Chromatography system speed increasing control method and device based on double integration and feedforward

Abstract

The invention discloses a color register system speed increasing control method and device based on double integration and feedforward. Designing a decoupling module to obtain a monochromatic group steady-speed decoupling model; designing a speed-up open-loop experiment of the color register system, and calculating the acceleration feedforward compensation amount of the monochromatic group according to speed-up open-loop experiment data and the steady-speed decoupling model of the monochromatic group; a double-integral controller is designed as a closed-loop controller according to the steady-speed decoupling model of the monochromatic group at different operation speeds, and the designed double-integral controller can ensure the stability of the system in the acceleration process from the initial speed to the target speed; in the speed raising control process of the color register system, according to the feedback quantity of a color register error sensor at each sampling moment, a control output instruction quantity is obtained through calculation of a double-integral controller, a feed-forward compensation quantity of the system is obtained through table look-up, the control output instruction quantity and the feed-forward compensation quantity are summed and input to the decoupling module, and a decoupling output quantity is obtained; and the speed increasing instruction and a system speed increasing instruction jointly act on an execution motor to adjust the running speed of the printing roller until the speed increasing process is finished.

Description

Technical Field

[0001] The present invention relates to the field of printing control technology, and in particular to a color registration system speed-up control method and device based on double integration plus feedforward. Background Art

[0002] In the printing process of the electronic axis gravure printing machine, complex color patterns are generally decomposed into multiple monochrome patterns and engraved on the printing plate roller for printing.

[0003] During printing, the printed material passes through each printing unit in a certain order. Each printing unit prints the corresponding monochrome pattern on the printed material, and finally a complex color pattern is formed, which is called the color matching process.

[0004] In the color registration steady speed stage, each printing plate roller is driven by the same group of motors and runs at a constant speed, so there is no large tension fluctuation between the color groups. In the color registration acceleration stage, each printing plate roller is driven by the motor to accelerate, and the guide roller is driven by the tension between the printing materials on both sides to accelerate, which means that there is a large tension fluctuation between the color groups, and this tension fluctuation is related to acceleration, and will have a serious impact on the color registration accuracy, resulting in a large color registration error.

[0005] At the same time, the dynamic characteristics of the color registration system in the acceleration process will become more complex, and common control methods such as PD plus feedforward control and model predictive control can only achieve limited performance.

[0006] In view of the importance of color registration accuracy to product quality, a control method for the speed-up process that can quickly and effectively reduce or eliminate color registration errors is particularly critical in industrial applications. Summary of the invention

[0007] Aiming at the disadvantage that the color registration accuracy is seriously affected by the tension fluctuation generated in the color registration speed-up process of the existing electronic axis gravure printing machine system, the present invention provides a color registration system speed-up control method and device based on double integration plus feedforward, which effectively reduces the color registration error generated in the speed-up process.

[0008] The present invention is achieved through the following technical solutions: A color registration system speed-up control method based on double integration plus feedforward, comprising: According to the steady-speed coupling mathematical model of the multi-color group of the color system, the coupling model is feedforward decoupled, and the decoupling module is designed to obtain the steady-speed decoupling model of the single-color group. Design the speed-up open-loop experiment of the color system, collect the speed-up open-loop experimental data, and calculate the acceleration feedforward compensation of the single-color group based on the speed-up open-loop experimental data and the steady-speed decoupling model of the single-color group. According to the steady speed decoupling model of the single color group at different operating speeds, a double integral controller is designed as a closed-loop controller, and the designed double integral controller can ensure the stability of the system during the speed increase from the starting speed to the target speed. During the speed increase control process of the color registration system, the control output instruction amount is calculated by the dual integral controller according to the feedback amount of the color registration error sensor at each sampling moment, and the system feedforward compensation amount is obtained by looking up the table. The sum of the two is input into the decoupling module to obtain the decoupling output amount, and it acts together with the system speed increase instruction on the execution motor to adjust the running speed of the plate roller until the speed increase process is completed.

[0009] Furthermore, the transfer function of the steady-speed decoupling model of the single-color group is: ; in, is the Laplace transform function of the color group color error signal, is the Laplace transform function of the motor position command signal, , V is the color group running speed, l is the material length of the unit, r is the radius of the printing plate roller, is the delay time, and L is the detection distance.

[0010] Furthermore, the speed-up open-loop experiment starts from the minimum working speed and increases the speed until the maximum target speed is reached. The speed-up open-loop experiment data includes the color registration error, the running speed, and the acceleration instruction of each color group at each sampling moment.

[0011] A storage medium stores a computer program, which implements the color registration system speed-up control method when executed by a processor.

[0012] A device comprises a memory, a processor and a color registration system speed-up control method stored in the memory and executable on the processor.

[0013] Compared with the prior art, the present invention has the following advantages and effects: The color registration system speed-up control method based on double integration and feedforward of the present invention can effectively reduce the color registration error, improve the color registration accuracy, save costs and improve economic benefits during the speed-up process of the color registration system.

[0014] The present invention is based on a color registration system speed-up control method with double integration and feedforward. On the basis of a steady-speed decoupling model, a double-integral controller is designed and used to suppress the disturbance generated in the speed-up process, thereby effectively reducing the color registration error generated in the system speed-up process and improving the color registration accuracy.

[0015] At the same time, based on the speed-up open-loop experimental data, the present invention calculates the feedforward compensation of the system acceleration, which is used for feedforward compensation in the speed-up process, thereby reducing the color registration error caused by the acceleration change in the speed-up process.

[0016] The control process of the invention is simple and easy, and can be applied in the color registration process of the electronic axis gravure printing machine, thereby saving production costs and improving economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a work flow chart of the present invention.

[0018] Figure 2 It is a curve chart of speed-up open-loop experimental data.

[0019] Figure 3 It is a schematic diagram of the structure of the color matching control system of the present invention.

[0020] Figure 4 It is the color error curve of each color group when the speed increases from 30m / min to 200m / min. DETAILED DESCRIPTION

[0021] The present invention will be further described in detail below in conjunction with embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0022] like Figure 1 As shown, the present invention discloses a color registration system speed-up control method based on double integration plus feedforward, which can be implemented by the following steps: According to the steady-speed coupling mathematical model of the multi-color group of the color system, S1 performs feedforward decoupling on the coupling model, designs a decoupling module, and obtains a steady-speed decoupling model of the single-color group.

[0023] Further, the model of the decoupling module is determined as: ; in, is the Laplace transform function of the control output signal of the ith color group after decoupling, is the Laplace transform function of the control output signal of the jth color group after decoupling, is the Laplace transform function of the control output signal of the ith color group before decoupling, It is a feedforward compensation controller used to eliminate the coupling effect of the jth color group on the i-th color group, and its form is: ; in, is the decoupling controller parameter, V is the color group running speed, and l is the unit material length.

[0024] Furthermore, the transfer function of the steady-speed decoupling model of the single-color group is: ; in, is the Laplace transform function of the color group color error signal, is the Laplace transform function of the motor position command signal, , V is the color group running speed, l is the material length of the unit, r is the radius of the printing plate roller, is the delay time, and L is the detection distance.

[0025] S2 designs an open-loop speed-up experiment for the color matching system, collects the open-loop speed-up experimental data, and calculates the acceleration feedforward compensation of the single-color group based on the open-loop speed-up experimental data and the steady-speed decoupling model of the single-color group.

[0026] Furthermore, the speed-up open-loop experiment starts from the minimum operating speed and increases the speed until the maximum target operating speed is reached.

[0027] Furthermore, the speed-up open-loop experimental data includes the color registration error, the running speed, and the acceleration instruction of each color group at each sampling moment.

[0028] Furthermore, for the system speed increase command in the speed increase open loop experiment The color registration error caused by the effect can be considered to be caused by the disturbance signal applied to the input end of the steady-speed decoupling model. There is a corresponding relationship between the disturbance signal and the acceleration command of the system. Therefore, the calculation method of the acceleration feedforward compensation amount is as follows: First, the steady-speed decoupling model is z-transformed to obtain the following z-transform model: ; in, is the sampling time, C is the circumference of the plate roller, and V is the running speed. ,n,m are model parameters, n is an integer, m is a decimal less than 1, It is the delay time.

[0029] Secondly, the differential equations of the input and output signals obtained from the z-transform model are as follows: ; Where k is the sampling time, u(k) is the equivalent disturbance input signal to be calculated, y(k) is the chromatic error data of the speed increase open-loop experiment, and the calculated u(k) is matched with the acceleration command at the corresponding sampling time. If there are multiple input signals of different sizes corresponding to the same acceleration command, mean filtering should be performed. Thus, the corresponding acceleration feedforward compensation is obtained. .

[0030] S3 designs a double-integral controller as a closed-loop controller according to the steady-speed decoupling model of the single-color group at different operating speeds, and ensures that the designed double-integral controller can ensure the stability of the system during the speed increase process from the starting speed to the target speed.

[0031] The determination method of the dual integral controller is as follows: Considering that the object characteristics are time-varying during the speed increase process, it is expected that the designed controller will make the open-loop system With the frequency domain characteristics that meet the requirements, the parameters of the double integral controller can be determined by the following formula: ; Furthermore, the transfer function of the desired open-loop system model is as follows: ; in, It is the parameter of the desired open-loop system, which determines the frequency domain Bode diagram of the open-loop system as well as system performance indicators such as phase and amplitude margin. is the object delay time.

[0032] Furthermore, the transfer function of the dual-integral controller is as follows: ; further, The value can be determined by frequency domain design method.

[0033] further, The value of is as follows: According to the transfer function of the desired open-loop system, the system phase margin formula can be obtained: ; in, is the frequency in rad / s. For the system phase margin required by the process, the frequency corresponding to the phase margin is obtained by gradient descent method, and then The value of satisfies that at this frequency, the amplitude of the open-loop system is 1.

[0034] S4 During the speed increase control process of the color registration system, according to the feedback amount of the color registration error sensor at each sampling moment, the control output instruction amount is calculated by the dual integral controller and the system feedforward compensation amount is obtained by looking up the table. The sum of the two is input into the decoupling module to obtain the decoupling output amount, and it acts together with the system speed increase instruction on the execution motor to adjust the running speed of the plate roller until the speed increase process is completed.

[0035] In this embodiment, the system equipment parameter values ​​are as follows: The circumference of the plate roller C=0.49m, the radius of the plate roller r=0.078m, the material length of the unit l=8.9m, the detection distance L=0.7m, the system operating speed increases from 30m / min to 200m / min, and the steady-speed decoupling model of the single-color group can be calculated and determined based on the parameters.

[0036] Design a speed-up open-loop experiment and collect speed-up open-loop experiment data such as Figure 2 As shown, the corresponding acceleration feedforward compensation is calculated.

[0037] For the parameter values ​​of the desired open-loop system, The values ​​are 0.1 and 100 respectively.

[0038] The target phase margin for the desired open-loop system is taken as 65°, which is determined by The value of .

[0039] Closed-loop control is performed during the speed increase process of the color registration system. The control block diagram is as follows: Figure 3 shown.

[0040] Figure 4 This is a curve diagram of the color registration error of each color group when the color registration system speed increases from 30m / min to 200m / min.

[0041] In summary, the color registration system speed-up control method based on double integration plus feedforward of the present invention has the advantages of being simple and easy to implement, having a fast response speed, and effectively reducing the color registration error.

[0042] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A color system speed-up control method based on double integration plus feedforward, characterized in that The steps include: S1. According to the steady-speed coupling mathematical model of the multi-color group of the color system, the coupling model is feedforward decoupled, a decoupling module is designed, and a steady-speed decoupling model of the single-color group is obtained; S2. Design a speed-up open-loop experiment for the color system, collect speed-up open-loop experimental data, and calculate the acceleration feedforward compensation of the single-color group based on the speed-up open-loop experimental data and the steady-speed decoupling model of the single-color group; S3. Design a double-integral controller as a closed-loop controller based on the steady-speed decoupling model of the single-color group at different operating speeds, and ensure that the designed double-integral controller can ensure the stability of the system during the speed increase process from the starting speed to the target speed; S4 During the speed increase control process of the color registration system, according to the feedback amount of the color registration error sensor at each sampling moment, the control output instruction amount is calculated by the dual integral controller and the system feedforward compensation amount is obtained by looking up the table. The sum of the two is input into the decoupling module to obtain the decoupling output amount, and it acts together with the system speed increase instruction on the execution motor to adjust the running speed of the plate roller until the speed increase process is completed.

2. According to claim 1, the color system speed-up control method based on double integration plus feedforward is characterized in that: In step S1, the model of the decoupling module is determined as: ； in, is the Laplace transform function of the control output signal of the ith color group after decoupling, is the Laplace transform function of the control output signal of the jth color group after decoupling, is the Laplace transform function of the control output signal of the ith color group before decoupling, It is a feedforward compensation controller used to eliminate the coupling effect of the jth color group on the i-th color group, and its form is: ； in, is the decoupling controller parameter, V is the color group running speed, and l is the unit material length.

3. According to claim 1, the color system speed-up control method based on double integration plus feedforward is characterized in that: In step S1, the transfer function of the steady-speed decoupling model of the single-color group is: ； in, is the Laplace transform function of the color group color error signal, is the Laplace transform function of the motor position command signal, , V is the color group running speed, l is the material length of the unit, r is the radius of the printing plate roller, is the delay time, and L is the detection distance.

4. According to claim 1, the color system speed-up control method based on double integration plus feedforward is characterized in that: In step S2, the speed-up open-loop experiment starts from the minimum operating speed and increases the speed until the maximum target operating speed is reached.

5. According to claim 1, the color system speed-up control method based on double integration plus feedforward is characterized in that: In step S2, the speed-up open-loop experimental data includes the color registration error, running speed, and acceleration instruction of each color group at each sampling moment.

6. The color registration system speed-up control method based on double integration plus feedforward according to claim 1 is characterized in that: In step S2, for the system speed increase instruction in the speed increase open loop experiment The color registration error caused by the action can be considered to be caused by the disturbance signal applied to the input end of the steady-speed decoupling model. There is a corresponding relationship between the disturbance signal and the acceleration command of the system. Therefore, the calculation method of the acceleration feedforward compensation is as follows: First, the steady-speed decoupling model is z-transformed to obtain the following z-transform model: ； in, is the sampling time, C is the circumference of the plate roller, V is the running speed, , n and m are model parameters, n is an integer, and m is a decimal less than 1. is the delay time; Secondly, the differential equations of the input and output signals obtained from the z-transform model are as follows: ； in, k is the sampling time, u(k) is the equivalent disturbance input signal to be calculated, y(k) is the color registration error data of the speed-up open-loop experiment, The calculated u(k) is matched with the acceleration command at the corresponding sampling moment. If there are acceleration commands of the same magnitude corresponding to multiple input signals of different magnitudes, mean filtering should be performed.

7. The color registration system speed-up control method based on double integration plus feedforward according to claim 1 is characterized in that: In step S3, the determination method of the double integral controller is as follows: Considering that the object characteristics are time-varying during the speed increase process, the controller is designed so that the open-loop system With the frequency domain characteristics that meet the requirements, the parameters of the double integral controller can be determined by the following formula: 。 8. The color registration system speed-up control method based on double integration plus feedforward according to claim 1 is characterized in that: In step S3, the transfer function of the open-loop system model is as follows: ； in, It is the parameter of the desired open-loop system, which determines the frequency domain Bode diagram of the open-loop system and the system performance indicators such as phase and amplitude margin. is the object delay time.

9. The color registration system speed-up control method based on double integration plus feedforward according to claim 1 is characterized in that: In step S3, the transfer function of the dual integral controller is as follows: ； The value can be determined by frequency domain design method; The value of is as follows: According to the transfer function of the expected open-loop system, the system phase margin formula can be obtained: ； in, is the frequency in rad / s; For the system phase margin required by the process, the frequency corresponding to the phase margin is obtained by gradient descent method, and then The value of satisfies that at this frequency, the amplitude of the open-loop system is 1.

10. A device comprising a memory, a processor, and a color registration system speed-up control method based on double integration and feedforward as described in any one of claims 1 to 9 which is stored in the memory and can be run on the processor.

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