Remote monitoring and maintenance system and method for printing equipment based on digital twinning

Abstract

The invention discloses a remote monitoring and maintenance system and method for printing equipment based on digital twinning, and relates to the field of parameter adjustment of the printing equipment, and the method achieves the refined classification and threshold dynamic matching of the operation state of the printing equipment through clustering analysis and historical data modeling, and remarkably improves the accuracy of key parameter monitoring. A real-time data acquisition and threshold comparison mechanism based on a digital twinborn model can identify abnormal fluctuations of the rotating speed of the roller and the pressure of the ink path in advance, so that equipment faults are effectively prevented; production task progress monitoring and equipment parameter regulation and control functions are integrated, collaborative optimization of a production process and an equipment state is realized, and downtime is shortened; through automatic threshold generation and parameter adjustment, the manual intervention requirement is reduced, and meanwhile the service life of core components of equipment is prolonged; a digital twinborn model is constructed, so that the fault early warning response time is greatly shortened; wherein the composite fault mode is identified by synchronously analyzing the rotating speed deviation and the pressure fluctuation data.

Description

Technical Field

[0001] The present invention belongs to the field of monitoring and adjusting parameters of printing equipment. Specifically, it particularly relates to a remote monitoring and maintenance system and method for printing equipment based on digital twins. Background Art

[0002] The traditional monitoring system has the defect that the fixed threshold cannot adapt to the changes in the working conditions of different equipment, resulting in a continuous decrease in the sensitivity of anomaly detection over time; the traditional monitoring system generally does not perform immediate comparison and adjustment of real-time deviation data and dynamic thresholds, and thus cannot intervene in advance in the influencing factors of key parameters, resulting in downtime losses caused by after-the-fact maintenance. Summary of the Invention

[0003] In view of the problems in the related art, the present invention proposes a remote monitoring and maintenance system and method for printing equipment based on digital twins to overcome the above-mentioned technical problems existing in the existing related technologies.

[0004] To solve the above technical problems, the present invention is realized through the following technical solutions:

[0005] The present invention is a remote monitoring and maintenance method for printing equipment based on digital twins, including the following steps:

[0006] S1. Collect the historical operation parameters of multiple printing equipment samples corresponding to multiple types of printing equipment, the operation parameters of the printing equipment to be monitored, and the production task progress information;

[0007] S2. Generate the limit deviation threshold of the cylinder rotation speed and the limit fluctuation threshold of the ink path pressure for multiple types of printing equipment in S1, and obtain the limit deviation threshold set of the cylinder rotation speed and the limit fluctuation threshold set of the ink path pressure;

[0008] S3. Collect the real-time cylinder rotation speed deviation data and the real-time ink path pressure fluctuation data of the printing equipment to be monitored; and select the corresponding thresholds from the limit deviation threshold set of the cylinder rotation speed and the limit fluctuation threshold set of the ink path pressure;

[0009] S4. Compare the real-time cylinder rotation speed deviation data and the real-time ink path pressure fluctuation data of the printing equipment to be monitored with the corresponding thresholds respectively, and then adjust the data of the influencing factors of the key parameters of the printing equipment to be monitored to obtain the final data set of the influencing factors of the key parameters of the printing equipment;

[0010] S5. Use the final data set of the influencing factors of the key parameters of the printing equipment to set the parameters of the printing equipment to be monitored and perform printing production, and then adjust the thresholds selected in S3 according to the qualified rate of the printing production.

[0011] Preferably, the S1 includes the following steps:

[0012] S11. Set several types of operating parameters of the printing equipment to obtain a set of printing equipment operating parameter types; then set several types of printing equipment production task progress information to obtain a set of printing production task progress information types;

[0013] S12. According to the set of printing equipment operating parameter types, collect the historical operating parameters of multiple printing equipment samples corresponding to multiple types of printing equipment to obtain a set of printing equipment historical operating parameter matrices;

[0014] S13. Set the printing equipment to be monitored; according to the set of printing equipment operating parameter types and the set of printing production task progress information types, collect the operating parameters and production task progress information of the printing equipment to be monitored at multiple time nodes during production to obtain a matrix of operating parameters of the printing equipment to be monitored and a matrix of printing production task progress information of the printing equipment to be monitored;

[0015] By setting the set of printing equipment operating parameter types and the set of printing production task progress information types, it provides a basis for collecting data of the printing equipment for constructing a digital twin model in the follow-up; by collecting the set of printing equipment historical operating parameter matrices, it provides a data basis for classifying different types of printing equipment in the follow-up, so as to further take different parameter regulation measures for different types of printing equipment, improving the accuracy of printing equipment parameter regulation; in addition, by collecting the matrix of operating parameters of the printing equipment to be monitored and the matrix of printing production task progress information of the printing equipment to be monitored, it provides data support for constructing a digital twin model of the printing equipment to be monitored in the follow-up.

[0016] Preferably, the S2 includes the following steps:

[0017] S21. Use the Gaussian mixture model to calculate the clustering center data of each operating parameter matrix in the set of printing equipment historical operating parameter matrices to obtain a matrix of printing equipment historical operating parameter clustering centers;

[0018] S22. Measure the drum speed deviation data and ink path pressure fluctuation data corresponding to the multiple printing equipment samples of the types of printing equipment in S12 when the printing qualification rate meets the requirements to obtain a matrix of historical drum speed deviation data and a matrix of historical ink path pressure fluctuation data; according to the matrix of historical drum speed deviation data and the matrix of historical ink path pressure fluctuation data, calculate the average values of the historical drum speed deviation data and the historical ink path pressure fluctuation data of each type of printing equipment to obtain a set of historical drum speed deviation average data and a set of historical ink path pressure fluctuation average data;

[0019] S23. Randomly set the threshold of the ultimate deviation of the roller speed and the threshold of the ultimate fluctuation of the ink path pressure corresponding to each type of printing equipment according to the historical average data set of the roller speed deviation and the historical average data set of the ink path pressure fluctuation, to obtain the set of thresholds of the ultimate deviation of the roller speed and the set of thresholds of the ultimate fluctuation of the ink path pressure;

[0020] By calculating the clustering center matrix of the historical operating parameters of the printing equipment, it provides a classification basis for subsequent classification of the collected operating parameters to obtain the type of the corresponding printing equipment. Furthermore, the thresholds of the ultimate deviation of the roller speed and the thresholds of the ultimate fluctuation of the ink path pressure corresponding to the type of the printing equipment can be used to determine whether the data of the roller speed deviation and the data of the ink path pressure fluctuation of the printing equipment to be monitored meet the requirements, and then adjust accordingly to ensure that the data of the roller speed deviation and the data of the ink path pressure fluctuation of the printing equipment to be monitored meet the requirements; in addition, since the clustering center matrix generated based on the Gaussian mixture model has probability distribution characteristics, randomly setting the thresholds can avoid the rigidification of the model caused by directly selecting the historical average value, and enhance the adaptability to the multi-modal operating states of the equipment; dynamically fuse the historical average data set of the roller speed deviation with the real-time monitoring data to achieve the adaptive adjustment of the thresholds with the aging degree of the equipment; randomly setting the thresholds simulates the actual working condition fluctuation range of the equipment, and can reduce the frequent false alarm rate caused by a single fixed threshold.

[0021] Preferably, the S3 includes the following steps:

[0022] S31. Construct a digital twin model of the printing equipment to be monitored according to the matrix of the printing operation parameters to be monitored and the matrix of the progress information of the printing production tasks to be monitored;

[0023] Calculate the mean value of each column of data in the matrix of the printing operation parameters to be monitored to obtain the set of mean values of the printing operation parameters to be monitored; and cooperate with the clustering center matrix of the historical operating parameters of the printing equipment to obtain the type of the printing equipment to be monitored;

[0024] S32. According to the digital twin model of the printing equipment to be monitored, collect the real-time roller speed deviation data and the real-time ink path pressure fluctuation data of the printing equipment to be monitored, to obtain the real-time roller speed deviation data to be monitored and the real-time ink path pressure fluctuation data to be monitored;

[0025] According to the set of thresholds of the ultimate deviation of the roller speed and the set of thresholds of the ultimate fluctuation of the ink path pressure, obtain the threshold of the ultimate deviation of the roller speed and the threshold of the ultimate fluctuation of the ink path pressure corresponding to the type of the printing equipment to be monitored, to obtain the threshold of the ultimate deviation of the roller speed to be monitored and the threshold of the ultimate fluctuation of the ink path pressure to be monitored;

[0026] By matching the parameter mean set through the cluster center matrix, adaptive classification of equipment types is achieved to avoid manual configuration errors. The roller speed / ink path pressure threshold set is automatically matched based on the equipment type to adapt to the differences in process requirements of equipment of different models. In addition, the operating parameters and production progress data are integrated to build a virtual-to-real mapping relationship, which greatly shortens the fault warning response time. The speed deviation and pressure fluctuation data are analyzed simultaneously to identify complex fault modes (such as chain reactions caused by mechanical wear).

[0027] Preferably, obtaining the type of printing equipment to be monitored by using the cluster center matrix of historical operating parameters of the printing equipment in S31 includes the following steps:

[0028] S311, calculate the Euclidean distance between the mean set of the printing operation parameters to be monitored and each row of data in the cluster center matrix of the historical operation parameters of the printing equipment to obtain the Euclidean distance set of the printing to be monitored; take the printing equipment type corresponding to the smallest Euclidean distance in the Euclidean distance set of the printing to be monitored as the printing equipment type to be monitored.

[0029] Preferably, S4 comprises the following steps:

[0030] S41, setting a set of influencing factors of key parameters of printing equipment;

[0031] S42, when the real-time roller speed deviation data to be monitored is greater than or equal to the roller speed limit deviation threshold to be monitored or the real-time ink circuit pressure fluctuation data to be monitored is greater than or equal to the ink circuit pressure limit fluctuation threshold to be monitored, the key parameter influencing factor data of the printing device to be monitored is adjusted according to the printing device key parameter influencing factor set, until the real-time roller speed deviation data to be monitored is less than the roller speed limit deviation threshold to be monitored and the real-time ink circuit pressure fluctuation data to be monitored is less than the ink circuit pressure limit fluctuation threshold to be monitored, so as to obtain a final printing device key parameter influencing factor data set;

[0032] By integrating multi-dimensional adjustable parameters such as servo motors, PID control, and mechanical gaps, a systematic adjustment strategy is formed to avoid chain imbalances caused by single parameter adjustment; through the linkage adjustment of the torque output curve and the proportional gain coefficient, the speed stability and ink path pressure accuracy are improved simultaneously; automatic identification of abnormal working conditions is achieved based on preset limit thresholds, reducing the frequency of manual intervention; an iterative adjustment mechanism is used to ensure that the dual standards of speed and pressure are met after parameter correction, eliminating the compatibility issues of traditional segmented processing; in addition, the influencing factor set covers all-field parameters such as mechanical (such as imprinting gap), electrical (such as PID parameters), and fluid (such as ink fountain opening), to adapt to the differentiated needs of different printing processes.

[0033] Preferably, in S42, the vulture optimization algorithm is used to adjust the data of the influencing factors of the key parameters of the printing equipment to be monitored;

[0034] The vulture optimization algorithm is used to synchronously optimize multi-dimensional parameters such as servo motor response, PID parameters, and mechanical clearance, avoiding parameter conflicts caused by manual step-by-step adjustment; among them, the algorithm fitness function incorporates both the rotational speed deviation and the pressure fluctuation index to achieve dual-objective balanced optimization; in addition, for non-linear relationships such as ink viscosity-pressure and load-rotational speed, the random search characteristic of the vulture algorithm is more effective than the traditional PID in breaking through the local optimal solution.

[0035] Preferably, the S5 includes the following steps:

[0036] S51. Use the dataset of the influencing factors of the key parameters of the final printing equipment to set the parameters of the printing equipment to be monitored, and obtain the printing equipment to be monitored after setting;

[0037] S52. Set the current printing qualification rate threshold; use the printing equipment to be monitored after setting to perform printing work; after the work is completed, collect the corresponding printing qualification rate to obtain the printing qualification rate to be monitored;

[0038] S53. When the printing qualification rate to be monitored is less than the current printing qualification rate threshold, adjust the limit deviation threshold of the rotational speed of the roller to be monitored and the limit fluctuation threshold of the ink path pressure to be monitored, and repeat S41, S42, S51, and S52 until the printing qualification rate to be monitored is greater than or equal to the current printing qualification rate threshold, and obtain the final limit deviation threshold of the rotational speed of the roller to be monitored and the final limit fluctuation threshold of the ink path pressure to be monitored;

[0039] S54. Update the final limit deviation threshold of the rotational speed of the roller to be monitored and the final limit fluctuation threshold of the ink path pressure to be monitored into the set of limit deviation thresholds of the rotational speed of the roller and the set of limit fluctuation thresholds of the ink path pressure;

[0040] By taking the printing qualification rate as the final evaluation index and inversely deriving the rationality of the rotational speed / pressure threshold, it is more in line with the actual production requirements than the traditional empirical setting method; the threshold dynamic adjustment process integrates the equipment state data and the quality inspection results to form a mapping relationship library of process parameters - product quality; by continuously updating the limit threshold set, the equipment can automatically adapt to the characteristic changes of different papers, inks and other materials; among them, the accumulation of historical optimal thresholds provides data support for the process development of new products and shortens the trial machine debugging cycle; in addition, when the qualification rate drops, the threshold is adjusted first rather than directly modifying the equipment parameters to avoid system instability caused by excessive intervention; the trend of equipment performance degradation can be quickly identified through the comparison of the threshold sets to achieve preventive maintenance.

[0041] Preferably, the adjustment of the limit deviation threshold of the rotation speed of the drum to be monitored and the limit fluctuation threshold of the ink path pressure in S53 includes the following steps:

[0042] S531. Randomly generate the initial positions of each vulture in the vulture population for adjusting the key parameter thresholds of the printing equipment according to the value ranges of the limit deviation threshold of the rotation speed of the drum to be monitored and the limit fluctuation threshold of the ink path pressure, and obtain the second initial position matrix;

[0043] S532. Construct the fitness function of the vulture population for adjusting the key parameter thresholds of the printing equipment;

[0044] S533. Update and iterate the second initial position matrix according to the fitness function of the vulture population for adjusting the key parameter thresholds of the printing equipment;

[0045] S534. When the maximum number of iterations is reached, stop the iteration to obtain the second final global best position and the second final global best fitness; when the second final global best fitness is greater than or equal to the current printing qualification rate threshold, the adjustment is completed;

[0046] Through the adaptive search ability of the vulture algorithm, quickly locate the optimal threshold combination in the multi-dimensional constraint space of speed deviation and pressure fluctuation. By reversely correcting the threshold parameters with the printing qualification rate as the core index, it more meets the actual quality requirements than the traditional empirical setting method; effectively avoids local optimal solutions and adapts to the complex working conditions of different paper / ink combinations; and the algorithm convergence speed is more than 50% higher than the manual trial-and-error method, significantly shortening the process commissioning cycle.

[0047] The remote monitoring and maintenance system for printing equipment based on digital twin includes a printing equipment data type setting module, a printing equipment data acquisition module, an operating parameter clustering center calculation module, a printing equipment key parameter measurement and calculation module, a key parameter threshold random setting module, a printing equipment type to be monitored determination module, a key parameter to be monitored acquisition module, a limit threshold acquisition module for the key parameter to be monitored, and a control module for influencing factors of the key parameter of the printing equipment to be monitored.

[0048] The present invention has the following beneficial effects:

[0049] 1. In the present invention, through clustering analysis and historical data modeling, refined classification of the operating state of printing equipment and dynamic matching of thresholds are achieved, significantly improving the accuracy of key parameter monitoring; based on the real-time data acquisition and threshold comparison mechanism of the digital twin model, abnormal fluctuations in the roller speed and ink path pressure can be identified in advance, effectively preventing equipment failures; integrating the production task progress monitoring and equipment parameter regulation functions, collaborative optimization of the production process and equipment state is realized, and the downtime is shortened; through automatic threshold generation and parameter adjustment, the need for manual intervention is reduced, and at the same time, the service life of the core components of the equipment is extended.

[0050] 2. In the present invention, by dynamically fusing the historical roller speed deviation average data set with the real-time monitoring data, the self-adaptive adjustment of the threshold with the degree of equipment aging is realized; the randomized threshold setting simulates the actual working condition fluctuation range of the equipment, which can reduce the frequent false alarm rate caused by a single fixed threshold.

[0051] 3. In the present invention, by integrating the operating parameters and production progress data, a virtual-real mapping relationship is constructed, greatly shortening the fault warning response time; among them, by synchronously analyzing the speed deviation and pressure fluctuation data, compound fault modes (such as chain reactions caused by mechanical wear) are identified.

[0052] 4. In the present invention, by adopting an iterative adjustment mechanism to ensure that the parameters meet both the speed and pressure dual criteria after correction, the compatibility problem of traditional segmented processing is eliminated; in addition, the influencing factor set covers all-field parameters such as machinery (such as impression gap), electricity (such as PID parameters), and fluid (such as ink fountain opening), adapting to the different requirements of different printing processes.

[0053] 5. In the present invention, the multi-dimensional parameters such as servo motor response, PID parameters, and mechanical clearance are synchronously optimized through the condor optimization algorithm, avoiding parameter conflicts caused by manual step-by-step adjustment; among them, the fitness function of the algorithm simultaneously incorporates the speed deviation and pressure fluctuation indicators to achieve dual-objective balanced optimization.

[0054] Of course, it is not necessary for any product implementing the present invention to achieve all the above-mentioned advantages simultaneously. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to more clearly illustrate the technical solutions of the embodiments of the invention, the drawings required for describing the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the invention, and those of ordinary skill in the art can also obtain other drawings based on these drawings without creative efforts.

[0056] Figure 1 It is a schematic diagram of the overall process of the remote monitoring and maintenance method for printing equipment based on digital twin of the present invention;

[0057] Figure 2 Schematic flow chart for setting key parameter thresholds of the printing equipment to be monitored in the present invention;

[0058] Figure 3 Schematic flow chart for adjusting data of influencing factors of key parameters of the printing equipment to be monitored in the present invention;

[0059] Figure 4 Schematic flow chart for adjusting key parameter thresholds of the printing equipment to be monitored in the present invention;

[0060] Figure 5 Schematic diagram of modules of the remote monitoring and maintenance system for printing equipment based on digital twin in the present invention. Specific embodiments

[0061] The following will clearly and completely describe the technical solutions in the embodiments of the invention with reference to the accompanying drawings in the embodiments of the invention. Obviously, the described embodiments are only a part of the embodiments of the invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the invention without creative efforts shall fall within the scope of protection of the invention.

[0062] Embodiment 1

[0063] Please refer to Figures 1-4 , this embodiment is a remote monitoring and maintenance method for printing equipment based on digital twin, including the following steps:

[0064] S1. Collect historical operation parameters of multiple printing equipment samples corresponding to multiple types of printing equipment, operation parameters of the printing equipment to be monitored, and production task progress information;

[0065] The step S1 includes the following steps:

[0066] S11. Set several types of operating parameters of the printing equipment to obtain a set of printing equipment operating parameter types. The set of printing equipment operating parameter types includes temperature, pressure, speed, current, etc. The operating parameters can be collected and obtained by sensors, PLCs, and cameras. Then, set several types of printing equipment production task progress information to obtain a set of printing production task progress information types. The set of printing production task progress information types includes order number, type of printed matter (poster / book), paper weight (such as 250g coated paper), format size (such as octavo), planned output (such as 100,000 copies), delivery date (accurate to the hour level), start and end times of processes such as pre-press preparation, printing, quality inspection, and packaging, formulated based on model matching (such as printing thick paper with CD102 model) and load balancing principles, manpower allocation (such as the number of ink adjusters), equipment utilization rate (such as the average daily printing duration of Komori machines), completed quantity (such as 65,000 sheets printed), and remaining uncompleted quantity (current gap of 35,000 sheets), etc. The printing equipment production task progress information can be obtained by accessing the ERP / MES system.

[0067] S12. According to the set of printing equipment operating parameter types, collect the historical operating parameters of multiple printing equipment samples corresponding to multiple types of printing equipment to obtain a set of printing equipment historical operating parameter matrices a = {a1,..., a i ,..., a a′}, where a i represents the historical operating parameter matrix corresponding to the i-th type of printing equipment collected, and a' represents the total number of collected printing equipment types. The multiple types of printing equipment include offset printers, digital printers, flexographic printers, gravure printers, screen printers, etc.

[0068] S13. Set the printing equipment to be monitored. According to the set of printing equipment operating parameter types and the set of printing production task progress information types, collect the operating parameters and production task progress information of the printing equipment to be monitored at multiple time nodes during production to obtain a matrix of operating parameters of the printing equipment to be monitored and a matrix of printing production task progress information of the printing equipment to be monitored.

[0069] S2. Generate the limit deviation threshold of the cylinder rotation speed and the limit fluctuation threshold of the ink path pressure for multiple types of printing equipment in S1 to obtain a set of limit deviation thresholds of the cylinder rotation speed and a set of limit fluctuation thresholds of the ink path pressure.

[0070] S2 includes the following steps:

[0071] S21. Use the Gaussian mixture model to calculate the clustering center data of each operating parameter matrix in the set of printing equipment historical operating parameter matrices to obtain a matrix of clustering centers of printing equipment historical operating parameters.

[0072] S22. Measure the drum speed deviation data and ink path pressure fluctuation data corresponding to multiple printing equipment samples of the types of printing equipment described in S12 when the printing qualification rate meets the requirements, and obtain a historical drum speed deviation data matrix and a historical ink path pressure fluctuation data matrix; according to the historical drum speed deviation data matrix and the historical ink path pressure fluctuation data matrix, calculate the average values of the historical drum speed deviation data and the historical ink path pressure fluctuation data for each type of printing equipment, and obtain a historical drum speed deviation average data set and a historical ink path pressure fluctuation average data set;

[0073] S23. Randomly set the drum speed limit deviation threshold and the ink path pressure limit fluctuation threshold corresponding to each type of printing equipment according to the historical drum speed deviation average data set and the historical ink path pressure fluctuation average data set, and obtain a drum speed limit deviation threshold set and an ink path pressure limit fluctuation threshold set;

[0074] The process of calculating the drum speed deviation data is as follows:

[0075] S2211. Select a 2048-line incremental encoder (such as the Omron E6C3 series) and directly install it on the drum drive shaft to collect the number of encoder grating lines; then use a PLC and collect the pulse signal through a high-speed counter module (the Siemens S7-1200 series can be used), and then obtain the pulse frequency data according to the collected pulse signal;

[0076] S2212. Calculate the drum speed data according to the encoder grating line number and the pulse frequency data; the calculation formula is as follows,

[0077]

[0078] In the formula, represents the drum speed data; respectively represent the pulse frequency data and the encoder grating line number;

[0079] S2213. Subtract the calculated drum speed data from the set drum data to obtain the drum speed deviation data;

[0080] The ink path pressure fluctuation data can be obtained by inserting an ultra-thin sensor into the ink roller nip and then obtaining the pressure peak value and distribution curve through a roller pressure tester in real time;

[0081] S3. Collect the real-time drum speed deviation data and the real-time ink path pressure fluctuation data of the printing equipment to be monitored; and select the corresponding thresholds from the drum speed limit deviation threshold set and the ink path pressure limit fluctuation threshold set;

[0082] The said S3 includes the following steps:

[0083] S31. Construct a digital twin model of the printing equipment to be monitored based on the matrix of printing operation parameters to be monitored and the matrix of printing production task progress information to be monitored;

[0084] Calculate the mean value of each column of data in the matrix of printing operation parameters to be monitored to obtain a set of mean values of printing operation parameters to be monitored; and combine it with the clustering center matrix of historical operation parameters of the printing equipment to obtain the type of printing equipment to be monitored;

[0085] The steps of obtaining the type of printing equipment to be monitored by combining with the clustering center matrix of historical operation parameters of the printing equipment in S31 include the following:

[0086] S311. Calculate the Euclidean distance between the set of mean values of printing operation parameters to be monitored and each row of data in the clustering center matrix of historical operation parameters of the printing equipment to obtain a set of Euclidean distances of printing to be monitored; take the type of printing equipment corresponding to the smallest Euclidean distance in the set of Euclidean distances of printing to be monitored as the type of printing equipment to be monitored;

[0087] S32. According to the digital twin model of the printing equipment to be monitored, collect the real-time drum speed deviation data and real-time ink path pressure fluctuation data of the printing equipment to be monitored to obtain the real-time drum speed deviation data to be monitored and the real-time ink path pressure fluctuation data to be monitored;

[0088] According to the set of drum speed limit deviation thresholds and the set of ink path pressure limit fluctuation thresholds, obtain the drum speed limit deviation threshold and the ink path pressure limit fluctuation threshold corresponding to the type of printing equipment to be monitored, and obtain the drum speed limit deviation threshold to be monitored and the ink path pressure limit fluctuation threshold to be monitored;

[0089] S4. Compare the real-time drum speed deviation data and the real-time ink path pressure fluctuation data of the printing equipment to be monitored with the corresponding thresholds respectively, and then adjust the data of the influencing factors of the key parameters of the printing equipment to be monitored to obtain the final dataset of the influencing factors of the key parameters of the printing equipment;

[0090] The said S4 includes the following steps:

[0091] S41. Set a set of influencing factors of the key parameters of the printing equipment; the set of influencing factors of the key parameters of the printing equipment includes the torque output curve of the servo motor parameters (which can be dynamically adjusted through PLC programming and directly affects the drum load compensation ability), the set value of the response delay time, the upper and lower limits of the adjustment range of the proportional gain coefficient in the PID control parameters (used to balance the ink path pressure fluctuation suppression speed and system stability), the integral time constant adjustment (which can eliminate the cumulative deviation of the drum speed), the impression cylinder gap, the ink fountain blade opening, etc.;

[0092] S42. When the real-time deviation data of the roller speed to be monitored is greater than or equal to the threshold value of the limit deviation of the roller speed to be monitored, or the real-time pressure fluctuation data of the ink path to be monitored is greater than or equal to the threshold value of the limit fluctuation of the ink path pressure to be monitored, adjust the data of the influencing factors of the key parameters of the printing equipment to be monitored according to the influencing factor set of the key parameters of the printing equipment until the real-time deviation data of the roller speed to be monitored is less than the threshold value of the limit deviation of the roller speed to be monitored and the real-time pressure fluctuation data of the ink path to be monitored is less than the threshold value of the limit fluctuation of the ink path pressure to be monitored, and obtain the final data set of the influencing factors of the key parameters of the printing equipment;

[0093] The adjustment of the data of the influencing factors of the key parameters of the printing equipment to be monitored in S42 includes the following steps:

[0094] S421. According to the influencing factor set of the key parameters of the printing equipment, set the value range of various influencing factor data of the printing equipment to be monitored, and obtain the value range set b1 of the influencing factors of the key parameters of the printing equipment to be monitored; as follows,

[0095]

[0096] Among them, respectively represent the lower limit and the upper limit of the value of the i-th type of influencing factor data of the key parameters of the printing equipment to be monitored, and b′ represents the total number of types of influencing factors of the key parameters of the printing equipment set;

[0097] Construct an adjustment vulture population of the key parameters of the printing and set the maximum number of iterations of the adjustment vulture population of the key parameters of the printing to be and the current number of iterations to be which are respectively recorded as the maximum number of iterations of factor adjustment and the current number of iterations of factor adjustment; the number of search space dimensions of the adjustment vulture population of the key parameters of the printing is the same as b′;

[0098] S422. Generate the initial position of each vulture in the adjustment vulture population of the key parameters of the printing according to the value range set of the influencing factors of the key parameters of the printing equipment to be monitored, and obtain the first initial position matrix; the generation formula is as follows,

[0099]

[0100] In the formula, represents the position classification of the j-th vulture in the adjustment vulture population of the key parameters of the printing on the i-th type of dimension of the key parameters of the printing equipment; rand ji represents for a random number generated between 0 and 1;

[0101] S423. Construct the fitness function c1 of the vulture population adjusted by the influencing factors of the printing key parameters as follows:

[0102] c1 = (c′1 - c′2) + (c′3 - c′4);

[0103] In the formula, c′1 and c′2 respectively represent the limit deviation threshold of the rotation speed of the roller to be monitored and the real-time rotation speed deviation data of the roller to be monitored; c′3 and c′4 respectively represent the limit fluctuation threshold of the ink path pressure to be monitored and the real-time ink path pressure fluctuation data to be monitored;

[0104] S424. Start the iteration. Before the iteration, set the current iteration number of the factor adjustment to 1. In the first round of iteration, use the fitness function of the vulture population adjusted by the influencing factors of the printing key parameters to calculate the fitness values of the initial positions of each vulture in the first initial position matrix, and obtain the first fitness value set. Take the maximum fitness value in the first fitness value set and the corresponding initial position of the vulture as the first global best fitness and the first global best position respectively. Update the initial positions of each vulture in the first initial position matrix according to the first global best fitness and the first global best position. After the update is completed, add 1 to the current iteration number of the factor adjustment and enter the next round of iteration;

[0105] In each subsequent round of iteration, use the fitness function of the vulture population adjusted by the influencing factors of the printing key parameters to calculate the fitness values of the positions of each vulture in the vulture population adjusted by the influencing factors of the printing key parameters updated in the previous round of iteration, and obtain the second fitness value set. Take the maximum fitness value in the second fitness value set and the corresponding position of the vulture as the second global best fitness and the second global best position respectively. Update the positions of each vulture in the vulture population adjusted by the influencing factors of the printing key parameters updated in the previous round of iteration according to the second global best fitness and the second global best position. After the update is completed, add 1 to the current iteration number of the factor adjustment and enter the next round of iteration;

[0106] S425. When , stop the iteration to obtain the first final global best position; otherwise, continue the iteration until . When the real-time rotation speed deviation data of the roller to be monitored is less than the limit deviation threshold of the rotation speed of the roller to be monitored and the real-time ink path pressure fluctuation data to be monitored is less than the limit fluctuation threshold of the ink path pressure to be monitored, take the first final global best position as the final data set of the influencing factors of the key parameters of the printing equipment; otherwise, return to S424 to continue the iteration;

[0107] S5. Use the dataset of influencing factors of the key parameters of the final printing equipment to set the parameters of the printing equipment to be monitored and conduct printing production, and then adjust the threshold value selected in S3 according to the qualified rate of the printing production;

[0108] The S5 includes the following steps:

[0109] S51. Use the dataset of influencing factors of the key parameters of the final printing equipment to set the parameters of the printing equipment to be monitored, and obtain the printing equipment to be monitored after setting;

[0110] S52. Set the current printing qualified rate threshold; use the printing equipment to be monitored after setting to conduct printing work; after the work is completed, collect the corresponding printing qualified rate to obtain the printing qualified rate to be monitored;

[0111] S53. When the printing qualified rate to be monitored is less than the current printing qualified rate threshold, adjust the limit deviation threshold of the rotation speed of the roller to be monitored and the limit fluctuation threshold of the ink path pressure to be monitored, and repeat S41, S42, S51, and S52 until the printing qualified rate to be monitored is greater than or equal to the current printing qualified rate threshold, and obtain the final limit deviation threshold of the rotation speed of the roller to be monitored and the final limit fluctuation threshold of the ink path pressure to be monitored;

[0112] The adjustment of the limit deviation threshold of the rotation speed of the roller to be monitored and the limit fluctuation threshold of the ink path pressure to be monitored in S53 includes the following steps:

[0113] S531. Respectively set the value ranges of the limit deviation threshold of the rotation speed of the roller to be monitored and the limit fluctuation threshold of the ink path pressure to be monitored, and obtain the value range of the limit deviation threshold of the rotation speed of the roller and the value range of the limit fluctuation threshold of the ink path pressure respectively represent the lower limit and the upper limit of the value of the limit deviation threshold of the rotation speed of the roller to be monitored, respectively represent the lower limit and the upper limit of the value of the limit fluctuation threshold of the ink path pressure to be monitored; construct a vulture population for adjusting the threshold of the key parameters of the printing equipment and set the maximum number of iterations of the vulture population for adjusting the threshold of the key parameters of the printing equipment to be and the current number of iterations to be respectively denoted as the maximum number of iterations for threshold adjustment and the current number of iterations for threshold adjustment; the number of search space dimensions of the vulture population for adjusting the threshold of the key parameters of the printing equipment is 2;

[0114] S532. Generate the initial position of each vulture in the vulture population for adjusting the threshold of the key parameters of the printing equipment according to the value range of the limit deviation threshold of the rotation speed of the roller and the value range of the limit fluctuation threshold of the ink path pressure, and obtain the second initial position matrix; the generation formula is as follows,

[0115]

[0116] Wherein, respectively represent the position components of the initial position of the j-th vulture in the vulture population for adjusting the key parameter thresholds of the printing equipment in the dimensions of the limit deviation threshold of the roller rotation speed and the limit fluctuation threshold of the ink path pressure to be monitored; respectively represent for random numbers generated between 0 and 1;

[0117] S533. Construct the fitness function c2 of the vulture population for adjusting the key parameter thresholds of the printing equipment as follows:

[0118] c2 = c'5;

[0119] Wherein, c'5 represents the printing qualification rate;

[0120] S534. Start iteration. Before iteration, set the current iteration number of threshold adjustment to 1. In the first round of iteration, use the fitness function of the vulture population for adjusting the key parameter thresholds of the printing equipment to calculate the fitness values of the initial positions of each vulture in the second initial position matrix, and obtain the third fitness value set. Take the maximum fitness value in the third fitness value set and the corresponding initial position of the vulture as the third global best fitness and the third global best position respectively. Update the initial positions of each vulture in the second initial position matrix according to the third global best fitness and the third global best position. After the update is completed, increment the current iteration number of threshold adjustment by 1 and enter the next round of iteration;

[0121] In each subsequent round of iteration, use the fitness function of the vulture population for adjusting the key parameter thresholds of the printing equipment to calculate the fitness values of the positions of each vulture in the vulture population for adjusting the key parameter thresholds of the printing equipment updated in the previous round of iteration, and obtain the fourth fitness value set. Take the maximum fitness value in the fourth fitness value set and the corresponding position of the vulture as the fourth global best fitness and the fourth global best position respectively. Update the positions of each vulture in the vulture population for adjusting the key parameter thresholds of the printing equipment updated in the previous round of iteration according to the fourth global best fitness and the fourth global best position. After the update is completed, increment the current iteration number of threshold adjustment by 1 and enter the next round of iteration;

[0122] S535. When is satisfied, stop iteration to obtain the second final global best position and the second final global best fitness; otherwise, continue iteration until until; when the second final global best fitness is greater than or equal to the current printing qualification rate threshold, the adjustment is completed; otherwise, return to S534 to continue the iteration until the second final global best fitness is greater than or equal to the current printing qualification rate threshold;

[0123] S54. Update the final threshold of the limit deviation of the rotational speed of the drum to be monitored and the final threshold of the limit fluctuation of the ink path pressure to be monitored into the set of threshold values of the limit deviation of the rotational speed of the drum and the set of threshold values of the limit fluctuation of the ink path pressure.

[0124] Embodiment 2

[0125] Please refer to Figure 5 , this embodiment discloses a remote monitoring and maintenance system for printing equipment based on digital twin. The system can implement the method of the above embodiment, including a printing equipment data type setting module, a printing equipment data acquisition module, an operating parameter clustering center calculation module, a printing equipment key parameter measurement and calculation module, a key parameter threshold random setting module, a printing equipment type to be monitored determination module, a key parameter to be monitored acquisition module, a limit threshold acquisition module for key parameters to be monitored of the printing equipment, and a control module for influencing factors of key parameters of the printing equipment to be monitored;

[0126] The printing equipment data type setting module sets the operating parameters of several types of printing equipment and the production task progress information, and obtains a set of printing equipment operating parameter types and a set of printing production task progress information types;

[0127] The printing equipment data acquisition module collects the historical operating parameters of multiple printing equipment samples corresponding to multiple types of printing equipment, the operating parameters of the printing equipment to be monitored, and the production task progress information according to the set of printing equipment operating parameter types and the set of printing production task progress information types;

[0128] The operating parameter clustering center calculation module calculates the clustering center data of multiple types of printing equipment in S1, and obtains a printing equipment historical operating parameter clustering center matrix;

[0129] The printing equipment key parameter measurement and calculation module measures the drum rotational speed deviation data and the ink path pressure fluctuation data of multiple printing equipment samples corresponding to multiple types of printing equipment respectively and calculates the average value, and obtains a historical drum rotational speed deviation average data set and a historical ink path pressure fluctuation average data set;

[0130] The key parameter threshold random setting module generates corresponding drum rotational speed limit deviation thresholds and ink path pressure limit fluctuation thresholds according to the historical drum rotational speed deviation average data set and the historical ink path pressure fluctuation average data set, and obtains a drum rotational speed limit deviation threshold set and an ink path pressure limit fluctuation threshold set;

[0131] The module for determining the type of printing equipment to be monitored obtains the type of printing equipment to be monitored based on the clustering center matrix of the historical operating parameters of the printing equipment and the operating parameters of the printing equipment to be monitored;

[0132] The module for collecting key parameters to be monitored collects the corresponding real-time roller speed deviation data and real-time ink path pressure fluctuation data by constructing a digital twin model of the printing equipment to be monitored, and obtains the real-time roller speed deviation data to be monitored and the real-time ink path pressure fluctuation data to be monitored;

[0133] The module for obtaining the limit threshold of key parameters to be monitored selects the corresponding thresholds from the set of limit deviation thresholds of roller speed and the set of limit fluctuation thresholds of ink path pressure according to the type of printing equipment to be monitored, and obtains the limit deviation threshold of roller speed to be monitored and the limit fluctuation threshold of ink path pressure to be monitored;

[0134] The module for regulating the influencing factors of key parameters of the printing equipment to be monitored compares the real-time roller speed deviation data to be monitored and the real-time ink path pressure fluctuation data to be monitored with the limit deviation threshold of roller speed to be monitored and the limit fluctuation threshold of ink path pressure to be monitored respectively, and adjusts the data of the influencing factors of the key parameters of the printing equipment to be monitored according to the comparison results, and obtains the final dataset of the influencing factors of the key parameters of the printing equipment.

[0135] In the description of this specification, the descriptions referring to the terms "one embodiment", "example", "specific example", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0136] The preferred embodiments of the invention disclosed above are only used to help explain the invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. Obviously, many modifications and variations can be made according to the content of this specification. These embodiments are selected and specifically described in this specification to better explain the principles and practical applications of the invention, so that those skilled in the art in the relevant technical field can understand and utilize the invention well.

Claims

1. A method for remote monitoring and maintenance of printing equipment based on digital twins, characterized in that, It includes the following steps: S1. Collect the historical operation parameters of multiple printing equipment samples corresponding to multiple types of printing equipment, the operation parameters of the printing equipment to be monitored, and the production task progress information; S2. Generate the maximum deviation threshold of the drum rotation speed and the maximum fluctuation threshold of the ink path pressure for multiple types of printing equipment in S1, and obtain the maximum deviation threshold set of the drum rotation speed and the maximum fluctuation threshold set of the ink path pressure; S3. Collect the real-time drum rotation speed deviation data and the real-time ink path pressure fluctuation data of the printing equipment to be monitored; and select the corresponding thresholds from the maximum deviation threshold set of the drum rotation speed and the maximum fluctuation threshold set of the ink path pressure; S4. Compare the real-time drum rotation speed deviation data and the real-time ink path pressure fluctuation data of the printing equipment to be monitored with the corresponding thresholds respectively, and then adjust the data of the influencing factors of the key parameters of the printing equipment to be monitored to obtain the final data set of the influencing factors of the key parameters of the printing equipment; S5. Use the final data set of the influencing factors of the key parameters of the printing equipment to set the parameters of the printing equipment to be monitored and carry out printing production, and then adjust the thresholds selected in S3 according to the qualification rate of the printing production.

2. The method for remote monitoring and maintenance of a printing device based on digital twin according to claim 1, wherein The S1 includes the following steps: S11. Set several types of operation parameters of the printing equipment to obtain a set of printing equipment operation parameter types; then set several types of printing equipment production task progress information to obtain a set of printing production task progress information types; S12. According to the set of printing equipment operation parameter types, collect the historical operation parameters of multiple printing equipment samples corresponding to multiple types of printing equipment to obtain a set of printing equipment historical operation parameter matrices; S13. Set the printing equipment to be monitored; according to the set of printing equipment operation parameter types and the set of printing production task progress information types, collect the operation parameters and production task progress information of the printing equipment to be monitored at multiple time nodes during production to obtain a matrix of the operation parameters of the printing equipment to be monitored and a matrix of the printing production task progress information to be monitored.

3. The method for remote monitoring and maintenance of a printing device based on digital twin according to claim 2, wherein The S2 includes the following steps: S21. Use the Gaussian mixture model to calculate the clustering center data of each operation parameter matrix in the set of printing equipment historical operation parameter matrices to obtain a matrix of the clustering centers of the printing equipment historical operation parameters; S22. Measure the drum rotation speed deviation data and the ink path pressure fluctuation data corresponding to multiple printing equipment samples of the types of printing equipment in S12 when the printing qualification rate meets the requirements to obtain a matrix of historical drum rotation speed deviation data and a matrix of historical ink path pressure fluctuation data; according to the matrix of historical drum rotation speed deviation data and the matrix of historical ink path pressure fluctuation data, calculate the average values of the historical drum rotation speed deviation data and the historical ink path pressure fluctuation data of each type of printing equipment to obtain an average data set of historical drum rotation speed deviation and an average data set of historical ink path pressure fluctuation; S23. Randomly set the drum speed limit deviation threshold and the ink path pressure limit fluctuation threshold corresponding to each type of printing equipment according to the historical drum speed deviation average data set and the historical ink path pressure fluctuation average data set, and obtain the drum speed limit deviation threshold set and the ink path pressure limit fluctuation threshold set.

4. The method for remote monitoring and maintenance of a printing device based on digital twin according to claim 3, wherein The said S3 includes the following steps: S31. Construct a digital twin model of the printing equipment to be monitored according to the matrix of printing operation parameters to be monitored and the matrix of printing production task progress information to be monitored; Calculate the mean value of each column of data in the matrix of printing operation parameters to be monitored to obtain the mean set of printing operation parameters to be monitored; and cooperate with the clustering center matrix of historical operation parameters of the printing equipment to obtain the type of printing equipment to be monitored. S32. According to the digital twin model of the printing equipment to be monitored, collect the real-time drum speed deviation data and the real-time ink path pressure fluctuation data of the printing equipment to be monitored, and obtain the real-time drum speed deviation data to be monitored and the real-time ink path pressure fluctuation data to be monitored. According to the drum speed limit deviation threshold set and the ink path pressure limit fluctuation threshold set, obtain the drum speed limit deviation threshold and the ink path pressure limit fluctuation threshold corresponding to the type of printing equipment to be monitored, and obtain the drum speed limit deviation threshold to be monitored and the ink path pressure limit fluctuation threshold to be monitored.

5. The method for remote monitoring and maintenance of a printing device based on digital twin according to claim 4, characterized in that, The steps of obtaining the type of printing equipment to be monitored by cooperating with the clustering center matrix of historical operation parameters of the printing equipment in S31 include the following steps: S311. Calculate the Euclidean distance between the mean set of printing operation parameters to be monitored and each row of data in the clustering center matrix of historical operation parameters of the printing equipment to obtain the Euclidean distance set of printing to be monitored; and take the type of printing equipment corresponding to the smallest Euclidean distance in the Euclidean distance set of printing to be monitored as the type of printing equipment to be monitored.

6. The method for remote monitoring and maintenance of a printing device based on digital twin according to claim 5, wherein, The said S4 includes the following steps: S41. Set the influencing factor set of key parameters of the printing equipment; S42. When the real-time drum speed deviation data to be monitored is greater than or equal to the drum speed limit deviation threshold to be monitored or the real-time ink path pressure fluctuation data to be monitored is greater than or equal to the ink path pressure limit fluctuation threshold to be monitored, adjust the influencing factor data of the key parameters of the printing equipment to be monitored according to the influencing factor set of key parameters of the printing equipment until the real-time drum speed deviation data to be monitored is less than the drum speed limit deviation threshold to be monitored and the real-time ink path pressure fluctuation data to be monitored is less than the ink path pressure limit fluctuation threshold to be monitored, and then obtain the final influencing factor data set of key parameters of the printing equipment.

7. The method for remote monitoring and maintenance of a printing device based on digital twin according to claim 6, characterized in that, In S42, the bald eagle optimization algorithm is used to adjust the influencing factor data of the key parameters of the printing equipment to be monitored.

8. The method for remote monitoring and maintenance of a printing device based on digital twin according to claim 7, wherein The said S5 includes the following steps: S51. Use the final influencing factor data set of key parameters of the printing equipment to set the parameters of the printing equipment to be monitored, and obtain the printing equipment to be monitored after setting; S52. Set the current printing qualification rate threshold; use the printing equipment to be monitored after setting to carry out printing work; after the work is completed, collect the corresponding printing qualification rate to obtain the printing qualification rate to be monitored. S53. When the qualified rate of the printing to be monitored is less than the current printing qualified rate threshold, adjust the limit deviation threshold of the rotation speed of the roller to be monitored and the limit fluctuation threshold of the ink path pressure to be monitored, and repeat S41, S42, S51, and S52 until the qualified rate of the printing to be monitored is greater than or equal to the current printing qualified rate threshold, so as to obtain the final limit deviation threshold of the rotation speed of the roller to be monitored and the final limit fluctuation threshold of the ink path pressure to be monitored; S54. Update the final limit deviation threshold of the rotation speed of the roller to be monitored and the final limit fluctuation threshold of the ink path pressure to be monitored into the set of limit deviation thresholds of the rotation speed of the roller and the set of limit fluctuation thresholds of the ink path pressure.

9. The method for remote monitoring and maintenance of a printing device based on digital twin according to claim 8, wherein, The adjustment of the limit deviation threshold of the rotation speed of the roller to be monitored and the limit fluctuation threshold of the ink path pressure to be monitored in S53 includes the following steps: S531. Randomly generate the initial position of each vulture in the vulture population for adjusting the threshold of the key parameters of the printing equipment according to the value range of the limit deviation threshold of the rotation speed of the roller to be monitored and the limit fluctuation threshold of the ink path pressure to be monitored, so as to obtain the second initial position matrix; S532. Construct the fitness function of the vulture population for adjusting the threshold of the key parameters of the printing equipment; S533. Update and iterate the second initial position matrix according to the fitness function of the vulture population for adjusting the threshold of the key parameters of the printing equipment; S534. When the maximum number of iterations is reached, stop the iteration to obtain the second final global best position and the second final global best fitness; when the second final global best fitness is greater than or equal to the current printing qualified rate threshold, the adjustment is completed.

10. A system for implementing the method for remote monitoring and maintenance of a printing equipment based on digital twin according to any one of claims 1-9.

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