Flying shear control method and system based on two-degree-of-freedom PID and SSA-GWO hybrid optimization

Abstract

The application provides a flying shear control method based on two-degree-of-freedom PID and SSA-GWO hybrid optimization, and belongs to the field of steel rolling automation control. The method collects the strip running linear velocity at the flying shear inlet, filters and processes to obtain the linear velocity, sets a shearing window based on the shearing process, calculates the flying shear reference angular velocity according to the linear velocity and the flying shear drum radius, constructs a control law by using a two-degree-of-freedom PID controller according to the reference angular velocity and the actual angular velocity, constructs a compound objective function based on the reference angular velocity, the actual angular velocity and the flying shear control amount calculated by the control law within the shearing window, constructs a parameter vector to be optimized and maps it to the compound objective function, constructs an optimization objective function, searches for an optimal parameter vector by using SSA-GWO, verifies the effectiveness of the optimal parameter vector, and calculates the flying shear control amount according to the control law in the next shearing window to complete synchronous shearing when the verification is passed. The application improves the flying shear control precision and accuracy.

Description

Technical Field

[0001] This invention belongs to the field of steel rolling automation control, specifically relating to a flying shear control method and system based on a hybrid optimization of two-degree-of-freedom PID and SSA-GWO. Background Technology

[0002] Flying shears are key length-cutting devices in the transverse shearing operation of hot-rolled and cold-rolled strip steel production lines. Their working principle involves a motor-driven blade that cuts the strip to a set length as it travels at high speed. With continuously increasing rolling speeds, flying shears need to operate at speeds of several meters per second or even higher, placing higher demands on the synchronization accuracy between the blade speed and the strip speed. If the two are mismatched, it will lead to burrs, tears, or skew at the cut edge, and in severe cases, even cause production accidents, affecting product quality and production line stability.

[0003] In existing technologies, hot rolling flying shear control mostly adopts traditional cascade or single-loop PID control, which uses speed loop and position (phase) loop to jointly regulate the drive motor, so that the cutter roller follows the strip within the shearing window. However, these PID parameters usually rely on on-site personnel to tune them based on experience. When there are frequent speed changes, fluctuations in incoming material thickness, or time lag on the drive side, the parameters are difficult to balance speed and stability. In actual operation, large speed overshoot and oscillation are prone to occur. In typical fixed-length shearing scenarios, the shearing length error is large, and in some working conditions, manual correction and repeated length compensation are required, affecting the production line rhythm and yield. Existing research has proposed control strategies such as ADRC, adaptive control, or fuzzy control, which can reduce speed overshoot to 2%–5% and shearing error to within ±2–±4 mm in simulations or small-scale experiments. However, these methods generally require additional state observers, online parameter estimation, or higher sampling frequencies, and the control cycle needs to be reduced to 1 ms or even lower. They also consume approximately 30%–60% more CPU resources and storage space than traditional PID controllers, placing higher demands on the computing power, instruction set, and debugging tools of domestic PLC / CODESYS controllers, making large-scale promotion in existing rolling mill control systems difficult. Therefore, there is an urgent need for a method that can automatically tune control parameters for the flying shear shearing process cycle without changing the existing flying shear control system structure. Summary of the Invention

[0004] To address the aforementioned issues, this invention provides a flying shear control method and system based on a hybrid optimization of two-degree-of-freedom PID and SSA-GWO. With shear window accuracy as the core objective, it employs a simple structure combining two-degree-of-freedom PID with physical feedforward compensation, and introduces SSA-GWO and its hybrid optimization to achieve parameter self-tuning. This avoids complex observers and system identification steps, facilitating rapid deployment on general-purpose control platforms. Simultaneously, by comprehensively considering engineering constraints such as ITAE, peak value, smoothness, and saturation penalty in the objective function, the accuracy of the shearing process and the robustness of the shear control results are improved.

[0005] To achieve the above objectives, the technical solutions adopted in the embodiments of the present invention are as follows:

[0006] In a first aspect, embodiments of the present invention provide a flying shear control method based on a hybrid optimization of two-degree-of-freedom PID and SSA-GWO, the method comprising the following steps:

[0007] Step S1: Collect the linear velocity of the strip at the inlet of the flying shear. And perform filtering to obtain Set the shearing window based on the shearing process;

[0008] Step S2, according to The flying shear drum radius is calculated, the flying shear reference angular velocity is determined, and dynamic smoothing is performed during acceleration and deceleration to obtain a continuous and smooth flying shear reference angular velocity trajectory. , serving as the tracking target for the flying shear motor speed;

[0009] Step S3, according to and the actual angular velocity feedback signal of the flying shear motor. A two-degree-of-freedom PID controller was used to construct the speed control law for the flying shear motor, and the flying shear control quantity output for each shearing window was calculated. ;

[0010] Step S4, within the clipping window based on , and Construct a composite objective function;

[0011] Step S5: Construct the parameter vector to be optimized based on the two-degree-of-freedom PID controller parameters and physical feedforward compensation parameters. , parameter vector Mapping to a composite objective function, constructing an optimization objective function;

[0012] Step S6, for the candidate parameter vector The flying shear control process is run within the shearing window to obtain the corresponding actual angular velocity response of the flying shear. and flying shear control quantity And calculate the corresponding composite objective function value. Based on the objective function, the optimal parameter vector is searched by using SSA for global search, GWO for local refinement, and combining clipping window boundary parameter updates.

[0013] Step S7: Using the optimal parameter vector as the control parameters for the next shearing window, calculate the composite objective function value of the next shearing window according to the control law, evaluate the control performance of the parameter vector within the actual shearing window based on the composite objective function value, and verify the effectiveness of the control parameters.

[0014] Step S8: If the verification passes, the optimal parameter vector is used as the controller parameter. In the next shearing window, the flying shear control quantity is calculated according to the control law, and the flying shear actuator is controlled to complete the synchronous shearing. If the verification fails, the parameters are adjusted, and the process returns to step S7.

[0015] In a preferred embodiment of the present invention, the shearing window mentioned in step S1 is the synchronous control time interval corresponding to the completion of one shearing operation by the flying shear. The starting point of the window is the moment when the flying shear begins to enter the synchronous control state for this shearing operation, and the ending point of the window is the moment when the shearing operation is completed or the flying shear exits the synchronous control state.

[0016] As a preferred embodiment of the present invention, when constructing the speed control law of the flying shear motor in step S3, the improvement steps of the two-degree-of-freedom PID controller include: setpoint proportional weighting, differential filtering, anti-integral saturation, output amplitude limiting and slope limiting constraints, and superimposed physical feedforward compensation terms; and the physical feedforward compensation terms are used to compensate for the dynamic characteristics of the flying shear actuator, including equivalent rotational inertia terms, viscous damping terms and friction terms.

[0017] As a preferred embodiment of the present invention, the flying shear motor speed control law constructed by the two-degree-of-freedom PID controller includes: inputting a setpoint r, introducing a setpoint weighting coefficient β into the proportional channel, and calculating anti-integral saturation on the weighted setpoint; inputting a measured value y, differentiating and filtering the measured value to obtain the N value; and after fusing the anti-integral saturation, the N value, and the physical feedforward compensation term, outputting the torque command u after being constrained by amplitude and slope limiting.

[0018] As a preferred embodiment of the present invention, the control law formula is as follows:

[0019] (1)

[0020] In equation (1), This represents the flying shear control quantity output in the kth sampling period, which is the actual control input of the flying shear motor drive device in the kth sampling period; This represents the gain coefficient of the proportional element, which is used to generate control based on the proportional error. This represents the weighting coefficient of the set value, used to adjust the intensity of the influence of the flying shear reference angular velocity on the proportional control effect; This represents the reference angular velocity of the flying shear in the kth sampling period; This represents the actual angular velocity of the flying shear motor measured in the nth sampling period; This represents the output of the integral term in the nth sampling period, used to eliminate steady-state error and include an anti-integral saturation pullback term as the integral term; The output of the differential element in the kth sampling period is applied only to the feedback angular velocity and a filter is added to improve the dynamic response of the system and suppress the influence of noise on the differential operation, and is used as the differential term. This represents the physical feedforward compensation term for the k-th sampling period.

[0021] In a preferred embodiment of the present invention, dynamic smoothing is performed in the acceleration and deceleration phase in step S2. The S-curve is used for dynamic smoothing to limit the changes in acceleration and jerk, thereby obtaining a continuous and smooth flying shear reference angular velocity trajectory and ensuring the continuity and controllability of the reference angular velocity trajectory.

[0022] In a preferred embodiment of the present invention, the composite objective function is defined as:

[0023] (2)

[0024] In equation (2), J represents the value of the composite objective function; This represents the time-weighted absolute error term composed of synchronization errors, used to measure the degree to which system errors accumulate over time; This represents the maximum peak value of the flying shear synchronization error within the shear window, used to constrain the system's transient performance. This represents the cumulative term consisting of control output increments, used to measure the magnitude of control output changes, constrain the smoothness of control quantities, and reduce actuator shocks. The smaller the value, the smoother the control. This indicates a penalty term when the control output exceeds the allowable range of the actuator, used to suppress control saturation behavior; It represents the time-weighted error index calculated under multiple operating stages or conditions, and is used to comprehensively evaluate the performance of control parameters in the full shearing process; , , , , Each represents its own coefficient.

[0025] As a preferred embodiment of the present invention, the constructed parameter vector to be optimized for:

[0026] (3)

[0027] In equation (3), These represent the components of the control parameters to be optimized in the two-degree-of-freedom PID controller parameters and the physical feedforward compensation parameters, respectively.

[0028] As a preferred embodiment of the present invention, parameter vector Mapping to a composite objective function, where the composite objective function is a function of the parameter vector, denoted as... The objective function for optimization is constructed as follows:

[0029] (4)

[0030] In equation (4), Ω represents the allowable range of values ​​for each control parameter.

[0031] Secondly, embodiments of the present invention also provide a flying shear control system based on a hybrid optimization of two-degree-of-freedom PID and SSA-GWO. The system includes a data acquisition module, a shear window setting module, a reference angular velocity calculation module, a control law construction module, a flying shear control quantity calculation module, a composite objective function construction module, an optimized objective function construction module, a control parameter optimization module, an effectiveness verification module, and a flying shear control module; wherein...

[0032] The data acquisition module is used to collect the linear velocity of the strip steel at the inlet of the flying shear. And perform filtering to obtain It is also used to receive the actual angular velocity feedback signal of the flying shear motor. ;

[0033] The shearing window setting module is used to set the shearing window based on the shearing process;

[0034] The reference angular velocity calculation module is used to calculate based on The flying shear drum radius is calculated, the flying shear reference angular velocity is determined, and dynamic smoothing is performed during acceleration and deceleration to obtain a continuous and smooth flying shear reference angular velocity trajectory. , serving as the tracking target for the flying shear motor speed;

[0035] The control law construction module is used to... and the actual angular velocity feedback signal of the flying shear motor. A two-degree-of-freedom PID controller is used to construct the speed control law for the flying shear motor;

[0036] The flying shear control quantity calculation module is used to calculate the flying shear control quantity output for each shearing window. ;

[0037] The composite objective function construction module is used to construct based on the clipping window. , and Construct a composite objective function;

[0038] The objective function construction module is used to construct the parameter vector to be optimized based on the two-degree-of-freedom PID controller parameters and the physical feedforward compensation parameters. , parameter vector Mapping to a composite objective function, constructing an optimization objective function;

[0039] The control parameter optimization module is used for optimizing candidate parameter vectors. The flying shear control process is run within the shearing window to obtain the corresponding actual angular velocity response of the flying shear. and flying shear control quantity And calculate the corresponding composite objective function value. Based on the objective function, the optimal parameter vector is searched by using SSA for global search, GWO for local refinement, and combining clipping window boundary parameter updates.

[0040] The validity verification module is used to use the optimal parameter vector as the control parameters for the next shearing window, calculate the composite objective function value of the next shearing window according to the control law, evaluate the control performance of the parameter vector within the actual shearing window based on the composite objective function value, and verify the validity of the control parameters; if the verification is successful, the flying shear control module is started; if the verification fails, the parameters are adjusted and the control parameter optimization module is started.

[0041] The flying shear control module is used to take the optimal parameter vector as the controller parameter, calculate the flying shear control quantity according to the control law in the next shearing window, and control the flying shear actuator to complete synchronous shearing.

[0042] The solutions of the embodiments of the present invention have the following beneficial effects:

[0043] The flying shear control method based on a hybrid optimization of two-degree-of-freedom PID and SSA-GWO provided in this invention introduces engineering enhancement mechanisms such as a two-degree-of-freedom structure, physical feedforward compensation, differential-only measurement with filtering, back-calculation anti-integral saturation, and torque limiting / gradient limiting on the basis of traditional PID control. This significantly reduces overshoot, steady-state error, and chattering in the flying shear motor's speed tracking and position synchronization control. While maintaining fast response, it improves the system's ability to suppress strip speed fluctuations, thickness changes, friction changes, and external disturbances, enabling the cutter speed to maintain higher precision synchronization with the strip speed. This effectively improves the cutting accuracy, cut quality, and process stability of the flying shear process, while reducing actuator saturation and mechanical impact, extending equipment life, and reducing energy consumption and noise. Furthermore, this invention constructs a composite evaluation index with the shear window as the core, employing Sparrow Search (SSA), Grey Wolf Optimization (GWO), and their hybrid (SSA-GWO) to evaluate the performance of the flying shear motor. This invention employs adaptive tuning of control parameters such as [specific parameters not provided in the original text], avoiding the problem of getting trapped in local optima due to repeated manual trial and error and single optimization methods. The obtained parameters maintain good robustness and consistency under different speed ranges, different strip specifications, and load disturbances, balancing error minimization within the window with smooth control and resource avoidance. This significantly shortens the debugging cycle and improves the ability to be used immediately upon startup and reused across production lines. This invention can be quickly implemented on general industrial platforms such as domestically produced controllers, has low software and hardware dependencies, strong portability, and provides parameter rollback and fault cascading protection, making it highly valuable for engineering applications and significant for widespread adoption.

[0044] Of course, implementing any product or method of the present invention does not necessarily require achieving all of the advantages described above at the same time. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0046] Figure 1 This is a flowchart of the flying shear control method based on the hybrid optimization of improved two-degree-of-freedom PID and SSA-GWO as described in the embodiments of the present invention;

[0047] Figure 2 This is a schematic diagram of the improved PID control structure in an embodiment of the present invention;

[0048] Figure 3 This is a flowchart of control parameter optimization and self-tuning in an embodiment of the present invention. Detailed Implementation

[0049] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. It should be noted that, without conflict, the embodiments and features in the embodiments of the present invention can also be combined with each other.

[0050] It should be noted that similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In the description of the embodiments of the present invention, the terms "first," "second," "third," "fourth," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance. In addition, sometimes a subscript such as W1 may be written in a non-subscript form such as W1, and their meanings are consistent unless the distinction is emphasized.

[0051] It should be understood that the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural. Additionally, the character " / " in this article generally indicates an "or" relationship between the preceding and following related objects, but it can also represent an "and / or" relationship. Please refer to the context for a more accurate understanding.

[0052] This invention provides a flying shear control method based on a hybrid optimization of two-degree-of-freedom PID and SSA-GWO. While maintaining the simplicity of the PID structure and its ease of implementation on existing controllers, a reference angular velocity trajectory for the flying shear is generated by acquiring the strip speed. Speed ​​control is achieved using a two-degree-of-freedom PID that incorporates proportional weighting, differential filtering, anti-integral saturation, and amplitude and slope limiting, thus introducing a two-degree-of-freedom structure. Within the shearing window, a composite objective function is constructed that simultaneously measures ITAE, peak error, control increment smoothness, and saturation penalty. Sparrow Search (SSA), Grey Wolf Optimization (GWO), and their hybrid algorithm (SSA-GWO) are used to adaptively tune the PID parameters and physical feedforward coefficients, significantly reducing speed error and control shock within the shearing window. This improves the speed synchronization accuracy, anti-disturbance performance, stability, and applicability of the flying shear within the shearing window, making it suitable for hot rolling and cold rolling production lines. This invention uses a shear window as the basic time unit for control performance evaluation and parameter update. Within the shear window, control parameters are frozen and control performance data is collected. After the shear window ends, the control parameters are optimized and updated based on composite performance evaluation indicators. When performance degrades, the control parameters are rolled back to the parameter combination corresponding to the previous window, thereby achieving quasi-online parameter tuning control suitable for flying shear processes.

[0053] like Figure 1 As shown, the flying shear control method based on a hybrid optimization of two-degree-of-freedom PID and SSA-GWO provided in this embodiment of the invention includes the following steps:

[0054] Step S1: Collect the linear velocity of the strip at the inlet of the flying shear. And perform filtering to obtain The shearing window is set based on the shearing process and serves as the basic time unit for control performance evaluation and parameter updates.

[0055] In this step, the strip running linear speed The speed is acquired in real time by a speed measuring device installed at the inlet of the flying shear. To reduce the impact of speed measurement noise on the stability of subsequent reference trajectory generation and control calculations, the acquired strip running linear velocity signal is filtered to obtain the strip linear velocity used for subsequent reference trajectory generation and control calculations. Preferably, the filtering process is a first-order low-pass filter.

[0056] The shearing window is the synchronous control time interval corresponding to the completion of one shearing operation by the flying shear, determined based on the process trigger signal or reference trajectory. The window starts at the moment when the flying shear enters the synchronous control state for this shearing operation, and ends at the moment when the shearing operation is completed or the flying shear exits the synchronous control state. The shearing window is used to evaluate the control performance within this time interval and serves as the basic time unit for updating control parameters.

[0057] Step S2, according to The flying shear drum radius is calculated, the flying shear reference angular velocity is determined, and dynamic smoothing is performed during acceleration and deceleration to obtain a continuous and smooth flying shear reference angular velocity trajectory. , serving as the tracking target for the flying shear motor speed.

[0058] In this step, the strip speed is collected in real time and then filtered. The flying shear drum radius is calculated online and updated in real time to determine the flying shear reference angular velocity. To avoid abrupt changes in the flying shear reference angular velocity trajectory during acceleration and deceleration, the acceleration and deceleration segments of the flying shear reference angular velocity trajectory are dynamically smoothed using an S-curve to limit changes in acceleration and jerk, thereby obtaining a continuous and smooth flying shear reference angular velocity trajectory and ensuring its continuity and controllability.

[0059] Step S3, according to and the actual angular velocity feedback signal of the flying shear motor. A two-degree-of-freedom PID controller was used to construct the speed control law for the flying shear motor, and the flying shear control quantity output for each shearing window was calculated. .

[0060] In this step, the actual angular velocity feedback signal of the flying shear motor The angular velocity signal is estimated by the encoder or motor and then filtered to obtain a stable signal, which is used to calculate the linear velocity of the flying shear drum and the synchronization error between it and the running linear velocity of the strip.

[0061] When constructing the speed control law for the flying shear motor, the improvements to the two-degree-of-freedom PID controller include: proportional weighting of the setpoint, differential filtering, anti-integral saturation, output amplitude and slope limiting constraints, and superimposed physical feedforward compensation terms. The physical feedforward compensation terms are used to compensate for the dynamic characteristics of the flying shear actuator, and their compensation amounts include equivalent rotational inertia, viscous damping, and friction terms. After summing the integral, differential, and physical feedforward compensation terms, amplitude and slope limiting constraints are set on the control output to ensure smooth changes in the control quantity and meet the physical constraints of the actuator. The control law outputs the flying shear control quantity based on the given right-hand side parameters to achieve flying shear control.

[0062] like Figure 2 As shown, in one executable embodiment, the flying shear motor speed control law constructed by the two-degree-of-freedom PID controller includes: inputting a setpoint r, introducing a setpoint weighting coefficient β into the proportional channel, and calculating anti-integral saturation on the weighted setpoint; inputting a measured value y, differentiating and filtering the measured value to obtain the N value; and after fusing the anti-integral saturation, the N value, and the physical feedforward compensation term, outputting a torque command u after amplitude and slope limiting constraints. The two-degree-of-freedom PID controller introduces a setpoint weighting structure in the proportional channel to adjust the influence of reference angular velocity changes on the transient response of the control output. The two-degree-of-freedom PID controller uses a fixed sampling period. The control law operates in each... This is executed once per cycle to generate the corresponding flying shear control quantity. The time period corresponding to the kth sampling period is... .

[0063] The control law formula is as follows:

[0064] (1)

[0065] In equation (1), This represents the flying shear control quantity (torque command or current command) output in the kth sampling period, which is the actual control input of the flying shear motor drive device in the kth sampling period; This represents the gain coefficient of the proportional element, which is used to generate control based on the proportional error. This represents the weighting coefficient of the set value, used to adjust the intensity of the influence of the flying shear reference angular velocity on the proportional control effect; This represents the reference angular velocity of the flying shear in the kth sampling period; This represents the actual angular velocity of the flying shear motor measured in the nth sampling period; This represents the output of the integral term in the nth sampling period, used to eliminate steady-state error and include an anti-integral saturation pullback term as the integral term; The output of the differential element in the kth sampling period is applied only to the feedback angular velocity and a filter is added to improve the dynamic response of the system and suppress the influence of noise on the differential operation, and is used as the differential term. This represents the physical feedforward compensation term for the k-th sampling period.

[0066] The integral term employs discrete integration and incorporates an anti-integral saturation mechanism to avoid the adverse effects of execution-end saturation on control performance. The differential term is constructed based on feedback angular velocity and uses filtering to suppress high-frequency noise interference in the differential operation. The physical feedforward compensation term is used to compensate for the equivalent rotational inertia, viscous damping, and frictional dynamic characteristics of the flying shear system, thereby improving the system's dynamic response performance.

[0067] Step S4, within the clipping window based on , and Construct a composite objective function.

[0068] In this step, within the shearing window, the flying shear reference angular velocity is used. Compared with the actual angular velocity of the flying shear Calculate the synchronization error signal and utilize the flying shear control quantity. A composite objective function is constructed to evaluate the control performance of given control parameters within a shear window. The control law outputs a flying shear control quantity to drive the flying shear system under given control parameters. The performance indicators of the flying shear system under the control law, such as speed response, error signal, and control output changes, serve as inputs to the composite objective function for evaluating and optimizing the control parameters. The composite objective function simultaneously considers the time-weighted absolute error, peak synchronization error, control output increment smoothness index, and control output saturation penalty term within the shear window. Specifically, the error signal corresponds to the time-weighted absolute error term and the peak synchronization error term; the control output change corresponds to the control output increment smoothness index; and the control output constraint corresponds to the control output saturation penalty term. The synchronization error and control output changes generated by the flying shear system under the control law serve as inputs to the composite objective function, used to construct the time-weighted absolute error term, the peak synchronization error term, the control output increment smoothness term, and the control output saturation penalty term, and based on these, the control parameters are evaluated and optimized.

[0069] Preferably, to avoid the control parameters only targeting the performance within the shearing window and ignoring the stability in the non-shearing stage, a time-weighted absolute error term based on full-time domain calculation is further introduced into the composite objective function as an auxiliary constraint term.

[0070] Specifically, the composite objective function is defined as:

[0071] (2)

[0072] In equation (2), J represents the value of the composite objective function; Indicated by synchronization error The time-weighted absolute error term is used to measure the degree to which systematic errors accumulate over time, and its weight increases with time. This represents the maximum peak value of the flying shear synchronization error within the shear window, used to constrain the system's transient performance. Indicates the increment of the control output. The accumulated terms are used to measure the magnitude of changes in control output, in order to constrain the smoothness of control quantity and reduce actuator shock. The smaller the value, the smoother the control. This indicates a penalty term when the control output exceeds the allowable range of the actuator, used to suppress control saturation behavior; It represents the time-weighted error index calculated under multiple operating stages or conditions, and is used to comprehensively evaluate the performance of control parameters in the full shearing process; , , , , Each represents its own coefficient.

[0073] Step S5: During the control parameter optimization process, to facilitate subsequent unified optimization and updates of the control parameters at the clipping window boundaries, a parameter vector to be optimized is constructed based on the two-degree-of-freedom PID controller parameters and physical feedforward compensation parameters. , parameter vector Map to a composite objective function to construct an optimization objective function.

[0074] In this step, the constructed parameter vector to be optimized is:

[0075] (3)

[0076] In equation (3), These represent the components of the parameters to be optimized in the two-degree-of-freedom PID controller parameters and the physical feedforward compensation parameters, respectively.

[0077] In one executable embodiment, ,and The parameter components to be optimized include proportional gain. Integral gain Differential gain Weighting coefficient of set value Anti-integral saturation gain Differential filter coefficients and physical feedforward compensation coefficient It can also be a subset of it, including at least one of the seven elements mentioned above.

[0078] The parameter vector is mapped to a composite objective function, which is a function of the parameter vector, denoted as . The optimization objective function is constructed based on the composite objective function value as follows:

[0079] (4)

[0080] In equation (4), Ω represents the allowable range of values ​​for each control parameter.

[0081] No. The candidate parameter vector is denoted as: , which represents a set of candidate control parameters used for performance evaluation during the optimization process.

[0082] Step S6, for the candidate parameter vector The flying shear control process is run within the shearing window to obtain the corresponding actual angular velocity response of the flying shear. and flying shear control quantity And calculate the corresponding composite objective function value. Based on the objective function, the optimal parameter vector is searched by using SSA for global search, GWO for local refinement, and combining clipping window boundary parameter updates.

[0083] In this step, the candidate parameter vector The value range is set according to the specifications of the flying shear equipment, its driving capability, and the characteristics of the material being sheared. For example, the proportional, integral, and derivative parameters are selected within a preset reasonable range, the setpoint weighting coefficient is used to adjust the intensity of the influence of the reference input on the control output, and the anti-integral saturation coefficient is used to suppress the adverse effects of actuator saturation on control performance.

[0084] During the non-shear control period, the Sparrow Search Algorithm (SSA), Grey Wolf Optimization Algorithm (GWO), or a hybrid optimization strategy thereof are used to optimize the parameter vector composed of the two-degree-of-freedom PID controller parameters and physical feedforward compensation parameters, with the composite objective function as the evaluation function.

[0085] The termination condition of the optimization process is set according to the shearing window duration, control cycle, and computational resource constraints. When the change of the composite objective function in multiple consecutive iterations is less than a preset threshold, the optimization process is determined to have converged and the iteration is terminated. The optimal parameter vector is output and used as the control parameter for the next shearing window.

[0086] Specifically, Figure 3This demonstrates a hybrid optimization process that uses SSA for global search, GWO for local refinement, and combines clipping window boundary parameter updates with KPI comparison. If the optimization result is better than the current parameters, the parameters are fixed; otherwise, a rollback is performed. The following section uses this hybrid optimization strategy as an example to further illustrate the control parameter optimization process. Figure 3 As shown, the search optimization process includes the following steps:

[0087] Step S61: Initialize the search range and candidate solution size of the control parameters. Generate several candidate parameter combinations within the allowable parameter range. Each candidate solution corresponds to a set of control parameters and feedforward compensation parameters to be optimized, and set the maximum number of iterations to start the parameter tuning process.

[0088] In step S62, during the parameter tuning process, an optimization strategy is introduced to search and update the candidate parameter combinations, thereby enhancing the global exploration capability of the parameter space and avoiding getting trapped in local optima.

[0089] Step S63: Based on the candidate parameter combinations obtained, the candidate solutions are further optimized and adjusted. By searching and updating within the local parameter range, the accuracy and stability of the parameter tuning results are improved, thereby obtaining a control parameter vector with better performance.

[0090] Step S64: Based on the composite objective function, evaluate the control performance of each candidate parameter combination within the clipping window to obtain corresponding performance indicators, which are used to compare the advantages and disadvantages of different parameter combinations. In step S54, for each candidate parameter vector... Calculate the corresponding composite objective function value. The parameters are sorted in ascending order of their composite objective function values, and the parameter vector with the smallest composite objective function value is selected as the optimal parameter candidate solution for the current clipping window.

[0091] Step S65: After the clipping window ends, the optimal parameter candidate vector obtained from the current clipping window is... Control parameter vector corresponding to the previous clipping window Compare the parameters; or when an abnormal operating condition is detected or the control performance deteriorates beyond a preset threshold, freeze the parameter update and revert to the control parameter vector corresponding to the previous clipping window.

[0092] when When, the parameter vector The new control parameters are applied to the next clipping window; otherwise, the control parameter vector corresponding to the previous clipping window is retained. Wherein, ε is a preset improvement threshold, used to avoid frequent parameter switching due to random fluctuations.

[0093] During the adaptive parameter tuning process, a quasi-online parameter tuning mechanism based on a clipping window is introduced to search and update the control parameters, thereby reducing reliance on manual parameter tuning and improving adaptability and control accuracy under complex operating conditions.

[0094] Using the performance evaluation results as the basis for parameter tuning, the optimal parameter combination is applied to the controller operation, thereby achieving high-precision synchronization between the blade speed and the strip speed during the critical shearing stage.

[0095] Step S7: Using the optimal parameter vector as the control parameters for the next shearing window, calculate the composite objective function value of the next shearing window according to the control law, evaluate the control performance of the parameter vector within the actual shearing window based on the composite objective function value, and verify the effectiveness of the control parameters.

[0096] In this step, the control parameters are no longer updated within the same clipping window; parameter updates only occur after the clipping window ends. If the improvement of the composite objective function within a preset number of consecutive clipping windows is less than a preset threshold, the parameter optimization process terminates; otherwise, step S5 continues after subsequent clipping windows to optimize and update the control parameters.

[0097] In step S8, if the verification passes, the optimal parameter vector is used as the controller parameter. In the next shearing window, the flying shear control quantity is calculated according to the control law, and the flying shear actuator is controlled to complete the synchronous shearing. If the verification fails, the parameters are adjusted, and the process returns to step S7 to re-optimize and search for the candidate control parameter vector until a control parameter vector that meets the performance requirements is obtained.

[0098] The torque or current command output by the controller is input to the motor drive device to drive the flying shear actuator to run, so that the flying shear blade completes synchronous shearing within the shearing window; closed-loop control is formed by the angular velocity or position feedback of the flying shear motor to achieve synchronous control of the flying shear drum angular velocity and the strip running linear velocity.

[0099] In this step, the flying shear actuator is driven by a motor. The controller output is applied to the flying shear drum via the drive device to adjust the drum's angular velocity. To ensure the safety and stability of the system operation, amplitude and slope limits are set on the control output at the drive end. When saturation occurs at the actuator end, an anti-integral saturation mechanism is used to suppress overshoot caused by control saturation.

[0100] Based on the above control method, this invention also provides a flying shear control system based on a hybrid optimization of two-degree-of-freedom PID and SSA-GWO. This system achieves synchronous control of the flying shear based on a two-degree-of-freedom PID control structure combined with a parameter adaptive tuning mechanism. The control system can be deployed on a programmable controller or an industrial computing platform, and interacts with sensors and drive devices in real time through an industrial communication network to adapt to application requirements under different production line conditions.

[0101] The control system supports multiple industrial communication methods and has functions such as parameter management, operation status monitoring, and fault recording, facilitating system maintenance and engineering promotion. The flying shear control system includes: a data acquisition module, a shear window setting module, a reference angular velocity calculation module, a control law construction module, a flying shear control quantity calculation module, a composite objective function construction module, an optimized objective function construction module, a control parameter optimization module, an effectiveness verification module, and a flying shear control module; wherein,

[0102] The data acquisition module is used to collect the linear velocity of the strip steel at the inlet of the flying shear. And perform filtering to obtain It is also used to receive the actual angular velocity feedback signal of the flying shear motor. ;

[0103] The shearing window setting module is used to set the shearing window based on the shearing process;

[0104] The reference angular velocity calculation module is used to calculate based on The flying shear drum radius is calculated, the flying shear reference angular velocity is determined, and dynamic smoothing is performed during acceleration and deceleration to obtain a continuous and smooth flying shear reference angular velocity trajectory. , serving as the tracking target for the flying shear motor speed;

[0105] The control law construction module is used to... and the actual angular velocity feedback signal of the flying shear motor. A two-degree-of-freedom PID controller is used to construct the speed control law for the flying shear motor;

[0106] The flying shear control quantity calculation module is used to calculate the flying shear control quantity output for each shearing window. ;

[0107] The composite objective function construction module is used to construct based on the clipping window. , and Construct a composite objective function;

[0108] The objective function construction module is used to construct the parameter vector to be optimized based on the two-degree-of-freedom PID controller parameters and the physical feedforward compensation parameters. , parameter vector Mapping to a composite objective function, constructing an optimization objective function;

[0109] The control parameter optimization module is used for optimizing candidate parameter vectors. The flying shear control process is run within the shearing window to obtain the corresponding actual angular velocity response of the flying shear. and flying shear control quantity And calculate the corresponding composite objective function value. Based on the objective function, the optimal parameter vector is searched by using SSA for global search, GWO for local refinement, and combining clipping window boundary parameter updates.

[0110] The validity verification module is used to use the optimal parameter vector as the control parameters for the next shearing window, calculate the composite objective function value of the next shearing window according to the control law, evaluate the control performance of the parameter vector within the actual shearing window based on the composite objective function value, and verify the validity of the control parameters; if the verification is successful, the flying shear control module is started; if the verification fails, the parameters are adjusted and the control parameter optimization module is started.

[0111] The flying shear control module is used to take the optimal parameter vector as the controller parameter, calculate the flying shear control quantity according to the control law in the next shearing window, and control the flying shear actuator to complete synchronous shearing.

[0112] The system or device for executing the method in this embodiment of the invention can be a terminal or a server. The system includes a processor, a memory, and / or a transceiver, etc., and is connected via a communication bus. Each module can be implemented by a processor, a memory, and / or a transceiver, etc. The processor can be, but is not limited to, one or more microprocessors (MPUs), central processing units (CPUs), network processors (NPs), digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), and other programmable logic devices, discrete gates, transistor logic devices, discrete hardware components, etc., or can be configured to implement one or more integrated circuits of this invention. The processor can perform various functions by running or executing software programs in the memory and calling data in the memory. The memory includes Random Access Memory (RAM), Read-Only Memory (ROM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Compact Disc Read-Only Memory (CD-ROM), and / or Non-Volatile Memory (NVM), etc. The transceiver is used to communicate with network devices or terminal devices, and includes a receiver and a transmitter. The memory and transceiver can be integrated with the processor or exist independently.

[0113] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of the present invention are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means.

[0114] It should also be noted that the flying shear control system based on the hybrid optimization of two-degree-of-freedom PID and SSA-GWO described in this embodiment corresponds to the flying shear control method based on the hybrid optimization of two-degree-of-freedom PID and SSA-GWO. The description and limitations of the method also apply to the system, and will not be repeated here.

[0115] It should be understood that, in various embodiments of the present invention, the order of the above-mentioned process numbers 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 the present invention.

[0116] The above description is merely a preferred embodiment of the present invention and an explanation of the technical principles employed, and is not intended to limit the scope of the claimed invention, but merely to illustrate preferred embodiments of the invention. Those skilled in the art should understand that the scope of the invention is not limited to the specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A flying shear control method based on a hybrid optimization of two-degree-of-freedom PID and SSA-GWO, characterized in that, The method includes the following steps: Step S1: Collect the linear velocity of the strip at the inlet of the flying shear. And perform filtering to obtain Set the shearing window based on the shearing process; Step S2, according to The flying shear drum radius is calculated, the flying shear reference angular velocity is determined, and dynamic smoothing is performed during acceleration and deceleration to obtain a continuous and smooth flying shear reference angular velocity trajectory. , serving as the tracking target for the flying shear motor speed; Step S3, according to and the actual angular velocity feedback signal of the flying shear motor. A two-degree-of-freedom PID controller was used to construct the speed control law for the flying shear motor, and the flying shear control quantity output for each shearing window was calculated. ; Step S4, within the clipping window based on , and Construct a composite objective function; Step S5: Construct the parameter vector to be optimized based on the two-degree-of-freedom PID controller parameters and physical feedforward compensation parameters. , parameter vector Mapping to a composite objective function, constructing an optimization objective function; Step S6, for the candidate parameter vector The flying shear control process is run within the shearing window to obtain the corresponding actual angular velocity response of the flying shear. and flying shear control quantity And calculate the corresponding composite objective function value. Based on the objective function, the optimal parameter vector is searched by using SSA for global search, GWO for local refinement, and combining clipping window boundary parameter updates. Step S7: Using the optimal parameter vector as the control parameters for the next shearing window, calculate the composite objective function value of the next shearing window according to the control law, evaluate the control performance of the parameter vector within the actual shearing window based on the composite objective function value, and verify the effectiveness of the control parameters. Step S8: If the verification passes, the optimal parameter vector is used as the controller parameter. In the next shearing window, the flying shear control quantity is calculated according to the control law, and the flying shear actuator is controlled to complete the synchronous shearing. If the verification fails, the parameters are adjusted, and the process returns to step S7.

2. The method according to claim 1, characterized in that, The shearing window mentioned in step S1 is the synchronous control time interval corresponding to the completion of one shearing action by the flying shear. The starting point of the window is the moment when the flying shear begins to enter the synchronous control state for this shearing action, and the ending point of the window is the moment when the shearing action is completed or the flying shear exits the synchronous control state.

3. The method according to claim 1, characterized in that, When constructing the speed control law for the flying shear motor in step S3, the improvement steps for the two-degree-of-freedom PID controller include: setpoint proportional weighting, differential filtering, anti-integral saturation, output amplitude limiting and slope limiting constraints, and superimposed physical feedforward compensation terms; and the physical feedforward compensation terms are used to compensate for the dynamic characteristics of the flying shear actuator, including equivalent rotational inertia terms, viscous damping terms, and friction terms.

4. The method according to claim 1, characterized in that, The speed control law of the flying shear motor constructed by the two-degree-of-freedom PID controller includes: inputting a setpoint r, introducing a setpoint weighting coefficient β into the proportional channel, and calculating anti-integral saturation on the weighted setpoint; inputting a measured value y, differentiating and filtering the measured value to obtain the N value; and after fusing the anti-integral saturation, the N value, and the physical feedforward compensation term, outputting the torque command u after amplitude and slope limiting constraints.

5. The method according to any one of claims 1 to 4, characterized in that, The control law formula is as follows: (1) In equation (1), This represents the flying shear control quantity output in the kth sampling period, which is the actual control input of the flying shear motor drive device in the kth sampling period; This represents the gain coefficient of the proportional element, which is used to generate control based on the proportional error. This represents the weighting coefficient of the set value, used to adjust the intensity of the influence of the flying shear reference angular velocity on the proportional control effect; This represents the reference angular velocity of the flying shear in the kth sampling period; This represents the actual angular velocity of the flying shear motor measured in the nth sampling period; This represents the output of the integral term in the nth sampling period, used to eliminate steady-state error and include an anti-integral saturation pullback term as the integral term; The output of the differential element in the kth sampling period is applied only to the feedback angular velocity and a filter is added to improve the dynamic response of the system and suppress the influence of noise on the differential operation, and is used as the differential term. This represents the physical feedforward compensation term for the k-th sampling period.

6. The method according to claim 5, characterized in that, In step S2, dynamic smoothing is performed during the acceleration and deceleration phase. The S-curve is used for dynamic smoothing to limit the changes in acceleration and jerk, thereby obtaining a continuous and smooth flying shear reference angular velocity trajectory and ensuring the continuity and controllability of the reference angular velocity trajectory.

7. The method according to claim 1, characterized in that, The composite objective function is defined as follows: (2) In equation (2), J represents the value of the composite objective function; This represents the time-weighted absolute error term composed of synchronization errors, used to measure the degree to which system errors accumulate over time; This represents the maximum peak value of the flying shear synchronization error within the shear window, used to constrain the system's transient performance. This represents the cumulative term consisting of control output increments, used to measure the magnitude of control output changes, constrain the smoothness of control quantities, and reduce actuator shocks. The smaller the value, the smoother the control. This indicates a penalty term when the control output exceeds the allowable range of the actuator, used to suppress control saturation behavior; It represents the time-weighted error index calculated under multiple operating stages or conditions, and is used to comprehensively evaluate the performance of control parameters in the full shearing process; , , , , Each represents its own coefficient.

8. The method according to claim 1, characterized in that, The constructed parameter vector to be optimized for: (3) In equation (3), These represent the components of the control parameters to be optimized in the two-degree-of-freedom PID controller parameters and the physical feedforward compensation parameters, respectively.

9. The method according to claim 8, characterized in that, Parameter vector Mapping to a composite objective function, where the composite objective function is a function of the parameter vector, denoted as... The objective function for optimization is constructed as follows: (4) In equation (4), Ω represents the allowable range of values ​​for each control parameter.

10. A flying shear control system based on a hybrid optimization of two-degree-of-freedom PID and SSA-GWO, characterized in that, The system includes a data acquisition module, a shear window setting module, a reference angular velocity calculation module, a control law construction module, a flying shear control quantity calculation module, a composite objective function construction module, an optimized objective function construction module, a control parameter optimization module, an effectiveness verification module, and a flying shear control module; among which... The data acquisition module is used to collect the linear velocity of the strip steel at the inlet of the flying shear. And perform filtering to obtain It is also used to receive the actual angular velocity feedback signal of the flying shear motor. ; The shearing window setting module is used to set the shearing window based on the shearing process; The reference angular velocity calculation module is used to calculate based on The flying shear drum radius is calculated, the flying shear reference angular velocity is determined, and dynamic smoothing is performed during acceleration and deceleration to obtain a continuous and smooth flying shear reference angular velocity trajectory. , serving as the tracking target for the flying shear motor speed; The control law construction module is used to... and the actual angular velocity feedback signal of the flying shear motor. A two-degree-of-freedom PID controller is used to construct the speed control law for the flying shear motor; The flying shear control quantity calculation module is used to calculate the flying shear control quantity output for each shearing window. ; The composite objective function construction module is used to construct based on the clipping window. , and Construct a composite objective function; The objective function construction module is used to construct the parameter vector to be optimized based on the two-degree-of-freedom PID controller parameters and the physical feedforward compensation parameters. , parameter vector Mapping to a composite objective function, constructing an optimization objective function; The control parameter optimization module is used for optimizing candidate parameter vectors. The flying shear control process is run within the shearing window to obtain the corresponding actual angular velocity response of the flying shear. and flying shear control quantity And calculate the corresponding composite objective function value. Based on the objective function, the optimal parameter vector is searched by using SSA for global search, GWO for local refinement, and combining clipping window boundary parameter updates. The validity verification module is used to use the optimal parameter vector as the control parameters for the next shearing window, calculate the composite objective function value of the next shearing window according to the control law, evaluate the control performance of the parameter vector within the actual shearing window based on the composite objective function value, and verify the validity of the control parameters; if the verification is successful, the flying shear control module is started; if the verification fails, the parameters are adjusted and the control parameter optimization module is started. The flying shear control module is used to take the optimal parameter vector as the controller parameter, calculate the flying shear control quantity according to the control law in the next shearing window, and control the flying shear actuator to complete synchronous shearing.

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