Active vibration isolation control method and system

Abstract

The application provides an active vibration isolation control method and system, and belongs to the technical field of vibration isolation. First, vibration information of an ultra-precision device is collected and preprocessed, then the preprocessed vibration information data is input into a rectangular integral PID algorithm in a multi-core control system to obtain PID output, and then an actuator is controlled based on the PID output to generate a reverse vibration signal; finally, vibration error of the ultra-precision device after vibration isolation is obtained to determine whether to adjust the rectangular integral PID algorithm or stop active vibration isolation control. The active vibration isolation control method uses a multi-core control system, can improve the system response speed, and is compatible with a more complex control system; meanwhile, the rectangular integral PID algorithm improves the effect of large-load active vibration isolation, and takes into account the algorithm execution efficiency and system response speed of the active vibration isolation system.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of vibration isolation, and particularly relates to an active vibration isolation control method and system. BACKGROUND

[0002] The active vibration isolation control method is a control method for resisting vibration by monitoring vibration signals in real time and actively applying reverse force, and is mainly used in the fields of semiconductor manufacturing, aerospace, etc., especially for active vibration isolation of semiconductor ultra-precision equipment, which can improve equipment performance and guarantee industrial automation efficiency. The prior art has an active vibration isolation method based on PID control, for example, the PID control is applied to an active vibration isolation system in the document "PID Model Reference Adaptive Control Technology in Active Vibration Isolation System". However, the differential element of the traditional PID control can amplify high-frequency noise collected by a sensor, thus resulting in poor effect of active vibration isolation for large loads, and the integral term of the traditional PID control may also cause system response delay. In addition, in the design of the active vibration isolation control system, the prior art usually adopts single-core control, which limits the execution efficiency of the system algorithm and the system response time. SUMMARY

[0003] In order to solve the above problems in the prior art, the application provides an active vibration isolation control method and system, which adopts an improved PID algorithm based on rectangular integration to at least solve the problems of low execution efficiency of the vibration isolation system algorithm, system response delay, and poor effect of vibration isolation for large loads in the prior active vibration isolation technology.

[0004] In order to achieve the above purpose, the application adopts the following technical scheme: an active vibration isolation control method, comprising the following steps: step S1: collecting vibration information of an ultra-precision equipment to obtain vibration information data; step S2: inputting the vibration information data into a multi-core control system and pre-processing to obtain pre-processed vibration information data; step S3: inputting the pre-processed vibration information data into a rectangular integral PID algorithm in the multi-core control system to obtain a PID output; step S4: obtaining a control instruction of an actuator based on the PID output, and controlling the actuator to respond according to the control instruction to generate a reverse vibration signal; and step S5: obtaining a vibration error of the ultra-precision equipment after vibration isolation based on the reverse vibration signal, adjusting initial parameters of the rectangular integral PID algorithm when the vibration error after vibration isolation does not meet a preset condition, and repeating the steps S3-S4, and ending the active vibration isolation control when the vibration error after vibration isolation meets the preset condition.

[0005] Further, the step S2 of importing the vibration information data into the multi-core control system and preprocessing the vibration information data comprises: a step S21 of performing outlier rejection on the vibration information data to obtain rejected vibration information data; and a step S22 of performing anti-aliasing filtering on the rejected vibration information data to obtain preprocessed vibration information data.

[0006] Further, the step S3 of using the rectangular integral PID algorithm comprises: a step S31 of defining initial parameters of the PID algorithm, the initial parameters comprising a proportional parameter Kp, an integral parameter Ki, a differential parameter Kd, and a vibration reference value; a step S32 of calculating a current error error and obtaining a previous error Lerror based on the preprocessed vibration information data and the vibration reference value; a step S33 of setting an initial moving window Mwindow and an initial integral value I1; a step S34 of calculating an integral update value I2 based on a rectangular integral logic; and a step S35 of comparing an absolute value of a difference between I1 and I2 with a preset threshold value, adjusting the initial moving window Mwindow to obtain an adjusted moving window when the difference is greater than the preset threshold value, and executing the step S34 based on the adjusted moving window, or taking the integral update value I2 as a final integral update value I2f to obtain a PID output when the difference is less than or equal to the preset threshold value.

[0007] Further, the step S34 of calculating the integral update value I2 based on the rectangular integral logic comprises:

[0008] The step S341 comprises performing iterative calculation according to the following logic:

[0009] ;

[0010] wherein i represents an iteration number, i=0, 1, …, round(1 / Mwindow)-1, round represents a rounding function, Mwindow represents the initial moving window, I2 represents the integral update value, I1 represents an iteration variable, I10=I1, k1 represents a first adjustment coefficient, k2 represents a second adjustment coefficient, Lerror represents the previous error, and error represents the current error. i

[0011] The step S342 comprises taking I1 i+1 as the integral update value I2.

[0012] Further, the step S35 of adjusting the initial moving window Mwindow comprises multiplying the initial moving window Mwindow by a first proportionality coefficient kp1 to obtain an adjusted moving window.

[0013] Further, the step S35 of obtaining the PID output comprises: ​

[0014] ;

[0015] wherein OUTpid represents the PID output.

[0016] The application further provides an active vibration isolation control system for executing the active vibration isolation control method described above, the active vibration isolation control system comprising a sensor, a multi-core control system and an actuator, the sensor being connected to the multi-core control system, and the multi-core control system being connected to the actuator.

[0017] The multi-core control system can comprise an FPGA and a DSP, the FPGA being used for pre-processing vibration information of the ultra-precision equipment acquired by the sensor and sending the pre-processed vibration information data to the DSP, and the DSP being used for executing the rectangular integral PID algorithm. The multi-core control system can also comprise an ARM and a DSP, the ARM being used for pre-processing vibration information of the ultra-precision equipment acquired by the sensor and sending the pre-processed vibration information data to the DSP, and the DSP being used for executing the rectangular integral PID algorithm.

[0018] The application has the beneficial technical effects compared with the prior art in that:

[0019] (1) The multi-core control system combined with FPGA and DSP or ARM and DSP is used, which can improve the system response speed and is compatible with more complex control systems.

[0020] (2) The improved PID algorithm based on the rectangular integral can smooth the influence of high-frequency noise through the moving window variable design, thereby improving the effect of large-load active vibration isolation; the moving window size is adjusted based on the different error changes, which can balance the algorithm execution efficiency and system response speed of the active vibration isolation system. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the application or the technical solutions in the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only exemplary, and for those skilled in the art, other drawings can also be obtained from the provided drawings without creative labor.

[0022] Figure 1 It is a flowchart of the active vibration isolation control method of the application.

[0023] Figure 2 It is a flowchart of the rectangular integral PID algorithm of the application. DETAILED DESCRIPTION

[0024] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of the present application.

[0025] The concepts involved in the present application will be described below in combination with the drawings. It should be pointed out here that the following description of each concept is only to make the content of the present application easier to understand, and does not mean a limitation on the protection scope of the present application. Meanwhile, the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0026] In combination with the drawings of the specification Figure 1 The present application adopts the following technical solutions: An active vibration isolation control method, comprising the following steps: Step S1: collecting operation and control information of an ultra-precision device and foundation vibration information where the ultra-precision device is located to determine vibration information data; Step S2: importing the vibration information data into a multi-core control system and pre-processing to obtain pre-processed vibration information data; including: Step S21: removing outliers from the vibration information data based on the 3sigma principle (normal distribution statistics) to obtain removed vibration information data; Step S22: inputting the removed vibration information data into a Butterworth filter (preferably 6th order or higher order) to perform anti-aliasing filtering on the removed vibration information data, eliminating distortion of the vibration information data caused by frequency aliasing in the sampling process, and obtaining pre-processed vibration information data.

[0027] Step S3: inputting the pre-processed vibration information data into a rectangular integral PID algorithm in the multi-core control system to obtain a PID output; Step S4: obtaining a control instruction of an actuator based on the PID output, and controlling the actuator to respond according to the control instruction to generate a reverse vibration signal to offset the vibration; Step S5: obtaining a vibration error of the ultra-precision device after isolation based on the reverse vibration signal, adjusting initial parameters (including proportional parameter Kp, integral parameter Ki, and differential parameter Kd) of the rectangular integral PID algorithm when the vibration error after isolation does not meet a preset condition, and repeating the steps S3-S4, and ending the active vibration isolation control when the vibration error after isolation meets the preset condition.

[0028] In combination with the drawings of the specification Figure 2The steps of the rectangular integral PID algorithm of the present application are introduced, and the rectangular integral PID algorithm specifically comprises: step S31: defining initial parameters of the PID algorithm, the initial parameters comprising a proportional parameter Kp, an integral parameter Ki, a differential parameter Kd, and a vibration reference value; step S32: based on the preprocessed vibration information data and the vibration reference value, calculating a current error error (that is, subtracting the preprocessed vibration information data from the vibration reference value), and obtaining a previous error Lerror, which can be an average error of a previous sampling period; step S33: setting an initial moving window Mwindow and an initial integral value I1; step S34: calculating an integral update value I2 based on the rectangular integral logic; step S35: comparing the absolute value of the difference between I1 and I2 with a preset threshold value, when the difference is greater than the preset threshold value, adjusting the initial moving window Mwindow to obtain an adjusted moving window, and based on the adjusted moving window, executing step S34; when the difference is less than or equal to the preset threshold value, taking the integral update value I2 as a final integral update value I2f, and obtaining a PID output.

[0029] In the step S34, the integral update value I2 is calculated based on the rectangular integral logic, specifically: step S341: performing iterative calculation according to the following logic:

[0030] ;

[0031] Where i represents the iteration number, i=0, 1, …, round(1 / Mwindow)-1, round represents the rounding function, Mwindow represents the initial moving window, I2 represents the integral update value, I1 i represents the iteration variable, I10=I1, k1 represents the first adjustment coefficient (preferably a positive number greater than 0 and less than 1), k2 represents the second adjustment coefficient (preferably a positive number greater than 1 and less than 3), Lerror represents the previous error, and error represents the current error; step S342: taking the I1 i+1 completed by iteration as the integral update value I2.

[0032] Further, in the step S35, the initial moving window Mwindow is adjusted, specifically by multiplying the initial moving window Mwindow by a first proportionality coefficient kp1 to obtain an adjusted moving window. In the present application, the first proportionality coefficient kp1 is preferably a positive number less than 1 and greater than 0. Through the adjustment of the moving window, a larger moving window is used at the beginning to quickly realize integral value calculation, and the moving window is gradually contracted for cases where the error changes dramatically, which can ensure calculation accuracy while optimizing calculation efficiency.

[0033] Further, in the step S35, the PID output is obtained, specifically:

[0034] ;

[0035] Wherein OUTpid represents the PID output, it can be seen that the above PID output is the sum of the proportional term, the integral term and the differential term, the proportional term can respond to the error adjustment output result, the integral term can eliminate the static error, and the differential term can suppress the overshoot of the output result.

[0036] The application further provides an active vibration isolation control system for executing the active vibration isolation control method, the active vibration isolation control system comprising a sensor, a multi-core control system and an actuator, the sensor being connected to the multi-core control system, and the multi-core control system being connected to the actuator.

[0037] The multi-core control system can comprise an FPGA and a DSP, the FPGA being used for pre-processing vibration information of the ultra-precision equipment acquired by the sensor and sending the pre-processed vibration information data to the DSP, and the DSP being used for executing the rectangular integral PID algorithm. The multi-core control system can also comprise an ARM and a DSP, the ARM being used for pre-processing vibration information of the ultra-precision equipment acquired by the sensor and sending the pre-processed vibration information data to the DSP, and the DSP being used for executing the rectangular integral PID algorithm. The active vibration isolation control system of the application can be compatible with different models of ARM, DSP and FPGA.

[0038] The above embodiments and / or implementation manners are only used to illustrate the preferred embodiments and / or implementation manners of the application, and do not limit the implementation manners of the application in any form. Any person skilled in the art can make some changes or modifications or other equivalent embodiments without departing from the scope of the technical means disclosed in the application, but should be considered as the same technology or embodiment as the application.

[0039] The principles and implementation manners of the application are described by using specific examples in the present application, and the above embodiment descriptions are only used to help understand the method and its core idea of the application. The above descriptions are only preferred embodiments of the application, and it should be pointed out that due to the limited nature of the language expression, there are infinite specific structures, and for ordinary skilled persons in the technical field, some improvements, refinements or changes can be made without departing from the principles of the application, and the above technical features can be combined in an appropriate manner; these improvements, refinements, changes or combinations, or the application of the inventive concept and technical solution to other occasions without improvement, should be considered as the protection scope of the application.

Claims

1. An active vibration isolation control method, characterized in that, Includes the following steps: Step S1: Collect vibration information from the ultra-precision equipment to obtain vibration data; Step S2: Import the vibration information data into the multi-core control system and preprocess it to obtain preprocessed vibration information data; Step S3: In the multi-core control system, the preprocessed vibration information data is input into the rectangular integral PID algorithm to obtain the PID output; The rectangular integral PID algorithm includes: Step S31: Define the initial parameters of the PID algorithm, including the proportional parameter Kp, the integral parameter Ki, the derivative parameter Kd, and the vibration reference value; Step S32: Based on the preprocessed vibration information data and vibration reference values, calculate the current error error and obtain the previous error Lerror; Step S33: Set the initial moving window Mwindow and the initial integral value I1; Step S34: Calculate the integral update value I2 based on the rectangular integral logic, specifically as follows: Step S341: Perform iterative calculations according to the following logic: ； Where i represents the iteration number, i = 0, 1, ..., round(1 / Mwindow)-1, round represents the rounding function, Mwindow represents the initial moving window, I2 represents the integral update value, and I1 represents the integral update value. i Let I10 represent the iteration variable, k1 represent the first adjustment coefficient, k2 represent the second adjustment coefficient, Lerror represent the previous error, and error represent the current error. Step S342: Transfer the completed iteration I1 i+1 As the integral update value I2; Step S35: Compare the absolute value of the difference between I1 and I2 with the size of a preset threshold. When the difference is greater than the preset threshold, adjust the initial moving window Mwindow to obtain the adjusted moving window, and execute step S34 based on the adjusted moving window. When the difference is less than or equal to the preset threshold, use the integral update value I2 as the final integral update value I2f to obtain the PID output. Step S4: Obtain the control command for the actuator based on the PID output, and control the actuator to respond according to the control command to generate a reverse vibration signal; Step S5: Obtain the vibration error of the ultra-precision equipment after vibration isolation based on the reverse vibration signal. When the vibration error after vibration isolation does not meet the preset conditions, adjust the initial parameters of the rectangular integral PID algorithm and repeat steps S3-S4. When the vibration error after vibration isolation meets the preset conditions, end the active vibration isolation control.

2. The active vibration isolation control method according to claim 1, characterized in that, Step S2 involves importing the vibration information data into the multi-core control system and performing preprocessing, including: Step S21: Remove outliers from the vibration information data to obtain the removed vibration information data; Step S22: Perform anti-aliasing filtering on the removed vibration information data to obtain preprocessed vibration information data.

3. The active vibration isolation control method according to claim 1, characterized in that, In step S35, adjusting the initial moving window Mwindow specifically involves multiplying the initial moving window Mwindow by a first proportional coefficient kp1 to obtain the adjusted moving window.

4. The active vibration isolation control method according to claim 3, characterized in that, The PID output is obtained in step S35 as follows: ； Where OUTpid represents the PID output.

5. An active vibration isolation control system, used to execute the active vibration isolation control method according to any one of claims 1-4, characterized in that, The active vibration isolation control system includes a sensor, a multi-core control system, and an actuator. The sensor is connected to the multi-core control system, and the multi-core control system is connected to the actuator.

6. The active vibration isolation control system according to claim 5, characterized in that, The multi-core control system includes an FPGA and a DSP. The FPGA is used to preprocess the vibration information of the ultra-precision equipment acquired by the sensor and send the preprocessed vibration information data to the DSP. The DSP is used to execute the rectangular integral PID algorithm.

7. The active vibration isolation control system according to claim 5, characterized in that, The multi-core control system includes an ARM and a DSP. The ARM is used to preprocess the vibration information of the ultra-precision equipment acquired by the sensor and send the preprocessed vibration information data to the DSP. The DSP is used to execute the rectangular integral PID algorithm.

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