A servo system vibration suppression method, device and medium

Abstract

This application discloses a vibration suppression method, device, and medium for a servo system. By combining two sets of notch filters and a set of A-mode vibration suppression, it can simultaneously suppress vibrations of three different frequencies, while avoiding phase interference caused by the notch filter frequencies being close together. In principle, the notch filter removes the signal, while the A-mode vibration suppression compensates for the signal. By improving the effectiveness and robustness of vibration suppression through these two different dimensions, the application enhances the effectiveness and robustness of vibration suppression.

Description

Technical Field

[0001] This application relates to the field of servo system technology, and in particular to a servo system vibration suppression method, device and medium. Background Technology

[0002] During operation, servo systems generate vibrations due to various factors, including mechanical and electrical control systems. These vibrations accelerate equipment wear and aging, and reduce control accuracy. Therefore, suppressing servo system vibration is a crucial engineering issue. Currently, vibration suppression in general-purpose servos is achieved through several methods, each with its own characteristics and limitations: 1. Current feedback filter circuit: Using hardware circuitry to perform low-pass filtering on the current can reduce noise from current feedback and make the current control loop less prone to high-frequency vibrations. However, this method has significant drawbacks. First, the cutoff frequency of the hardware circuitry's low-pass filter is fixed and cannot be freely adjusted. Second, the cutoff frequency for low-frequency filtering of current feedback cannot be too low, otherwise it will severely affect the system's response speed and cause excessive operational deviations in general-purpose servos. Therefore, this method can only solve some of the high-frequency vibrations caused by feedback and is ineffective against the medium- and low-frequency vibrations that may occur during the operation of general-purpose servos.

[0003] 2. Notch filter algorithm: Notch filters are widely used in vibration analysis. A traditional notch filter is a type of band-stop filter that filters out signals of a specific frequency, typically used in control systems for resonance or fixed-frequency vibration. Because a notch filter is essentially a band-stop filter, it causes a phase change in the signal near the target frequency; the deeper the notch, the greater the phase effect. Therefore, a notch filter may induce stronger vibrations when two vibration frequencies are close, presenting significant limitations. Furthermore, the load on general-purpose servos varies randomly during operation, and the vibration frequency may change with variations in load and structure. Since typical notch filters can only be set to a fixed frequency, they cannot handle complex operating environments.

[0004] 3. Vibration prediction: By establishing a dynamic model of the system and accurately identifying relevant equipment parameters, the system's operating state is predicted using system feedback signals as input. This determines whether vibration has occurred and feeds the vibration frequency to algorithms such as notch filters. This method can handle changing operating postures, but it places high demands on system parameters, such as inertia and inductance, which need to be identified online with high accuracy. When the predicted frequencies differ significantly or are unstable, the general-purpose servo may operate abnormally, potentially causing harm to operators or the production line. Summary of the Invention

[0005] This application provides a vibration suppression method, device, and medium for a servo system. Its advantage lies in using a combination of two notch filters and a type A vibration suppression system to simultaneously suppress vibrations of three different frequencies, while avoiding phase interference caused by the notch filter frequencies being too close. In principle, the notch filter removes the signal, while the type A vibration suppression compensates for the signal, thus improving the effectiveness and robustness of vibration suppression through these two different dimensions.

[0006] The technical solution of this application is as follows: On the one hand, this application provides a vibration suppression method for a servo system, comprising the following steps: Acquire servo system operation data and detect whether vibration occurs based on the operation data; Configure a first notch filter, a second notch filter, and a type A vibration suppression algorithm to suppress vibration when it occurs.

[0007] Furthermore, the servo system operating data includes current and speed feedback signals. The current and speed feedback signals are subjected to a fast Fourier transform to obtain a vibration signal. When the vibration amplitude in the vibration signal reaches a set threshold, vibration is determined to have occurred.

[0008] Furthermore, the first and second notch filters are used to suppress vibrations above 300Hz, and when the first and second notch filters are used simultaneously, the frequency interval between the two notch filters is greater than 100Hz; the type A vibration suppression algorithm is used to suppress vibrations below 2000Hz.

[0009] Furthermore, the first notch filter, the second notch filter, and the Type A vibration suppression algorithm are enabled through the following control logic: When vibration is detected and the maximum vibration frequency is greater than 300Hz, the first notch filter is activated to suppress vibration; when the first notch filter is already activated or the vibration suppression is ineffective, the second notch filter is activated to suppress vibration; when the vibration frequency is less than 2000Hz and both the first and second notch filters are already activated or the vibration suppression is ineffective, the Type A vibration suppression algorithm is activated to suppress vibration. When vibration is detected and the maximum vibration frequency is no greater than 300Hz, the Type A vibration suppression algorithm is activated to suppress vibration.

[0010] Furthermore, when the first or second notch filter is activated, the effectiveness of vibration suppression is determined by the following steps: Write the vibration suppression frequency into the notch filter and set the depth of the notch filter to 20; After running for a set time, a vibration test is performed: if the vibration disappears or the vibration frequency is not near the notch filter's suppression frequency, the vibration suppression is deemed effective, and the notch filter parameters are saved. If the vibration frequency is still near the suppression frequency of the notch filter, determine whether the vibration amplitude has decreased. If it has not decreased, the notch filter is deemed ineffective in suppressing vibration. If the amplitude has decreased, deepen the notch filter until the notch filter depth is 0. If the vibration frequency is still near the suppression frequency when the notch filter depth is 0, the notch filter is deemed ineffective in suppressing vibration.

[0011] Furthermore, when the Type A vibration suppression algorithm is enabled, the effectiveness of vibration suppression is determined through the following steps: Write the damping frequency into the Type A damping algorithm; After running for a set time, vibration detection is performed: if the vibration disappears or the vibration frequency is not near the suppression frequency of the Type A vibration suppression algorithm, the vibration suppression is deemed effective, and the parameters of the Type A vibration suppression algorithm are saved. If the vibration frequency is still near the suppression frequency of the Type A vibration suppression algorithm, determine whether the vibration amplitude has decreased. If it has not decreased, the Type A vibration suppression algorithm is deemed ineffective. If the amplitude has decreased, increase the Type A vibration suppression damping up to 500 and deepen the notch filter until the notch filter depth is 0. If the vibration frequency is still near the suppression frequency when the Type A vibration suppression damping is 500, the Type A vibration suppression algorithm is deemed ineffective.

[0012] Furthermore, when the first notch filter, the second notch filter, and the Type A vibration suppression algorithm are all ineffective, it is determined as a suppression failure. The number of suppression failures is counted. When the number of suppression failures is less than 3, all vibration suppression parameters are reset. If the number of suppression failures is not less than 3, automatic vibration suppression is exited directly, and a vibration suppression failure alarm is issued.

[0013] Furthermore, the first notch filter, the second notch filter, and the A-type vibration suppression algorithm are controlled by a state machine.

[0014] In another aspect, this application provides a servo system vibration suppression device, including a processor and a memory, wherein the memory stores a computer program, and when the computer program is called and executed by the processor, it implements the steps in the method described above.

[0015] In another aspect, this application provides a computer-readable medium storing a computer program that, when executed by a computer, implements the steps in the method described above.

[0016] In summary, the beneficial effects of this application are as follows: 1. Combination of Multiple Vibration Suppression Algorithms: By combining two sets of notch filters and one set of A-type vibration suppression, vibrations of three different frequencies can be suppressed simultaneously. This also avoids the phase interference problem caused by the notch filter frequencies being close together. In principle, the notch filter removes the signal, while the A-type vibration suppression compensates for the signal; these two different approaches improve the effectiveness and robustness of vibration suppression.

[0017] 2. Automatic Vibration Suppression: Through detailed state machine design and data processing, the vibration frequency is identified and fed into an algorithm for targeted vibration suppression. This method solves the problem that notch filters and A-type vibration damping can only suppress fixed frequencies when working independently. Furthermore, due to the diverse applications of general-purpose servo systems, automated vibration suppression has become the preferred choice for this type of application.

[0018] 3. Significant Vibration Suppression Efficiency: Generally, a typical servo motor may have 2-3, or even more, vibration frequencies. Traditional debugging methods involve manually testing relevant data, analyzing it, and then using a combination of methods to input the vibration frequency parameters to the target location. This method is inefficient, and the servo system remains in an abnormal vibration state during testing, which is dangerous and could potentially cause property damage. This technology, however, can analyze the vibration frequency and update the vibration parameters synchronously within 6ms, offering high efficiency and safety. Attached Figure Description

[0019] Figure 1 This is a block diagram of the control serial relationship in a servo system; Figure 2 This is a schematic diagram of the basic initialization process of a servo system; Figure 3 This is a state machine state-one logic block diagram; Figure 4 This is a state machine state two logic block diagram; Figure 5 This is a three-state logic block diagram of a state machine; Figure 6 This is the block diagram of vibration suppression logic A. Detailed Implementation

[0020] The specific embodiments of this application are described in detail below with reference to the accompanying drawings.

[0021] A specific embodiment of this application provides a servo system vibration suppression method, including the following steps: acquiring servo system operating data; detecting whether vibration occurs based on the operating data; configuring a first notch filter, a second notch filter, and a type A vibration suppression algorithm to suppress vibration when it occurs. Figure 1 As shown.

[0022] The servo system's operating data includes current and speed feedback signals. A fast Fourier transform is performed on these signals to obtain a vibration signal. Vibration is determined to occur when the vibration amplitude in the vibration signal reaches a set threshold. The first and second notch filters are used to suppress vibrations above 300Hz, and when both filters are activated simultaneously, the frequency interval between their suppression frequencies is greater than 100Hz. The Type A vibration suppression algorithm is used to suppress vibrations below 2000Hz, as shown in the table below.

[0023] Frequency range / Hz Using algorithms Remark 300<<2000 Notch filter or Type A vibration suppression The rejection frequencies of the two notch filters need to be more than 100Hz apart. >2000 Notch filter The rejection frequencies of the two notch filters need to be more than 100Hz apart. <300 Type A vibration suppression The general frequency is not less than 100Hz.

[0024] By real-time identification of the current and speed feedback signals of the servo system, a Fast Fourier Transform (FFT) is performed on the current feedback and speed deviation to obtain the real-time vibration signal. Through state machine design, the actual vibration frequency is identified, and this frequency is automatically fed into a Type A vibration suppression algorithm or a notch filter for vibration suppression. This scheme solves both the limitation of notch filters operating independently and the uncertainty of model prediction. The core technologies lie in real-time data processing, the Type A vibration suppression algorithm, the state machine, and automatic vibration suppression. This technology is generally used for vibration suppression above 100Hz; low-frequency jitter at the end is not within the scope of this research.

[0025] The first notch filter, the second notch filter, and the Type A vibration damping algorithm are enabled through the following control logic: When vibration is detected and the maximum vibration frequency is greater than 300Hz, the first notch filter is activated to suppress vibration; when the first notch filter is already activated or the vibration suppression is ineffective, the second notch filter is activated to suppress vibration; when the vibration frequency is less than 2000Hz and both the first and second notch filters are already activated or the vibration suppression is ineffective, the Type A vibration suppression algorithm is activated to suppress vibration. When vibration is detected and the maximum vibration frequency is no greater than 300Hz, the Type A vibration suppression algorithm is activated to suppress vibration.

[0026] When the first or second notch filter is activated, determine whether the vibration suppression is effective by following these steps: Write the vibration suppression frequency into the notch filter and set the depth of the notch filter to 20; After running for a set time, a vibration test is performed: if the vibration disappears or the vibration frequency is not near the notch filter's suppression frequency, the vibration suppression is deemed effective, and the notch filter parameters are saved. If the vibration frequency is still near the suppression frequency of the notch filter, determine whether the vibration amplitude has decreased. If it has not decreased, the notch filter is deemed ineffective in suppressing vibration. If the amplitude has decreased, deepen the notch filter until the notch filter depth is 0. If the vibration frequency is still near the suppression frequency when the notch filter depth is 0, the notch filter is deemed ineffective in suppressing vibration.

[0027] When the Type A vibration suppression algorithm is enabled, the following steps are used to determine whether the vibration suppression is effective: Write the damping frequency into the Type A damping algorithm; After running for a set time, vibration detection is performed: if the vibration disappears or the vibration frequency is not near the suppression frequency of the Type A vibration suppression algorithm, the vibration suppression is deemed effective, and the parameters of the Type A vibration suppression algorithm are saved. If the vibration frequency is still near the suppression frequency of the Type A vibration suppression algorithm, determine whether the vibration amplitude has decreased. If it has not decreased, the Type A vibration suppression algorithm is deemed ineffective. If the amplitude has decreased, increase the Type A vibration suppression damping up to 500 and deepen the notch filter until the notch filter depth is 0. If the vibration frequency is still near the suppression frequency when the Type A vibration suppression damping is 500, the Type A vibration suppression algorithm is deemed ineffective.

[0028] Whether the vibration frequency is near the damping frequency is determined by the difference between the vibration frequency and the damping frequency. In this embodiment, a frequency difference of less than 180Hz is considered as a close frequency.

[0029] When the first notch filter, the second notch filter, and the Type A vibration suppression algorithm are all ineffective, it is determined as a suppression failure. The number of suppression failures is counted. When the number of suppression failures is less than 3, all vibration suppression parameters are reset. If the number of suppression failures is not less than 3, automatic vibration suppression is exited directly and a vibration suppression failure alarm is issued.

[0030] In this embodiment, vibration suppression of the servo system also includes a manual vibration suppression mode. The manual vibration suppression mode involves manually inputting vibration parameters to suppress a fixed vibration frequency, which is existing technology. This embodiment combines the manual vibration suppression mode and the automatic vibration suppression mode; the automatic vibration suppression mode employs the aforementioned vibration suppression method. Figure 2 As shown, after the servo system is powered on, it reads the parameter configuration from the relevant configuration registers, including preset vibration threshold, vibration frequency, notch filter depth, notch filter width, and vibration suppression mode status flag. Based on the read parameters, it determines whether to enter automatic or manual vibration suppression. Automatic vibration suppression dynamically identifies the vibration frequency during operation and suppresses vibration through state machine transitions. Manual vibration suppression involves manually inputting vibration parameters to suppress a fixed vibration frequency.

[0031] If entering automatic vibration suppression mode, the frequency threshold for automatic vibration suppression, the parameters for type A vibration suppression, the frequency of the notch filter, the notch depth, the notch width, etc., are initialized. If entering manual mode, the corresponding data in the parameter configuration is read, such as the relevant frequency, gain, damping, etc. of the notch filter and type A vibration suppression.

[0032] In automatic vibration damping mode, the system enters the automatic vibration damping state machine, performing real-time FFT analysis of current feedback and velocity deviation. It outputs the corresponding frequency every 500 data points, and automatically dampes vibration when a vibration frequency is detected. In manual mode, it directly enters the relevant functions for notch filter or Type A vibration damping.

[0033] The first notch filter, the second notch filter, and the A-type vibration suppression algorithm are controlled by a state machine. The state machine logic is as follows: Figure 3-5 .

[0034] 1. State 1: Automatically use the first notch filter to suppress vibration. After the system starts running, it checks for vibration. When the detected vibration amplitude exceeds a set threshold, it checks if the first notch filter is being used. If it is, it jumps to state two; otherwise, it records the maximum vibration frequency f1 and its corresponding amplitude G1. It checks if f1 is greater than 300Hz. If not, it jumps to state three; if it is, it writes f1 to the first notch filter and sets its depth to 20. After running 2500 sets of data, it checks if vibration still exists. If not, it saves the relevant parameters of the first notch filter and continues waiting for vibration to reappear. If vibration still exists, and the vibration frequency is not close to f1, it saves the relevant parameters of the first notch filter and jumps back to state one. If the vibration frequency is still near f1, it checks if the amplitude G1 has decreased. If it has not decreased, it jumps to state three. If G1 decreases, the depth of the first notch filter is increased until the depth of the first notch filter is 0. If the vibration frequency is still near f1 when the depth of the first notch filter is 0, then jump to state three. If the frequency f1 is effectively suppressed during the process of decreasing to 0, then save the relevant parameters of the first notch filter.

[0035] 2. State Two: Automatically use the second notch filter to suppress vibration. After jumping to state two, it checks if vibration exists. If the vibration amplitude is greater than a set threshold, it checks if the second notch filter is used. If it is used, it jumps to state three. If not, it records the vibration frequency f2 with the largest current amplitude and the corresponding amplitude G2. It checks if f2 is greater than 300Hz and not near f1. If not, it jumps to state three. If it is, f2 is written to the second notch filter and the depth of the second notch filter is set to 20. After running 2500 sets of data, it checks if vibration still exists. If not, it saves the relevant parameters of the second notch filter and continues to wait for vibration to appear. If vibration still exists and the vibration frequency is not close to f2, it saves the relevant parameters of the second notch filter and jumps back to state one. If the vibration frequency is still near f2, it checks if the amplitude G2 has decreased. If it has not decreased, it jumps to state three. If G2 decreases, the depth of the second notch filter is increased until the depth of the second notch filter is 0. If the vibration frequency is still near f2 when the depth of the second notch filter is 0, then jump to state three. If the frequency f2 is effectively suppressed during the process of decreasing to 0, then save the relevant parameters of the second notch filter.

[0036] 3. State Three: Automatically use Type A vibration damping. After jumping to state three, it checks if vibration exists. If the detected vibration amplitude is greater than the set threshold, it checks if type A vibration suppression is used. If used, the vibration suppression failure counter is incremented. If the vibration suppression failure counter is less than 3, all vibration suppression parameters are reset and the process jumps to state one. If the vibration suppression failure counter is not less than 3, automatic vibration suppression exits directly, and vibration suppression is considered a failure. If type A vibration suppression is not used when the detected vibration frequency is greater than the set threshold, the vibration frequency f3 with the largest current amplitude and the corresponding amplitude G3 are recorded. f3 is written into type A vibration suppression. After running 2500 sets of data, it checks if vibration still exists. If not, the relevant parameters of type A vibration suppression are saved, and the process continues to wait for vibration to reappear. If vibration still exists, and the vibration frequency is not close to f3, the relevant parameters of type A vibration suppression are saved, and the process jumps back to state one. If the vibration frequency is still near f3, it checks if the amplitude G3 has decreased. If it has not decreased, the vibration suppression failure counter is incremented. If G3 decreases, increase the type A damping up to 500. If the vibration frequency is still near f3 when the type A damping is 500, increment the damping failure counter. If the frequency f3 is effectively suppressed during the increase to 500, save the relevant parameters of type A damping.

[0037] The control principle block diagram of the Type A vibration suppression algorithm is as follows: Figure 6 First, the target signal is differentiated. The greater the signal fluctuation, the stronger the differentiation effect; when the signal is stable, the differentiation effect is zero. Differentiation is equivalent to increasing the system's attenuation of the signal, thus increasing the system's damping. The fundamental reason for the oscillation or even instability of a closed-loop control system lies in the large lag factor. The differentiation term can predict the trend of error changes, and this leading effect can offset the influence of the lag factor. Appropriate differentiation control can reduce overshoot and increase system stability. Then, the differentiated signal is processed, including but not limited to bandpass filtering and high-pass filtering. The main purpose is to extract the required relevant signals and remove DC information.

[0038] The basic principle of a notch filter is a second-order band-stop filter. Through parameter transformation, the parameters of the notch filter are adjusted to three parameters: notch frequency, notch depth, and notch width. This parameter transformation maps the relevant parameters of the band-stop filter to the application of the notch filter, allowing algorithm developers to intuitively use the corresponding functions. The advantage of using a second-order filter is that it can effectively suppress parameters at the corresponding frequency while minimizing the impact on the phase near the notch frequency, making the target system more stable and robust.

[0039] Another embodiment of this application provides a servo system vibration suppression device, including a processor and a memory. The memory stores a computer program, which, when executed by the processor, implements the steps in the method described above.

[0040] Another embodiment of this application provides a computer-readable medium storing a computer program, which, when executed by a computer, implements the steps in the method described above.

[0041] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several modifications and improvements can be made without departing from the inventive concept of this application, and these all fall within the protection scope of this application.

Claims

1. A vibration suppression method for a servo system, characterized in that, Includes the following steps: Acquire servo system operation data and detect whether vibration occurs based on the operation data; Configure a first notch filter, a second notch filter, and a type A vibration suppression algorithm to suppress vibration when it occurs.

2. The servo system vibration suppression method according to claim 1, characterized in that, The servo system operation data includes current and speed feedback signals. The current and speed feedback signals are subjected to fast Fourier transform to obtain vibration signals. When the vibration amplitude in the vibration signal reaches a set threshold, vibration is determined to have occurred.

3. The servo system vibration suppression method according to claim 1, characterized in that, The first and second notch filters are used to suppress vibrations above 300Hz, and when the first and second notch filters are used simultaneously, the frequency interval between the two notch filters is greater than 100Hz; the type A vibration suppression algorithm is used to suppress vibrations below 2000Hz.

4. The servo system vibration suppression method according to claim 3, characterized in that, The first notch filter, the second notch filter, and the Type A vibration suppression algorithm are enabled through the following control logic: When vibration is detected and the maximum vibration frequency is greater than 300Hz, the first notch filter is activated to suppress vibration; when the first notch filter is already activated or the vibration suppression is ineffective, the second notch filter is activated to suppress vibration; when the vibration frequency is less than 2000Hz and both the first and second notch filters are already activated or the vibration suppression is ineffective, the Type A vibration suppression algorithm is activated to suppress vibration. When vibration is detected and the maximum vibration frequency is no greater than 300Hz, the Type A vibration suppression algorithm is activated to suppress vibration.

5. The servo system vibration suppression method according to claim 4, characterized in that, When the first or second notch filter is activated, determine whether the vibration suppression is effective by following these steps: Write the vibration suppression frequency into the notch filter and set the depth of the notch filter to 20; After running for a set time, a vibration test is performed: if the vibration disappears or the vibration frequency is not near the notch filter's suppression frequency, the vibration suppression is deemed effective, and the notch filter parameters are saved. If the vibration frequency is still near the suppression frequency of the notch filter, determine whether the vibration amplitude has decreased. If it has not decreased, the notch filter is deemed ineffective in suppressing vibration. If the amplitude has decreased, deepen the notch filter until the notch filter depth is 0. If the vibration frequency is still near the suppression frequency when the notch filter depth is 0, the notch filter is deemed ineffective in suppressing vibration.

6. The servo system vibration suppression method according to claim 4, characterized in that, When the Type A vibration suppression algorithm is enabled, the following steps are used to determine whether the vibration suppression is effective: Write the damping frequency into the Type A damping algorithm; After running for a set time, vibration detection is performed: if the vibration disappears or the vibration frequency is not near the suppression frequency of the Type A vibration suppression algorithm, the vibration suppression is deemed effective, and the parameters of the Type A vibration suppression algorithm are saved. If the vibration frequency is still near the suppression frequency of the Type A vibration suppression algorithm, determine whether the vibration amplitude has decreased. If it has not decreased, the Type A vibration suppression algorithm is deemed ineffective. If the amplitude has decreased, increase the Type A vibration suppression damping up to 500 and deepen the notch filter until the notch filter depth is 0. If the vibration frequency is still near the suppression frequency when the Type A vibration suppression damping is 500, the Type A vibration suppression algorithm is deemed ineffective.

7. The servo system vibration suppression method according to claim 5 or 6, characterized in that, When the first notch filter, the second notch filter, and the Type A vibration suppression algorithm are all ineffective, it is determined as a suppression failure. The number of suppression failures is counted. When the number of suppression failures is less than 3, all vibration suppression parameters are reset. If the number of suppression failures is not less than 3, automatic vibration suppression is exited directly and a vibration suppression failure alarm is issued.

8. The servo system vibration suppression method according to claim 1, characterized in that, The first notch filter, the second notch filter, and the A-type vibration suppression algorithm are controlled by a state machine.

9. A vibration suppression device for a servo system, characterized in that, It includes a processor and a memory, the memory storing a computer program, which, when executed by the processor, implements the steps of the method as described in any one of claims 1-8.

10. A computer-readable medium, characterized in that, The computer-readable medium stores a computer program that, when executed by a computer, implements the steps of the method as described in any one of claims 1-8.

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