A multi-working-condition adaptive PID control method and device of a coiled material tension controller

Abstract

The present application relates to a kind of multi-working condition adaptive PID control method and device of coiled material tension controller, belong to coiled material tension control technical field.The present application is by pre-configured respectively corresponding normal operation, acceleration and deceleration, three kinds of working conditions of PID parameter and control auxiliary parameter;Real-time acquisition coiled material tension feedback value and generate current control deviation, according to the comparison result of control deviation amplitude and preset deviation amplitude, segmented selection gain value smaller deviation P parameter or the proportional gain of current working condition corresponding is involved in operation;Real-time detection system output working condition trigger signal to identify current running working condition, matching call corresponding PID parameter;When working condition switches, execute smooth transition processing, when switching to emergency stop working condition, first according to preset emergency stop coefficient to the output value ratio of before switching scaling transition again;PID operation result is exported after output direction matching and output upper limit limiting.

Description

Technical Field

[0001] This invention relates to the field of roll tension control technology, and in particular to a multi-condition adaptive PID control method for roll tension controllers. Background Technology

[0002] In the production and processing of roll-type products such as printing, packaging, lithium electrode sheet processing, textiles, and film slitting, stable control of roll tension is a core element in ensuring processing accuracy, product yield, and production line efficiency. Insufficient tension control accuracy or excessive fluctuations can easily lead to problems such as roll misalignment, stretching deformation, registration errors, and material breakage, directly affecting the final product quality and production continuity. PID control, due to its simple structure and strong robustness, is currently the most widely used control algorithm in the field of roll tension control. Conventional roll tension PID control schemes mostly use a single set of fixed PID parameters, which can only achieve optimal control results under specific steady-state operating conditions. When the production line is in dynamic operating conditions such as speed increase, speed decrease, start and stop, the dynamic tension characteristics of the coil material change significantly. Fixed parameters cannot simultaneously take into account both steady-state control accuracy and dynamic response speed: if the PID parameters are tuned according to the steady-state accuracy requirements, the control response will lag significantly under dynamic conditions, which can easily lead to problems such as coil material slack and insufficient tension; if the PID parameters are tuned according to the dynamic response requirements, continuous tension oscillations are likely to occur during steady-state operation, resulting in decreased control stability and making it unsuitable for production scenarios with continuous operation under multiple conditions.

[0003] To address these issues, existing technologies employ a control scheme based on multiple sets of PID parameters for switching operating conditions. This scheme identifies the parameters corresponding to the switching of operating conditions to adapt to the control requirements under different operating states. However, such schemes still have several limitations in practical applications: First, the parameters change abruptly during operating condition switching, easily causing a step-like change in the control output, leading to instantaneous tension impacts and increasing the risk of tensile deformation or even breakage of the roll material. Second, there is no differentiated gain adjustment based on the magnitude of the tension deviation. In steady-state scenarios with small deviations, the conventional proportional gain is still used, which easily leads to overshoot oscillations and makes it difficult to achieve high-precision steady-state tension control. Third, the handling of safety conditions such as emergency stops is relatively simple, directly switching to the emergency stop parameters without adaptive scaling of the control output before the switch. The large tension change amplitude at the moment of emergency stop cannot effectively avoid the risk of over-tensioning and breakage of the roll material. Fourth, all operating conditions use a uniform PID control structure without differentiating the control terms according to the characteristics of the operating conditions. Under dynamic conditions, the derivative term easily amplifies system disturbance noise, which in turn exacerbates tension fluctuations.

[0004] In summary, existing PID control technology for coil tension cannot simultaneously achieve steady-state control accuracy, dynamic operating condition response speed, and smoothness of operating condition switching, and therefore cannot fully meet the control requirements of high-speed, high-reliability coil processing production lines. Summary of the Invention

[0005] The main objective of this invention is to provide a multi-condition adaptive PID control method for a coil tension controller, which aims to resolve the contradiction between the timeliness and stability of tension response under different operating conditions such as acceleration / deceleration, emergency stop, and steady-state small error, and to avoid material slack or over-tension breakage.

[0006] To achieve the above objectives, the present invention provides a multi-condition adaptive PID control method for a roll material tension controller, comprising the following steps:

[0007] The system includes pre-configured PID parameters and control auxiliary parameters. The PID parameters include normal operating condition parameters, acceleration / deceleration condition parameters, and emergency stop condition parameters. The control auxiliary parameters include preset deviation amplitude, deviation P parameter, emergency stop coefficient, preset output upper limit, preset transition time, and INCINC / INCDEC control logic.

[0008] The tension feedback value of the roll material is collected in real time, and the tension feedback value is compared with the preset target tension value to obtain the current control deviation;

[0009] The operating condition trigger signal output by the tension control system is detected in real time. The current operating condition is identified based on the effective status of the operating condition trigger signal, and the PID parameters corresponding to the current operating condition are matched and called.

[0010] Determine whether the current operating condition has changed relative to the previous control cycle. If no change has occurred, maintain the current control output reference and enter the PID calculation stage. If a change has occurred, use the control output value of the control cycle before the change as the starting reference, and smoothly transition to the target output value obtained by the PID parameter calculation of the new operating condition within a preset transition time. This ensures a smooth transition of the control output before and after the operating condition change. When the target operating condition after the change is an emergency stop condition, first scale the control output value before the change using an emergency stop coefficient, and then use the scaled output value as the starting reference for a smooth transition.

[0011] The absolute value of the control deviation is compared with the preset deviation amplitude. If it is less than the preset deviation amplitude, the deviation P parameter is used as the current proportional gain. If it is greater than or equal to the preset deviation amplitude, the proportional gain in the currently called PID parameter is used as the current proportional gain. The gain value of the deviation P parameter is less than the gain value of the proportional gain in the PID parameter.

[0012] Based on the current proportional gain and the integral and derivative parameters in the currently invoked PID parameters, a PID calculation is performed in conjunction with the current control deviation. The PID calculation result is then adjusted according to the INCINC / INCDEC control logic to obtain the tension control quantity.

[0013] Furthermore, the step of identifying the current operating condition based on the valid state of the operating condition trigger signal output by the real-time detection tension control system, and matching and calling the PID parameters corresponding to the current operating condition, includes:

[0014] The working condition trigger signals output by the roll material tension control system are detected in real time. The working condition trigger signals include acceleration / deceleration trigger signals and emergency stop trigger signals.

[0015] The working condition is determined based on the valid state of the working condition trigger signal, wherein the determination priority of the emergency stop trigger signal is higher than that of the acceleration / deceleration trigger signal.

[0016] When the emergency stop trigger signal is valid, it is determined to be an emergency stop condition, and the PID parameters corresponding to the emergency stop condition are called.

[0017] When the emergency stop trigger signal is invalid and the acceleration / deceleration trigger signal is valid, it is determined to be an acceleration / deceleration condition, and the PID parameters corresponding to the acceleration / deceleration condition are called.

[0018] When both the emergency stop trigger signal and the acceleration / deceleration trigger signal are invalid, the system is determined to be in normal operating condition, and the PID parameters corresponding to the normal operating condition are called.

[0019] Furthermore, the switching between using the deviation P parameter as the current proportional gain and using the proportional gain in the currently invoked PID parameters as the current proportional gain is provided with a hysteresis interval: when the absolute value of the control deviation increases from less than the preset deviation amplitude to the preset deviation amplitude, the switching is made to use the proportional gain in the currently invoked PID parameters.

[0020] When the absolute value of the control deviation decreases from greater than the preset deviation amplitude to the product of the preset deviation amplitude and the preset hysteresis coefficient, the deviation parameter P is switched to be used.

[0021] Further, the step of performing PID calculation based on the current proportional gain, the integral and derivative parameters in the currently invoked PID parameters, and the current control deviation, and processing the PID calculation result according to the control logic while simultaneously limiting the output upper limit to obtain the tension control quantity includes:

[0022] Using the currently determined proportional gain as the proportional term coefficient, and combining it with the integral and derivative parameters in the currently called PID parameters, perform PID calculation on the current control deviation to obtain the initial calculation output value;

[0023] The initial operation output value is matched with the output direction using INCINC control logic or INCDEC control logic to obtain a matched output value that is compatible with the polarity of the actuator. The INCINC control logic is a positive output logic in which the tension increases as the control output increases, and the INCDEC control logic is a negative output logic in which the tension decreases as the control output increases.

[0024] The matched output value is compared with the preset output upper limit. If the matched output value is greater than or equal to the preset output upper limit, the preset output upper limit is taken as the output value after limiting. If it is less than the preset output upper limit, the matched output value is taken as the output value after limiting, and the output value after limiting is output as the tension control amount.

[0025] Furthermore, the acceleration / deceleration parameters include positive acceleration / deceleration parameters and negative acceleration / deceleration parameters corresponding to different control deviation directions, and the emergency stop parameters include positive emergency stop parameters and negative emergency stop parameters corresponding to different control deviation directions.

[0026] The control deviation where the actual tension feedback value corresponding to the positive acceleration / deceleration parameter and the positive emergency stop parameter is less than the preset target tension value; and the control deviation where the actual tension feedback value corresponding to the negative acceleration / deceleration parameter and the negative emergency stop parameter is greater than the preset target tension value.

[0027] The positive acceleration / deceleration parameters, negative acceleration / deceleration parameters, positive emergency stop parameters, and negative emergency stop parameters all include at least a proportional gain term and an integral coefficient term.

[0028] Furthermore, when the operating condition changes, a differentiated transition process is performed based on the target operating condition type after the change, specifically including:

[0029] When the target operating condition after switching is normal operating condition or acceleration / deceleration condition, the control output value of the control cycle before switching is used as the starting reference, and the system smoothly transitions to the target output value obtained by PID parameter calculation corresponding to the target operating condition within a preset transition time.

[0030] When the target operating condition after switching is an emergency stop condition, the control output value of the previous control cycle before switching is first multiplied by the preset emergency stop coefficient to obtain the initial emergency stop output value. Then, using the initial emergency stop output value as the starting reference, the system smoothly transitions to the target output value obtained by the PID parameter calculation corresponding to the emergency stop condition within a preset transition time.

[0031] Furthermore, the integral term is independently limited during PID calculation, with different integral limit values ​​corresponding to different operating conditions;

[0032] When the operating condition changes, the integral term value before the change is clamped according to the integral limit of the target operating condition after the change, and used as the initial value for the integral calculation after the change.

[0033] When switching to emergency stop mode, the integral term is cleared to zero, and only the proportional term participates in the initial calculation.

[0034] Furthermore, the normal operating condition parameters include proportional gain, integral coefficient, and derivative coefficient, and a complete PID control structure is adopted;

[0035] Both the acceleration / deceleration parameters and the emergency stop parameters adopt a PI control structure, which only includes proportional gain and integral coefficient, and does not enable derivative coefficient.

[0036] Further, the step of real-time acquisition of the roll material tension feedback value and comparison of the tension feedback value with a preset target tension value to obtain the current control deviation includes:

[0037] The actual tension feedback value of the roll material is collected and converted according to the preset sampling period. The difference between the actual tension feedback value and the preset target tension value is calculated to obtain the current control deviation with positive and negative polarities.

[0038] The present invention also provides a multi-condition adaptive PID control device for a roll material tension controller, comprising:

[0039] The parameter configuration module is used to pre-configure PID parameters and control auxiliary parameters. The PID parameters include normal operating condition parameters, acceleration / deceleration condition parameters, and emergency stop condition parameters. The control auxiliary parameters include preset deviation amplitude, deviation P parameter, emergency stop coefficient, preset output upper limit, preset transition time, and INCINC / INCDEC control logic.

[0040] The deviation generation module is used to collect the tension feedback value of the roll material in real time, and compare the tension feedback value with the preset target tension value to obtain the current control deviation;

[0041] The working condition identification and matching module is used to detect the working condition trigger signal output by the tension control system in real time, identify the current operating condition based on the effective state of the working condition trigger signal, and match and call the PID parameters corresponding to the current operating condition.

[0042] The switching transition module is used to determine whether the current operating condition has changed relative to the previous control cycle. If no change has occurred, the current control output reference is maintained and the PID calculation stage is entered. If a change has occurred, the control output value of the control cycle before the change is used as the starting reference, and the system smoothly transitions to the target output value obtained by the PID parameter calculation of the new operating condition within a preset transition time. This ensures that the control output transitions smoothly before and after the operating condition change. When the target operating condition after the change is an emergency stop condition, the control output value before the change is first scaled by an emergency stop coefficient, and then the scaled output value is used as the starting reference for a smooth transition.

[0043] The gain selection module is used to compare the absolute value of the control deviation with the preset deviation amplitude. If it is less than the preset deviation amplitude, the deviation P parameter is used as the current proportional gain. If it is greater than or equal to the preset deviation amplitude, the proportional gain in the currently called PID parameter is used as the current proportional gain. The gain value of the deviation P parameter is less than the gain value of the proportional gain in the PID parameter.

[0044] The PID output module performs PID calculations based on the current proportional gain and the integral and derivative parameters in the currently called PID parameters, combined with the current control deviation. The PID calculation results are then adjusted according to the INCINC / INCDEC control logic to obtain the tension control quantity.

[0045] The present invention provides a multi-condition adaptive PID control method and device for a roll material tension controller, which has the following beneficial effects:

[0046] With fast dynamic response and no steady-state oscillation, the system features automatic PID parameter matching for multiple operating conditions, combined with segmented gain adjustment based on deviation amplitude. Tension converges rapidly under dynamic conditions, and overshoot oscillation is suppressed in steady-state scenarios with small deviations, balancing response speed and control accuracy. Emergency stops are smooth and breakage is prevented. In emergency stop conditions, the output is scaled up and down by the emergency stop coefficient before a smooth transition, avoiding instantaneous tension shocks during condition switching and effectively preventing over-tensioning and breakage of the roll material, thus improving production safety. It is highly adaptable, with all control parameters supporting on-site tuning, flexibly adapting to different roll material materials, production line speeds, and processing techniques, making it highly practical for engineering applications. Attached Figure Description

[0047] Figure 1 This is a flowchart illustrating the multi-condition adaptive PID control method for a roll tension controller according to an embodiment of the present invention.

[0048] Figure 2 This is a structural block diagram of a multi-condition adaptive PID control device for a roll material tension controller according to an embodiment of the present invention;

[0049] Figure 3 This is a timing diagram of the working condition switching in one embodiment of the present invention;

[0050] Figure 4 This is a schematic diagram of the deviation double-gain hysteresis characteristic in one embodiment of the present invention;

[0051] Figure 5 This is a timing diagram of emergency stop control in one embodiment of the present invention.

[0052] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0054] The multi-condition adaptive PID control method for the coil tension controller described in this embodiment is applied to a coil tension control system. The coil tension control system includes a tension sensor, a tension controller, and an actuator. The actuator can be any one of a magnetic powder clutch, a magnetic powder brake, or a servo motor. The tension sensor detects the actual tension value of the coil in real time and outputs it to the tension controller. The tension controller performs calculations according to the method described above and outputs a control quantity to the actuator. Closed-loop control of the coil tension is achieved by adjusting the output torque or speed of the actuator.

[0055] Reference Figure 1 This is a flowchart illustrating a multi-condition adaptive PID control method for a roll material tension controller proposed in this invention, comprising the following steps:

[0056] S1, pre-configure PID parameters and control auxiliary parameters. The PID parameters include normal operating condition parameters, acceleration / deceleration condition parameters, and emergency stop condition parameters. The control auxiliary parameters include preset deviation amplitude, deviation P parameter, emergency stop coefficient, preset output upper limit, preset transition time, and INCINC / INCDEC control logic.

[0057] Specifically, the PID parameters are divided into three groups according to the operating conditions, and the control structure and configuration method of the PID parameters in each group are as follows:

[0058] The normal operating condition parameters employ a complete PID control structure, including three parameters: proportional gain P, integral coefficient I, and derivative coefficient D. In a specific embodiment, the proportional gain P ranges from 1 to 200, the integral coefficient I ranges from 0 to 100, and the derivative coefficient D ranges from 0 to 100. The normal operating condition corresponds to the production line operating in a steady-state, constant-speed state. At this time, the dynamic tension characteristics of the coil surface are stable, and the complete PID control structure is used to balance steady-state control accuracy with the ability to suppress minor disturbances.

[0059] The acceleration / deceleration parameters employ a PI control structure, including proportional gain and integral coefficients, without using derivative coefficients. These parameters include positive and negative acceleration / deceleration parameters, corresponding to different control deviation directions: the positive acceleration / deceleration parameter corresponds to a control deviation where the actual tension feedback value is less than the target tension value (i.e., the deviation is positive), and includes a positive proportional gain and a positive integral coefficient; the negative acceleration / deceleration parameter corresponds to a control deviation where the actual tension feedback value is greater than the target tension value (i.e., the deviation is negative), and includes a negative proportional gain and a negative integral coefficient. In a specific embodiment, the positive and negative proportional gains range from 5 to 200, and the positive and negative integral coefficients range from 1 to 100. The acceleration / deceleration condition corresponds to the dynamic process of the production line accelerating or decelerating. During this process, the coil tension changes rapidly. Using a PI control structure avoids amplifying system disturbance noise through the derivative term. Furthermore, by differentiating between positive and negative deviation directions and configuring different parameters, it adapts to the different dynamic characteristics during tension increase and decrease.

[0060] The emergency stop parameters employ a PI control structure, including proportional gain and integral coefficients, but without using derivative coefficients. The emergency stop parameters further include positive and negative parameters, corresponding to different control deviation directions: the positive parameter corresponds to the control deviation where the actual tension feedback value is less than the preset target tension value, and includes a positive proportional gain and a positive integral coefficient; the negative parameter corresponds to the control deviation where the actual tension feedback value is greater than the preset target tension value, and includes a negative proportional gain and a negative integral coefficient. In a specific embodiment, the values ​​of the positive and negative proportional gains are in the range of 5–200, and the values ​​of the positive and negative integral coefficients are in the range of 1–100. The emergency stop condition corresponds to the safety state of the production line triggering an emergency stop. At this time, it is necessary to quickly and smoothly reduce the tension to a safe range. A PI control structure is used, distinguishing between positive and negative deviation directions, to achieve controllable convergence of tension during the emergency stop process.

[0061] The specific meanings and configurations of the control auxiliary parameters are as follows:

[0062] The preset deviation amplitude is the threshold value for the segmented gain switching of the deviation amplitude. It is set according to the material of the roll, the target tension, and the allowable steady-state fluctuation range, and is usually selected as 1% to 10% of the target tension. Its configurable range is 0 to 999999. The preset deviation amplitude divides the control deviation into a small deviation range and a large deviation range: when the absolute value of the deviation falls into the small deviation range, a smaller proportional gain is used for fine-tuning; when it falls into the large deviation range, a larger proportional gain is used for rapid adjustment. The emergency stop coefficient is a factor used to scale the control output value before the switch when switching to the emergency stop condition. In a specific embodiment, its value ranges from 0 to 500 (in percentage). The deviation P parameter is the proportional gain used in the small deviation range. Its gain value is less than the proportional gain in the PID parameters of each condition. In a specific embodiment, its value ranges from 0.1 to 100. The emergency stop coefficient is determined based on the configured INCINC / INCDEC control logic: when configured with INCINC control logic, the emergency stop coefficient is typically less than 100 to quickly reduce control output and coil tension during an emergency stop; when configured with INCDEC control logic, the emergency stop coefficient is typically greater than 100 to quickly increase braking output and reduce coil tension during an emergency stop. The preset output upper limit is the maximum allowable value of the control output, and in a specific embodiment, its value ranges from 0 to 100 (in percentage). The transition time is the duration of the smooth transition of the control output during operating condition switching, set according to the production line's mechanical inertia, coil elasticity characteristics, and allowable tension change rate; in a specific embodiment, its value ranges from 0 to 200 seconds. The INCINC / INCDEC control logic is used to match the polarity of the actuator. The INCINC control logic is a positive output logic where tension increases with increasing control output, suitable for actuators such as magnetic powder clutches; the INCDEC control logic is a reverse output logic where tension decreases with increasing control output, suitable for actuators such as magnetic powder brakes.

[0063] The aforementioned PID parameters and control auxiliary parameters can be set through the operation panel of the tension controller, or remotely configured by the host computer through the communication interface.

[0064] S2, collect the tension feedback value of the roll material in real time, and compare the tension feedback value with the preset target tension value to obtain the current control deviation.

[0065] Specifically, the tension controller samples the analog signal output by the tension sensor according to a preset sampling period, and obtains the actual tension feedback value of the roll material through analog-to-digital conversion. In one specific embodiment, the sampling period can be selected as 6.25ms, 12.5ms, 50ms, 100ms, 200ms, 400ms, 800ms, or 1600ms. The sampling period is the same as the control period, and the tension controller performs a PID calculation and output update once after completing each tension sampling.

[0066] The difference between the actual tension feedback value and the preset target tension value is calculated to obtain the current control deviation, which has positive and negative polarities. When the actual tension feedback value is less than the preset target tension value, the control deviation is positive; when the actual tension feedback value is greater than the preset target tension value, the control deviation is negative.

[0067] In one specific embodiment, the actual tension feedback value obtained by sampling is digitally filtered. The filtering method can be first-order inertial filtering or moving average filtering to suppress the influence of on-site electromagnetic interference and sensor noise on control deviation.

[0068] S3, Real-time detection of the working condition trigger signal output by the tension control system, identification of the current operating condition based on the valid state of the working condition trigger signal, and matching and calling the PID parameters corresponding to the current operating condition.

[0069] Specifically, the tension controller monitors the operating condition trigger signals output by the roll material tension control system in real time. These trigger signals include acceleration / deceleration trigger signals and emergency stop trigger signals. The acceleration / deceleration trigger signals and emergency stop trigger signals can be received through the switch input port of the tension controller, or triggered by commands sent from a host computer or PLC via a communication interface.

[0070] The operating condition is determined based on the validity status of the operating condition trigger signals. The emergency stop trigger signal has a higher priority than the acceleration / deceleration trigger signal. The specific determination logic is as follows: When the emergency stop trigger signal is valid, regardless of whether the acceleration / deceleration trigger signal is valid, it is determined to be an emergency stop condition, and the PID parameters corresponding to the emergency stop condition are called; when the emergency stop trigger signal is invalid but the acceleration / deceleration trigger signal is valid, it is determined to be an acceleration / deceleration condition, and the PID parameters corresponding to the acceleration / deceleration condition are called; when both the emergency stop trigger signal and the acceleration / deceleration trigger signal are invalid, it is determined to be a normal operating condition, and the PID parameters corresponding to the normal operating condition are called.

[0071] When calling acceleration / deceleration parameters or emergency stop parameters, the corresponding positive or negative parameters must be selected based on the polarity of the current control deviation.

[0072] If the polarity of the control deviation changes during acceleration / deceleration or emergency stop, the corresponding positive or negative parameter will be reselected according to the polarity of the changed deviation. When switching between positive and negative parameters, the control output value of the previous control cycle is used as the starting reference, and the system will smoothly transition to the target output value calculated by the new parameter within a preset transition time to avoid output jumps caused by parameter switching.

[0073] S4 determines whether the current operating condition has changed relative to the previous control cycle. If no change has occurred, the current control output reference is maintained and the PID calculation is entered. If a change has occurred, the control output value of the control cycle before the change is used as the starting reference, and the system smoothly transitions to the target output value obtained by the PID parameter calculation of the new operating condition within a preset transition time, so that the control output smoothly transitions before and after the operating condition change. When the target operating condition after the change is an emergency stop condition, the control output value before the change is first scaled by an emergency stop coefficient, and then the scaled output value is used as the starting reference for smooth transition.

[0074] Specifically, the operating condition identified in the current control cycle is compared with the operating condition of the previous control cycle. If no operating condition switch occurs, the current control output reference is maintained before entering the PID calculation stage. The control output reference is the tension control value output after output limiting in the previous control cycle. If an operating condition switch occurs, the control output value of the control cycle before the switch is used as the starting reference, and the system smoothly transitions to the target output value obtained from the PID parameter calculation of the new operating condition within a preset transition time.

[0075] Reference Figure 3 When the operating condition trigger signal changes, the PID parameters switch synchronously, and the control output transitions linearly from the initial output value to the target output value within the transition time T, with the transition slope being (target output value − initial output value) / T; when switching to the emergency stop condition, the control output is first scaled by the emergency stop coefficient to obtain the initial emergency stop output value, and then smoothly transitions from that value.

[0076] The smooth transition employs linear interpolation. Starting from the moment of the operating condition switch, linear interpolation is performed cycle by cycle within the total transition duration (i.e., the transition time parameter configured in step S1). The current output value = initial reference value + (target output value - initial reference value) × (cumulative transition time / total transition duration). The cumulative transition time is accumulated from the moment of switch, and the transition ends when the total transition duration is reached, at which point the output value becomes the target output value. Linear interpolation avoids abrupt changes in control output due to sudden changes in PID parameters during operating condition switching, thus preventing instantaneous impact on the coil tension. The target output value is the output value calculated using the PID parameters corresponding to the new operating condition and the current control deviation at the moment of operating condition switch, and serves as a fixed transition endpoint within the preset transition time. After the transition ends, normal cycle-by-cycle PID calculation resumes.

[0077] It should be noted that when the target operating condition after switching is an emergency stop condition, the control output needs to be scaled by the emergency stop coefficient before entering a smooth transition. This scaling calculation is completed within a single control cycle and is a rapid pre-adjustment under the emergency stop condition. Its purpose is to quickly pull the control output to a suitable initial level for emergency stop control at the moment the emergency stop is triggered, avoiding excessive tension impact on the roll material during the emergency stop. The smooth transition after scaling can avoid secondary output jumps caused by sudden changes in PID parameters. The switch between normal operating conditions and acceleration / deceleration conditions does not involve scaling by the emergency stop coefficient; instead, a smooth transition is performed directly using the control output value before the switch as the starting point.

[0078] Based on the target operating condition type after the switch, differentiated transition processing is performed: When the target operating condition after the switch is a normal operating condition or an acceleration / deceleration condition, the control output value of the control cycle before the switch is directly used as the starting reference value, and the transition is smoothed to the target output value calculated by the PID parameters corresponding to the target operating condition within the total transition time; when the target operating condition after the switch is an emergency stop condition, the control output value of the control cycle before the switch is first multiplied by the emergency stop coefficient (the actual multiplier is the emergency stop coefficient / 100) to obtain the initial emergency stop output value, and then the initial emergency stop output value is used as the starting reference value, and the transition is smoothed to the target output value calculated by the PID parameters corresponding to the emergency stop condition within the total transition time. By scaling the output value before the switch using the emergency stop coefficient, the control output can be quickly adjusted to a suitable starting level for emergency stop control at the moment of emergency stop triggering, avoiding excessive tension impact on the roll material during the emergency stop process. When switching from emergency stop to normal operation or acceleration / deceleration, the control output value of the last control cycle of the emergency stop is used as the starting reference. Within a preset transition time, the system smoothly transitions to the target output value calculated by the PID parameters corresponding to the target operation. Since the integral term is cleared to zero under emergency stop, zero is used as the initial value for integral calculation after the switch, and the integral is gradually accumulated according to the integral limit of the target operation. Referring to Figure 5, when the emergency stop trigger signal is valid, the control output is first scaled to Out0×K by the emergency stop coefficient K as the initial emergency stop output. At the same time, the integral term is cleared to zero, and then the system smoothly transitions into the closed-loop adjustment of the emergency stop PID parameters, so that the tension feedback value drops steadily to a safe value, avoiding tension shock at the moment of emergency stop.

[0079] During the switching of operating conditions, the integral term of the PID calculation is independently limited. Normal operation, acceleration / deceleration, and emergency stop conditions are each configured with their own upper and lower integral limits. The integral limit for each condition is determined based on the allowable cumulative integral amount under that condition. In one specific embodiment, the upper integral limit for each condition ranges from 0 to 100 (in percentage of full scale), and the lower integral limit ranges from -100 to 0. The integral limit for each condition is independently configured according to actual control requirements. When a switching of operating conditions occurs, the integral term value before the switch is clamped according to the integral limit of the target condition after the switch: if the integral term value before the switch is greater than the upper integral limit of the target condition, the upper integral limit of the target condition is used as the initial value for the integral calculation after the switch; if the integral term value before the switch is less than the lower integral limit of the target condition, the lower integral limit of the target condition is used as the initial value for the integral calculation after the switch; if the integral term value before the switch is within the integral limit range of the target condition, the original value is retained as the initial value for the integral calculation after the switch. When switching to emergency stop mode, the integral term is cleared to zero, and only the proportional term participates in the initial calculation to avoid the accumulation of historical integrals affecting the speed of emergency stop response.

[0080] S5. Compare the absolute value of the control deviation with the preset deviation amplitude. If it is less than the preset deviation amplitude, use the deviation P parameter as the current proportional gain. If it is greater than or equal to the preset deviation amplitude, use the proportional gain in the currently called PID parameter as the current proportional gain. The gain value of the deviation P parameter is less than the gain value of the proportional gain in the PID parameter.

[0081] Specifically, the absolute value of the current control deviation is calculated and compared with a preset deviation amplitude. If the absolute value of the current control deviation is less than the preset deviation amplitude, the deviation parameter P is used as the current proportional gain. Adjustments are made with a smaller proportional gain within a small deviation range to avoid overshoot and oscillation caused by excessive proportional action, thus improving steady-state control accuracy. If the absolute value of the current control deviation is greater than or equal to the preset deviation amplitude, the proportional gain from the currently invoked PID parameters is used as the current proportional gain to accelerate deviation convergence and improve dynamic response capability.

[0082] Referring to Figure 4, the proportional gain exhibits a double-step characteristic with the magnitude of the control deviation: the gain switches from small to large at the preset deviation magnitude E when the deviation increases, and the gain switches from large to small at the product of the preset deviation magnitude and the hysteresis coefficient kE when the deviation decreases. A hysteresis interval is formed between the two, which can avoid frequent switching of the gain near the threshold.

[0083] To prevent frequent switching of the proportional gain when the control deviation fluctuates around a preset deviation amplitude, a hysteresis interval is set between the deviation parameter P and the proportional gain of the currently called PID parameter: when the absolute value of the control deviation gradually increases from less than the preset deviation amplitude to the preset deviation amplitude, the proportional gain of the currently called PID parameter is used; when the absolute value of the control deviation gradually decreases from greater than the preset deviation amplitude to the product of the preset deviation amplitude and the hysteresis coefficient, the deviation parameter P is used. The hysteresis coefficient is a positive number less than 1, set according to the steady-state fluctuation amplitude of the system, and in a specific embodiment, its value ranges from 0.5 to 0.99. The smaller the hysteresis coefficient, the wider the hysteresis interval, and the stronger the anti-jitter capability, but the more obvious the gain switching lag. By setting a hysteresis interval, control output jitter caused by frequent switching of the proportional gain around the threshold can be avoided.

[0084] S6. Based on the current proportional gain and the integral and derivative parameters in the currently called PID parameters, and combined with the current control deviation, perform PID calculation, and adjust the PID calculation result according to the INCINC / INCDEC control logic to obtain the tension control quantity.

[0085] Specifically, using the currently determined proportional gain as the proportional term coefficient, and combining it with the integral and derivative parameters in the currently invoked PID parameters, a PID calculation is performed on the current control deviation to obtain the initial calculation output value.

[0086] The PID calculation uses the positional PID algorithm, and its calculation formula is as follows:

[0087] Initial operation output value =

[0088] in, For the current proportional gain, The integral coefficient in the currently invoked PID parameters. The derivative coefficients in the currently invoked PID parameters (under acceleration / deceleration and emergency stop conditions). (Take 0), e(k) is the current control deviation, and e(k-1) is the control deviation of the previous control cycle. The integral cumulative value used to control the deviation.

[0089] During PID calculation, the integral term... Independent limiting control is implemented to restrict the integral accumulation value to between the upper and lower limits of the integral corresponding to the current operating condition, preventing overshoot and response lag caused by integral saturation.

[0090] After obtaining the initial calculation output value, the output direction of the initial calculation output value is matched using INCINC control logic or INCDEC control logic to obtain a matched output value that is compatible with the polarity of the actuator: When configured with INCINC control logic, the matched output value = the initial calculation output value, that is, the tension increases as the control output increases, which is suitable for actuators such as magnetic powder clutches that increase the tension of the roll material by increasing the output torque; when configured with INCDEC control logic, the matched output value = the upper limit of the output - the initial calculation output value, that is, the tension decreases as the control output increases, which is suitable for actuators such as magnetic powder brakes that decrease the tension of the roll material by increasing the braking torque.

[0091] The matched output value is compared with the upper limit of the output. If the matched output value is greater than or equal to the upper limit, the upper limit is used as the output value after limiting; if the matched output value is less than the upper limit, the matched output value is used as the output value after limiting. The output value after limiting is used as the tension control quantity and is output to the actuator after digital-to-analog conversion. Setting the upper limit of the output can prevent the control output from exceeding the rated working range of the actuator, and at the same time avoid the tension of the roll material from exceeding the material's bearing limit.

[0092] Reference Figure 2 Here is a structural block diagram of a multi-condition adaptive PID control device for a roll material tension controller according to an embodiment of the present invention, comprising:

[0093] The parameter configuration module is used to pre-configure PID parameters and control auxiliary parameters. The PID parameters include normal operating condition parameters, acceleration / deceleration condition parameters, and emergency stop condition parameters. The control auxiliary parameters include preset deviation amplitude, deviation P parameter, emergency stop coefficient, preset output upper limit, preset transition time, and INCINC / INCDEC control logic.

[0094] The deviation generation module is used to collect the tension feedback value of the roll material in real time, and compare the tension feedback value with the preset target tension value to obtain the current control deviation;

[0095] The working condition identification and matching module is used to detect the working condition trigger signal output by the tension control system in real time, identify the current operating condition based on the effective state of the working condition trigger signal, and match and call the PID parameters corresponding to the current operating condition.

[0096] The switching transition module is used to determine whether the current operating condition has changed relative to the previous control cycle. If no change has occurred, the current control output reference is maintained and the PID calculation stage is entered. If a change has occurred, the control output value of the control cycle before the change is used as the starting reference, and the system smoothly transitions to the target output value obtained by the PID parameter calculation of the new operating condition within a preset transition time. This ensures that the control output transitions smoothly before and after the operating condition change. When the target operating condition after the change is an emergency stop condition, the control output value before the change is first scaled by an emergency stop coefficient, and then the scaled output value is used as the starting reference for a smooth transition.

[0097] The gain selection module is used to compare the absolute value of the control deviation with the preset deviation amplitude. If it is less than the preset deviation amplitude, the deviation P parameter is used as the current proportional gain. If it is greater than or equal to the preset deviation amplitude, the proportional gain in the currently called PID parameter is used as the current proportional gain. The gain value of the deviation P parameter is less than the gain value of the proportional gain in the PID parameter.

[0098] The PID output module performs PID calculations based on the current proportional gain and the integral and derivative parameters in the currently called PID parameters, combined with the current control deviation. The PID calculation results are then adjusted according to the INCINC / INCDEC control logic to obtain the tension control quantity.

[0099] For the specific implementation of each unit in the above device example, please refer to the method embodiments described above, and will not be repeated here.

[0100] In summary, this invention pre-configures PID parameters and control auxiliary parameters corresponding to three operating conditions: normal operation, acceleration / deceleration, and emergency stop. It collects the coil tension feedback value in real time and generates the current control deviation. Based on the comparison between the control deviation amplitude and the preset deviation amplitude, it selects the deviation parameter P with the smaller gain value or the proportional gain corresponding to the current operating condition for segmented calculations. It detects the operating condition trigger signal output by the system in real time to identify the current operating condition and matches and calls the corresponding PID parameters. When the operating condition changes, it performs a smooth transition process. When switching to the emergency stop condition, it first scales the output value before the switch by a preset emergency stop coefficient before transitioning. The PID calculation result is output after matching the output direction and limiting the output upper limit. This invention can achieve automatic adaptation of PID parameters under different operating conditions, balancing steady-state control stability and dynamic operating condition response speed, effectively avoiding coil slack and over-tension breakage.

[0101] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods.

[0102] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, apparatus, article, or method that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, apparatus, article, or method. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, apparatus, article, or method that includes that element.

[0103] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A multi-condition adaptive PID control method for a roll material tension controller, the method being applied to a roll material tension control system, characterized in that, Includes the following steps: The system includes pre-configured PID parameters and control auxiliary parameters. The PID parameters include normal operating condition parameters, acceleration / deceleration condition parameters, and emergency stop condition parameters. The control auxiliary parameters include preset deviation amplitude, deviation P parameter, emergency stop coefficient, preset output upper limit, preset transition time, and INCINC / INCDEC control logic. The tension feedback value of the roll material is collected in real time, and the tension feedback value is compared with the preset target tension value to obtain the current control deviation; The operating condition trigger signal output by the tension control system is detected in real time. The current operating condition is identified based on the effective status of the operating condition trigger signal, and the PID parameters corresponding to the current operating condition are matched and called. Determine whether the current operating condition has changed relative to the previous control cycle. If no change has occurred, maintain the current control output reference and enter the PID calculation stage. If a change has occurred, use the control output value of the control cycle before the change as the starting reference, and smoothly transition to the target output value obtained by the PID parameter calculation of the new operating condition within a preset transition time. This ensures a smooth transition of the control output before and after the operating condition change. When the target operating condition after the change is an emergency stop condition, first scale the control output value before the change using an emergency stop coefficient, and then use the scaled output value as the starting reference for a smooth transition. The absolute value of the control deviation is compared with the preset deviation amplitude. If it is less than the preset deviation amplitude, the deviation P parameter is used as the current proportional gain. If it is greater than or equal to the preset deviation amplitude, the proportional gain in the currently called PID parameter is used as the current proportional gain. The gain value of the deviation P parameter is less than the gain value of the proportional gain in the PID parameter. Based on the current proportional gain and the integral and derivative parameters in the currently invoked PID parameters, a PID calculation is performed in conjunction with the current control deviation. The PID calculation result is then adjusted according to the INCINC / INCDEC control logic to obtain the tension control quantity.

2. The multi-condition adaptive PID control method for the roll tension controller according to claim 1, characterized in that, The steps of detecting the working condition trigger signal output by the real-time tension control system, identifying the current operating condition based on the valid state of the working condition trigger signal, and matching and calling the PID parameters corresponding to the current operating condition include: The working condition trigger signals output by the roll material tension control system are detected in real time. The working condition trigger signals include acceleration / deceleration trigger signals and emergency stop trigger signals. The working condition is determined based on the valid state of the working condition trigger signal, wherein the determination priority of the emergency stop trigger signal is higher than that of the acceleration / deceleration trigger signal. When the emergency stop trigger signal is valid, it is determined to be an emergency stop condition, and the PID parameters corresponding to the emergency stop condition are called. When the emergency stop trigger signal is invalid and the acceleration / deceleration trigger signal is valid, it is determined to be an acceleration / deceleration condition, and the PID parameters corresponding to the acceleration / deceleration condition are called. When both the emergency stop trigger signal and the acceleration / deceleration trigger signal are invalid, the system is determined to be in normal operating condition, and the PID parameters corresponding to the normal operating condition are called.

3. The multi-condition adaptive PID control method for the roll tension controller according to claim 1, characterized in that, The switching between using the deviation P parameter as the current proportional gain and using the proportional gain in the currently invoked PID parameters as the current proportional gain is provided with a hysteresis interval: when the absolute value of the control deviation increases from less than the preset deviation amplitude to the preset deviation amplitude, the switching is made to use the proportional gain in the currently invoked PID parameters. When the absolute value of the control deviation decreases from greater than the preset deviation amplitude to the product of the preset deviation amplitude and the preset hysteresis coefficient, the deviation parameter P is switched to be used.

4. The multi-condition adaptive PID control method for the roll tension controller according to claim 1, characterized in that, The steps of performing PID calculations based on the current proportional gain, the integral and derivative parameters in the currently invoked PID parameters, and the current control deviation, and processing the PID calculation results according to the control logic while simultaneously limiting the output upper limit to obtain the tension control quantity, include: Using the currently determined proportional gain as the proportional term coefficient, and combining it with the integral and derivative parameters in the currently called PID parameters, perform PID calculation on the current control deviation to obtain the initial calculation output value; The initial operation output value is matched with the output direction using INCINC control logic or INCDEC control logic to obtain a matched output value that is compatible with the polarity of the actuator. The INCINC control logic is a positive output logic in which the tension increases as the control output increases, and the INCDEC control logic is a negative output logic in which the tension decreases as the control output increases. The matched output value is compared with the preset output upper limit. If the matched output value is greater than or equal to the preset output upper limit, the preset output upper limit is taken as the output value after limiting. If it is less than the preset output upper limit, the matched output value is taken as the output value after limiting, and the output value after limiting is output as the tension control amount.

5. The multi-condition adaptive PID control method for the roll tension controller according to claim 1, characterized in that, The acceleration / deceleration parameters include positive and negative acceleration / deceleration parameters corresponding to different control deviation directions, and the emergency stop parameters include positive and negative emergency stop parameters corresponding to different control deviation directions. The control deviation where the actual tension feedback value corresponding to the positive acceleration / deceleration parameter and the positive emergency stop parameter is less than the preset target tension value; and the control deviation where the actual tension feedback value corresponding to the negative acceleration / deceleration parameter and the negative emergency stop parameter is greater than the preset target tension value. The positive acceleration / deceleration parameters, negative acceleration / deceleration parameters, positive emergency stop parameters, and negative emergency stop parameters all include at least a proportional gain term and an integral coefficient term.

6. The multi-condition adaptive PID control method for the roll tension controller according to claim 1, characterized in that, When the operating condition changes, a differentiated transition process is performed based on the target operating condition type after the change, specifically including: When the target operating condition after switching is normal operating condition or acceleration / deceleration condition, the control output value of the control cycle before switching is used as the starting reference, and the system smoothly transitions to the target output value obtained by PID parameter calculation corresponding to the target operating condition within a preset transition time. When the target operating condition after switching is an emergency stop condition, the control output value of the previous control cycle before switching is first multiplied by the preset emergency stop coefficient to obtain the initial emergency stop output value. Then, using the initial emergency stop output value as the starting reference, the system smoothly transitions to the target output value obtained by the PID parameter calculation corresponding to the emergency stop condition within a preset transition time.

7. The multi-condition adaptive PID control method for the roll tension controller according to claim 1, characterized in that, During PID calculation, the integral term is independently limited, and different integral limit values ​​correspond to different operating conditions. When the operating condition changes, the integral term value before the change is clamped according to the integral limit of the target operating condition after the change, and used as the initial value for the integral calculation after the change. When switching to emergency stop mode, the integral term is cleared to zero, and only the proportional term participates in the initial calculation.

8. The multi-condition adaptive PID control method for the roll tension controller according to claim 1, characterized in that, The normal operating condition parameters include proportional gain, integral coefficient and derivative coefficient, and a complete PID control structure is adopted. Both the acceleration / deceleration parameters and the emergency stop parameters adopt a PI control structure, which only includes proportional gain and integral coefficient, and does not enable derivative coefficient.

9. The multi-condition adaptive PID control method for the roll tension controller according to claim 1, characterized in that, The step of acquiring the real-time tension feedback value of the roll material and comparing the tension feedback value with the preset target tension value to obtain the current control deviation includes: The actual tension feedback value of the roll material is collected and converted according to the preset sampling period. The difference between the actual tension feedback value and the preset target tension value is calculated to obtain the current control deviation with positive and negative polarities.

10. A multi-condition adaptive PID control device for a roll material tension controller, characterized in that, include: The parameter configuration module is used to pre-configure PID parameters and control auxiliary parameters. The PID parameters include normal operating condition parameters, acceleration / deceleration condition parameters, and emergency stop condition parameters. The control auxiliary parameters include preset deviation amplitude, deviation P parameter, emergency stop coefficient, preset output upper limit, preset transition time, and INCINC / INCDEC control logic. The deviation generation module is used to collect the tension feedback value of the roll material in real time, and compare the tension feedback value with the preset target tension value to obtain the current control deviation; The working condition identification and matching module is used to detect the working condition trigger signal output by the tension control system in real time, identify the current operating condition based on the effective state of the working condition trigger signal, and match and call the PID parameters corresponding to the current operating condition. The switching transition module is used to determine whether the current operating condition has changed relative to the previous control cycle. If no change has occurred, the current control output reference is maintained and the PID calculation stage is entered. If a change has occurred, the control output value of the control cycle before the change is used as the starting reference, and the system smoothly transitions to the target output value obtained by the PID parameter calculation of the new operating condition within a preset transition time. This ensures that the control output transitions smoothly before and after the operating condition change. When the target operating condition after the change is an emergency stop condition, the control output value before the change is first scaled by an emergency stop coefficient, and then the scaled output value is used as the starting reference for a smooth transition. The gain selection module is used to compare the absolute value of the control deviation with the preset deviation amplitude. If it is less than the preset deviation amplitude, the deviation P parameter is used as the current proportional gain. If it is greater than or equal to the preset deviation amplitude, the proportional gain in the currently called PID parameter is used as the current proportional gain. The gain value of the deviation P parameter is less than the gain value of the proportional gain in the PID parameter. The PID output module performs PID calculations based on the current proportional gain and the integral and derivative parameters in the currently called PID parameters, combined with the current control deviation. The PID calculation results are then adjusted according to the INCINC / INCDEC control logic to obtain the tension control quantity.

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