Servo drive system and method

Abstract

The application discloses a kind of servo driving systems and methods.The driving system includes: damping filter instruction compensator, it is arranged in the receiving side of position instruction, for when vibration occurs when motor executes positioning action, current position instruction is handled, new position instruction is obtained, and is input to position controller, makes position controller output speed instruction;Feedback vibration compensator is arranged in the receiving side of position feedback information, for position feedback information is handled, and obtains the signal of inhibiting vibration;Speed instruction generation module is arranged in the receiving side of speed instruction and the signal of inhibiting vibration, for according to speed instruction and the signal of inhibiting vibration generates new speed instruction, and is input to speed controller.The application comprehensively considers the buffeting influence caused by position instruction, position feedback, eliminates the buffeting component in position instruction by setting damping filter instruction compensator and feedback vibration compensator, so that the positioning end jitter of servo system is preferably inhibited.

Description

Technical Field

[0001] This invention relates to the field of servo control, and more particularly to a servo drive system and method. Background Technology

[0002] High speed and high precision are always crucial technical specifications for servo systems. However, strong vibrations often occur during high-speed positioning in servo systems, which severely affect their trajectory tracking and positioning performance. This is because servo systems often contain elastic reduction gears. These gears provide...

[0003] Large driving torque can cause elastic torsion between the motor and the load, resulting in positioning vibration of the servo system. Therefore, these elastic deceleration mechanisms must be considered when designing a servo system controller.

[0004] When the motor is not positioned accurately, it will cause the mechanical end to be positioned inaccurately. The residual oscillation at the end will seriously affect its positioning accuracy and working efficiency, resulting in inaccurate production and processing accuracy. Long-term operation will also cause wear and tear on mechanical connecting devices, damage machine tools, and in severe cases, lead to production accidents.

[0005] Related technologies disclose an input shaper for suppressing residual vibrations in mechanical systems. This involves decomposing the original position command into a series of pulse signals and inputting them sequentially into the system. In other words, the command is shaped into a form that will not induce residual vibrations in the system, thereby eliminating end-effector jitter. However, this method does not consider the impact of actual position jitter on the resonant frequency of the velocity, nor the phase lag problem after using the shaper, resulting in inaccurate stable position control.

[0006] Related technologies also disclose a control method for eliminating position jitter using a compensating torque observer. This involves detecting current oscillations and then applying filtered phase torque compensation. However, multiple factors influence current oscillations; while compensation is performed using current, it can also affect speed oscillations and current overshoot during motor operation. Summary of the Invention

[0007] In view of this, the present invention discloses a servo drive system and method to solve the problem of motor positioning jitter.

[0008] To achieve the above objectives, the technical solution adopted by this invention is as follows:

[0009] The first aspect of this invention discloses a servo drive system, including a position controller and a speed controller, the servo drive system further including:

[0010] The vibration damping filter command compensator is set on the receiving side of the position command. It is used to process the current position command when the motor vibrates during the positioning action, obtain a new position command, and input it to the position controller so that the position controller outputs a speed command.

[0011] The feedback vibration compensator is installed on the receiving side of the position feedback information and is used to process the position feedback information to obtain a signal that suppresses vibration.

[0012] The speed command generation module is located on the receiving side of the speed command and vibration suppression signal. It is used to generate new speed commands based on the speed command and vibration suppression signal and input them to the speed controller.

[0013] Further, optionally, it also includes:

[0014] The vibration determination module is used to acquire the current motor speed, determine the vibration information of the current motor speed, and determine whether vibration has occurred based on the vibration information of the current motor speed when the motor performs a positioning action.

[0015] Optionally, the vibration determination module is also used to configure the model parameters of the vibration reduction filter command compensator based on the determined vibration information when the motor performs a positioning action for the first time and vibration occurs.

[0016] Alternatively, the vibration determination module can also be used to perform FFT analysis on the current motor speed to obtain vibration information.

[0017] Further optionally, the vibration damping filter command compensator includes a vibration damping filter and a compensator, wherein:

[0018] Vibration damping filter, used to filter out high-frequency signals in position commands;

[0019] The compensator is used to integrate the phase and response time of the position command after it has been filtered by the vibration damping filter to obtain a new position command.

[0020] Optionally, the vibration information of the current motor speed includes the frequency, bandwidth, and amplitude of the current motor speed vibration;

[0021] The transfer function of the vibration damping filter is:

[0022]

[0023]

[0024] The compensator includes Type I integrator, with a proportional coefficient of K C ,

[0025] Wherein, ω0 is the frequency point at which the vibration reduction filter operates, and its value is the same as the frequency of the current motor speed vibration; k1 is the notch bandwidth parameter, and its value is equal to the bandwidth of the current motor speed vibration; k2 is the notch depth parameter, and its value is equal to the amplitude of the current motor speed vibration.

[0026] Further optionally, the feedback vibration compensator includes a second-order tracking differentiator and a vibration harmonic compensator;

[0027] A second-order tracking differentiator is set on the position feedback information receiving side to perform noise reduction processing on the position feedback information and obtain the position feedback differential signal;

[0028] A vibration harmonic compensator is used to process the position feedback differential signal to obtain a signal that suppresses vibration.

[0029] Further, optionally, the transfer function of the second-order tracking differentiator:

[0030]

[0031] Where r represents the position loop gain, the larger r is, the clearer the position feedback differential signal;

[0032] The transfer function of the vibration harmonic compensator is:

[0033] Where ω is the vibration frequency when the motor is in a stable position, and K is the adjustment gain for suppressing vibration.

[0034] Alternatively, the system may also include a parameter adjustment module;

[0035] The parameter adjustment module is used to increase the vibration suppression adjustment gain K when the motor performs the positioning action again and vibration occurs, and to decrease the position loop gain r when the vibration noise is determined to be large.

[0036] The second aspect of this invention discloses a driving method for the servo drive system provided in the first aspect, the method comprising:

[0037] When the motor vibrates during positioning, the vibration damping filter compensator processes the current position command to obtain a new position command, which is then input to the position controller, causing the position controller to output a speed command.

[0038] The position feedback information is received by the feedback vibration compensator, and the position feedback information is processed to obtain a signal that suppresses vibration.

[0039] A new speed command is generated based on the speed command and the vibration suppression signal, and then input into the speed controller.

[0040] Further, optionally, it also includes:

[0041] When the motor performs its first positioning action and vibration occurs, the model parameters of the vibration reduction filter command compensator are determined based on the vibration information of the current motor speed.

[0042] When the motor performs a positioning action again and vibration occurs, increase the vibration suppression adjustment gain K in the feedback vibration compensator; and when the vibration noise is determined to be large, decrease the position loop gain r in the feedback vibration compensator.

[0043] Beneficial effects: This invention comprehensively considers the jitter effects caused by position commands and position feedback. By setting up a vibration reduction filter command compensator and a feedback vibration compensator, the jitter component in the position command is eliminated, thereby effectively suppressing the jitter at the positioning end of the servo system. Attached Figure Description

[0044] The above and other objects, features, and advantages of the present invention will become more apparent from the detailed description of exemplary embodiments with reference to the accompanying drawings. The drawings described below are merely some embodiments disclosed in the present invention; those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0045] Figure 1 A schematic diagram of a servo drive system according to an embodiment of the present invention is shown.

[0046] Figure 2 A schematic diagram of a vibration damping filter command compensator according to an embodiment of the present invention is shown.

[0047] Figure 3 A schematic diagram of a feedback vibration compensator according to an embodiment of the present invention is shown.

[0048] Figure 4 A flowchart illustrating a driving method according to an embodiment of the present invention is shown.

[0049] Figure 5 A schematic diagram of a position jitter detection interface according to an embodiment of the present invention is shown.

[0050] Figure 6 A flowchart illustrating a driving method according to an embodiment of the present invention is shown. Detailed Implementation

[0051] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0052] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” used in the embodiments of this invention and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. “Multiple” generally includes at least two, but does not exclude the inclusion of at least one.

[0053] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0054] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a product or system comprising a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a product or system. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the product or system that includes said element.

[0055] To address the problem of motor positioning jitter, this embodiment discloses a servo drive system in the first aspect, combined with... Figure 1 The servo drive system includes a position controller and a speed controller, and also includes:

[0056] The vibration damping filter command compensator is set on the receiving side of the position command. It is used to process the current position command when the motor vibrates during the positioning action, obtain a new position command, and input it to the position controller so that the position controller outputs a speed command.

[0057] The feedback vibration compensator is installed on the receiving side of the position feedback information and is used to process the position feedback information to obtain a signal that suppresses vibration.

[0058] The speed command generation module is located on the receiving side of the speed command and vibration suppression signal. It is used to generate new speed commands based on the speed command and vibration suppression signal and input them to the speed controller.

[0059] In one specific implementation, when the motor positioning jitter occurs, a vibration damping filter compensator filters and compensates for the mid-to-high frequency jitter signal of the feedback speed in the position command, thereby generating a new position command. The position feedback information reflects the current position jitter situation. First, the position feedback information is differentiated by a feedback vibration compensator, and then vibration differential compensation is performed on the differentiated position feedback information to obtain a vibration-suppressing signal. The above speed command and the vibration-suppressing signal are superimposed to obtain a new speed command, which is applied to the speed controller, thereby eliminating the jitter component in the position command.

[0060] This embodiment takes into account the jitter effects caused by position commands and position feedback. By setting up a vibration reduction filter command compensator and a feedback vibration compensator, the jitter component in the position command is eliminated, thereby effectively suppressing the jitter at the positioning end of the servo system.

[0061] This invention directly addresses low-frequency resonance in position commands, compensates for phase lag, and addresses factors affecting speed in the feedback position, resulting in more precise jitter elimination, reduced costs, and improved efficiency. Furthermore, by compensating from the position angle, this invention avoids the speed oscillation problems caused by applying additional torque compensation.

[0062] In addition, motor positioning vibration only needs to be detected once, reducing vibration detection and processing time. After eliminating vibration in motor positioning, the vibration situation is significantly improved, thus improving motor performance.

[0063] Furthermore, the servo drive system also includes:

[0064] The vibration determination module is used to acquire the current motor speed, determine the vibration information of the current motor speed, and determine whether vibration has occurred based on the vibration information of the current motor speed when the motor performs a positioning action.

[0065] The vibration detection module has a sampling unit for sampling motor speed and position. This unit acquires the position and motor speed during positioning. When vibration occurs during motor positioning, the position and speed are sampled and transmitted to the controller. The controller performs calculations based on the collected speed data to determine the frequency of the vibration speed during positioning and the vibration error. Furthermore, the vibration results are sent to the upper-level interface and displayed. If severe vibration occurs, an alarm is triggered. Otherwise, normal operation continues. The display interface is as follows: Figure 5As shown, the jitter result includes the position command, actual position, position jitter error, and steady-state speed. The position jitter error is equal to the difference between the target position in the position command and the actual position. The steady-state speed refers to the speed at which the actual motor position fluctuates within a certain range above and below the target position. In this embodiment, the target speed for motor positioning is zero.

[0066] Furthermore, the vibration determination module is also used to perform FFT analysis on the current motor speed to obtain vibration information.

[0067] FFT is an efficient algorithm of DFT, called Fast Fourier Transform. Fourier Transform is one of the most fundamental methods in time-domain to frequency-domain transform analysis. When motor positioning exhibits jitter, the motor speed is sampled, and an FFT operation is performed on the sampled motor speed to obtain the vibration information of the current speed, including frequency, bandwidth, and amplitude.

[0068] Furthermore, the vibration determination module is also used to configure the model parameters of the vibration reduction filter command compensator based on the determined vibration information when the motor performs its first positioning action and vibration occurs.

[0069] By configuring the model parameters of the vibration damping and filtering command compensator based on the vibration situation of the motor during positioning, the parameters of the vibration damping and filtering command compensator can be configured with high precision, thereby improving the filtering and compensation effect of the vibration damping and filtering command compensator.

[0070] Furthermore, the vibration damping filter command compensator includes a vibration damping filter and a compensator, wherein:

[0071] Vibration damping filter, used to filter out high-frequency signals in position commands;

[0072] The compensator is used to integrate the phase and response time of the position command after it has been filtered by the vibration damping filter to obtain a new position command.

[0073] After the position command passes through this vibration damping filter, the mid-to-high frequency signals are filtered out, but this also introduces phase lag and a slower response time. Therefore, after passing through the vibration damping filter, the signal enters the compensator, which consists of an integrator. and proportionality coefficient K C After the compensation process, a new position command will be generated and enter the position control.

[0074] Furthermore, the vibration information of the current motor speed includes the frequency, bandwidth, and amplitude of the current motor speed vibration;

[0075] The transfer function of the vibration damping filter is:

[0076]

[0077]

[0078] The compensator includes Type I integrator, with a proportional coefficient of K C ,

[0079] Wherein, ω0 is the frequency point at which the vibration reduction filter operates, and its value is the same as the frequency of the current motor speed vibration; k1 is the notch bandwidth parameter, and its value is equal to the bandwidth of the current motor speed vibration; k2 is the notch depth parameter, and its value is equal to the amplitude of the current motor speed vibration.

[0080] Based on the filter's operating frequency ω0, notch bandwidth parameter k1, and notch depth parameter k2, three variables determine the filter's three coefficients: a, b, and c. Configuring these vibration damping filter parameters requires quickly and accurately obtaining the resonance at the resonant point; this necessitates setting the parameters on the Bode plot obtained through FFT.

[0081] Furthermore, the feedback vibration compensator includes a second-order tracking differentiator and a vibration harmonic compensator;

[0082] A second-order tracking differentiator is set on the position feedback receiving side to perform noise differentiation processing on the position feedback to obtain the position feedback differential signal;

[0083] A vibration harmonic compensator is used to process the position feedback differential signal to obtain a signal that suppresses vibration.

[0084] The position feedback is first processed by a second-order tracking differentiator to obtain the differential signal of the position feedback. Its function is to obtain a low-noise differential signal. The transfer function of the second-order tracking differentiator is shown below:

[0085]

[0086] Where r represents the position loop gain, the larger r is, the clearer the position feedback differential signal; in practice, r needs to be adjusted according to the actual system. Then, its low-noise differential signal is injected into the vibration harmonic compensator to obtain a signal that suppresses vibration. The transfer function of the vibration harmonic compensator is shown below:

[0087]

[0088] Where ω is the vibration frequency when the motor is in a stable position, K is the adjustment gain for suppressing vibration, and the preferred value of K is 2ω.

[0089] Alternatively, the servo drive system may also include a parameter adjustment module;

[0090] The parameter adjustment module is used to increase the vibration suppression adjustment gain K when the motor performs the positioning action again and vibration occurs, and to decrease the position loop gain r when the vibration noise is determined to be large.

[0091] Combination Figure 4 The implementation method of this embodiment is further described in detail below:

[0092] Step 1: When motor positioning jitter occurs, sample the position and speed.

[0093] Step 2: Perform an FFT operation on the sampled velocity to obtain the frequency of the current velocity fluctuation. An improved dual-T network notch filter is selected as the vibration damping filter, and its transfer function is shown below:

[0094]

[0095] in,

[0096] Based on the filter's operating frequency ω0, notch bandwidth parameter k1, and notch depth parameter k2, three variables determine the filter's three coefficients: a, b, and c. Configuring these vibration damping filter parameters requires quickly and accurately obtaining the resonance at the resonant point; this necessitates setting the points on the Bode plot obtained through FFT. Position commands passing through this vibration damping filter will exhibit phase lag and a slower response time. Therefore, after passing through the vibration damping filter, the signal enters a compensation stage, which consists of an integrator. and K C .

[0097] in,

[0098] After the compensation process, a new position command is generated and enters the position control. The specific control process is as follows: Figure 2 As shown.

[0099] Step 3: Perform vibration compensation on the jitter feedback. The position feedback is first passed through a second-order tracking differentiator to obtain the differential signal of the position feedback. Its function is to obtain a low-noise differential signal. The transfer function of the second-order tracking differentiator is shown below:

[0100]

[0101] Where r represents the convergence speed of the system. The larger r is, the clearer the low-noise differential signal obtained. In practice, r needs to be adjusted according to the actual system.

[0102] The low-noise differential signal is then injected into the vibration harmonic compensator to obtain a signal that suppresses vibration. The transfer function of the vibration harmonic compensator is as follows:

[0103]

[0104] Where ω is the angular frequency of jitter when the position is stable, and K is the adjustment gain for jitter suppression. The specific control mechanism is as follows: Figure 3 As shown. In one specific embodiment, K = 2ω.

[0105] Step 4: If vibration occurs during the initial equipment run, set the parameters as described above. Upon subsequent equipment runs, if positional vibration occurs, increase the vibration suppression gain K. If significant noise occurs, decrease the gain r. The overall workflow is as follows: Figure 4 As shown.

[0106] The second aspect of this embodiment discloses a driving method for the servo drive system provided in the first aspect, combined with... Figure 6 The method includes S1 to S3, wherein:

[0107] S1, when the motor vibrates during positioning, the vibration damping filter command compensator processes the current position command to obtain a new position command, which is then input to the position controller, causing the position controller to output a speed command.

[0108] S2, using a feedback vibration compensator to receive position feedback information, processing the position feedback information to obtain a signal to suppress vibration;

[0109] S3 generates a new speed command based on the speed command and the vibration suppression signal, and inputs it into the speed controller.

[0110] This embodiment takes into account the jitter effects caused by position commands and position feedback. By setting up a vibration reduction filter command compensator and a feedback vibration compensator, the jitter component in the position command is eliminated, thereby effectively suppressing the jitter at the positioning end of the servo system.

[0111] Furthermore, the method also includes steps A1 to A2, wherein:

[0112] A1, when the motor performs its first positioning action and vibration occurs, the model parameters of the vibration reduction filter command compensator are determined based on the vibration information of the current motor speed.

[0113] A2, when the motor performs the positioning action again and vibration occurs, increase the vibration suppression adjustment gain K in the feedback vibration compensator, and when the vibration noise is determined to be large, decrease the position loop gain r in the feedback vibration compensator.

[0114] When the motor performs a positioning action again and vibration occurs, the vibration suppression adjustment gain K in the feedback vibration compensator is increased. Conversely, if the vibration noise is determined to be significant, the position loop gain r in the feedback vibration compensator is decreased. The adjustment increments of these two parameters can be set according to actual conditions; this embodiment does not impose specific limitations.

[0115] This invention significantly improves vibration control by eliminating jitter in motor positioning, resulting in excellent positioning accuracy, minimal current oscillation, and a marked improvement in the dimensional quality of processed products. Furthermore, motor positioning jitter only requires a single detection, reducing jitter detection and processing time and enhancing motor performance.

[0116] In addition, this invention can modularize the position stabilization mechanism, making it an easy-to-operate driving device with a simple structure, low cost, high real-time performance, easy observation, and strong practicality.

[0117] In the different embodiments provided by this invention, the same parameters, terms, logic, etc. should be understood to have the same meaning, and this application does not intentionally repeat the description in each embodiment.

[0118] Exemplary embodiments of the present disclosure have been specifically shown and described above. It should be understood that the present disclosure is not limited to the detailed structures, arrangements, or implementation methods described herein; rather, the present disclosure is intended to cover various modifications and equivalent arrangements contained within the spirit and scope of the appended claims.

Claims

1. A servo drive system, comprising a position controller and a speed controller, characterized in that, The servo drive system also includes: A vibration damping filter command compensator is installed on the receiving side of the position command. It is used to process the current position command when the motor vibrates during the positioning action, obtain a new position command, and input it to the position controller so that the position controller outputs a speed command. A feedback vibration compensator is installed on the receiving side of the position feedback information to process the position feedback information and obtain a signal to suppress vibration. A speed command generation module is located on the receiving side of the speed command and the vibration suppression signal, and is used to generate a new speed command based on the speed command and the vibration suppression signal, and input it to the speed controller; The feedback vibration compensator includes a second-order tracking differentiator and a vibration harmonic compensator. The second-order tracking differentiator is set on the position feedback information receiving side and is used to perform noise differentiation processing on the position feedback information to obtain the position feedback differential signal. The vibration harmonic compensator is used to process the position feedback differential signal to obtain the vibration-suppressing signal; The transfer function of the second-order tracking differentiator: ； Where r represents the position loop gain, the larger r is, the clearer the position feedback differential signal; The transfer function of the vibration harmonic compensator is: ; Where ω is the vibration frequency when the motor is in a stable position, and K is the adjustment gain for suppressing vibration.

2. The servo drive system as described in claim 1, characterized in that, Also includes: The vibration determination module is used to acquire the current motor speed when the motor performs a positioning action, determine the vibration information of the current motor speed, and determine whether vibration has occurred based on the vibration information of the current motor speed.

3. The servo drive system as described in claim 2, characterized in that, The vibration determination module is also used to configure the model parameters of the vibration reduction filter command compensator according to the determined vibration information when the motor performs a positioning action for the first time and vibration occurs.

4. The servo drive system as described in claim 3, characterized in that, The vibration determination module is also used to perform FFT analysis on the current motor speed to obtain the vibration information.

5. The servo drive system according to any one of claims 2-4, characterized in that, The vibration damping filter command compensator includes a vibration damping filter and a compensator, wherein: The vibration damping filter is used to filter out high-frequency signals in the position command; The compensator is used to integrate the phase and response time of the position command after it has been filtered by the vibration reduction filter to obtain the new position command.

6. The servo drive system as described in claim 5, characterized in that, The vibration information of the current motor speed includes the frequency, bandwidth, and amplitude of the vibration at the current motor speed. The transfer function of the vibration reduction filter is: ； ； The compensator includes Type I integrator, its proportional coefficient is , ; in, The frequency point at which the vibration reduction filter operates is the same as the frequency of the current motor speed vibration. This is the notch bandwidth parameter, and its value is equal to the bandwidth of the current motor speed vibration. The notch depth parameter is equal to the amplitude of the vibration at the current motor speed.

7. The servo drive system as described in claim 1, characterized in that, The system also includes a parameter adjustment module; The parameter adjustment module is used to increase the vibration suppression adjustment gain K when the motor performs the positioning action again and vibration occurs, and to decrease the position loop gain r when it is determined that the vibration noise is large.

8. A driving method for a servo drive system as described in any one of claims 1-7, characterized in that, The method includes: When the motor vibrates during positioning, the vibration damping filter command compensator processes the current position command to obtain a new position command, which is then input to the position controller, causing the position controller to output a speed command. The position feedback information is received by the feedback vibration compensator, and the position feedback information is processed to obtain a signal that suppresses vibration. A new speed command is generated based on the speed command and the vibration suppression signal, and then input to the speed controller.

9. The driving method as described in claim 8, characterized in that, Also includes: When the motor performs its first positioning action and vibrates, the model parameters of the vibration reduction and filtering command compensator are determined based on the determined vibration information. When the motor performs a positioning action again and vibration occurs, the vibration suppression adjustment gain K in the feedback vibration compensator is increased, and when the vibration noise is determined to be large, the position loop gain r in the feedback vibration compensator is decreased.

Images