Observer-based sliding mode roll-to-roll electronic shaft gravure press overprinting control method, system and device and medium

Abstract

The invention discloses a sliding mode roll-to-roll electronic shaft gravure press overprinting control method, system and device based on an observer and a medium. The method comprises the steps that the overprinting error of each color group and a first color group in the printing process of an electronic shaft gravure press is detected; constructing a Luenberger observer according to a first mathematical model of the color register error and the angular velocity variation of the printing plate roller, and determining a predicted value of the tension fluctuation quantity through the Luenberger observer; a sliding mode controller is constructed according to the first mathematical model, and the angular velocity control quantity is determined through the sliding mode controller according to the predicted value; adjusting the angular velocity of the printing roller according to the angular velocity control quantity. According to the method, the observer is used for estimating the system tension fluctuation quantity, the sliding mode controller is combined for restraining system disturbance and coupling effects, printing errors in the accelerated printing process can be eliminated, the system response speed and the color register precision are improved, and the method can be widely applied to the technical field of printing control.

Description

Technical Field

[0001] The present invention relates to the field of printing control technology, and in particular to an observer-based sliding mode roll-to-roll electronic axis gravure printing machine overprint control method, system, device and medium. Background Art

[0002] Color registration control is a complex technical issue, requiring different methods for different printing methods. Common industrial methods maintain a control accuracy of approximately ±0.15mm. During the printing process on an electronic axis gravure press, a complex pattern is typically broken down into several simpler patterns, each of which is engraved onto the printing plate roller. During actual printing, the substrate passes through the feed section and sequentially through each printing unit. Each printing unit then applies a corresponding simple pattern to the substrate, ultimately creating a complex printed pattern. However, due to tension changes caused by the acceleration process and external interference, accurate positioning of the patterns between the units during the printing process often presents problems, resulting in color registration error. Color registration accuracy is directly related to product quality. Therefore, when positional deviations occur between the patterns of the various printing units during the printing process, effective control methods must be implemented to reduce or eliminate these errors to ensure the accuracy of the final print. Given the critical impact of color registration accuracy on product quality, control methods that can quickly reduce or eliminate color registration error are particularly important. Summary of the Invention

[0003] The purpose of the present invention is to solve one of the technical problems existing in the prior art to at least a certain extent.

[0004] To this end, one purpose of an embodiment of the present invention is to provide an observer-based sliding mode roll-to-roll electronic axis gravure printing machine overprint control method, which estimates the system tension fluctuation through the observer and combines the sliding mode controller to suppress system disturbances and coupling effects, thereby solving the technical problems of slow control response speed and low color registration accuracy in the accelerated printing process in the prior art.

[0005] Another object of an embodiment of the present invention is to provide an observer-based sliding mode roll-to-roll electronic axis gravure printing machine register control system.

[0006] In order to achieve the above technical objectives, the technical solutions adopted by the embodiments of the present invention include:

[0007] In a first aspect, an embodiment of the present invention provides an observer-based sliding mode roll-to-roll electronic axis gravure printing machine register control method, comprising:

[0008] Detect the color registration error between each color group and the first color group during the printing process of the electronic axis gravure printing machine;

[0009] constructing a Romberg observer based on the first mathematical model of the color registration error and the change in the angular velocity of the printing plate roller, and determining a predicted value of the tension fluctuation through the Romberg observer;

[0010] constructing a sliding mode controller according to the first mathematical model, and determining an angular velocity control amount according to the predicted value by the sliding mode controller;

[0011] The angular velocity of the printing plate roller is adjusted according to the angular velocity control amount.

[0012] Furthermore, the first mathematical model is:

[0013]

[0014] The system state space equation of the first mathematical model is:

[0015]

[0016] C=[I 0]

[0017]

[0018]

[0019] C′=diag{c1(t),c2(t),…,c n-1 (t)}.

[0020]

[0021] C′ Δ =diag{c Δ1 , c Δ2 ,…,c Δ(n-1 )}.

[0022] Among them, E i (t) is the color error between the i-th color group printing cursor and the first color group printing cursor, ΔT i (t) is the change in tension between the i-th printing plate roller and the i+1-th printing plate roller, ω * (t) is the synchronous angular velocity of the plate roller of the electronic axis gravure printing machine, K is the tensile coefficient of the printing material, T * is the tension of the printing material in the equilibrium tensile state, r is the radius of the printing plate roller, l i is the mesh length between the ith printing plate roller and the i+1th printing plate roller, is the angular velocity change of the ith printing plate roller, and A Δ is the first uncertainty parameter, A ΔThe dimension of B is 2(n-1)×2(n-1), Δ is the second uncertainty parameter, B Δ The dimension of is 2(n-1)×(n-1), d(t) is the structural uncertainty and the external disturbance parameter of the system, the dimension of d(t) is (n-1)×1, u(t) is the angular velocity change of the system input, the dimension of u(t) is (n-1)×1, x1(t) is the chromatic error of the system, the dimension of x1(t) is (n-1)×1, x2(t) is the tension fluctuation of the system, the dimension of x2(t) is (n-1)×1, A Δ 、B Δ and d(t) are bounded.

[0023] Furthermore, the expression of the angular velocity control amount is:

[0024]

[0025] The decoupling formula of the angular velocity control quantity is:

[0026]

[0027] According to the decoupling formula, the state space equation of the tension variation of the decoupled system is:

[0028]

[0029]

[0030] in, is the decoupling amount of the preceding printing unit of the i-th printing unit, The i-th printing unit is used to eliminate the disturbance d i-1 (t) The amount of compensation for the chromatic aberration caused by the chromatic aberration.

[0031] Furthermore, the sliding mode function of the sliding mode controller is:

[0032] s(t)=λx1(t)+x2(t)

[0033]

[0034] Δ(t)=λC′ Δ x2(t)+A′ Δ x2(t)+B Δd u c (t)+d(t)

[0035] λ=diag{λ1,λ2,…,λ n-1}

[0036] The Lyapunov energy function of the sliding mode controller is:

[0037]

[0038] The saturation function of the sliding mode controller is:

[0039]

[0040] Where Δ(t) is the total disturbance of the system, the dimension of Δ(t) is (n-1)×1, |Δ(t)|≤D is bounded, λ is the chromatic error gain coefficient, λ>0, V(t) is the Lyapunov energy function, V(t)>0, t≠0, η is the switching term gain, sat(s) is the saturation function, Δ is the boundary layer, and k is the inverse of Δ.

[0041] Furthermore, the angular velocity control amount is solved by the following formula:

[0042] u(t)=B d -1 (-λC′x2(t)-A′x2(t)-ηsat(s(t))-ps(t))

[0043] η={η1,η2,…,η n-1} T

[0044] p=diag{p1,p2,…,p n-1}

[0045] Among them, η is the switching gain, η i >0,p i is the linear gain term, p i >0, 1≤i≤n-1.

[0046] Furthermore, the Lumberg observer is:

[0047]

[0048]

[0049] in, is the estimated value of the chromatic error, The dimension is (n-1)×1, is the estimated value of the tension fluctuation, The dimension is (n-1)×1, is the estimated value of the chromatic error output by the system, The dimension of is (n-1)×1, Y(t) is the chromatic error actually collected by the system, the dimension of Y(t) is (n-1)×1, L is the observer estimation matrix, and the dimension of L is (n-1)×(n-1).

[0050] Furthermore, the electronic gravure printing machine includes at least two printing units, the color group is a printing unit equipped with corresponding colors, and the printing unit is configured with a sensing device and a controller. The sensing device is used to detect the color registration error, and the controller is used to determine the predicted value of the tension fluctuation amount through the Romberg observer, and determine the angular velocity control amount according to the predicted value through the sliding mode controller, and then adjust the angular velocity of the printing plate roller according to the angular velocity control amount.

[0051] In a second aspect, an embodiment of the present invention provides an observer-based sliding mode roll-to-roll electronic axis gravure printing machine register control system, comprising:

[0052] A color registration error detection module is used to detect the color registration error between each color group and the first color group during the printing process of the electronic axis gravure printing machine;

[0053] a tension fluctuation prediction module, configured to construct a Romberg observer based on a first mathematical model of the color registration error and the change in the angular velocity of the printing plate roller, and determine a predicted value of the tension fluctuation through the Romberg observer;

[0054] an angular velocity control variable calculation module, configured to construct a sliding mode controller according to the first mathematical model, and determine the angular velocity control variable according to the predicted value through the sliding mode controller;

[0055] The angular velocity adjustment module is used to adjust the angular velocity of the printing plate roller according to the angular velocity control amount.

[0056] In a third aspect, an embodiment of the present invention provides a device, including:

[0057] at least one processor;

[0058] at least one memory for storing at least one program;

[0059] When the at least one program is executed by the at least one processor, the at least one processor implements the above-mentioned observer-based sliding mode roll-to-roll electronic axis gravure printing machine register control method.

[0060] In a fourth aspect, an embodiment of the present invention further provides a computer-readable storage medium storing a program executable by a processor, wherein the program executable by the processor is used to execute the above-mentioned observer-based sliding-mode roll-to-roll electronic axis gravure printing machine overprint control method when executed by the processor.

[0061] The advantages and benefits of the present invention will be described in part in the following description and will become apparent from the following description or learned through practice of the present invention:

[0062] The embodiment of the present invention is based on a fully decoupled steady-speed model of the accelerated printing process of an electronic axis gravure printing machine and a dynamic model of the acceleration stage. By constructing a Lumberg observer, the internal tension fluctuation of the system is estimated. A sliding mode function is established in combination with the state space equation of the system, and the system state is forced to enter a predetermined "sliding mode surface" and slide on the surface. The control quantity of the system is calculated in this way, which theoretically ensures that the overprint error in the acceleration stage is 0. The sliding mode control has strong robustness to model uncertainty, external disturbances and parameter changes, can respond quickly, effectively eliminate the overprint error of the system, and improve the color registration accuracy. By introducing a dynamic coupling compensation term and adopting a dynamic decoupling strategy to suppress tension disturbance in real time, a stable decoupling effect can be maintained under disturbance conditions, further improving the color registration accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 A schematic diagram of the steps of an observer-based sliding mode roll-to-roll electronic axis gravure printing machine overprint control method provided by an embodiment of the present invention;

[0064] Figure 2 Deviation diagram between the estimated values ​​and actual values ​​of the Lumberg observer for the second to fourth printing units provided in an embodiment of the present invention;

[0065] Figure 3 A tension variation estimation curve diagram of the second to fourth printing units provided in an embodiment of the present invention;

[0066] Figure 4 A register error map of the second printing unit provided in an embodiment of the present invention;

[0067] Figure 5 A register error diagram of the third printing unit provided in an embodiment of the present invention;

[0068] Figure 6 A register error diagram of the fourth printing unit provided in an embodiment of the present invention;

[0069] Figure 7 A register error diagram of the fifth printing unit provided in an embodiment of the present invention;

[0070] Figure 8 A register error diagram of the sixth printing unit provided in an embodiment of the present invention;

[0071] Figure 9 A register error graph of the seventh printing unit provided in an embodiment of the present invention;

[0072] Figure 10 A graph comparing the error of the second color group between an observer-based sliding mode roll-to-roll electronic axis gravure printing machine overprint control method and an FDPD control method provided by an embodiment of the present invention;

[0073] Figure 11 A graph showing the error comparison of the third color group between an observer-based sliding mode roll-to-roll electronic axis gravure printing machine overprint control method and an FDPD control method provided by an embodiment of the present invention;

[0074] Figure 12 A graph showing the error comparison of the fourth color group between an observer-based sliding mode roll-to-roll electronic axis gravure printing machine overprint control method and an FDPD control method provided by an embodiment of the present invention;

[0075] Figure 13 A graph showing the error comparison between the fifth color group of an observer-based sliding mode roll-to-roll electronic axis gravure printing machine overprint control method and an FDPD control method provided by an embodiment of the present invention;

[0076] Figure 14 A graph showing the error comparison between the sixth color group of an observer-based sliding mode roll-to-roll electronic axis gravure printing machine overprint control method and an FDPD control method provided in an embodiment of the present invention;

[0077] Figure 15 A graph showing the error comparison between the seventh color group of an observer-based sliding mode roll-to-roll electronic axis gravure printing machine overprint control method and an FDPD control method provided by an embodiment of the present invention;

[0078] Figure 16 A schematic diagram of an observer-based sliding mode roll-to-roll electronic axis gravure printing machine register control system provided by an embodiment of the present invention;

[0079] Figure 17 A schematic structural diagram of a device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0080] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention and are not to be construed as limiting the present invention. The step numbers in the following embodiments are provided for ease of explanation only and do not limit the order of the steps. The order of execution of the steps in the embodiments can be adaptively adjusted according to the understanding of those skilled in the art.

[0081] In the description of the present invention, "a plurality" means two or more. The terms "first" and "second" are used solely to distinguish technical features and are not to be construed as indicating or implying relative importance, or as implicitly indicating the number of the indicated technical features, or as implicitly indicating the order of the indicated technical features. Furthermore, unless otherwise defined, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art.

[0082] The control system of a typical electronic gravure printing press primarily consists of two main components: a tension control system and a color registration control system. The goal of tension control is to maintain tension balance in the rewinding and unwinding sections of the printing equipment, preventing wrinkles or breaks in the printed material while providing a stable foundation for color registration control. The goal of color registration control, on the other hand, is to eliminate color registration errors caused by various disturbances, thereby improving color registration accuracy and product quality. Although these two control systems have different control objectives, their core issue is actually tension control. In the rewinding and unwinding sections, tension is detected by installed pressure sensors. The system adjusts the speed of the rewinding and unwinding motors based on the tension feedback from the sensors to maintain tension balance. Between each printing unit, color registration control uses color difference feedback from a color difference detection device to adjust the angular velocity of the printing plate roller, thereby adjusting the tension between color groups and ultimately eliminating color registration errors.

[0083] The electronic axis gravure printing machine of this application primarily consists of three main components: the unwinding and feeding section, the printing unit, and the discharging and rewinding section. The unwinding and feeding section is responsible for feeding the printing material from the reel into the printing unit at a constant angular velocity and is equipped with a specialized tension control system to ensure stable printing tension. The printing units sequentially print single-color patterns on the printing material. A dryer is installed between each color group to ensure that the material is dry after each color print, thereby preventing blurring of the freshly printed pattern. To improve color registration accuracy, each color group is also equipped with an independent color registration control system. The discharging and rewinding section is responsible for smoothly winding the printed material into the rewinding section. At the beginning of the printing process, a complete color pattern is broken down into several single-color negatives and engraved onto a circular printing plate roller. During printing, the unwinding and feeding section feeds the printing material to the printing unit. The material passes through each color group in sequence for single-color printing and hot air drying. Finally, after all color groups have been printed, the material enters the discharging and rewinding section, where it is smoothly reeled up by the rewinding motor. This completes the printing process of a complete color pattern.

[0084] Figure 1 A schematic diagram of a method for controlling the register of a sliding mode roll-to-roll electronic axis gravure printing machine based on an observer is provided in accordance with an embodiment of the present invention. Figure 1 The embodiment of the present invention provides an observer-based sliding mode roll-to-roll electronic axis gravure printing machine register control method, comprising:

[0085] S101, detecting the color registration error between each color group and the first color group during the printing process of the electronic axis gravure printing machine;

[0086] S102, constructing a Romberg observer based on the first mathematical model of the color registration error and the angular velocity change of the printing plate roller, and determining a predicted value of the tension fluctuation through the Romberg observer;

[0087] S103, constructing a sliding mode controller according to the first mathematical model, and determining an angular velocity control amount according to the predicted value through the sliding mode controller;

[0088] S104, adjusting the angular velocity of the printing plate roller according to the angular velocity control amount.

[0089] In some optional embodiments, the first mathematical model is:

[0090]

[0091] The system state space equation of the first mathematical model is:

[0092] C==[I0]

[0093] C′=diag{c1(t),c2(t),…,C n-1 (t)}.

[0094]

[0095]

[0096] C′ Δ =diag{c Δ1 , c Δ2 ,…,c Δ(n-1 )}.

[0097] Among them, E i (t) is the color error between the i-th color group printing cursor and the first color group printing cursor, ΔT i (t) is the change in tension between the i-th printing plate roller and the i+1-th printing plate roller, ω * (t) is the synchronous angular velocity of the plate roller of the electronic axis gravure printing machine, K is the tensile coefficient of the printing material, T * is the tension of the printing material in the equilibrium tensile state, r is the radius of the printing plate roller, l i is the mesh length between the ith printing plate roller and the i+1th printing plate roller, is the angular velocity change of the ith printing plate roller, and A Δ is the first uncertainty parameter, AΔ The dimension of B is 2(n-1)×2(n-1), Δ is the second uncertainty parameter, B Δ The dimension of is 2(n-1)×(n-1), d(t) is the structural uncertainty and the external disturbance parameter of the system, the dimension of d(t) is (n-1)×1, u(t) is the angular velocity change of the system input, the dimension of u(t) is (n-1)×1, x1(t) is the chromatic error of the system, the dimension of x1(t) is (n-1)×1, x2(t) is the tension fluctuation of the system, the dimension of x2(t) is (n-1)×1, A Δ 、B Δ and d(t) are bounded.

[0098] In some optional embodiments, the expression of the angular velocity control amount is:

[0099]

[0100] The decoupling formula of the angular velocity control quantity is:

[0101]

[0102] According to the decoupling formula, the state space equation of the tension variation of the decoupled system is:

[0103]

[0104]

[0105] in, is the decoupling amount of the preceding printing unit of the i-th printing unit, The i-th printing unit is used to eliminate the disturbance d i-1 (t) The amount of compensation for the chromatic aberration caused by the chromatic aberration.

[0106] Specifically, in this embodiment, since the uncertainty of each parameter itself is unmeasurable, its elements are uniformly expressed in one form. The derivation process of the decoupling strategy is:

[0107] The first mathematical model for the color registration error and the change in the angular velocity of the printing plate roller between color groups is:

[0108]

[0109] The system state space equation of the first mathematical model is:

[0110]

[0111] The expression of the control quantity is:

[0112]

[0113] In order to eliminate the coupling of the control quantity of the 2nd printing unit to the 3rd printing unit, according to formula (1) and formula (2), we can get:

[0114]

[0115] Similarly, the decoupling formula for the control quantity of printing unit i is as follows:

[0116]

[0117] According to formula (5), the state space equation of the tension variation of the decoupled R2R (Roll-to-Roll) printing system is:

[0118]

[0119] make

[0120]

[0121] It can be recognized that after decoupling, each unit of the system input is relatively independent, which provides convenience for subsequent controller design.

[0122] In some optional embodiments, the sliding mode function of the sliding mode controller is:

[0123] s(t)=λx1(t)+x2(t)

[0124]

[0125] Δ(t)=λC′ Δ x2(t)+A′ Δ x2(t)+B Δd u c (t)+d(t)

[0126] λ=diag{λ1,λ2,…,λ n-1}

[0127] The Lyapunov energy function of the sliding mode controller is:

[0128]

[0129] The saturation function of the sliding mode controller is:

[0130]

[0131] Where Δ(t) is the total disturbance of the system, the dimension of Δ(t) is (n-1)×1, |Δ(t)|≤D is bounded, λ is the chromatic error gain coefficient, λ>0, V(t) is the Lyapunov energy function, V(t)>0, t≠0, η is the switching term gain, sat(s) is the saturation function, Δ is the boundary layer, and k is the inverse of Δ.

[0132] Specifically, in this embodiment, the sliding mode function of the sliding mode controller is defined as:

[0133] s(t)=λx1(t)+x2(t) (7)

[0134] Based on formula (2) and formula (6), we can derive formula (7):

[0135]

[0136] Define the Lyapunov energy function as

[0137]

[0138] By taking the derivative of formula (9), we can get:

[0139]

[0140] when When s(t)≡0, according to the LaSelle invariance principle, the closed-loop system is asymptotically stable. When t→∞, s(t)→0. When the modeling uncertainty and interference are large, the switching term gain η needs to be larger, which will cause greater chattering. To reduce chattering, the saturation function sat(s) is used in the control, that is:

[0141]

[0142] Where Δ is the boundary layer. Using a saturation function allows the error function to use switching control outside the boundary layer, bringing the system closer to a sliding mode. Feedback control is used within the boundary layer to reduce chattering caused by rapid switching between sliding modes and ensure that s(t) remains within the boundary layer.

[0143] In some optional embodiments, the angular velocity control amount is solved by the following formula:

[0144] u(t)=B d -1 (-λC′x2(t)-A′x2(t)-ηsat(s(t))-ps(t))

[0145] η={η1,η2,…,η n-1} T

[0146] p=diag{p1,p2,...,P n-1}

[0147] Among them, η is the switching gain, η i >0,p i is the linear gain term, p i >0, 1≤i≤n-1.

[0148] Specifically, when the control method in this embodiment is used for control, the expression of the control amount is:

[0149] u(t)=B d -1 (-λC′x2(t)-A′x2(t)-ηsat(s(t))-ps(t)) (11)

[0150] The state feedback controller needs to be based on measurable state variables to control the system. However, in actual production, it is too expensive to implement tension detection on each unit of the roll-to-roll system. The tension fluctuation cannot be directly obtained and can only be estimated through input and output. Therefore, this paper adopts the state observer model to estimate the internal tension fluctuation of the system. The necessary and sufficient condition for the observability of the system is that its observability matrix Q o Full rank, that is, the rank is equal to the number of system state variables. In order to verify the observability of the R2R printing system, the observability matrix Q is constructed according to formula (2): o as follows:

[0151] C=[I 0],

[0152] Among them, the C matrix dimension is (n-1)×2(n-1), and I is the identity matrix with dimension (n-1)×(n-1). In order to solve the observation matrix Q o Rank. By block calculation,

[0153] rank(C)=n-1,

[0154] Get rank(Q o )=2(n-1), that is, the observation matrix is ​​full rank. Therefore, the R2R printing system is observable.

[0155] In some alternative embodiments, the Lumberg observer is:

[0156]

[0157] in, is the estimated value of the chromatic error, The dimension is (n-1)×1, is the estimated value of the tension fluctuation, The dimension is (n-1)×1, is the estimated value of the chromatic error output by the system, The dimension of is (n-1)×1, Y(t) is the chromatic error actually collected by the system, the dimension of Y(t) is (n-1)×1, L is the observer estimation matrix, and the dimension of L is (n-1)×(n-1).

[0158] Specifically, in this embodiment, the model of the Lumberg observer is:

[0159]

[0160] in,

[0161]

[0162] In order to make the estimated state closer to the actual state, the error function is defined as follows:

[0163]

[0164] Taking the derivative of the error function e(t) yields:

[0165]

[0166] When the matrix P is a Hurwitz matrix, the eigenvalue Re(λ i )<0, the entire system is asymptotically stable, and the error function e(t)→0 converges. Therefore, by calculating the eigenvalues ​​of the matrix P, we can obtain the observer gain. In other words, we can design the elements of the gain matrix L so that the eigenvalues ​​of the matrix P are less than 0, thereby making the error function e(t)→0, so that the estimated state can approach the actual state.

[0167] In some optional embodiments, the electronic gravure printing machine includes at least two printing units, the color group is a printing unit equipped with corresponding colors, the printing unit is equipped with a sensing device and a controller, the sensing device is used to detect the color registration error, the controller is used to determine the predicted value of the tension fluctuation amount through the Romberg observer, and determine the angular velocity control amount according to the predicted value through the sliding mode controller, and then adjust the angular velocity of the printing plate roller according to the angular velocity control amount.

[0168] Specifically, in this embodiment, the sensing device is a photoelectric eye, and each printing unit is equipped with a color registration control system. The color registration control system consists of a sensing device and a controller. The sensing device is used to detect color registration errors. The controller estimates the tension fluctuation amount through the Romberg observer and calculates the angular velocity adjustment amount in combination with the sliding mode controller. Multiple guide rollers are provided between continuous printing plate rollers (printing units), and the observer estimates the tension fluctuation amount through the error signal detected by the photoelectric eye. The radius of each printing plate roller in the printing system is the same, the material threading length between each color group is also the same, and the guide rollers are evenly distributed between two adjacent printing plate rollers. Therefore, multiple guide rollers between adjacent printing plate rollers can be regarded as one guide roller. The gain matrix of the Lumberg observer is designed through pole configuration. The decoupling matrix in the sliding mode controller is used to suppress the coupling between color groups, and the saturation function is used to reduce chattering. The sliding mode controller and the observer are used to achieve zero steady-state control of the color error and tension fluctuation. That is, the control target is that the overprint error and tension fluctuation of each unit converge to zero in the steady state. The color error is the cumulative coupling error of each color group relative to the first color group, including the dynamic coupling effect of the previous color group. The calculation of the control quantity is based on the real-time color error between the current color group and the first color group.

[0169] During the accelerated printing process, the printed material passes through each printing control unit of the electronic axis gravure press in sequence, completing the printing of the corresponding color group (a color group is a printing unit equipped with corresponding colors). The error detection system for color group i determines whether there is a registration error between the current color group i and color group 1. If an error exists, the control system of color group i calculates the registration error between it and color group 1 (the registration error includes the coupling error between the current color group and all previous color groups). Based on a precise mathematical model, the state observer model Romberg is used to estimate the internal tension fluctuation of the system within a preset color registration accuracy. A sliding mode function is established based on the system's state space equations, forcing the system state to enter a predetermined "sliding mode surface" and slide on it. This function calculates the system's control variable, which is the angular velocity change of the printing roller of each color group. The control system transmits the calculated results as control commands to the servo motor of the electronic axis gravure press. Upon receiving the commands, the servo motor adjusts the angular velocity of the printing roller of color group i until the registration error between color group i and color group 1 is eliminated. For each subsequent color group, the error detection system sequentially determines whether there is a color registration error between the current color group and color group 1. If an error exists, adjustments are made according to the above method until the error between each color group and color group 1 is eliminated.

[0170] According to formula (11), the control quantity of printing unit No. 2 can be obtained:

[0171]

[0172] According to formula (2) and formula (6), the state space equation of the overprint error of the two units and their tension fluctuation can be obtained:

[0173]

[0174] According to formula (12), the observer state space equation of the overprint error of the two units and their tension fluctuation is:

[0175]

[0176] Similarly, subsequent color groups can be substituted according to the above formula.

[0177] In this embodiment, Table 1 is a system parameter table provided in this embodiment, and the system parameters are shown in Table 1:

[0178] Table 1

[0179] Material length L between two adjacent units 7.5(m) <![CDATA[Equilibrium state material tension T * > 100(N) Material elastic modulus K 0.00023(1 / N) Plate roller circumference 0.52(m)

[0180] At the beginning of the experiment, the observer is verified and the parameters of the observer are set. Figure 2 As shown. Figure 2 As a result, the absolute value of the deviation between the observer estimation value and the actual value of 2-4 printing units is less than 6×10 -5 m, indicating that the deviation is small, the overprint error estimated by the observer can closely track the actual overprint error curve, showing a high tracking accuracy. Figure 3 As can be seen, the maximum estimated tension variation for printing unit 2 is 0.2N, for printing unit 3 it is 0.26N, and for printing unit 4 it is 0.35N. During the acceleration phase, the estimated tension variation is significantly higher than during the steady-state phase. The tension variation for subsequent printing units is greater than that for preceding units, a trend consistent with open-loop overprint error. In summary, the observer's estimates are highly reliable and accurate.

[0181] Under the simultaneous action of decoupling and sliding mode control methods, the error of the 7-color printing unit is as follows Figure 4-Figure 9 As shown, the overall registration error accuracy of the 7-color printing unit is within ±10×10 -5 After the acceleration is completed and the speed is stabilized, the registration error accuracy of the 2-6 printing units is stabilized at ±5×10 -5 m, and the registration error accuracy of 7 printing units is stable at ±6×10 -5 m. The whole system achieves high-precision overprint control, which verifies the effectiveness of this method in multi-unit control. By comparing the fully decoupled proportional-derivative control method (Fully Decoupled Proportional-Derivative Control, FDPD), the superiority of the control algorithm proposed in this invention is verified. Figures 10-16As shown in the figure, the system overprint error under FDPD control increases with the number of printing units, and the error peak of printing unit No. 7 reaches 146×10 -5 m, resulting in a significant increase in the scrap rate of products in the acceleration stage; the control method (OBSMC) proposed in this application strictly controls the error of the 2-7 printing units within ±10×10 -5 m, and the overprint accuracy during the steady-state phase is superior to that of FDPD. This difference demonstrates that OBSMC significantly improves the robustness of multi-unit coordinated control by suppressing tension disturbances in real time through a dynamic decoupling strategy, particularly under acceleration conditions. Further analysis reveals that the limitations of FDPD stem from its static decoupling strategy for coupling effects, while this method maintains a stable decoupling effect under perturbations by introducing a dynamic coupling compensation term. This characteristic is of great value in the engineering practice of high-precision roll-to-roll printing systems.

[0182] It can be recognized that the embodiment of the present invention, based on the fully decoupled steady-speed model of the accelerated printing process of the electronic axis gravure printing machine and the dynamic model of the acceleration stage, estimates the internal tension fluctuation of the system by constructing a Lumberg observer, and establishes a sliding mode function in combination with the state space equation of the system, and forces the system state to enter a predetermined "sliding mode surface" and slide on this surface, so as to calculate the control quantity of the system, which theoretically ensures that the overprint error in the acceleration stage is 0, and the sliding mode control has strong robustness to model uncertainty, external disturbances and parameter changes, can respond quickly, effectively eliminate the overprint error of the system, and improve the color registration accuracy; by introducing a dynamic coupling compensation term and adopting a dynamic decoupling strategy to suppress tension disturbance in real time, a stable decoupling effect can be maintained under disturbance conditions, and the color registration accuracy can be further improved.

[0183] Reference Figure 16 The embodiment of the present invention provides an observer-based sliding mode roll-to-roll electronic axis gravure printing machine register control system, comprising:

[0184] The contents of the above method embodiments are all applicable to the present system embodiments. The functions specifically implemented by the present system embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0185] Reference Figure 17 , an embodiment of the present invention provides a device, including:

[0186] at least one processor;

[0187] at least one memory for storing at least one program;

[0188] When the at least one program is executed by the at least one processor, the at least one processor implements the above-mentioned observer-based sliding mode roll-to-roll electronic axis gravure printing machine register control method.

[0189] An embodiment of the present invention also provides a computer-readable storage medium storing a program executable by a processor. When executed by the processor, the program executable by the processor is used to execute the above-mentioned observer-based sliding-mode roll-to-roll electronic axis gravure printing machine overprint control method.

[0190] A computer-readable storage medium according to an embodiment of the present invention can execute an observer-based sliding-mode roll-to-roll electronic axis gravure printing machine overprint control method provided by an embodiment of the method of the present invention, can execute any combination of implementation steps of the method embodiment, and has the corresponding functions and beneficial effects of the method.

[0191] The embodiment of the present invention also discloses a computer program product or computer program, which includes computer instructions stored in a computer-readable storage medium. A processor of a device can read the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the device performs Figure 1 The chip design method based on multi-core heterogeneous architecture is shown.

[0192] In some optional embodiments, the function / operation mentioned in the block diagram may not occur in the order mentioned in the operation diagram. For example, depending on the function / operation involved, the two boxes shown in succession can actually be executed substantially simultaneously or the above-mentioned boxes can sometimes be executed in reverse order. In addition, the embodiment presented and described in the flow chart of the present invention is provided in an exemplary manner for the purpose of providing a more comprehensive understanding of the technology. The disclosed method is not limited to the operation and logic flow presented herein. Optional embodiments are contemplated in which the order of the various operations is changed and the sub-operations described as a part of a larger operation are performed independently.

[0193] In addition, although the present invention is described in the context of functional modules, it should be understood that, unless otherwise stated, one or more of the above-mentioned functions and / or features can be integrated into a single physical device and / or software module, or one or more functions and / or features can be implemented in separate physical devices or software modules. It is also understood that a detailed discussion of the actual implementation of each module is not necessary for understanding the present invention. More specifically, given the properties, functions, and internal relationships of the various functional modules in the devices disclosed herein, the actual implementation of the module will be understood within the routine skills of an engineer. Therefore, a person skilled in the art can implement the present invention set forth in the claims using ordinary skills without undue experimentation. It is also understood that the specific concepts disclosed are merely illustrative and are not intended to limit the scope of the present invention, which is determined by the full scope of the appended claims and their equivalents.

[0194] If the above functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the above methods of each embodiment of the present invention. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0195] The logic and / or steps represented in the flowcharts or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing the logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (e.g., a computer-based system, a system including a processor, or other system that can fetch and execute instructions from an instruction execution system, apparatus, or device). For purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by, or in conjunction with, an instruction execution system, apparatus, or device.

[0196] More specific examples (a non-exhaustive list) of computer-readable media include the following: an electrical connection with one or more wires (electronic devices), a portable computer disk cartridge (magnetic devices), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disc read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable media on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other media, followed by editing, deciphering, or processing in another suitable manner as necessary, and then stored in a computer memory.

[0197] It should be understood that various parts of the present invention can be implemented using hardware, software, firmware, or a combination thereof. In the above-described embodiments, multiple steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application-specific integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0198] In the above description of this specification, reference to the terms "one embodiment / example," "another embodiment / example," or "certain embodiments / examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0199] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

[0200] The above is a specific description of the preferred implementation of the present invention, but the present invention is not limited to the above embodiments. Those skilled in the art can make various equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A sliding mode roll-to-roll electronic axis gravure printing machine register control method based on an observer, characterized in that: include: Detect the color registration error between each color group and the first color group during the printing process of the electronic axis gravure printing machine; constructing a Romberg observer based on the first mathematical model of the color registration error and the change in the angular velocity of the printing plate roller, and determining a predicted value of the tension fluctuation through the Romberg observer; constructing a sliding mode controller according to the first mathematical model, and determining an angular velocity control amount according to the predicted value by the sliding mode controller; The angular velocity of the printing plate roller is adjusted according to the angular velocity control amount.

2. The method for register control of a sliding mode roll-to-roll electronic axis gravure printing machine based on an observer according to claim 1, characterized in that: The first mathematical model is: The system state space equation of the first mathematical model is: C′=diag{c1(t),c2(t),…,c n-1 (t)}. C′ Δ =diag{c Δ1 , c Δ2 …, c Δ(n-1) Among them, E i (t) is the color error between the i-th color group printing cursor and the first color group printing cursor, ΔT i (t) is the change in tension between the i-th printing plate roller and the i+1-th printing plate roller, ω * (t) is the synchronous angular velocity of the plate roller of the electronic axis gravure printing machine, K is the tensile coefficient of the printing material, T * is the tension of the printing material in the equilibrium tensile state, r is the radius of the printing plate roller, l i is the mesh length between the ith printing plate roller and the i+1th printing plate roller, is the angular velocity change of the ith printing plate roller, and A Δ is the first uncertainty parameter, A Δ The dimension of B is 2(n-1)×2(n-1), Δ is the second uncertainty parameter, B Δ The dimension of is 2(n-1)×(n-1), d(t) is the structural uncertainty and the external disturbance parameter of the system, the dimension of d(t) is (n-1)×1, u(t) is the angular velocity change of the system input, the dimension of u(t) is (n-1)×1, x1(t) is the chromatic error of the system, the dimension of x1(t) is (n-1)×1, x2(t) is the tension fluctuation of the system, the dimension of x2(t) is (n-1)×1, A Δ 、B Δ and d(t) are bounded.

3. The method for register control of a sliding mode roll-to-roll electronic axis gravure printing machine based on an observer according to claim 2, characterized in that: The expression of the angular velocity control amount is: The decoupling formula of the angular velocity control quantity is: According to the decoupling formula, the state space equation of the tension variation of the decoupled system is: in, is the decoupling amount of the preceding printing unit of the i-th printing unit, The i-th printing unit is used to eliminate the disturbance d i-1 (t) The amount of compensation for the chromatic aberration caused by the chromatic aberration.

4. The method for register control of a sliding mode roll-to-roll electronic axis gravure printing machine based on an observer according to claim 3, characterized in that: The sliding mode function of the sliding mode controller is: s(t)=λx1(t)+x2(t) Δ(t)=λC′ Δ x2(t)+A′ Δ x2(t)+B Δd u c (t)+d(t) λ=diag{λ1,λ2…,λ n-1 } The Lyapunov energy function of the sliding mode controller is: The saturation function of the sliding mode controller is: Where Δ(t) is the total disturbance of the system, the dimension of Δ(t) is (n-1)×1, |Δ(t)|≤D is bounded, λ is the chromatic error gain coefficient, λ>0, V(t) is the Lyapunov energy function, V(t)>0, t≠0, η is the switching term gain, sat(s) is the saturation function, Δ is the boundary layer, and k is the inverse of Δ.

5. The method for register control of a sliding mode roll-to-roll electronic axis gravure printing machine based on an observer according to claim 4, characterized in that: The angular velocity control amount is solved by the following formula: u(t)=B d -1 (-λC′x2(t)-A′x2(t) -ηsat(s(t))-ps(t)) n = {n1, n2, ..., n n-1 } T p=diag{p1,p2,…,p n-1 } Among them, η is the switching gain, η i >0,p i is the linear gain term, p i >0, 1≤i≤n-1.

6. The method for register control of a sliding mode roll-to-roll electronic axis gravure printing machine based on an observer according to claim 5, characterized in that: The Lumberg observer is: in, is the estimated value of the chromatic error, The dimension is (n-1)×1, is the estimated value of the tension fluctuation, The dimension is (n-1)×1, is the estimated value of the chromatic error output by the system, The dimension of is (n-1)×1, Y(t) is the chromatic error actually collected by the system, the dimension of Y(t) is (n-1)×1, L is the observer estimation matrix, and the dimension of L is (n-1)×(n-1).

7. The method for register control of a sliding mode roll-to-roll electronic axis gravure printing machine based on an observer according to claim 1, characterized in that: The electronic gravure printing machine includes at least two printing units, the color group is a printing unit equipped with corresponding colors, and the printing unit is configured with a sensing device and a controller. The sensing device is used to detect the color registration error, and the controller is used to determine the predicted value of the tension fluctuation amount through the Romberg observer, and determine the angular velocity control amount according to the predicted value through the sliding mode controller, and then adjust the angular velocity of the printing plate roller according to the angular velocity control amount.

8. A sliding mode roll-to-roll electronic axis gravure printing machine register control system based on an observer, characterized in that: include: A color registration error detection module is used to detect the color registration error between each color group and the first color group during the printing process of the electronic axis gravure printing machine; a tension fluctuation prediction module, configured to construct a Romberg observer based on a first mathematical model of the color registration error and the change in the angular velocity of the printing plate roller, and determine a predicted value of the tension fluctuation through the Romberg observer; an angular velocity control variable calculation module, configured to construct a sliding mode controller according to the first mathematical model, and determine the angular velocity control variable according to the predicted value through the sliding mode controller; The angular velocity adjustment module is used to adjust the angular velocity of the printing plate roller according to the angular velocity control amount.

9. A device, characterized in that: include: at least one processor; at least one memory for storing at least one program; When the at least one program is executed by the at least one processor, the at least one processor implements the observer-based sliding mode roll-to-roll electronic axis gravure printing machine register control method according to any one of claims 1 to 7.

10. A computer-readable storage medium storing a program executable by a processor, characterized in that: The program executable by the processor is used to execute the observer-based sliding mode roll-to-roll electronic axis gravure printing machine register control method when executed by the processor according to any one of claims 1 to 7.

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