A device and method for suppressing and controlling vibration and interference in a servo system.

Abstract

This invention discloses a vibration and interference suppression control device and method for a servo system, belonging to the field of servo system control technology. The method includes: acquiring the three-phase currents Iu, Iv, and Iw of the motor and the mechanical angular velocity ωm; converting the three-phase currents from the stationary uvw coordinate system to the d-axis current Id and q-axis current Iq in the rotating dq coordinate system; performing speed control, current control, and interference compensation calculations based on Id, Iq, and ωm; superimposing the obtained d-axis voltage compensation dvd and q-axis voltage compensation dvq onto the output side of the current controller; and generating inverter switching signals Su, Sv, and Sw to drive the motor. The device includes a controller, an inverter, a motor, and a speed sensor. Compared with the prior art, this invention, by performing voltage compensation on the output side of the current controller without significantly changing the characteristics of the current controller, can effectively suppress mid-to-high frequency vibration and interference in the servo system, and can also suppress low-frequency interference through a dual interference observer structure.

Description

Technical Field

[0001] This invention belongs to the field of servo system control technology, and more specifically, relates to a servo system vibration and interference suppression control device and method. Background Technology

[0002] Servo systems are widely used in robots, CNC machine tools, handling equipment, and precision actuators. In actual operation, factors such as guide rail friction and elastic deformation, ball screw friction and elastic deformation, bearing support friction and deformation, insufficient shaft rigidity, and gear backlash in the reducer can all cause system vibration. At the same time, load changes, gripping objects of different weights, and external braking force disturbances can also cause the system to be disturbed. The aforementioned vibrations and interferences can cause speed fluctuations, decreased positioning accuracy, machining stripes, mechanical impacts, and even workpiece damage. Although existing technologies can suppress these vibrations and interferences by using interference observers, the compensation amount is usually applied to the input side of the current controller, which can easily change the characteristics of the current controller. This approach is basically suitable for suppressing low-frequency vibrations and interferences, such as those below 500Hz. Therefore, it is necessary to provide a new control device and method to improve the servo system's ability to suppress mid-to-high frequency vibrations and interferences without significantly affecting the characteristics of the current controller. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a device and method for suppressing vibration and interference in a servo system. It can suppress high-frequency vibration and interference in the servo system by superimposing the compensation amount on the output side of the current controller without significantly changing the characteristics of the current controller.

[0004] The present invention provides a method for suppressing and controlling vibration and interference in a servo system, comprising: Step 1: Obtain the three-phase current of the motor , , and mechanical angular velocity ; Step 2: Convert the three-phase currents in the stationary uvw coordinate system , , Converted to d-axis current in rotating dq coordinate system and q-axis current ; Step 3: Based on the d-axis current q-axis current and mechanical angular velocity Perform speed control calculations, current control calculations, and disturbance compensation calculations to generate compensation values; Step 4: Superimpose the compensation amount onto the output side of the current controller to obtain the compensated d-axis voltage command and q-axis voltage command; Step 5: Based on the outputs of the d-axis and q-axis current controllers after superimposing the compensation amounts, perform drive signal generation operations, such as inverse Clarke and inverse Park transforms and sinusoidal pulse width modulation (SPWM), to generate the inverter's switching signals. , , This is to control the inverter to drive the motor, thereby suppressing vibration and interference in the servo system.

[0005] As a further improvement of the present invention, in step three, the interference compensation calculation is performed by an interference observer module located after the current controller; the interference observer module uses q-axis voltage and / or d-axis voltage, and mechanical angular velocity... The input is a low-pass filter used to calculate the disturbance, and the output is the d-axis voltage compensation value. and q-axis voltage compensation , As a further improvement of the present invention, for the surface-mounted magnet motor SPM, the command value setting of its d-axis current is... Its q-axis voltage formula can be expressed as: ; Inside the interference observer, the estimated q-axis current value required for high-frequency interference observation is obtained by inverse transformation of the q-axis voltage equation using the following formula. : ; Using the above q-axis current and mechanical angular velocity The interference observer calculates a q-axis compensation current, and the output of this q-axis compensation current after passing through the low-pass filter Q is denoted as... , this current Substituting back into the motor's voltage equation, we obtain the d-axis voltage compensation amount. and q-axis voltage compensation The specific calculation equation is as follows: ; ; In the formula, R is the phase resistance of the motor. and These are the d-axis and q-axis inductances, respectively. The electrical angular velocity of the motor. Let be the flux linkage of a permanent magnet, and s denote the Laplace operator in the complex frequency domain. This represents the q-axis current variation output after passing through the low-pass filter Q.

[0006] As a further improvement of the present invention, the q-axis current input source directly adopts the q-axis current command value output by the speed controller. Or the voltage compensation amount corresponding to the sampled q-axis feedback current. and The formula for calculating the structure is: : .

[0007] As a further improvement of the present invention, the input quantity of the interference observer is directly configured as the torque of the motor. and mechanical speed The system first calculates the estimated value of the unfiltered interference torque. The observed disturbance torque is then obtained through Q-calculation using a low-pass filter. ,satisfy ; ; Then this Divide by the torque coefficient to convert Shaft current variation Substitute into the voltage compensation formula: ; .

[0008] As a further improvement of the present invention, a first interference observer and a second interference observer are provided, wherein the second interference observer is disposed before the current controller and is used to generate the current compensation quantity dI. q2 To suppress low-frequency vibrations and interference; the first interference observer is positioned after the current controller and is used to generate the compensation current. And further generate the d-axis voltage compensation amount. and q-axis voltage compensation To suppress mid-to-high frequency vibrations and interference, the second interference observer is executed first during the control process, followed by the first interference observer.

[0009] A control device for suppressing vibration and interference in a servo system includes a controller, an inverter, a motor, and a speed sensor. The output of the controller is connected to the input of the inverter, the output of the inverter is connected to the motor, the motor is connected to the controller, and the speed sensor is connected to the controller. The controller is configured to operate based on three-phase current. , , and mechanical angular velocity Perform speed control calculations, current control calculations, and disturbance compensation calculations to obtain the d-axis voltage compensation amount. and q-axis voltage compensation and the d-axis voltage compensation amount and the q-axis voltage compensation amount The current is superimposed on the output sides of the d-axis current controller and the q-axis current controller respectively to control the inverter to drive the motor, thereby suppressing the vibration and interference of the servo system.

[0010] Compared to existing technologies, the advantages of this invention are as follows: because this invention uses the compensation amount calculated by the interference observer... , This compensation path, applied directly to the output of the current controller, does not affect the closed-loop feedback regulation of the current loop and does not impact the characteristics of the current controller. It fundamentally avoids the problem of altering the current loop gain and phase characteristics caused by the introduction of an interference observer, a problem inherent in traditional techniques. Since the current loop characteristics remain unaffected, the time constant of the low-pass filter Q in the interference observer can be reduced. This means improving the response speed of the interference observer, thereby providing stronger attenuation and suppression capabilities for medium- and high-frequency mechanical resonance and interference. Its effect is that when the system has vibration components or the load on the load side changes, the disturbance observer can immediately generate a compensation amount to suppress vibration or compensate for changes in torque, thereby preventing speed jitter or large changes; it can employ dual disturbance observers, by controlling the timing to execute the preceding low-frequency disturbance observer first, followed by the subsequent high-frequency disturbance observer, so that the low-frequency time constant is... With high frequency time constant Each component performs its specific function, which broadens the overall system's vibration suppression bandwidth while ensuring that each frequency band works in coordination without interfering with the others. Attached Figure Description

[0011] Figure 1 This is a control principle block diagram of Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the overall structure of the control system of the present invention; Figure 3 This is a control principle block diagram of Embodiment 2 of the present invention; Figure 4 This is a control principle block diagram of Embodiment 3 of the present invention; Figure 5 This is a control principle block diagram of Embodiment 4 of the present invention; Figure 6 This is a control principle block diagram of Embodiment 5 of the present invention.

[0012] Explanation of the labels in the diagram: Controller 1; Inverter 2; Motor 3; Speed ​​sensor 4. Detailed Implementation

[0013] Specific Implementation Example 1: Please refer to Figures 1-2 This invention relates to a control device for suppressing vibration and interference in a servo system, comprising a controller 1, an inverter 2, a motor 3, and a speed sensor 4. The output terminal of the controller 1 is connected to the input terminal of the inverter 2, and is used to output a switching signal to the inverter 2. , , The output terminal of the inverter 2 is connected to the motor 3, and is used to output a three-phase voltage V to the motor 3. u V v V w The motor 3 is connected to the controller 1 and is used to feed back three-phase current to the controller 1. , , The speed sensor 4 is connected to the controller 1 and is used to feed back the mechanical angular velocity of the motor 3 to the controller 1. ; The controller is configured to operate based on the three-phase current. , , and mechanical angular velocity Perform speed control calculations, current control calculations, and disturbance compensation calculations to obtain the d-axis voltage compensation amount dv. d and q-axis voltage compensation dv q and the d-axis voltage compensation amount dv d and the q-axis voltage compensation amount dv q The current is superimposed on the output sides of the d-axis current controller and the q-axis current controller respectively to control the inverter to drive the motor, thereby suppressing the vibration and interference of the servo system.

[0014] A method for suppressing and controlling vibration and interference in a servo system, comprising: Step 1: The data acquisition module collects the operating status parameters of the motor in the servo system in real time, including the three-phase current. , , and actual motor speed ; Step 2: The coordinate transformation module transforms the three-phase currents in the stationary uvw coordinate system. , , Perform Clarke and Park transformations to decouple the three-phase currents and convert them into d-axis feedback currents in a rotating dq coordinate system. and q-axis feedback current ; For surface-mounted magnet motors (SPMs), the commanded value for the d-axis current is set to I. d =0A, and its q-axis voltage formula is expressed as: ; Where R is the phase resistance of the motor. and These are the d-axis inductance and the q-axis inductance, respectively. For electrical angular velocity, It is a permanent magnet flux linkage. Transform the above q-axis voltage equation to obtain the q-axis current. The conversion formula is as follows: ; Step 3: The control and interference compensation module is based on the actual motor speed. With the set target speed Perform speed loop proportional-integral (PI) control calculations and output the q-axis reference current. And combined with the d-axis feedback current and q-axis feedback current Perform current loop PI control calculations and output the d-axis base control voltage. and q-axis base control voltage Simultaneously, the interference observer module is used to perform interference compensation calculations, generating d-axis voltage compensation quantities to offset internal mechanical vibrations and external load interference. and q-axis voltage compensation ; Obtain q-axis current The d-axis voltage compensation amount was then calculated using an interference observer. and q-axis voltage compensation The d-axis voltage compensation amount dv d and the q-axis voltage compensation amount The voltage equation based on the SPM motor is obtained according to the following relationship: ; ; in To compensate for the current; Step 4: The superposition module calculates the d-axis voltage compensation amount. and q-axis voltage compensation It is directly superimposed on the output side of the current loop PI control operation, that is, it is respectively superimposed on the d-axis base control voltage. and q-axis base control voltage Algebraic addition is performed to avoid affecting the current loop characteristics, generating a final d-axis control voltage on the output side that is opposite to the original vibration or interference direction of the servo system. and q-axis final control voltage This directly counteracts the vibration and interference of the servo system; Step 5: The inverter drive module controls the final voltage of the d-axis. and q-axis final control voltage Perform inverse Park transform and space vector pulse width modulation (SVPWM) operations, or perform inverse Clarke and inverse Park transform and sinusoidal pulse width modulation (SPWM) operations to generate the inverter's switching signals. , , It is used to control the switching on and off of the power devices of the three-phase inverter, drive the motor to run, and suppress the vibration and interference of the servo system.

[0015] Specific Implementation Example 2: Please refer to Figure 3 The difference from Embodiment 1 lies in the different configuration method for acquiring the input source in the interference observer. In this embodiment, the input terminal of the interference observer will use the output of the speed controller, that is, the q-axis current command value output by the speed loop PI controller. The variables are directly used as input to the disturbance observer, and their respective variations are extracted by the filter Q(s). Then, using the voltage relationship: ; ; The required d-axis and q-axis voltage compensation amounts are calculated and superimposed on the output side of the current loop. This method reduces the computational overhead of the control chip.

[0016] Specific Implementation Example 3: Please refer to Figure 4 The difference from Embodiment 1 lies in the different configuration of the input source in the interference observer; the input quantity of the interference observer is the q-axis current. The q-axis feedback current obtained from sampling is used to compensate the voltage. and The method for obtaining it remains the same, also through the voltage relationship: ; ; Calculate the required d-axis and q-axis voltage compensation amounts and add them to the output side of the current loop.

[0017] Specific Implementation Example 4: Please refer to Figure 5 The difference from Embodiment 1 lies in the different configuration method for acquiring the input source in the interference observer; the input quantity of the interference observer is the torque of the motor. and mechanical speed First, the estimated value of the unfiltered interference torque is calculated. The observed disturbance torque is then obtained through Q-calculation using a low-pass filter. The specific formula for obtaining it is: ; ; The interference torque Converted to q-axis current variation The d-axis voltage compensation amount and q-axis voltage compensation The calculation formula is: ; .

[0018] Specific Implementation Example 5: Please refer to Figure 6 The interference observer includes a first interference observer for mid-to-high frequency vibration and interference suppression, and a second interference observer for low-frequency vibration and interference suppression. The first interference observer is located after the current controller to generate the d-axis voltage compensation amount. and q-axis voltage compensation And superimposed on the output side of the current controller, the filter of the first interference observer The time constant is set to The second interference observer is located before the current controller to generate the current compensation amount. And this is superimposed on the input side of the current controller, the filter of the second interference observer. The time constant is set to ,in .

[0019] In a further embodiment, such as Figure 6 As shown, in each micro-control cycle, the software program first executes the second interference observer and then the first interference observer to perform calculations. The first interference observer is directly located on the voltage output side at the very end. The change in current loop characteristics caused by the second interference observer is completely outside the feedback loop of the first interference observer. Therefore, it has no negative impact on the excellent performance of the first interference observer in eliminating high-frequency mechanical resonance. The combined effect of the two observers constructs an extremely wide anti-interference bandwidth for the servo system.

[0020] The controller 1 can be implemented by a DSP, MCU, FPGA or other programmable processor, or by analog circuit. The control method described above can be stored in a non-transitory computer-readable storage medium through program instructions and executed on the processor.

Claims

1. A method for suppressing and controlling vibration and interference in a servo system, characterized in that: include Step 1: Obtain the three-phase current of the motor , , and mechanical angular velocity ; Step 2: Convert the three-phase currents in the stationary uvw coordinate system , , Converted to d-axis current in rotating dq coordinate system and q-axis current ; Step 3: Based on the d-axis current q-axis current and mechanical angular velocity Perform speed control calculations, current control calculations, and disturbance compensation calculations to generate compensation quantities. , ; Step 4: Superimpose the compensation amount onto the output side of the current controller to obtain the compensated d-axis voltage command and q-axis voltage command; Step 5: Based on the outputs of the d-axis and q-axis current controllers after superimposing the compensation amount, perform drive signal generation calculations to generate the inverter's switching signals. , , This is to control the inverter to drive the motor, thereby suppressing vibration and interference in the servo system.

2. The method for suppressing and controlling vibration and interference in a servo system according to claim 1, characterized in that: The interference compensation calculation is performed by an interference observer, which measures the q-axis voltage. and / or d-axis voltage and mechanical angular velocity As input, the disturbance of the servo system is observed in conjunction with the low-pass filter Q, and the compensated d-axis voltage compensation is output. and q-axis voltage compensation .

3. The method for suppressing and controlling vibration and interference in a servo system according to claim 1, characterized in that: In step 3, the interference observer uses the q-axis voltage and electrical angular velocity For input quantities, where the command value for the d-axis current is set by I. d ∗ When the current is 0A, its q-axis voltage formula can be expressed as: ； Where R is the phase resistance of the motor, L d and L q These are the d-axis inductance and q-axis inductance, respectively, ω e Φ is the electrical angular velocity. f For permanent magnet flux linkage; The q-axis current can be obtained by inverse transformation of the q-axis voltage equation. The conversion formula is as follows: ； Using the above q-axis current and mechanical angular velocity The interference observer calculates a q-axis compensation current, and the output of this q-axis compensation current after passing through the low-pass filter Q is denoted as... , this current Substituting back into the motor's voltage equation, we obtain the following d-axis voltage compensation amount. and q-axis voltage compensation : ； ； Where, ω e L is the electrical angular velocity. q R is the q-axis inductance, R is the motor phase resistance, and dI is the inductance. q To compensate for the current.

4. The method for suppressing and controlling vibration and interference in a servo system according to claim 1, characterized in that: The q-axis current is obtained from the q-axis current command output by the speed controller. The d-axis voltage compensation amount and q-axis voltage compensation The calculation formula is: ； ； ， 。 5. The method for suppressing and controlling vibration and interference in a servo system according to claim 1, characterized in that: In step 3, the input to the interference observer is the torque of the motor. and mechanical speed First, the estimated value of the unfiltered interference torque is calculated. The observed disturbance torque is then obtained through Q-calculation using a low-pass filter. The specific formula for obtaining it is: ； The interference matrix Transform into shaft current change The Shaft voltage compensation and Shaft voltage compensation The calculation formula is: ； 。 6. The method for suppressing and controlling vibration and interference in a servo system according to claim 1, characterized in that: A first interference observer and a second interference observer are provided. The second interference observer generates a current compensation quantity dI. q2 To suppress low-frequency vibrations and interference; the first interference observer generates a compensation current. To suppress mid-to-high frequency vibrations and interference.

7. The method for suppressing and controlling vibration and interference in a servo system according to claim 6, characterized in that: During the control process, the second interference observer is executed first, followed by the first interference observer.

8. A control device for suppressing vibration and interference in a servo system, characterized in that: The system includes a controller (1), an inverter (2), a motor (3), and a speed sensor (4). The output of the controller is connected to the input of the inverter (2), the output of the inverter (2) is connected to the motor (3), the motor (3) is connected to the controller, and the speed sensor (4) is connected to the controller. The controller is configured to operate based on three-phase current. , , and mechanical angular velocity Perform speed control calculations, current control calculations, and interference compensation calculations, and adjust the d-axis voltage compensation amount. and the q-axis voltage compensation amount The current is superimposed on the output sides of the d-axis current controller and the q-axis current controller, respectively, and the control device is capable of executing the control method for suppressing vibration and interference of the servo system as described in any one of claims 1 to 7.

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