Real-time detection method and system for motor-driven mechanical oscillation based on SOGI-FLL

Abstract

The present invention relates to the technical field of motor excitation test, and discloses a real-time detection method and system for motor-driven mechanical oscillation based on SOGI-FLL. The method extracts a given speed signal based on the SOGI-FLL strategy, detects the amplitude and frequency of the observed speed corresponding to the given speed signal in real time, and determines that oscillation occurs if the threshold is exceeded for a specified time. The scheme can detect the amplitude and frequency of the given speed in advance, and issue a fault alarm when the motor outputs an obvious oscillation signal, thereby improving the service life of the objective lens switcher system; the software strategy is adopted instead of the hardware method, which reduces the cost of additional detection equipment and system redundancy of the system on the one hand, and can flexibly adjust the oscillation detection threshold on the other hand, thereby improving the flexibility and accuracy of the detection.

Description

Technical Field

[0001] The present invention relates to the technical field of motor excitation testing, and in particular to a method and system for real-time detection of motor-driven mechanical oscillation based on SOGI-FLL. Background Art

[0002] With the development of the semiconductor industry, the imaging accuracy requirements of semiconductor inspection equipment are getting higher and higher. The usual semiconductor inspection process is to quickly scan under a low-power microscope. When a large defect is detected, a high-power microscope is used to obtain a clearer image. In order to meet the needs of different objective lenses and improve the efficiency of semiconductor inspection, a separate objective lens switching device, the objective lens switcher, is required. In order to obtain a clear and non-shaking image under a high-power microscope, the accuracy requirements of the objective lens switcher in the locked state are higher. For example, if the static jitter exceeds +-0.1µm under a 20x microscope, the image jitter will be more serious. For a 50x microscope, the static jitter requirements are higher. Therefore, for a lens switcher-like system, a suitable way to detect system oscillation is essential. The source of the oscillation of the lens switcher-like system may be excessive load (excessive load on the objective lens), unreasonable parameter settings, and gaps during installation (irregular use). For such high-precision equipment, too many system oscillations will cause static jitter, thereby affecting the service life.

[0003] At present, the objective lens switcher system oscillation detection technology usually uses hardware detection devices for detection, and the common ones are acceleration fluctuation detection devices, position fluctuation detection devices, force fluctuation detection devices, and speed fluctuation devices. On the one hand, the detection of hardware detection devices will increase the redundancy and construction cost of the entire system. On the other hand, it cannot be used for small systems. Small systems such as objective lens switcher systems are not suitable for adding additional detection equipment. In addition, although there is a patent proposing the SOGI-FLL strategy, the fields of application are different, and there are differences in the implementation of the strategy, and it cannot be directly used in the field of system oscillation detection.

[0004] Therefore, for motor-driven mechanical vibration detection such as objective lens switching systems, the existing technology lacks a solution that can be controlled from the software level and does not require additional hardware equipment. Summary of the invention

[0005] In order to solve the problems in the prior art, an object of the embodiments of the present invention is to provide a method and system for real-time detection of motor drive mechanical oscillation based on SOGI-FLL.

[0006] In order to achieve the above-mentioned objectives, the first aspect of the present invention provides a real-time detection method for motor-driven mechanical oscillation based on SOGI-FLL. The speed given signal is extracted based on the SOGI-FLL strategy, and the amplitude and frequency of the observed speed corresponding to the speed given signal are detected in real time. If the threshold is exceeded for a specified time, it is determined that oscillation occurs.

[0007] The second aspect of the present invention provides a real-time detection system for motor-driven mechanical oscillation based on SOGI-FLL, comprising:

[0008] A digital controller is used to extract a speed given signal based on the SOGI-FLL strategy and detect the amplitude and frequency of the observed speed corresponding to the speed given signal in real time;

[0009] A timer, used to determine the time when the amplitude and frequency of the observed speed exceed the threshold value according to the detection result of the digital controller;

[0010] The control module is used to receive the timing result of the timer, and determine that oscillation occurs if the timing result exceeds a preset time.

[0011] A third aspect of the present invention provides a machine-readable storage medium having instructions stored thereon, the instructions being used to enable a machine to execute the above-mentioned method for real-time detection of motor-driven mechanical oscillation based on SOGI-FLL.

[0012] Through the above technical scheme, the objective lens switcher system oscillation detection strategy based on SOGI-FLL can solve the problem that the objective lens switcher system causes static jitter due to multiple oscillations, thereby affecting the service life of the objective lens switcher. The strategy proposed in the present invention can detect the amplitude and frequency of a given speed in advance, and issue a fault alarm when the motor outputs an obvious oscillation signal, thereby improving the service life of the objective lens switcher system; the use of software strategies rather than hardware methods, on the one hand, reduces the cost of additional system detection equipment and system redundancy, and on the other hand, can flexibly adjust the oscillation detection threshold, improve the flexibility and accuracy of detection, and can ignore the influence of harmonic signals on the oscillation detection logic, with strong anti-interference signal capability; compared with the existing patents using the SOGI-FLL algorithm, the technical scheme of the present invention realizes the application of the algorithm in the field of high-precision motor control.

[0013] Other features and advantages of the embodiments of the present invention will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the embodiments of the present invention, but do not constitute a limitation on the embodiments of the present invention. In the accompanying drawings:

[0015] Figure 1 It is a schematic diagram of the real-time detection process of motor-driven mechanical oscillation based on SOGI-FLL according to an embodiment of the present invention;

[0016] Figure 2 It is a schematic diagram of the embedding points of the SOGI-FLL algorithm in the three-loop control algorithm in the motor cascade control according to an embodiment of the present invention;

[0017] Figure 3 It is a schematic diagram of the implementation principle of the SOGI-FLL algorithm according to an embodiment of the present invention;

[0018] Figure 4 is a curve showing the change of a given speed over time in Test Example 1 of the present invention;

[0019] Figure 5 It is the experimental data curve of observed speed frequency in Test Example 1 of the present invention;

[0020] Figure 6 It is the experimental data curve of observed velocity amplitude in Test Example 1 of the present invention;

[0021] Figure 7 It is a schematic diagram of the simulation model in Test Example 2 of the present invention. DETAILED DESCRIPTION

[0022] The specific implementation of the embodiment of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the embodiment of the present invention, and is not used to limit the embodiment of the present invention.

[0023] The embodiment of the present invention is applicable to the detection of vibrations generated by motor-driven mechanical motion in a lens switching system. Taking the lens switching system as an example, when the lens switcher system actually vibrates, the lens switcher often presents a sinusoidal change at a fixed frequency and amplitude ( V r = A m sin ωt ) is extracted into the formula A m and oh The specific values ​​of these two quantities can be adjusted to determine whether they exceed the detection threshold to generate an oscillation error, thereby preventing the system from experiencing higher energy oscillations and affecting its service life.

[0024] The first aspect of an embodiment of the present invention provides a real-time detection method for motor-driven mechanical oscillation based on SOGI-FLL. The speed given signal is extracted based on the SOGI-FLL strategy, and the amplitude and frequency of the observed speed corresponding to the speed given signal are detected in real time. If the threshold is exceeded for a specified time, it is determined that oscillation occurs.

[0025] The oscillation detection solution used in the embodiment of the present invention solves the problem of system oscillation detection from the software level, has higher detection accuracy, and can conveniently adjust the amplitude of the observation speed and the detection threshold of the frequency, with higher flexibility.

[0026] Furthermore, the real-time detection process of motor drive mechanical oscillation based on SOGI-FLL is as follows: Figure 1 The following is a state machine implementation:

[0027] Step 1: Extract the speed given signal through the SOGI-FLL strategy, detect the amplitude and frequency of the observed speed corresponding to the speed given signal in real time, and V r Real-time detection of amplitude and frequency;

[0028] Step 2: When the detected amplitude is > 800µm / s and the frequency is > 160Hz, the alarm count is increased by 1, otherwise

[0029] Go to step 4; the count is increased by 1 to prevent the oscillation detection from triggering falsely and to improve the robustness of the detection logic, so a time judgment is added; the numerical settings of the amplitude and frequency can be flexibly adjusted according to the application scenario and needs;

[0030] Step 3: When the objective lens switcher system oscillation is detected to last for 200ms (the detection program time interval is about 1ms, and the actual alarm count is about 200 times) or more, it is considered that the objective lens switcher actually oscillates, an error occurs, and the process goes to step 5, otherwise it goes to step 4;

[0031] Step 4: When the condition is not met, the alarm count is reduced by 1 until it is reduced to 0, and the count is kept at 0 to ensure that the next detection count value starts from 0, and the next alarm count is increased by 1 again; the purpose is to detect that when the amplitude and frequency of the value Vr are falsely triggered, 1 will also be added, and when it returns to normal, the error count must be cleared;

[0032] Step 5: The state machine oscillation error flag position is 1 (ERROR=1), and the lens switcher will switch from the LOCK state (it may also be the MOVE state, SLOW state, END_STATE state, DEBUG state) to the unlocked state, and the motor will be unlocked to prevent higher energy vibration from affecting the life of the lens switcher.

[0033] Further, for step 1, the SOGI-FLL strategy The embedding point of the SOGI-FLL algorithm in the three-loop control algorithm is where the position loop outputs and the speed loop is given, such as Figure 2 The motor cascade control schematic diagram is shown in Figure 1. The SOGI-FLL algorithm implementation principle is as follows Figure 3As shown, using a digital controller, the SOGI-FLL control strategy is described in the form of a difference equation:

[0034] The amplitude of the observed velocity is calculated using the formula:

[0035] ,

[0036] The frequency calculation formula of the observed speed is as follows:

[0037] oh ( n+ 1)= oh ( n )+ oh ( n )×K / ( A m ( n+ 1)+0.001)× err ( n )×ETA× QV r ( n+ 1) ×dt oh ( n + 1)≥0.5

[0038] in ,

[0039] V r ( n ) is the given speed at time n, V' r ( n ) is the SOGI-FLL observation speed at time n, QV r ( n ) is the orthogonal component of the SOGI-FLL observed velocity at time n, V' r ( n+ 1) is the SOGI-FLL observation speed at time n+1, QV r ( n+ 1) is the orthogonal component of SOGI-FLL observed velocity at time n+1, oh ( n ) is the frequency of observing the velocity at time n, oh ( n+ 1) is the frequency of observing the velocity at time n+1, err ( n ) is the deviation between the given speed and the observed speed, dt is the speed loop calculation frequency, A m ( n+1) is the amplitude of the observed velocity at time n+1, K is the adjustable control parameter 1, and ETA is the adjustable control parameter 2 and is a negative value.

[0040] like Figure 3 The first part of the control block diagram is a schematic diagram of the amplitude detection principle. Its main function is to extract the observed speed corresponding to a given speed. Vr 'The orthogonal components of the observed values. When the actual system oscillates, the speed given observed values ​​and orthogonal components are expressed as:

[0041] V r = A m sin ωt , Q V r = A m cos ωt

[0042] So according to the formula The amplitude of a given velocity observation can be obtained.

[0043] like Figure 3 The second part of the control block diagram is a schematic diagram of the frequency detection principle. Its main function is to extract the frequency of the given speed observation value, perform normalization processing and frequency limiting. The normalization processing and frequency limiting processing in the frequency calculation formula of the observed speed are very important in the digital controller to implement the detection algorithm. They can avoid the digital controller dividing by 0 and the frequency signal not converging. oh ( n ) is very small, oh ( n+ 1) It is inevitable that it is also very small (the sum of infinitesimal quantities is still an infinitesimal quantity). For example, the frequency limit is not less than 0.5. It is worth noting that the frequency limit can be any number greater than 0 as long as it does not make the detection frequency become an infinitesimal value.

[0044] The principle of this formula to extract the frequency of a given velocity observation is:

[0045] when oh > oh0 When err and Q V ' r In this case, you need to set ETA to a negative value and K to a positive value. oh near oh 0 , oh ( n ) from the top to oh0 Move closer:

[0046] oh (n+ 1)= oh ( n )+ oh ( n )×K / ( A m ( n+ 1)+0.001)× err ( n )×ETA× QV r ( n+ 1) ×dt

[0047] when oh < oh0 When err and Q V ' r In this case, you need to set ETA to a negative value and K to a positive value. oh near oh 0 , oh ( n ) from the bottom to oh0 Move closer:

[0048] oh ( n+ 1)= oh ( n )+ oh ( n )×K / ( A m ( n+ 1)+0.001)× err ( n )×ETA× QV r ( n+ 1)×dt.

[0049] in oh0 is the true frequency of a given speed, which means that the formula can be infinitely close to oh0 , so we can extract the current time oh ( n ) as the frequency of the observed velocity. If there is no clipping, two infinitesimals may be added together, causing the observation strategy to fail.

[0050] Through the technical solution of the present invention, the following beneficial effects are achieved: the speed signal is observed, and the amplitude and frequency of the speed signal are directly obtained through the control strategy. Compared with some offline identification strategies that need to extract data for offline calculation, the present application does not require additional offline calculation; the observed speed signal is lower-limited to effectively avoid the failure of the observation strategy due to the frequency and amplitude of the signal that may not be observed (infinitesimal addition or infinitesimal), thereby improving the preparedness and robustness of the detection; the SOGI-FLL strategy is normalized, and 0.001 is added at the same time to prevent the digital controller from reporting a division error; the SOGI-FLL algorithm is applied in the field of motor oscillation detection, and is inserted at the output of the position loop in the three loops, which will not affect the cascade control of the motor and can detect system oscillation in real time.

[0051] The application field of SOGI-FLL algorithm is the field of motor oscillation detection. It is inserted at the output of the position loop in the three loops and will not affect the cascade control of the motor. It is a real-time system oscillation detection method.

[0052] Based on the same inventive concept, a second aspect of an embodiment of the present invention provides a real-time detection system for motor-driven mechanical oscillation based on SOGI-FLL, comprising:

[0053] A digital controller is used to extract a speed given signal based on the SOGI-FLL strategy and detect the amplitude and frequency of the observed speed corresponding to the speed given signal in real time;

[0054] A timer, used to determine the time when the amplitude and frequency of the observed speed exceed the threshold value according to the detection result of the digital controller;

[0055] The control module is used to receive the timing result of the timer, and determine that oscillation occurs if the timing result exceeds a preset time.

[0056] The working principle of the real-time detection system of motor-driven mechanical oscillation based on SOGI-FLL is as follows:

[0057] Step 1: The digital controller extracts the speed reference signal through the SOGI-FLL strategy, detects the amplitude and frequency of the observed speed corresponding to the speed reference signal in real time, and V r Real-time detection of amplitude and frequency;

[0058] Step 2: The timer determines the time when the amplitude and frequency of the observed speed exceed the threshold value according to the detection result of the digital controller. When the detected amplitude is greater than 800µm / s and the frequency is greater than 160Hz, the alarm count is increased by 1, otherwise the alarm count is cleared and the count is kept at 0 to ensure that the next detection count value starts from 0, and the next alarm count is increased by 1 again;

[0059] Step 3: The control module receives the timing result of the timer. When it is detected that the objective lens switcher system oscillation occurs for 200ms (the detection program time interval is approximately 1ms, and the actual alarm count is approximately 200 times) or more, it is regarded that the objective lens switcher actually oscillates, an error occurs, and the oscillation error flag position 1 (ERROR=1) is controlled to switch the objective lens switcher from the LOCK state (it may also be the MOVE state, SLOW state, END_STATE state, DEBUG state) to the unlocked state, and at the same time, the motor is unlocked to prevent higher energy vibration from affecting the life of the objective lens switcher.

[0060] Based on the same inventive concept, a third aspect of an embodiment of the present invention provides a machine-readable storage medium, on which instructions are stored, and the instructions are used to enable a machine to execute the above-mentioned real-time detection method for motor drive mechanical oscillation based on SOGI-FLL.

[0061] Test Example 1:

[0062] In order to illustrate the control effect of the SOGI-FLL algorithm of the present invention, when the actual objective lens switcher system is excited, the curve of monitoring the change of a given speed over time is as follows: Figure 4 As shown, the curve of the given speed is approximately a sine curve, with an amplitude of about 800 μm / s and a frequency of about 200 Hz. The real-time detection method for motor-driven mechanical oscillation based on the SOGI-FLL of the embodiment of the present invention detects the observed speed corresponding to the given speed. The experimental data of the frequency of the observed speed is as follows: Figure 5 As shown, the frequency is about 200Hz and the duration is more than 200ms; the amplitude experimental data is as follows Figure 6 As shown in the figure, it is about 800µm / s and lasts for more than 200ms. Figure 5 and Figure 6 The data in the figure show that the objective lens switch system is oscillating. Figure 4 The vibration results in FIG. 1 are consistent with those in FIG. 1 , and the technical solution of the present invention can effectively detect system vibration.

[0063] Test Example 2:

[0064] In order to illustrate the control effect of the SOGI-FLL algorithm of the present invention, a basic model is built in SIMULINK as follows Figure 7 As shown in the figure, point 1 is the injection point of the speed given signal, 2 represents the signal observation frequency, and 3 represents the signal observation amplitude. Two signals are injected at point 1 in the figure:

[0065]

[0066] After using the SOGI-FLL detection strategy, we can get the observed frequency at 2 in the figure and the observed amplitude at 3 in the figure. The actual simulation results are an observed frequency of 101.3Hz, an observed amplitude of 207.7µm / s, and a given signal V r2 The results are very close, which means that the SOGI-FLL algorithm can extract a signal with higher amplitude and frequency from the two signals, which means that the influence of the harmonic signal on the oscillation detection logic can be ignored when actually detecting the signal for a given speed.

[0067] To sum up, the technical solution of the present invention is based on the objective lens switcher system oscillation detection strategy of SOGI-FLL. Aiming at the problem that the objective lens switcher system causes static jitter due to multiple oscillations, thereby affecting the service life of the objective lens switcher, the strategy proposed by the present invention can detect the amplitude and frequency of a given speed in advance, and issue a fault alarm when the motor outputs an obvious oscillation signal, thereby improving the service life of the objective lens switcher system; the use of software strategies rather than hardware methods, on the one hand, reduces the cost of additional system detection equipment and system redundancy, and on the other hand, can flexibly adjust the oscillation detection threshold, improve the flexibility and accuracy of detection, and can ignore the influence of harmonic signals on the oscillation detection logic, and has a strong ability to resist interference signals; compared with the existing patents using the SOGI-FLL algorithm, the technical solution of the present invention realizes the application of the algorithm in the field of high-precision motor control.

[0068] It is worth pointing out that the oscillation of the objective lens switcher system is inevitable (unreasonable installation process, unreasonable load loading, etc. will cause oscillation). The present invention provides a more complete implementation solution based on the implementation of the SOGI-FLL algorithm.

[0069] It should also be noted that the terms "comprises," "includes," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity, or apparatus.

[0070] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the claims of the present application.

Claims

1. A real-time detection method for motor drive mechanical oscillation based on SOGI-FLL, characterized in that: Based on the SOGI-FLL strategy, the speed given signal is extracted, and the amplitude and frequency of the observed speed corresponding to the speed given signal are detected in real time. If it exceeds the threshold for a specified time, it is determined that oscillation occurs; The amplitude calculation formula of the observed velocity is as follows: ， The frequency calculation formula of the observed speed is as follows: ω ( n+ 1)= ω ( n )+ ω ( n )×K / A m ( n+ 1)× err ( n )×ETA× QV r ( n+ 1) × dt, where ，V r ( n ) is the given speed at time n, V' r ( n ) is the SOGI-FLL observation speed at time n, QV r ( n ) is the orthogonal component of the SOGI-FLL observed velocity at time n, V' r ( n+ 1) is the SOGI-FLL observation speed at time n+1, QV r ( n+ 1) is the orthogonal component of SOGI-FLL observed velocity at time n+1, ω ( n ) is the frequency of observing the velocity at time n, ω ( n+ 1) is the frequency of observing the velocity at time n+1, err ( n ) is the deviation between the given speed and the observed speed, dt is the speed loop calculation frequency, A m ( n+ 1) is the amplitude of the observed velocity at time n+1, K is the adjustable control parameter 1, and ETA is the adjustable control parameter 2 and is a negative value.

2. The method according to claim 1, characterized in that The frequency of the observed speed is normalized and limited, and the calculation formula is as follows: ω ( n+ 1)= ω ( n )+ ω ( n )×K / ( A m ( n+ 1)+0.001)× err ( n )×ETA× QV r ( n+ 1)×dt ω ( n+ 1)≥0.5。 3. The method according to claim 1 or 2, characterized in that: The conditions for judging the occurrence of oscillation are: the amplitude of the detected observed speed is greater than 800 µm / s, the frequency of the observed speed is greater than 160 Hz, and the time when the amplitude and frequency exceed the threshold reaches 200 ms.

4. The method according to claim 3, characterized in that The SOGI-FLL strategy extracts the injection point of the speed given signal as the position loop output point in the three-loop control.

5. A real-time detection system for motor-driven mechanical oscillation based on SOGI-FLL, characterized in that: include: A digital controller is used to extract a speed given signal based on the SOGI-FLL strategy and detect the amplitude and frequency of the observed speed corresponding to the speed given signal in real time; A timer, used to determine the time when the amplitude and frequency of the observed speed exceed the threshold value according to the detection result of the digital controller; The amplitude calculation formula of the observed velocity is as follows: ， The frequency calculation formula of the observed speed is as follows: ω ( n+ 1)= ω ( n )+ ω ( n )×K / A m ( n+ 1)× err ( n )×ETA× QV r ( n+ 1) × dt, where ，V r ( n ) is the given speed at time n, V' r ( n ) is the SOGI-FLL observation speed at time n, QV r ( n ) is the orthogonal component of the SOGI-FLL observed velocity at time n, V' r ( n+ 1) is the SOGI-FLL observation speed at time n+1, QV r ( n+ 1) is the orthogonal component of SOGI-FLL observed velocity at time n+1, ω ( n ) is the frequency of observing the velocity at time n, ω ( n+ 1) is the frequency of observing the velocity at time n+1, err ( n ) is the deviation between the given speed and the observed speed, dt is the speed loop calculation frequency, A m ( n+ 1) is the amplitude of the observed speed at time n+1, K is the adjustable control parameter 1, and ETA is the adjustable control parameter 2 and is a negative value; The control module is used to receive the timing result of the timer, and determine that oscillation occurs if the timing result exceeds a preset time.

6. The system according to claim 5, characterized in that The timer is used to determine the time when the amplitude and frequency of the observed speed exceed the threshold value based on the detection results of the digital controller. Specifically, when the amplitude and frequency of the observed speed exceed the threshold value, the alarm count is increased by 1, otherwise the alarm count is cleared to 0 to ensure that the next detection count value starts from 0; if the alarm count accumulates to a preset value, it is deemed to exceed the preset time.

7. The system according to claim 6, characterized in that After determining that oscillation occurs, the control module controls the motor to unlock to prevent vibration with higher energy.

8. A machine-readable storage medium having instructions stored thereon, the instructions being used to enable a machine to execute the method according to any one of claims 1 to 4.

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