Hydraulic automatic badge production line control method

Abstract

This application relates to the field of industrial control technology, and particularly to a control method for a hydraulic automatic badge production line. The method includes: acquiring the real-time oil temperature and pressure of the hydraulic press during continuous pressing; determining the compensation amount for the pressure setpoint based on the interpolation relationship between the real-time oil temperature and a pre-calibrated oil temperature-pressure compensation table, and correcting the pressure setpoint; obtaining the pressure error of the current control cycle based on the difference between the corrected pressure setpoint and the real-time pressure; adjusting the proportional control gain according to the changing trend of the pressure error; performing integral separation judgment on the pressure error and updating the integral term; calculating the control output value based on the adjusted proportional control gain, the pressure error, the determined integral term, and the derivative term; and converting the control output value into an electrical signal and outputting it to a proportional relief valve to drive the hydraulic press to maintain the set pressure. The method provided in this application can solve the problem of low product quality.

Description

Technical Field

[0001] This application belongs to the field of industrial control technology, and in particular relates to a control method for a hydraulic automatic badge production line. Background Technology

[0002] The badge hydraulic production line can use a four-column hydraulic press to cold extrude metal blanks (copper, zinc alloy, stainless steel), and the pressure control precision directly determines the forming quality of the badge pattern.

[0003] During continuous pressing, the hydraulic oil continuously heats up due to the throttling effect of the hydraulic pump and relief valve. As the oil temperature rises, the kinematic viscosity of the hydraulic oil decreases significantly, and the flow-pressure characteristics of the proportional relief valve drift accordingly. This results in unclear edges and blurry text in the produced badges, affecting product quality.

[0004] Meanwhile, in traditional proportional-integral-derivative (PID) controllers, the integral term is designed to eliminate steady-state errors. However, in the actual operating conditions of a badge production line, there are various scenarios that can lead to sudden errors. For example, when restarting pressing after changing a mold, the pressure setpoint may jump from 8 MPa to 12 MPa, at which point the pressure error instantly reaches 4 MPa. Another example is the brief, large fluctuation in system pressure during the hydraulic cylinder reversal process in pressing. Under these high-error conditions, the integral term accumulates continuously with a constant integral gain. When the error recovers to near zero, the accumulated integral term value is extremely large, leading to severe overshoot and reverse overshoot in the control output. In other words, in continuous production, the overshoot and oscillation caused by integral saturation can directly result in multiple defective castings, seriously affecting product quality. Meanwhile, traditional differential terms only use the error difference between the current control cycle and the previous control cycle to calculate the error rate of change. This two-point difference-based approach has two limitations: first, it is easily affected by noise within a single control cycle, leading to misjudgments; second, it can only reflect the instantaneous rate of error change and cannot predict the trend of pressure error over a medium-term time scale based on data from multiple consecutive control cycles. Therefore, when oil temperature changes rapidly or external disturbances persist, traditional controllers cannot make predictive responses in the early stages when the error shows a continuous increasing trend, resulting in delayed correction actions. The pressure deviation accumulates to a large value before effective suppression begins, and the insufficient pressure generated during this period directly affects the molding quality of the badges. Furthermore, in traditional proportional-integral-derivative controllers, the proportional gain is a fixed parameter, and its value is determined based on the steady-state characteristics of the system during controller parameter tuning. However, in actual production, when oil temperature changes rapidly (such as the start and stop of the cooling fan, or oil circuit switching after mold change) or when external disturbances suddenly occur, the pressure error shows a rapid increasing trend. At this point, the proportional control effect generated by the fixed proportional gain is proportional to the error, but its response strength is insufficient to quickly suppress the further expansion of the error in the early stage of the error increase. When the error increases to a certain extent, although the proportional control effect increases, the error has already accumulated to a large value, and it takes a longer time to restore the pressure to near the set value. The pressure deviation generated during this period will lead to insufficient pressing force, which in turn leads to a decline in product quality.

[0005] The three types of problems mentioned above often occur simultaneously and overlap in actual production. Oil temperature drift continuously generates steady-state deviation, which accumulates as the integral term tries to eliminate it. When external disturbances or changes in the setpoint cause large errors, the accumulated integral term further exacerbates integral saturation. Furthermore, as the error rapidly increases, the fixed proportional gain cannot provide sufficient correction. The combined effect of these three problems results in a scrap rate in badge pressing that is far higher than the process requirements, severely impacting product quality. Summary of the Invention

[0006] This application provides a control method for a hydraulic automatic badge production line, which can solve the problem that in the continuous pressing process, the scrap rate of badge pressing is much higher than the process requirements due to the use of traditional technology, which seriously affects the quality of the product.

[0007] In a first aspect, embodiments of this application provide a control method for a hydraulic automatic badge production line, comprising: To obtain the real-time oil temperature and pressure of the hydraulic press during the continuous pressing process; Based on the interpolation relationship between the real-time oil temperature and the pre-calibrated oil temperature-pressure compensation table, the compensation amount of the pressure setpoint is determined, and the pressure setpoint is corrected according to the compensation amount. The pressure error for the current control cycle is obtained based on the difference between the corrected pressure setpoint and the real-time pressure. Based on the pressure error of the current control cycle and the previous N consecutive control cycles, the changing trend of the pressure error is predicted by linear fitting, and the proportional control gain is adjusted according to the changing trend. The pressure error is integrally separated and judged. When the absolute value of the pressure error exceeds the preset threshold or the control output value reaches the boundary of the output limit, the integral term is frozen; otherwise, the integral term is updated according to the variable integral coefficient. The control output value is calculated based on the adjusted proportional control gain, the pressure error, the integral term determined after integral separation and the derivative term; wherein the derivative term is determined based on the derivative gain, the current pressure error, the pressure error of the previous control cycle, and the control cycle time. The control output value is converted into an electrical signal and output to the proportional relief valve to drive the hydraulic press to maintain the set pressure.

[0008] The technical solutions described in this application embodiment have at least the following technical effects: The hydraulic automatic badge production line control method provided in this application determines the compensation amount of the pressure setpoint based on the interpolation relationship between the real-time oil temperature and a pre-calibrated oil temperature-pressure compensation table. The pressure setpoint is then corrected based on this compensation amount. Since the viscosity of the hydraulic oil decreases when the oil temperature rises, leading to a reduction in the actual output pressure of the proportional relief valve under the same control voltage, the compensation amount is calculated based on the oil temperature-pressure compensation table and added to the pressure setpoint. This results in a corresponding increase in the corrected pressure setpoint, compensating for the pressure drop caused by oil temperature drift and ensuring the hydraulic press maintains the accuracy of the set pressure during continuous pressing. By linearly fitting the pressure error based on the current control cycle and the pressure errors of the previous N consecutive control cycles, the method predicts the trend of pressure error changes and dynamically adjusts the proportional control gain according to this trend. This accelerates the response speed and shortens the time for the pressure to recover to the set pressure when the pressure error increases. Furthermore, by performing integral separation judgment on the pressure error, the integral term is frozen when the absolute value of the pressure error exceeds a preset threshold or the control output reaches the output limit boundary. Within the normal range, the integral term is updated according to a variable integral coefficient, effectively preventing integral saturation and avoiding overshoot and oscillation in the control output. Based on the adjusted proportional control gain, pressure error, updated integral term, and derivative term, the proportional-integral-derivative control output is calculated. The control output is then limited and output to the proportional relief valve to drive the hydraulic press to maintain the set pressure, thereby achieving pressure control accuracy and helping to improve product quality.

[0009] Secondly, embodiments of this application provide a hydraulic automatic badge production line control system, applied to a hydraulic automatic badge production line, for implementing the hydraulic automatic badge production line control method described in any one of the first aspects above. The hydraulic automatic badge production line control system includes: The acquisition unit is used to acquire the real-time oil temperature and real-time pressure of the hydraulic press during the continuous pressing process; The correction unit is used to determine the compensation amount of the pressure setpoint based on the interpolation relationship between the real-time oil temperature and the pre-calibrated oil temperature-pressure compensation table, and to correct the pressure setpoint according to the compensation amount. The calculation unit is used to obtain the pressure error of the current control cycle based on the difference between the corrected pressure setpoint and the real-time pressure. The adjustment unit is used to predict the changing trend of the pressure error by linear fitting based on the pressure error of the current control cycle and the previous N consecutive control cycles, and adjust the proportional control gain according to the changing trend. The judgment unit is used to perform integral separation judgment on the pressure error. When the absolute value of the pressure error exceeds the preset threshold or the control output value reaches the boundary of the output limit, the integral term is frozen; otherwise, the integral term is updated according to the variable integral coefficient. The output unit is used to calculate the control output value based on the adjusted proportional control gain, the pressure error, the integral term determined after integral separation and judgment, and the derivative term; wherein the derivative term is determined based on the derivative gain, the current pressure error, the pressure error of the previous control cycle, and the control cycle time; The transmitting unit is used to convert the control output value into an electrical signal and output it to the proportional relief valve to drive the hydraulic press to maintain the set pressure.

[0010] Thirdly, embodiments of this application provide a hydraulic automatic badge production line, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the hydraulic automatic badge production line control method described in any one of the first aspects above.

[0011] It is understood that the beneficial effects of the second and third aspects mentioned above can be found in the relevant descriptions in the first aspect mentioned above, and will not be repeated here. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a schematic flowchart of a hydraulic automatic badge production line control method provided in an embodiment of this application; Figure 2 This is a schematic diagram of the control of the proportional overflow valve in the hydraulic automatic badge production line control method provided in an embodiment of this application; Figure 3 This is a schematic diagram of the interpolation relationship in the hydraulic automatic badge production line control method provided in an embodiment of this application; Figure 4 This is a schematic diagram illustrating the change of pressure error over time in a hydraulic automatic badge production line control method provided in an embodiment of this application; Figure 5 This is a schematic diagram of the structure of the hydraulic automatic badge production line control system provided in the embodiments of this application; Figure 6 This is a schematic diagram of the structure of the hydraulic automatic badge production line provided in the embodiments of this application. Detailed Implementation

[0014] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0015] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0016] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0017] As used in this application specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if the described condition or event is detected" may be interpreted, depending on the context, as "once determined," "in response to determination," "once the described condition or event is detected," or "in response to the detection of the described condition or event."

[0018] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0019] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0020] In related technologies, these problems often occur simultaneously and superimpose in actual production. Oil temperature drift continuously generates steady-state deviation, which accumulates as the integral term tries to eliminate it. When external disturbances or changes in the setpoint cause large errors, the accumulated integral term further exacerbates integral saturation. Furthermore, as the error rapidly increases, the fixed proportional gain cannot provide sufficient correction. The combined effect of these three problems results in a scrap rate in badge pressing that is far higher than the process requirements, severely impacting product quality.

[0021] To address the aforementioned issues, this application provides a control method for a hydraulic automatic badge production line.

[0022] This method determines the compensation amount for the pressure setpoint based on the interpolation relationship between the real-time oil temperature and a pre-calibrated oil temperature-pressure compensation table, and corrects the pressure setpoint according to the compensation amount. This effectively eliminates the steady-state pressure error caused by oil temperature drift, enabling the hydraulic press to maintain the accuracy of the set pressure during continuous pressing. By linearly fitting the pressure error based on the current control cycle and the pressure errors of the previous N consecutive control cycles, the method predicts the trend of pressure error change and dynamically adjusts the proportional control gain according to the trend. This accelerates the response speed and shortens the time for the pressure to recover to the set pressure when the pressure error increases. By performing integral separation judgment on the pressure error, the integral term is frozen when the absolute value of the pressure error exceeds a preset threshold or the control output reaches the output limit boundary. Within the normal range, the integral term is updated according to a variable integral coefficient, effectively preventing integral saturation and avoiding overshoot and oscillation in the control output. The proportional-integral-derivative control output is calculated based on the adjusted proportional control gain, pressure error, updated integral term, and derivative term. The control output is then limited and output to the proportional relief valve to drive the hydraulic press to maintain the set pressure, achieving accurate pressure control and contributing to improved product quality.

[0023] The hydraulic automatic badge production line control method provided in this application embodiment can be applied to a hydraulic automatic badge production line. In this case, the hydraulic automatic badge production line is the execution subject of the hydraulic automatic badge production line control method provided in this application embodiment. This application embodiment does not impose any restrictions on the specific type of hydraulic automatic badge production line.

[0024] For example, a hydraulic automated badge production line may include a hydraulic press equipped with a proportional overflow valve, a loading robot, a unloading robot, and a control device. The control device is electrically connected to the hydraulic press, the loading robot, and the unloading robot, respectively. The hydraulic press applies controlled pressure to metal blanks (copper, zinc alloy, stainless steel, etc.) to press and shape badge designs. The loading robot transports the raw metal blanks to the hydraulic press processing station. The unloading robot removes the finished badges from the hydraulic press processing station. The control device can control the loading robot to transport the raw metal blanks to the hydraulic press processing station. Then, the control device can control the hydraulic press to apply controlled pressure to the metal blanks to press and shape badge designs. Finally, the control device can control the unloading robot to remove the finished badges from the hydraulic press processing station.

[0025] For example, the control device can be a PLC (Programmable Logic Controller), a microcontroller, a tablet computer, a laptop computer, an ultra-mobile personal computer (UMPC), a netbook, a desktop computer, a computing device, or a computer connected to a wireless modem, a laptop computer, a handheld communication device, a handheld computing device, etc.

[0026] For ease of understanding, the technical terms used in this application are explained below.

[0027] A proportional relief valve is a hydraulic control element that regulates the working pressure of a hydraulic system by changing the magnitude of the input electrical signal. Its working principle is as follows: when the input electrical signal (usually a voltage signal between 0 and 10 volts) increases, the electromagnetic force generated by the electromagnet increases, pushing the valve core to a new equilibrium position, thereby increasing the opening of the relief port and reducing the system pressure; conversely, when the input electrical signal decreases, the opening of the relief port decreases, and the system pressure increases. There is an approximately linear relationship between the input signal and the output pressure of a proportional relief valve, but this linear relationship will drift due to changes in oil viscosity at different oil temperatures.

[0028] Oil temperature drift: refers to the phenomenon that during continuous operation of a hydraulic system, the oil viscosity decreases due to the increase in oil temperature, which in turn reduces the actual output pressure of the proportional relief valve under the same valve control voltage signal.

[0029] The control output value consists of three components: a proportional component (proportional to the current error), an integral component (proportional to the cumulative amount of error), and a derivative component (proportional to the rate of change of error). The proportional component corrects the current error in real time, the integral component eliminates steady-state error, and the derivative component predicts and corrects the trend of error change in advance.

[0030] Integral saturation: When a system has a persistent large error, the integral term will accumulate to a very large value. When the error is eliminated, the accumulated integral term will cause the control output to overshoot, resulting in a large overshoot and a long settling time. This phenomenon is called integral saturation.

[0031] To better understand the hydraulic automatic badge production line control method provided in the embodiments of this application, the specific implementation process of the hydraulic automatic badge production line control method provided in the embodiments of this application will be described by way of example below.

[0032] Figure 1 This illustration shows a schematic flowchart of a hydraulic automatic badge production line control method provided in an embodiment of this application. The hydraulic automatic badge production line control method includes: S100 acquires the real-time oil temperature and pressure of the hydraulic press during continuous pressing.

[0033] It can be understood that real-time oil temperature can be the temperature value of the hydraulic oil at the current moment, and real-time pressure can be the inlet pressure value corresponding to the proportional relief valve at the current moment. Real-time oil temperature can be obtained through a temperature sensor installed in the hydraulic oil tank or hydraulic pipeline, and real-time pressure can be obtained through a pressure sensor installed in the main oil line of the hydraulic system.

[0034] S200 determines the compensation amount of the pressure setpoint based on the interpolation relationship between the real-time oil temperature and the pre-calibrated oil temperature-pressure compensation gauge, and corrects the pressure setpoint according to the compensation amount.

[0035] It is understandable that the oil temperature-pressure compensation gauge can be obtained through experimental calibration during the commissioning phase of the hydraulic press.

[0036] For example, the calibration process can be performed as follows: Under stable operation of the hydraulic press, the hydraulic oil temperature is gradually increased to N consecutive preset temperature nodes through natural heating. At each temperature node, the control voltage of the proportional relief valve is set to the voltage value corresponding to the target pressure. After the pressure stabilizes, the actual measured steady-state pressure value is recorded, and the deviation between this steady-state pressure value and the target pressure setting value (actual pressure minus target pressure) is calculated. The negative of this deviation is used as the pressure compensation value corresponding to that temperature node. In this way, each temperature node and its corresponding pressure compensation value can be associated and stored as two sets of one-dimensional arrays, thus forming an oil temperature-pressure compensation table.

[0037] For example, the compensation amount corresponding to the real-time oil temperature can be located by using a pre-calibrated oil temperature-pressure compensation gauge. The compensation amount is then added to the original pressure setting value to obtain the corrected pressure setting value.

[0038] In one possible implementation, please refer to Figure 3, Step S200, determining the compensation amount of the pressure setting value based on the interpolation relationship between the real-time oil temperature and the pre-calibrated oil temperature-pressure compensation table, including: S210, for multiple discrete oil temperature nodes, respectively obtaining the steady-state pressure deviation of the hydraulic press under the same pressure setting value, and associatively storing each oil temperature node with the corresponding pressure compensation value to form an oil temperature-pressure compensation table.

[0039] It can be understood that in the no-load or load-stable operation state of the hydraulic press, through the natural operation heating method, the hydraulic oil temperature reaches N consecutive preset temperature nodes respectively. At each temperature node, the control voltage of the proportional overflow valve is set to the voltage value corresponding to the target pressure. After waiting for the pressure to stabilize (usually waiting for 10 to 30 seconds), record the actually measured steady-state pressure value, calculate the deviation between the steady-state pressure value and the target pressure setting value (actual pressure minus target pressure), and use the opposite number of this deviation as the pressure compensation value corresponding to this temperature node. Associatively store each temperature node and the corresponding pressure compensation value as two one-dimensional arrays, that is, form an oil temperature-pressure compensation table.

[0040] S220, locating two adjacent oil temperature nodes in the oil temperature-pressure compensation table according to the real-time oil temperature.

[0041] In the embodiment of the present application, since only the compensation values of a limited number of discrete temperature nodes are stored in the oil temperature-pressure compensation table, and the oil temperature in actual operation can be any continuously changing value, interpolation between adjacent nodes is required to obtain the compensation value of any temperature point.

[0042] Specifically, first, determine whether the real-time oil temperature value T1 is equal to any oil temperature node in the oil temperature-pressure compensation table. If so, use the pressure compensation value corresponding to this oil temperature node as the current compensation amount without interpolation calculation; otherwise, find an index i in the oil temperature-pressure compensation table such that T[i] ≤ T1 < T[i + 1], so as to locate two adjacent oil temperature nodes T[i] and T[i + 1].

[0043] S230, calculating the pressure compensation value corresponding to the real-time oil temperature through linear interpolation, and using the calculated pressure compensation value corresponding to the real-time oil temperature as the compensation amount.

[0044] In this embodiment, the linear interpolation calculation formula is as follows: q=(T1-T[i])÷(T[i+1]-T[i]), compensation amount ΔP=P[i]+q×(P[i+1]-P[i]), where q is the interpolation factor, T1 is the real-time oil temperature value, T[i] and T[i+1] are two adjacent oil temperature nodes, P[i] is the pressure compensation value corresponding to oil temperature node T[i] and P[i+1] is the pressure compensation value corresponding to oil temperature node T[i+1], and ΔP is the calculated pressure compensation value (unit: megapascals).

[0045] For example, assuming the real-time oil temperature T1 = 47.5 degrees Celsius, the temperature node array of the oil temperature-pressure compensation table is T[0, ..., 4] = {35, 40, 45, 50, 55}, and the corresponding pressure compensation value array is P[0, ..., 4] = {0.0, 0.0, 0.3, 0.7, 1.2} (unit: MPa). By traversing the temperature node array, two adjacent oil temperature nodes can be located as T[2] = 45 degrees Celsius and T[3] = 50 degrees Celsius, with corresponding compensation values ​​of P[2] = 0.3 MPa and P[3] = 0.7 MPa. The interpolation factor and pressure compensation value are calculated as follows: q = (47.5 - 45) ÷ (50 - 45) = 0.5, ΔP = 0.3 + 0.5 × (0.7 - 0.3) = 0.5 MPa. Therefore, when the real-time oil temperature is 47.5 degrees Celsius, the pressure compensation value is 0.5 MPa.

[0046] S300 calculates the pressure error for the current control cycle based on the difference between the corrected pressure setpoint and the real-time pressure.

[0047] For example, the difference between the corrected pressure setpoint and the real-time pressure is subtracted. When the pressure error e>0, it means that the actual pressure is lower than the set pressure, and the control voltage of the proportional relief valve needs to be increased to increase the system pressure. When the pressure error e<0, it means that the actual pressure is higher than the set pressure, and the control voltage of the proportional relief valve needs to be decreased to reduce the system pressure.

[0048] S400 predicts the trend of pressure error change by linear fitting based on the current control cycle and the pressure error of the previous N consecutive control cycles, and adjusts the proportional control gain according to the trend.

[0049] It is understandable that the trend of pressure error is used to reflect the direction of increase or decrease of pressure error over time in multiple consecutive control cycles.

[0050] For example, the pressure error of the current control cycle and the preceding N consecutive control cycles (e.g., 3, 4, 5, 6, 7, etc.) are stored in a sliding window buffer. The sliding window buffer is a circular buffer of length N used to store the pressure error values ​​of the most recent N control cycles. Whenever a new control cycle arrives, the pressure error value e of the current cycle is stored in the buffer, while the earliest written error value is discarded. In this way, the sliding window buffer always holds the error data of the most recent N cycles.

[0051] For example, the time numbers corresponding to each pressure error in the sliding window buffer are set to 0, 1, 2, 3, and 4, respectively. A straight line e = k × t + b is fitted using the least squares method. The slope k of this line is the slope of the pressure error as a function of time. k > 0 indicates that the pressure error is increasing (i.e., the actual pressure is deviating from the set pressure), k < 0 indicates that the pressure error is decreasing (i.e., the actual pressure is approaching the set pressure), and k = 0 indicates that the pressure error remains stable. The larger the absolute value of the slope |k|, the faster the pressure error changes.

[0052] Specifically, since the time sequence numbers are fixed (0, 1, 2, 3, 4), the mean of the time sequence numbers is always equal to 2, and the sum of squares of the deviations of the time sequence numbers is always equal to 10, the slope can be calculated as follows: mean = (0+1+2+3+4)÷5=2; sum of squares of deviations = (0-2)^2+(1-2)^2+(2-2)^2+(3-2)^2+(4-2)^2=10; k=Σ(i-mean)×e[i]÷sum of squares of deviations, i=0,1,2,3,4; where i is the time sequence number, e[i] is the pressure error value corresponding to the i-th time sequence number (unit: megapascal), and k is the slope obtained by fitting (unit: megapascal / control cycle).

[0053] For example, suppose the sliding window buffer stores five pressure error values ​​e[0, ..., 4] = {0.1, 0.15, 0.22, 0.3, 0.4}, with corresponding time sequence deviations of {-2, -1, 0, 1, 2}. The covariance sum is calculated as follows: cov = (-2) × 0.1 + (-1) × 0.15 + 0 × 0.22 + 1 × 0.3 + 2 × 0.4 = 0.75. Therefore, k = cov ÷ sum of squared deviations = 0.75 ÷ 10 = 0.075.

[0054] In traditional techniques, the differential term only uses the error difference between the current cycle and the previous cycle to reflect the rate of error change. This has two drawbacks: first, it is easily affected by single-point noise; second, it can only reflect the instantaneous rate of change and cannot predict the trend. The implementation method of this application maintains a sliding window, collects pressure error data for N consecutive control cycles, and uses linear fitting to obtain the slope of the error change over time. This slope can more stably and accurately reflect the overall trend of pressure error change.

[0055] For example, the proportional control gain is a key parameter that determines the strength of the proportional control action. In traditional control output values, the proportional control gain is fixed. However, in this embodiment, when rapid changes in oil temperature or external disturbances cause the pressure error to show a continuous increasing trend, the fixed proportional gain may not be sufficient to quickly suppress the expansion of the error, resulting in a slow control response. This embodiment dynamically adjusts the proportional gain by monitoring the error slope: when the error slope is greater than a preset slope threshold, the proportional gain is temporarily increased to strengthen the proportional control action and accelerate the response speed; when the error slope falls back below the threshold, the proportional gain is restored to the base value.

[0056] For example, when the slope corresponding to the trend is greater than a preset slope threshold, the current proportional control gain is set to the base proportional gain multiplied by an adjustment factor greater than 1 and not exceeding 1.5; when the slope corresponding to the trend is less than or equal to the preset slope threshold, the current proportional control gain is restored to the base proportional gain. The preset slope threshold can be a pre-set judgment criterion used to distinguish whether the error change is in a state of rapid increase. The preset slope threshold can be set according to the actual situation, such as 0.02.

[0057] In one possible implementation, please refer to Figure 4 Step S400, based on the pressure error of the current control cycle and the previous N consecutive control cycles, predicts the changing trend of the pressure error through linear fitting, including: S410 stores the pressure error of the current control cycle and the previous N consecutive control cycles into the sliding window, where N is an integer greater than or equal to 3.

[0058] The sliding window buffer can be understood as a circular buffer of length N, used to store the pressure error values ​​of the most recent N control cycles. Whenever a new control cycle arrives, the pressure error value e of the current cycle is stored in the buffer, while the earliest written error value is discarded. In this way, the sliding window buffer always holds the error data of the most recent N cycles.

[0059] For example, the pressure error of the current control cycle and the previous N consecutive control cycles (e.g., 3, 4, 5, 6, 7, etc.) are stored in a sliding window buffer.

[0060] S420 performs least-squares linear fitting on each pressure error within the sliding window and the corresponding time sequence number to obtain the slope of the pressure error changing with time.

[0061] It is understandable that the time sequence numbers corresponding to each pressure error in the sliding window buffer are set to 0, 1, 2, 3, and 4 respectively, and a straight line e=k×t+b is fitted by the least squares method. The slope k of this straight line is the slope of the pressure error changing with time.

[0062] S430 uses the slope as a trend of pressure error variation.

[0063] For example, the slope calculated in step S420 can be used as the trend of pressure error.

[0064] In one possible implementation, step S400, adjusting the proportional control gain according to the changing trend, includes: S440, when the slope corresponding to the trend of change is greater than the preset slope threshold, the current proportional control gain is set to the base proportional gain multiplied by an adjustment coefficient greater than 1 and not exceeding 1.5.

[0065] It is understandable that the preset slope threshold can be a pre-set judgment standard, which is used to distinguish whether the change in error is in a state of rapid increase.

[0066] For example, when the base proportional gain = 2.5, the adjustment coefficient = 1.3, and the preset slope threshold = 0.02, when the calculated slope k = 0.075, since k = 0.075 > 0.02, the current proportional control gain is adjusted as follows: Current proportional control gain = base proportional gain × adjustment coefficient = 2.5 × 1.3 = 3.25.

[0067] S450: When the slope corresponding to the changing trend is less than or equal to the preset slope threshold, the current proportional control gain is restored to the basic proportional gain.

[0068] For example, when the slope corresponding to the trend of change is less than or equal to a preset slope threshold, the current proportional control gain is restored to the basic proportional gain.

[0069] In this embodiment, when the slope corresponding to the trend of change is less than or equal to a preset slope threshold, it indicates that the pressure error is no longer increasing rapidly (it may have stabilized or is decreasing). At this time, there is no need to further enhance the proportional control effect. The proportional gain is restored to the base value to maintain the stability and normal control performance of the system.

[0070] It should be noted that in some embodiments, to avoid frequent switching of the proportional control gain when the pressure error slope fluctuates near the preset slope threshold, a hysteresis mechanism can be introduced: when the slope crosses the preset slope threshold from below, the gain is increased, and the basic gain is only restored when the slope drops below a certain proportion (e.g., 80%) of the preset slope threshold. Specifically, a slope increase trigger threshold kx and a slope drop threshold ky can be set, where ky = kx × α, and α is a preset hysteresis coefficient (e.g., 0.8). When k > kx, the proportional gain is increased; when k ≤ ky, the basic proportional gain is restored; and when ky < k ≤ kx, the current proportional gain remains unchanged.

[0071] S500, perform integral separation judgment on the pressure error. When the absolute value of the pressure error exceeds the preset threshold or the control output value reaches the boundary of the output limit, freeze the integral term; otherwise, update the integral term according to the variable integral coefficient.

[0072] It can be understood that the role of the integral term in the control output value is to eliminate the steady-state error. The preset threshold can be an error boundary value preset for judging the integral separation condition. The output limit can impose upper and lower limits on the control output value to make the output signal within the allowable range of the input signal of the proportional overflow valve. The variable integral coefficient can be a proportional coefficient dynamically calculated according to the magnitude of the current pressure error, and the variable integral coefficient β is used to adjust the update speed of the integral term.

[0073] Exemplarily, judge whether the absolute value |e| of the pressure error is greater than the preset threshold, or judge whether the control output value of the current control cycle reaches the boundary of the output limit.

[0074] For example, when |e| > the preset threshold, it indicates that the current error is large and the system is in the large-amplitude adjustment stage. At this time, if the integral term continues to accumulate, it is easy to cause integral saturation, so the integral term should be frozen. In the implementation mode of this application, the value of the preset threshold can be 0.3. The setting basis of this preset threshold is: 0.3 MPa is about 3% of the rated working pressure of the hydraulic press, which belongs to the upper limit of normal steady-state control accuracy. When the error exceeds this value, it usually means that the system is undergoing a large transition process or disturbance.

[0075] Specifically, the input signal of the proportional overflow valve is usually an electrical signal of 0 to 10 volts. Therefore, the lower limit of the electrical signal corresponding to the control output value is 0 volts (or the minimum value close to 0 volts), and the upper limit is 10 volts (or the maximum value close to 10 volts). When the electrical signal corresponding to the control output value ≥ the maximum value - 0.1 (e.g., the electrical signal corresponding to the control output value ≥ 9.9 volts) or the electrical signal corresponding to the control output value ≤ the minimum value + 0.1 (e.g., the electrical signal corresponding to the control output value ≤ 0.1 volts), it indicates that the output is saturated and the control amount cannot continue to increase or decrease.

[0076] If any of the following conditions are met: |e| ≥ preset threshold or the control output value of the current control cycle reaches the output limit boundary, then the integral update enable flag integral_enable is set to FALSE, the integral term is frozen, and the integral value of the previous control cycle remains unchanged, i.e.: intg = intg_prev, where intg is the integral term of the current control cycle and intg_prev is the integral term of the previous control cycle.

[0077] In this embodiment, the integral update enable flag `integral_enable` can be a Boolean variable indicating whether integral term updates are allowed in the current control cycle. When `integral_enable=FALSE`, the value of the integral term remains the same as in the previous control cycle, and the pressure error of the current cycle is not integrated and accumulated. By freezing the integral term, excessive accumulation of the integral term during periods of large error or output saturation is avoided, thereby effectively preventing integral saturation problems.

[0078] If |e| < the preset threshold and the control output value of the current control cycle has not reached the boundary of the output limit, then set the integral update enable flag integral_enable to TRUE, allowing the integral term to be updated according to the variable integral coefficient.

[0079] In this embodiment, when the error falls back to a small range and the output is not saturated, it indicates that the system is in a normal adjustment state. At this time, the integral term is allowed to be updated to eliminate the residual steady-state error. The purpose of using variable integral coefficients is to slow down the integration speed when the error is large (but still less than the preset threshold) and speed up the integration speed when the error is small, thereby achieving a balance between reducing overshoot and eliminating steady-state error.

[0080] For example, when the integral update enable flag `integral_enable` is TRUE, the variable integral coefficient β is calculated based on the ratio of the absolute value of the pressure error |e| to a preset threshold. The formula for calculating the variable integral coefficient is as follows: β = 1 - |e| ÷ preset threshold, where the value of β is between 0 and 1. That is, if β < 0, then β = 0; if β is greater than 1, then β = 1. According to the above formula, when |e| = 0, β = 1, indicating that the integral update is performed at full speed; when |e| approaches e_th, β approaches 0, indicating that the integral update speed is extremely slow. By truncating β between 0 and 1, the integral update amount is prevented from becoming negative or excessively large.

[0081] For example, assuming a preset threshold of 0.3 MPa and a current pressure error |e| of 0.15 MPa, the variable integral coefficient is calculated as follows: β = 1 - |e| ÷ preset threshold = 1 - 0.15 ÷ 0.3 = 0.5. Then, the variable integral coefficient β is multiplied by the integral gain Ki, the pressure error e, and the control cycle time Ts to obtain the integral increment. The formula for calculating the integral increment is as follows: Δz = β × Ki × e × Ts, where Δz is the integral increment (unit: MPa), β is the variable integral coefficient, Ki is the integral gain, e is the pressure error of the current control cycle (unit: MPa), and Ts is the control cycle time (unit: seconds). The introduction of the variable integral coefficient β allows the integral increment to adapt to the magnitude of the error, realizing dynamic adjustment of the integral speed.

[0082] For example, assuming the variable integral coefficient β = 0.5, integral gain Ki = 0.8, pressure error e = 0.15 MPa, and control cycle time Ts = 0.01 seconds, the integral increment is calculated as follows: Δz = 0.5 × 0.8 × 0.15 × 0.01 = 0.0006 MPa. Then, the integral value of the previous control cycle is added to the integral increment to obtain the integral term of the current control cycle.

[0083] In this embodiment, the accumulation formula for the integral term is as follows: intg = intg_prev + Δz, where intg is the integral term of the current control cycle (unit: megapascals), intg_prev is the integral term of the previous control cycle (unit: megapascals), and Δz is the integral increment of the current control cycle (unit: megapascals). In each control cycle where integral updates are allowed (i.e., when integral_enable = TRUE), the integral increment calculated in the current cycle is accumulated onto the integral term. When integral_enable = FALSE (integral separation state), the integral term remains unchanged, and no accumulation operation is performed.

[0084] For example, assuming the integral term intg_prev of the previous control cycle is 0.05 MPa and the integral increment Δz of the current cycle is 0.0006 MPa, the integral term of the current control cycle is calculated as follows: intg = intg_prev + Δz = 0.05 + 0.0006 = 0.0506 MPa.

[0085] In one possible implementation, step S500, which involves integrating and separating the pressure error, includes: S510 determines whether the absolute value of the pressure error is greater than a preset threshold, or whether the control output value of the current control cycle has reached the boundary of the output limit.

[0086] It is understandable that the preset threshold can be a pre-set error boundary value used to determine the integral separation condition.

[0087] For example, the absolute value of the pressure error is compared with a preset threshold to determine whether the absolute value of the pressure error is greater than the preset threshold. Alternatively, it can be determined whether the control output value of the current control cycle has reached the boundary of the output limit.

[0088] S520: If any condition in the judgment process is met, the integral update enable flag is set to invalid, the integral term is frozen, and the integral value of the previous control cycle remains unchanged.

[0089] For example, if any condition in the judgment process is met, the integral update enable flag integral_enable is set to FALSE, the integral term is frozen, and the integral value of the previous control cycle remains unchanged, that is: intg = intg_prev, where intg is the integral term of the current control cycle and intg_prev is the integral term of the previous control cycle.

[0090] It's understandable that the integral update enable flag `integral_enable` can be a Boolean variable indicating whether integral term updates are allowed in the current control cycle. When `integral_enable=FALSE`, the value of the integral term remains the same as in the previous control cycle, and the pressure error of the current cycle is not integrated and accumulated. By freezing the integral term, excessive accumulation of the integral term during periods of large error or output saturation is avoided, thus effectively preventing integral saturation problems.

[0091] S530 If all conditions in the judgment process are not met, the integral update enable flag is set to valid, allowing the integral term to be updated.

[0092] For example, if all conditions in the judgment process are not met, the integral update enable flag integral_enable is set to TRUE, allowing the integral term to be updated according to the variable integral coefficient.

[0093] In one possible implementation, in step S530, if all conditions in the judgment process are not met, the integral update enable flag is set to valid, allowing the integral term to be updated. After this, the hydraulic automatic badge production line control method further includes: S531, when the integral update enable flag is valid, the variable integral coefficient is calculated based on the ratio of the absolute value of the pressure error to a preset threshold. The variable integral coefficient decreases linearly as the absolute value of the pressure error increases.

[0094] For example, when the integral update enable flag `integral_enable` is TRUE, the absolute value of the pressure error, |e|, is divided by a preset threshold, and then the variable integral coefficient β is calculated. The formula for calculating the variable integral coefficient is as follows: β = 1 - |e| ÷ preset threshold, where the value of β is between 0 and 1, that is: if β < 0, then β = 0, and if β is greater than 1, then β = 1.

[0095] S532 obtains the integral increment based on the variable integral coefficient, integral gain, pressure error, and control cycle time.

[0096] For example, the integral increment is obtained by multiplying the variable integral coefficient β by the integral gain Ki, the pressure error e, and the control cycle time Ts. The formula for calculating the integral increment is as follows: Δz = β × Ki × e × Ts, where Δz is the integral increment (unit: megapascals), β is the variable integral coefficient, Ki is the integral gain, e is the pressure error of the current control cycle (unit: megapascals), and Ts is the control cycle time (unit: seconds).

[0097] S533 adds the integral increment to the integral value of the previous control cycle to obtain the new integral term for the current control cycle.

[0098] For example, the calculated integral increment is superimposed on the integral value of the previous control cycle to obtain a new integral term for the current control cycle.

[0099] S600 calculates the control output value based on the adjusted proportional control gain, pressure error, the integral term determined after integral separation, and the derivative term. The derivative term is determined based on the derivative gain, the current pressure error, the pressure error of the previous control cycle, and the control cycle time.

[0100] For example, the control output value = Kp × e + intg + deriv, where Kp is the adjusted proportional control gain, e is the pressure error of the current control cycle, intg is the integral term of the current control cycle, and deriv is the derivative term (unit: megapascals). The proportional component (Kp × e) is used to correct the current error in real time, the integral component (intg) is used to eliminate the cumulative effect of historical errors (steady-state error), and the derivative component (deriv) is used to predict and correct the trend of error changes in advance. The three components work synergistically.

[0101] For example, assuming the adjusted proportional control gain Kp = 3.25, pressure error e = 0.15 MPa, integral term intg = 0.0506 MPa, and derivative term deriv = 2.0 MPa, the calculations for each component and the control output are as follows: Proportional component = Kp × e = 3.25 × 0.15 = 0.4875 MPa, Control output value = Kp × e + intg + deriv = 0.4875 + 0.0506 + 2.0 = 2.5381 MPa.

[0102] The S700 converts the control output value into an electrical signal and outputs it to the proportional relief valve to drive the hydraulic press to maintain the set pressure.

[0103] For example, a digital quantity (such as a control output value) can be converted into a corresponding electrical signal by a digital-to-analog converter module, and then transmitted to the electromagnet drive circuit of the proportional relief valve via a cable. The electromagnet generates a corresponding electromagnetic force according to the magnitude of the input voltage, pushing the valve core to the corresponding position, thereby regulating the pressure of the hydraulic system.

[0104] This setup, by determining the compensation amount for the pressure setpoint based on the interpolation relationship between the real-time oil temperature and a pre-calibrated oil temperature-pressure compensation table, and correcting the pressure setpoint according to the compensation amount, effectively eliminates the steady-state pressure error caused by oil temperature drift, enabling the hydraulic press to maintain the accuracy of the set pressure during continuous pressing. By linearly fitting the pressure error based on the current control cycle and the pressure errors of the previous N consecutive control cycles, the trend of pressure error change is predicted, and the proportional control gain is dynamically adjusted according to the trend. This accelerates the response speed and shortens the time for the pressure to recover to the set pressure when the pressure error increases. By performing integral separation judgment on the pressure error, the integral term is frozen when the absolute value of the pressure error exceeds a preset threshold or the control output reaches the output limit boundary, and the integral term is updated within the normal range according to a variable integral coefficient, effectively preventing integral saturation and avoiding overshoot and oscillation in the control output. Based on the adjusted proportional control gain, pressure error, updated integral term, and derivative term, the proportional-integral-derivative control output is calculated. The control output is then limited and output to the proportional relief valve to drive the hydraulic press to maintain the set pressure, achieving accurate pressure control and contributing to improved product quality.

[0105] In one possible implementation, the hydraulic automatic badge production line control method further includes: S701, under stable operation of the hydraulic press, fixes the pressure setpoint to the target value for each temperature node, continuously monitors the pressure parameters until the pressure stabilizes, records the deviation between the stable pressure and the target value, and uses the negative of the deviation between the stable pressure and the target value as the pressure compensation value corresponding to the temperature node.

[0106] For example, under stable operation of the hydraulic press, the hydraulic oil temperature is gradually increased to N consecutive preset temperature nodes through natural heating. At each temperature node, the control voltage of the proportional relief valve is set to the voltage value corresponding to the target pressure. After the pressure stabilizes, the actual measured steady-state pressure value is recorded, and the deviation between this steady-state pressure value and the target pressure setting value (actual pressure minus target pressure) is calculated. The negative of this deviation is used as the pressure compensation value corresponding to that temperature node.

[0107] S702 associates and stores each temperature node with the corresponding pressure compensation value to obtain an oil temperature-pressure compensation table.

[0108] For example, each temperature node is associated with its corresponding pressure compensation value and stored as two sets of one-dimensional arrays, thus forming an oil temperature-pressure compensation table.

[0109] In one possible implementation, after obtaining the pressure error of the current control cycle based on the difference between the corrected pressure setpoint and the real-time pressure in step S300, the hydraulic automatic badge production line control method further includes: The differential term is calculated based on the differential gain, the difference between the current pressure error and the pressure error of the previous control cycle, and the control cycle time.

[0110] For example, the differential term equals the differential gain multiplied by the difference between the pressure error of the current control cycle and the pressure error of the previous control cycle, divided by the control cycle time. The formula for calculating the differential term is as follows: Differential term = Differential gain × (Pressure error of the current control cycle - Pressure error of the previous control cycle) ÷ Control cycle time. The differential term can be a numerical derivative of the pressure error, reflecting the rate of change of the pressure error. When the pressure error is increasing rapidly, the differential term is a large positive value, prompting the control output value to increase rapidly to suppress further expansion of the error; when the pressure error is decreasing rapidly, the differential term is a large negative value, acting as an early brake to prevent excessive pressure overshoot.

[0111] For example, assume the pressure error of the current control cycle is 0.5 MPa, the pressure error of the previous control cycle is 0.3 MPa, the differential gain Kd is 0.1, and the control cycle time is 0.01 seconds. Then the differential term is calculated as follows: Differential term = 0.1 × (0.5 - 0.3) ÷ 0.01 = 0.1 × 0.2 ÷ 0.01 = 2.0 MPa In one possible implementation, please refer to Figure 2 The S700 converts the control output value into an electrical signal and outputs it to the proportional relief valve to drive the hydraulic press to maintain the set pressure, including: The control output value is converted from a digital quantity to an electrical signal by the digital-to-analog converter module and sent to the drive end of the proportional relief valve to drive the hydraulic press to maintain the set pressure.

[0112] For example, a digital quantity (such as a control output value) can be converted into a corresponding electrical signal by a digital-to-analog converter module, and then transmitted to the electromagnet drive circuit of the proportional relief valve via a cable. The electromagnet generates a corresponding electromagnetic force according to the magnitude of the input voltage, pushing the valve core to the corresponding position, thereby regulating the pressure of the hydraulic system.

[0113] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0114] Corresponding to the hydraulic automatic badge production line control method described in the above embodiments, this application also provides a hydraulic automatic badge production line control system, in which each unit can realize each step of the hydraulic automatic badge production line control method. Figure 5 A structural block diagram of the hydraulic automatic badge production line control system provided in an embodiment of this application is shown. For ease of explanation, only the parts related to the embodiment of this application are shown.

[0115] Reference Figure 5 The hydraulic automatic badge production line control system includes: The acquisition unit is used to acquire the real-time oil temperature and real-time pressure of the hydraulic press during the continuous pressing process.

[0116] The correction unit is used to determine the compensation amount of the pressure setpoint based on the interpolation relationship between the real-time oil temperature and the pre-calibrated oil temperature-pressure compensation table, and to correct the pressure setpoint according to the compensation amount.

[0117] The calculation unit is used to obtain the pressure error of the current control cycle based on the difference between the corrected pressure setpoint and the real-time pressure.

[0118] The adjustment unit is used to predict the changing trend of pressure error based on the current control cycle and the pressure error of the previous N consecutive control cycles through linear fitting, and adjust the proportional control gain according to the changing trend.

[0119] The judgment unit is used to perform integral separation judgment on the pressure error. When the absolute value of the pressure error exceeds the preset threshold or the control output value reaches the boundary of the output limit, the integral term is frozen; otherwise, the integral term is updated according to the variable integral coefficient.

[0120] The output unit is used to calculate the control output value based on the adjusted proportional control gain, pressure error, integral term and derivative term determined after integral separation judgment.

[0121] The transmitting unit is used to convert the control output value into an electrical signal and output it to the proportional relief valve to drive the hydraulic press to maintain the set pressure.

[0122] It should be noted that the information interaction and execution process between the above systems / units are based on the same concept as the method embodiments of this application. For details on their specific functions and technical effects, please refer to the method embodiments section, and they will not be repeated here.

[0123] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units is merely an example. In practical applications, the above functions can be assigned to different functional units as needed, that is, the internal structure of the system can be divided into different functional units to complete all or part of the functions described above. The functional units in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0124] This application also provides a hydraulic automatic badge production line. Figure 6 This is a schematic diagram of the structure of a hydraulic automatic badge production line provided in one embodiment of this application. Figure 6 As shown, the hydraulic automatic badge production line 6 of this embodiment includes: at least one processor 60 ( Figure 6 Only one is shown in the image), at least one memory 61 ( Figure 6 (Only one is shown in the image) and a computer program 62 stored in the at least one memory 61 and executable on the at least one processor 60, wherein when the processor 60 executes the computer program 62, it causes the hydraulic automatic badge production line 6 to perform the steps in any of the above embodiments of the hydraulic automatic badge production line control method, or causes the hydraulic automatic badge production line 6 to perform the functions of each unit in the above embodiments of the system.

[0125] For example, the computer program 62 may be divided into one or more units, which are stored in the memory 61 and executed by the processor 60 to complete this application. The one or more units may be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of the computer program 62 in the hydraulic automatic badge production line 6.

[0126] The hydraulic automatic badge production line 6 may include a hydraulic press equipped with a proportional overflow valve, a loading robot, a unloading robot, and a control device. The control device is electrically connected to the hydraulic press, the loading robot, and the unloading robot, respectively. The hydraulic press is used to apply controllable pressure to metal blanks (copper, zinc alloy, stainless steel, etc.) to press and form badge patterns. The loading robot is used to transport the raw metal blanks to the hydraulic press processing station. The unloading robot is used to remove the finished badges from the hydraulic press processing station. The control device can control the loading robot to transport the raw metal blanks to the hydraulic press processing station. Then, the control device can control the hydraulic press to apply controllable pressure to the metal blanks to press and form badge patterns. Finally, the control device can control the unloading robot to remove the finished badges from the hydraulic press processing station. The hydraulic automatic badge production line 6 may include, but is not limited to, a processor 60 and a memory 61. Those skilled in the art will understand that... Figure 6 This is merely an example of the hydraulic automatic badge production line 6 and does not constitute a limitation on the hydraulic automatic badge production line 6. It may include more or fewer components than shown, or combine certain components, or different components, such as input / output devices, network access devices, buses, etc.

[0127] The processor 60 can be a Central Processing Unit (CPU), or it can be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor.

[0128] In some embodiments, the memory 61 can be an internal storage unit of the hydraulic automatic badge production line 6, such as a hard drive or memory. In other embodiments, the memory 61 can be an external storage device of the hydraulic automatic badge production line 6, such as a plug-in hard drive, smart media card (SMC), secure digital (SD) card, flash card, etc., equipped on the hydraulic automatic badge production line 6. Furthermore, the memory 61 can include both internal storage units and external storage devices of the hydraulic automatic badge production line 6. The memory 61 is used to store operating systems, applications, bootloaders, data, and other programs, such as the program code of computer programs. The memory 61 can also be used to temporarily store data that has been output or will be output.

[0129] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps in any of the above method embodiments.

[0130] This application provides a computer program product that, when run on a hydraulic automatic badge production line, enables the hydraulic automatic badge production line to perform the steps described in any of the above method embodiments.

[0131] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments of this application can be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include at least: any entity or device capable of carrying the computer program code to the hydraulic automatic badge production line, a recording medium, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium, such as a USB flash drive, a portable hard drive, a magnetic disk, or an optical disk.

[0132] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0133] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0134] In the embodiments provided in this application, it should be understood that the disclosed hydraulic automatic badge production line / hydraulic automatic badge production line control system and hydraulic automatic badge production line control method can be implemented in other ways. For example, the embodiments of the hydraulic automatic badge production line / hydraulic automatic badge production line control system described above are merely illustrative. For instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices, or units, and may be electrical, mechanical, or other forms.

[0135] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0136] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A control method for a hydraulic automatic badge production line, characterized in that, The method includes: To obtain the real-time oil temperature and pressure of the hydraulic press during the continuous pressing process; Based on the interpolation relationship between the real-time oil temperature and the pre-calibrated oil temperature-pressure compensation table, the compensation amount of the pressure setpoint is determined, and the pressure setpoint is corrected according to the compensation amount. The pressure error for the current control cycle is obtained based on the difference between the corrected pressure setpoint and the real-time pressure. Based on the pressure error of the current control cycle and the previous N consecutive control cycles, the changing trend of the pressure error is predicted by linear fitting, and the proportional control gain is adjusted according to the changing trend. The pressure error is integrally separated and judged. When the absolute value of the pressure error exceeds the preset threshold or the control output value reaches the boundary of the output limit, the integral term is frozen; otherwise, the integral term is updated according to the variable integral coefficient. The control output value is calculated based on the adjusted proportional control gain, the pressure error, the integral term determined after integral separation and the derivative term; wherein the derivative term is determined based on the derivative gain, the current pressure error, the pressure error of the previous control cycle, and the control cycle time. The control output value is converted into an electrical signal and output to the proportional relief valve to drive the hydraulic press to maintain the set pressure.

2. The hydraulic automatic badge production line control method as described in claim 1, characterized in that, The determination of the compensation amount for the pressure setpoint based on the interpolation relationship between the real-time oil temperature and the pre-calibrated oil temperature-pressure compensation table includes: For multiple discrete oil temperature nodes, the steady-state pressure deviation of the hydraulic press under the same pressure setpoint is obtained, and each oil temperature node is associated with the corresponding pressure compensation value and stored to form an oil temperature-pressure compensation table. Based on the real-time oil temperature, locate two adjacent oil temperature nodes in the oil temperature-pressure compensation table; The pressure compensation value corresponding to the real-time oil temperature is calculated by linear interpolation, and the calculated pressure compensation value corresponding to the real-time oil temperature is used as the compensation amount.

3. The hydraulic automatic badge production line control method as described in claim 1, characterized in that, The method of predicting the trend of pressure error change based on the pressure error of the current control cycle and the previous N consecutive control cycles through linear fitting includes: The pressure error of the current control cycle and the previous N consecutive control cycles is stored in a sliding window, where N is an integer greater than or equal to 3; The slope of the pressure error as a function of time is obtained by performing least squares linear fitting on each pressure error within the sliding window and the corresponding time number of each pressure error. The slope is used as the trend of change in the pressure error.

4. The hydraulic automatic badge production line control method as described in claim 3, characterized in that, The step of adjusting the proportional control gain according to the changing trend includes: When the slope corresponding to the trend of change is greater than the preset slope threshold, the current proportional control gain is set to the base proportional gain multiplied by an adjustment coefficient greater than 1 and not exceeding 1.

5. When the slope corresponding to the changing trend is less than or equal to a preset slope threshold, the current proportional control gain is restored to the basic proportional gain.

5. The hydraulic automatic badge production line control method as described in claim 1, characterized in that, The integral separation and judgment of the pressure error includes: Determine whether the absolute value of the pressure error is greater than a preset threshold, or determine whether the control output value of the current control cycle has reached the boundary of the output limit. If any condition in the judgment process is met, the integral update enable flag is set to invalid, the integral term is frozen, and the integral value of the previous control cycle remains unchanged. If none of the conditions in the judgment process are met, then the integral update enable flag is set to valid, allowing the integral term to be updated.

6. The hydraulic automatic badge production line control method as described in claim 5, characterized in that, If none of the conditions in the judgment process are met, then the integral update enable flag is set to valid, allowing the integral term to be updated. After this, the method further includes: When the integral update enable flag is valid, the variable integral coefficient is calculated based on the ratio of the absolute value of the pressure error to the preset threshold; wherein the variable integral coefficient decreases linearly as the absolute value of the pressure error increases. The integral increment is obtained based on the variable integral coefficient, integral gain, pressure error, and control cycle time. The integral value of the previous control cycle is added to the integral increment to obtain the new integral term for the current control cycle.

7. The hydraulic automatic badge production line control method as described in claim 2, characterized in that, The method further includes: When the hydraulic press is running stably, for each temperature node, the pressure setpoint is fixed as the target value, and the pressure parameters are continuously monitored until the pressure stabilizes. The deviation between the stable pressure and the target value is recorded, and the negative number of the deviation between the stable pressure and the target value is used as the pressure compensation value corresponding to the temperature node. Each temperature node is associated with and stored in relation to the corresponding pressure compensation value to obtain the oil temperature-pressure compensation table.

8. The hydraulic automatic badge production line control method as described in claim 1, characterized in that, After obtaining the pressure error of the current control cycle based on the difference between the corrected pressure setpoint and the real-time pressure, the method further includes: The differential term is calculated based on the differential gain, the difference between the current pressure error and the pressure error of the previous control cycle, and the control cycle time.

9. The hydraulic automatic badge production line control method as described in claim 1, characterized in that, The step of converting the control output value into an electrical signal and outputting it to the proportional relief valve to drive the hydraulic press to maintain the set pressure includes: The control output value is converted from a digital quantity to an electrical signal by a digital-to-analog converter module and sent to the drive end of the proportional relief valve to drive the hydraulic press to maintain the set pressure.

10. A hydraulic automatic badge production line, characterized in that, The method includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, implements the method as claimed in any one of claims 1 to 9.

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