the negative pressure test box, is positive, and when the moving coil moves towards the body of the vibration stand, is negative, the offset the moving coil is determined by means of a displacement sensor in real time, and it is determined whether the inequality is satisfied , Where denotes the threshold of the equilibrium position of the moving coil, and when the inequality is not satisfied, then step S3 is performed, and when the inequality is satisfied, then step S2 is performed again.

[0065] In step S3, the displacement of the moving coil is detected by means of a displacement sensor, the speed of the moving coil is calculated and obtained during the adjustment, the opening degree of the solenoid valve 8 for the vacuum connecting the second vacuum pump 1 and the body 2 of the vibration table, or the opening degree of the solenoid valve 8 for the air source connecting the high-pressure air source 7 and the body of the vibration table 2 is adjusted using a linear control function so as to ensure that the speed of the moving coil is equal to zero when the moving coil reaches the equilibrium position, the specific steps are as follows.

[0066] When , the solenoid valve for vacuum is opened, and means that the moving coil moves to the negative pressure test box, and the initial opening degree of the solenoid valve for vacuum is , and then the opening degree of the solenoid valve for vacuum is adjusted using an appropriate linear control function according to the speed of the moving coil so as to ensure that the moving coil can be quickly brought to the equilibrium position.

[0067] When , the solenoid valve for the air source is opened, and means that the moving coil moves toward the vibration table body; and then the opening degree of the solenoid valve for the air source is adjusted using the corresponding linear control function according to the speed of the moving coil, so as to ensure that the moving coil can quickly move to the equilibrium position.

[0068] At step S4, the test is completed and the test specimen is removed.

[0069] In the method for controlling the balance of a moving coil in a low-pressure horizontal vibration test provided in the present invention, the speed of the moving coil is obtained by detecting the displacement of the moving coil, and the opening degree of the solenoid valve for the vacuum or the opening degree of the solenoid valve for the air source is adjusted so as to ensure that the speed of the moving coil is zero when the moving coil reaches the equilibrium position, so that the moving coil can be quickly and smoothly returned to the equilibrium position when the moving coil exceeds the equilibrium position threshold.

[0070] In an optimal embodiment, in step 3, the vacuum solenoid valve or the air source solenoid valve is adjusted to open according to the position of the moving coil, and different control methods are applied according to different distances between the moving coil and the equilibrium position, which specifically includes the following steps.

[0071] When the inequality is satisfied , the opening degree of the solenoid valve for the vacuum or the opening degree of the solenoid valve for the air source is adjusted using a linear control function with the first slope according to the speed of the moving coil, so as to ensure that the moving coil can be quickly brought to the equilibrium position.

[0072] When the inequality is satisfied , the opening degree of the solenoid valve for the vacuum or the opening degree of the solenoid valve for the air source is adjusted using a linear control function with a second slope according to the speed of the moving coil, so as to ensure that the moving coil can move smoothly.

[0073] When equality is satisfied , the opening degree of the solenoid valve for the vacuum or the opening degree of the solenoid valve for the air source is adjusted using the opening degree-offset control function, and wherein the first slope is greater than the second slope.

[0074] Here denotes the displacement of the moving coil at a given moment in time , denotes the coefficient for the first distance and is in the range from 0.5 to 0.6, denotes the coefficient for the second distance and ranges from 0.8 to 0.9.

[0075] denotes the distance between the initial position of the moving coil adjustment and the initial position of the moving coil.

[0076] , denotes the moments of time when the measurement is taken, and the position at which the moving coil is most distant from the initial position of the moving coil is the initial position of the regulation, and at this moment in time .

[0077] In the method for controlling the balance of a moving coil in a low-pressure horizontal vibration test provided in the present invention, different control methods are adopted according to different distances between the moving coil and the equilibrium position during adjustment of the position of the moving coil. When the moving coil is relatively far from the equilibrium position, the opening degree of the solenoid valve for the vacuum or the opening degree of the solenoid valve for the air source is adjusted using a linear control function with a large slope to ensure that the moving coil can quickly approach the equilibrium position;and when the moving coil is at a middle distance from the equilibrium position, the opening degree of the solenoid valve for the vacuum or the opening degree of the solenoid valve for the air source is adjusted using a small-slope linear control function to ensure that the moving coil can move smoothly; and when the moving coil is relatively close to the equilibrium position, the opening degree of the solenoid valve for the vacuum or the opening degree of the solenoid valve for the air source is adjusted using a displacement-dependent control function, which ensures the control accuracy during the adjustment of the position of the moving coil.

[0078] In the optimal implementation, when the inequality is satisfied , that is, displacement moving coil at the moment of time is the first distance, then steps S31 to S32 are performed to calculate the speed of the moving coil.

[0079] At step S31, the offset moving coil at the moment of time obtained by means of a displacement sensor to calculate and obtain the speed moving coil at the moment of time , and determine in real time whether the speed is satisfactory inequality , Where denotes the lower limit of the speed threshold of the moving coil at the first distance, denotes the upper limit of the speed threshold of the moving coil at the first distance when the inequality is not satisfied, the opening degree of the solenoid valve for vacuum or the opening degree of the solenoid valve for air source is regulated, which specifically has the following form.

[0080] When adjusting the opening degree of the solenoid valve for vacuum, .

[0081] When adjusting the opening degree of the solenoid valve for the air source, , and step S31 is performed again, where denotes the initial degree of opening of the solenoid valve for vacuum, denotes the initial degree of opening of the solenoid valve for the air source, denotes the control coefficient for the opening degree of the solenoid valve at the first distance, denotes the average value for the speed thresholds at the first distance, where calculated using the formula , and when the inequality is satisfied , the opening degree of the solenoid valve is kept unchanged, then step S32 is performed.

[0082] At step S32, the offset moving coil at the moment of time obtained by means of a displacement sensor in real time, it is determined whether the displacement satisfies moving coil inequality , when inequality is not satisfied, return to step S31; and when the inequality is satisfied, step S33 is performed.

[0083] At step S33, when the inequality is satisfied, that is, the displacement moving coil at the moment of time is the second distance, the control stages are as follows. Speed moving coil at the moment of time are calculated and obtained, and in real time it is determined whether it satisfies inequality , Where denotes the lower limit of the moving coil speed threshold at the second distance.

[0084] denotes the upper limit of the speed threshold of the moving coil at the second distance, and , When does not satisfy the inequality , the opening degree of the solenoid valve for vacuum or the opening degree of the solenoid valve for air source is adjusted as , and repeat step S5, where denotes the opening degree of the solenoid valve for vacuum or the opening degree of the solenoid valve for air source when the moving coil just enters the second distance stage, denotes the control coefficient for the opening degree of the solenoid valve for vacuum or the opening degree of the solenoid valve for the air source at the second distance, and , denotes the average value for the speed thresholds at the second distance, and calculated using the formula , when the inequality is satisfied , the opening degree of the vacuum valve or the opening degree of the air source solenoid valve is kept unchanged, then step S34 is performed.

[0085] At step S34, the offset moving coil at the moment of time are obtained by means of a displacement sensor in real time and it is determined whether the displacement satisfies moving coil inequality , when inequality is not satisfied, return to step S33, and when the inequality is satisfied, step S35 is performed.

[0086] At step S35, when equality is satisfied , that is, displacement moving coil at the moment of time is the third distance, the specific control steps are as follows. The solenoid valve for vacuum or solenoid valve for air closes, the displacement moving coil at the moment of time obtained through a displacement sensor in real time to calculate and obtain the speed moving coil at the moment of time , When , determine whether the equality is satisfied , and when equality is not satisfied, perform step S36, and when equality is satisfied, the vibration test is completed.

[0087] At step S36, when the inequality is satisfied , the solenoid valve for the air source is opened, the opening degree of the solenoid valve for the air source is , Where denotes the displacement of the moving coil when the speed of the moving coil is at step S35, when , return to step S35 when the inequality is satisfied , the solenoid valve for vacuum is opened, the degree of opening of the valve for vacuum is , and when , return to the execution of step S35.

[0088] In the present invention, the displacement stage of the moving coil is further divided, the opening degree of the solenoid valve for the vacuum or the opening degree of the solenoid valve for the air source is specifically adjusted, the corresponding thresholds and control coefficients are set at different stages of the distance, so that the moving state of the moving coil at each stage is more controllable during the return to the equilibrium position.The opening degree of the solenoid valve for the vacuum or the opening degree of the solenoid valve for the air source is dynamically adjusted by the speed of the moving coil and the displacement of the moving coil, which prevents the moving coil from passing the equilibrium position or generating relatively large fluctuations due to excessive speed or improper control when approaching the equilibrium position, and also effectively improves the accuracy and stability of returning the moving coil to the equilibrium position, so that the reliability of the entire low-pressure horizontal vibration testing apparatus is improved.

[0089] In the optimal embodiment, the speed of the moving coil is calculated using the formula , Where denotes the speed of the moving coil at a given moment in time , denotes the displacement of the moving coil at a given moment in time , denotes displacement moving coil at the moment of time , and the speed of the moving coil at the moment of time write it down as .

[0090] In the optimal implementation, the threshold The equilibrium position of the moving coil is in the range from 0.5 mm to 1.0 mm.

[0091] The equilibrium position threshold of the moving coil is in the range of 0.5mm to 1.0mm, which can effectively reduce the situation in which the adjustment mechanism is often triggered due to minor offset fluctuations caused by the vibration of the moving coil, avoid over-regulation of the system, reduce system energy consumption and equipment wear, ensure that effective control can be performed in time when the offset of the moving coil exceeds a reasonable range, and maintain the stable operation of the testing device with the precondition of ensuring the balance accuracy of the moving coil.

[0092] In the optimal embodiment, the initial opening degree solenoid for the air source is in the range of 0.4 to 0.6, and the initial opening degree The solenoid valve for vacuum is in the range from 0.4 to 0.6.

[0093] It can be understood that the initial opening degree of the air source solenoid valve and the vacuum solenoid valve within this range can not only eliminate the unstable movement of the moving coil due to sudden changes in air pressure caused by an excessively large initial opening degree, but also prevent the moving coil from adjusting too slowly due to an excessively small initial opening degree, which is beneficial to accelerating the speed of the moving coil moving to the equilibrium position on the basis of ensuring the smooth movement of the moving coil, and improve the regulation efficiency and response performance of the system.

[0094] In the optimal implementation, the lower limit The speed threshold of the moving coil at the first distance is in the range from 8 mm / s to 9 mm / s, and the upper limit The speed threshold of the moving coil at the first distance is in the range from 10 mm / s to 11 mm / s.

[0095] Lower Limit The speed threshold of the moving coil at the second distance is in the range from 7 mm / s to 8 mm / s, and the upper limit The speed threshold of the moving coil at the second distance is in the range from 8 mm / s to 9 mm / s.

[0096] These thresholds are set based on the motion characteristics and control requirements of the moving coil at different displacement stages, and can accurately determine the reasonable range of the moving coil speed. When the moving coil speed exceeds the corresponding threshold, the opening degree of the solenoid valve is adjusted in a timely manner. This effectively prevents the moving coil from deviating from the expected trajectory due to excessively fast or slow speed, ensures the stability of the moving coil's motion and control accuracy at different stages, and guarantees the reliability of the entire testing process.

[0097] In the optimal implementation, the control coefficient the opening degree of the solenoid valve at the first distance is in the range from 0.06 to 0.07, and the control coefficient The opening degree of the solenoid valve at the second distance is in the range from 0.03 to 0.04.

[0098] When the moving coil is relatively far from the equilibrium position, a relatively large control gain is adopted. This can give the solenoid valve opening degree a more pronounced control effect on the change in the moving coil displacement and quickly reduce the distance between the dynamic coil and the equilibrium position. When the moving coil is relatively close to the equilibrium position, a relatively small control gain is adopted. This can achieve precise adjustment of the solenoid valve opening degree and eliminate the possibility of moving coil overshoot or instability due to excessive control range. Thus, control accuracy and stability are improved throughout the entire process of adjusting the position of the moving coil.

[0099] As shown in Fig. 1, the present invention also discloses a device for horizontal vibration testing under low pressure, using a method for controlling the balance of a moving coil in a horizontal vibration test under low pressure. The device comprises a negative pressure test box, a vacuum vibration test bench and a control unit. The negative pressure test box comprises a negative pressure box housing, a first vacuum pump configured to create a negative pressure in the negative pressure box housing, a supporting table protruding from the bottom wall of the negative pressure box housing into the negative pressure box housing, a mounting table for test specimens slidably located on the supporting table, and a connector connecting the mounting table for test specimens and the moving coil.

[0100] The vacuum vibration test bench comprises a vibration bench body, a moving coil connected to the vibration bench body to provide vibration, a second vacuum pump connected to the vibration bench body, a high-pressure air source connected to the vibration bench body, and a displacement sensor configured to detect the position of the moving coil.

[0101] The device further comprises a solenoid valve for vacuum connecting the second vacuum pump and the vibration stand body, a solenoid valve for air source connecting the high-pressure air source and the vibration stand body, a check solenoid valve configured to connect the negative pressure box and external air, and a solenoid valve for negative pressure configured to control the opening and closing of the first vacuum pump.

[0102] The control unit signal input terminal is in connection with the displacement sensor, and the control unit signal output terminal is in connection with the vacuum solenoid valve, the air source solenoid valve, the check solenoid valve, and the negative pressure solenoid valve.

[0103] In an optional embodiment, the vacuum solenoid valve and the air source solenoid valve are both proportional solenoid valves.

[0104] In summary, the method for controlling the balance of a moving coil in a low-pressure horizontal vibration test proposed in the present invention solves the problem that the moving coil is difficult to accurately reach the equilibrium position, and can ensure that the moving coil can return to the equilibrium position quickly and smoothly after exceeding the equilibrium position threshold, which effectively guarantees the control accuracy in the process of adjusting the position of the moving coil.

Claims

1. A method for controlling the balance of a moving coil in a low-pressure horizontal vibration test, comprising the following steps: Step S1, placing a test specimen on a test specimen setting table; detecting an initial position of the movable coil with a displacement sensor; generating a negative pressure inside the negative pressure test box and the vibration test bench body to stabilize the position of the movable coil; and starting the vacuum vibration test bench to vibrate the test specimen on the test specimen setting table; step S2, determining whether the moving coil exceeds the equilibrium position threshold of the moving coil, more specifically, recording the displacement of the moving coil before adjusting the position of the moving coil as , wherein when the moving coil moves towards the test box with negative pressure, is positive, and when the moving coil moves towards the body of the vibration stand, is negative; displacement sensor determination of displacement moving coil in real time and determining whether the inequality is satisfied , Where denotes the threshold of the equilibrium position of the moving coil; when the inequality is not satisfied, execution of stage S3; and when the inequality satisfied, repeat step S2; step S3, detecting, by the displacement sensor, the displacement of the moving coil during the adjustment and calculating and obtaining the speed of the moving coil; and adjusting, using a linear control function, the opening degree of the solenoid valve (3) for vacuum connecting the second vacuum pump (1) and the body (2) of the vibration table, or the opening degree of the solenoid valve (8) for the air source connecting the high-pressure air source (7) and the body (2) of the vibration table, so as to ensure that the speed of the moving coil is equal to zero when the moving coil reaches the equilibrium position, namely: opening when , solenoid valve for vacuum, while means that the moving coil moves to the negative pressure test box; and then adjusting, using the corresponding linear control function, the opening degree of the solenoid valve for vacuum according to the speed of the moving coil; opening when , solenoid valve for the air source, while means that the moving coil moves toward the body of the vibration table; and then adjusting, using the corresponding linear control function, the opening degree of the solenoid valve for the air source according to the speed of the moving coil; and step S4, performing the test and removing the test specimen, wherein, in step S3, the solenoid valve for the vacuum or the solenoid valve for the air source are adjusted to open according to the position of the moving coil, and different control methods are applied according to different distances between the moving coil and the equilibrium position, namely: when the inequality is satisfied , the opening degree of the solenoid valve for vacuum or the opening degree of the solenoid valve for air source is adjusted using a linear control function with the first slope according to the speed of the moving coil; when the inequality is satisfied , the opening degree of the solenoid valve for vacuum or the opening degree of the solenoid valve for air source is adjusted using a linear control function with a second slope according to the speed of the moving coil; when equality is satisfied , the opening degree of the solenoid valve for the vacuum or the opening degree of the solenoid valve for the air source is adjusted using a control function with an opening degree-offset dependence, wherein the first slope is greater than the second slope; Where denotes the displacement of the moving coil at a given moment in time , denotes the coefficient for the first distance and is in the range from 0.5 to 0.6, denotes the coefficient for the second distance and ranges from 0.8 to 0.9, denotes the distance between the initial position of the moving coil adjustment and the initial position of the moving coil and , denotes the moments of time when the measurement is taken, and the position at which the moving coil is most distant from the initial position of the moving coil is the initial position of the regulation, and at this moment in time .

2. A method for controlling the balance of a moving coil in a low-pressure horizontal vibration test according to claim 1, characterized in that when the inequality is satisfied , that is, displacement moving coil at the moment of time is the first distance, then steps S31 to S32 are performed to calculate the speed of the moving coil, and in particular includes: step S31, calculating and obtaining the speed moving coil at the moment of time ; and determining whether the speed is satisfactory inequality , in real time, where denotes the lower limit of the speed threshold of the moving coil at the first distance, denotes the upper limit of the moving coil speed threshold at the first distance; when inequality is not satisfied, the regulation of the opening degree of the solenoid valve for vacuum or the opening degree of the solenoid valve for the air source, namely: when regulating the degree of opening of the solenoid valve for vacuum - maintaining equality ; when regulating the degree of opening of the solenoid valve for the air source - maintaining equality ; and repeating step S31, where denotes the initial degree of opening of the solenoid valve for vacuum, denotes the initial degree of opening of the solenoid valve for the air source, denotes the control coefficient for the opening degree of the solenoid valve at the first distance, denotes the average value for the speed thresholds at the first distance, calculated using the formula ; when inequality is satisfied, maintaining the opening degree of the solenoid valve unchanged, then executing step S32; step S32, the displacement sensor receives the displacement moving coil at the moment of time in real time; determining whether the offset is satisfied moving coil inequality ; when inequality is not satisfied, return to step S31; and when the inequality satisfied, execution of step S33; stage S33, when the inequality is satisfied , that is, displacement moving coil at the moment of time is the second distance, the execution of the following control steps: calculating and obtaining the speed moving coil at the moment of time ; and determining whether it satisfies inequality , in real time, where denotes the lower limit of the speed threshold of the moving coil at the second distance and denotes the upper limit of the speed threshold of the moving coil at the second distance, and ; When does not satisfy the inequality , adjusting the opening degree of the solenoid valve for vacuum or the opening degree of the solenoid valve for air source as and repeating step S5, where denotes the opening degree of the solenoid valve for vacuum or the opening degree of the solenoid valve for air source when the moving coil just enters the second distance stage, denotes the control coefficient for the opening degree of the solenoid valve for vacuum or the opening degree of the solenoid valve for the air source at the second distance, and , denotes the average value for the speed thresholds at the second distance, and calculated using the formula ; when inequality is satisfied, maintaining the opening degree of the vacuum valve or the opening degree of the air source solenoid valve unchanged, then executing step S34; step S34, the displacement sensor receives the displacement moving coil at the moment of time in real time; and determining whether the offset satisfies moving coil inequality ; when inequality is not satisfied, return to step S33; and when the inequality satisfied, execution of step S35; stage S35, when equality is satisfied , that is, displacement moving coil at the moment of time is the third distance, performing the following specific control steps: closing the solenoid valve for vacuum or the solenoid valve for air; calculating and obtaining the speed moving coil at the moment of time ; When , determining whether equality is satisfied , when equality is not satisfied, execution of step S36, and when equality satisfied, completion of vibration testing; and stage S36, when the inequality is satisfied , opening of the solenoid valve for the air source, wherein the degree of opening of the solenoid valve for the air source is , Where denotes the displacement of the moving coil when the speed of the moving coil is at step S35; when , return to step S35; and when the inequality is satisfied , opening of the solenoid valve for vacuum, while the degree of opening of the valve for vacuum is ; When , return to stage S35.

3. A method for controlling the balance of a moving coil in a horizontal vibration test under low pressure according to claim 1, characterized in that the speed of the moving coil is calculated using the formula , Where denotes the speed of the moving coil at a given moment in time , denotes the displacement of the moving coil at a given moment in time , denotes displacement moving coil at the moment of time , and the speed of the moving coil at the moment of time write it down as .

4. A method for controlling the balance of a moving coil in a horizontal vibration test under low pressure according to claim 1, characterized in that the threshold the equilibrium position of the moving coil is in the range from 0.5 to 1.0 mm.

5. A method for controlling the balance of a moving coil in a horizontal vibration test under low pressure according to claim 2, characterized in that the initial degree of opening solenoid for the air source is in the range from 0.4 to 0.6 and the initial opening degree The solenoid valve for vacuum is in the range from 0.4 to 0.

6.

6. A method for controlling the balance of a moving coil in a horizontal vibration test under low pressure according to claim 2, characterized in that the lower limit the threshold speed of the moving coil at the first distance is in the range from 8 to 9 mm / s, and the upper limit the threshold speed of the moving coil at the first distance is in the range from 10 to 11 mm / s, lower limit the speed threshold of the moving coil at the second distance is in the range from 7 to 8 mm / s, and the upper limit The speed threshold of the moving coil at the second distance is in the range from 8 to 9 mm / s.

7. A method for controlling the balance of a moving coil in a horizontal vibration test under low pressure according to claim 2, characterized in that the control coefficient for the opening degree of the solenoid valve at the first distance is in the range from 0.06 to 0.07, and the control coefficient for the opening degree of the solenoid valve at the second distance is in the range from 0.03 to 0.

04.

8. A low pressure horizontal vibration test apparatus using the method of controlling the balance of a moving coil in a low pressure horizontal vibration test according to any one of claims 1 to 7, wherein the apparatus comprises a negative pressure test box (6), a vacuum vibration test stand and a control unit, wherein the negative pressure test box comprises a negative pressure box housing, a first vacuum pump (4) configured to create a negative pressure in the negative pressure box housing, a support table (12) protruding from the bottom wall of the negative pressure box housing into the negative pressure box housing, a mounting table (11) for test samples, slidably located on the support table, and a connector (10) connecting the mounting table for test samples and a movable coil (9); the vacuum vibration test bench comprises a vibration stand housing (2), a moving coil (9) connected to the vibration stand housing (2) for providing vibration, a second vacuum pump (1) connected to the vibration stand housing (2), a high-pressure air source (7) connected to the vibration stand housing (2) and a displacement sensor configured to determine the position of the moving coil (9); wherein the device further comprises a solenoid valve (3) for vacuum, connecting the second vacuum pump (1) and the housing (2) of the vibration stand, a solenoid valve (8) for an air source, connecting the source (7) of high-pressure air and the housing (2) of the vibration stand, a check solenoid valve, configured to connect the box with negative pressure and external air, and a solenoid valve (5) for negative pressure, configured to control the opening and closing of the first vacuum pump (5); and wherein the terminal for inputting signals of the control unit is in connection with the displacement sensor and the terminal for outputting signals of the control unit is in connection with the solenoid valve (3) for vacuum, the solenoid valve (8) for the air source, the check solenoid valve and the solenoid valve (5) for negative pressure.

9. The apparatus for horizontal vibration testing under low pressure according to claim 8, characterized in that the solenoid valve (3) for the vacuum and the solenoid valve (8) for the air source are both solenoid valves with a proportional connection.

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