Permanent magnet synchronous motor multi-machine cooperative synchronous control method and system for precision casting production line

Abstract

The invention relates to the technical field of multi-machine cooperative control, in particular to a permanent magnet synchronous motor multi-machine cooperative synchronous control method and system for a precision casting production line. Forming a scheduling target which takes minimization of total completion time as a main part and simultaneously comprises capability matching gain, path conflict regularization and key process delay punishment, and generating a time-equipment-task ternary scheduling matrix; performing field-oriented performability judgment on the matrix, finishing matrix correction by adopting a structured minimum disturbance strategy of first time translation and then equipment migration, and maintaining task chain continuity by chained time sequence buffer to ensure that process connection is not damaged by correction; and generating a control instruction diagram by taking the corrected scheduling matrix as a blue, mapping each scheduling unit into an instruction node, and introducing a synchronous edge based on a uniform clock to realize parallel action alignment, so that beat consistency can be kept under complex working conditions and equipment heterogeneous conditions.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of multi-machine cooperative control, in particular to a permanent magnet synchronous motor multi-machine cooperative synchronous control method and system for a precision casting production line. BACKGROUND

[0002] The comprehensive requirements of precision casting production line on tempo, precision and stability make multiple permanent magnet synchronous motors need to work cooperatively under strict time and space constraints, but most of the existing schemes follow the simplified strategy of master-slave or equal cycle synchronization, which is difficult to handle the sequential dependence of process task chain, spatial conflict of path resources, heterogeneous differences of device capacity and real-time fluctuations of field state at the same time.

[0003] In a typical production line, tasks such as mold handling, preheating, wax injection, dewaxing and mold closing have clear tempo and work station path dependence, however, traditional control often disperses these constraints into multiple sub-logics, lacks a unified carrier that can combine task structure and device capacity modeling, leading to disconnection between task allocation and actual executability; when the mold state is not up to standard, the positioning accuracy deviates or the drive end fluctuates, the system usually stops or intervenes manually, lacks a structured correction mechanism for executability, thereby breaking the continuity of the task chain and amplifying the production line congestion; even in the configuration with redundant devices, the existing method rarely takes into account the device capacity difference and path conflict constraints in the scheduling target, making it difficult to reduce waiting and misalignment in the key process connection phase; in addition, the control layer generally issues linear instruction sequences, lacks a control instruction graph structure corresponding to the scheduling matrix and a unified clock synchronization trigger strategy, and cannot guarantee the alignment and smooth start of multiple devices under parallel cooperative action, which is easy to cause fixture impact, mold posture disturbance and work station occupation conflict.

[0004] Overall, the existing technology lacks a task graph-centered modeling entry, lacks a scheduling optimization target combining device capacity and path conflict, lacks a minimum disturbance correction mechanism for executability, and lacks a control instruction graph and synchronization trigger system that is isomorphic to the scheduling structure, making it difficult to meet the requirements of precision casting scenarios for high consistency and high robust cooperative control. SUMMARY

[0005] The present application proposes a multi-PMSM cooperative synchronous control method and system for precision casting scenarios, a task graph-centered modeling entry, a scheduling optimization target combining device capacity and path conflict, which solves the problem that the existing technology is difficult to meet the requirements of precision casting scenarios for high consistency and high robust cooperative control.

[0006] To achieve the above purpose, the technical scheme adopted by the present application is:

[0007] In an aspect, a permanent magnet synchronous motor (PMSM) multi-machine cooperative synchronization control method for a precision casting production line is provided, comprising the following steps:

[0008] According to a plurality of operation steps on the precision casting production line, a casting process task graph is constructed, and then by acquiring capability parameters of each PMSM, a capability value thereof is calculated, the capability parameters including a maximum rotating speed, a task type weight, and a mechanical precision factor, and then a motor capability matrix is constructed according to different installation modes, load mechanisms, and control precisions of different PMSM devices.

[0009] In the casting process task graph, an intersection calculation is performed on a path of each task and other task paths to obtain a conflict matrix, the conflict matrix and the motor capability matrix are input into a constructed constraint optimization model, and a task scheduling matrix is output, the task scheduling matrix being used to determine a starting time of each task on a time axis and which PMSM executes the task.

[0010] Based on the task scheduling matrix, mold state data, motor operating states, and a combination index function, a dynamic feasibility determination of task execution and a structured modification of the scheduling matrix are performed, when a value of the combination index function of any task is 0, a structured modification mechanism of the scheduling matrix is started, and a modified scheduling matrix is output, the modification process including a phase one and a phase two, the phase one being a time translation modification, and the phase two being a backup motor migration.

[0011] Based on the modified scheduling matrix, a multi-PMSM synchronization control instruction graph is generated, the instruction graph being a directed graph with a synchronization dependent edge, and a synchronization edge is introduced to complete cooperative starting of the motors through a unified clock trigger mechanism.

[0012] As a preferred, the casting process task graph construction process includes a PLC control logic graph based on a production line, an action timing graph, and a task instruction table configured in a SCADA system, all task nodes are extracted and constructed into the casting process task graph according to an actual order and a dependency relationship.

[0013] More preferably, the task nodes include a process beat, a space path label, and a process type label.

[0014] The process beat represents a maximum completion time of the task, the space path label represents a start and end space position involved in the task, and the process type label represents an operation type of the task.

[0015] As a preferred, in the conflict matrix, if an intersection of two task paths is non-empty and an execution time overlaps, a value of the conflict matrix is 1, otherwise, the value is 0.

[0016] More preferably, in the constraint optimization model, only one permanent magnet synchronous motor can execute each task; the starting time of the task must be after the completion of all its predecessor tasks; if the value of the path conflict matrix is 1, then the interval between the starting times of the two tasks must be greater than the safety time interval of the production line.

[0017] Preferably, the mold state data includes mold temperature and mold alignment deviation, and the motor operating state includes motor current and rotating speed.

[0018] Preferably, the correction step of the first stage includes: for any permanent magnet synchronous motor, if the value of the combined index function is 1 after delaying the minimum safety interval at the original scheduling time, the scheduling time is updated; if it still cannot be executed, enter the second stage.

[0019] The correction step of the second stage includes: finding a standby permanent magnet synchronous motor, requiring its capability value to be greater than the minimum task capability value that meets the task, and within the maximum safety interval time window interval at the original scheduling time, there is a time point that meets the value of the combined index function is 1, update the scheduling time.

[0020] Preferably, in the instruction graph generation process, first map each scheduling unit to a control graph node, and the control graph node contains a position control instruction parameter triple, which is a target displacement, a speed and an acceleration.

[0021] Preferably, in the starting process of the permanent magnet synchronous motor, an acceleration inertia buffer correction mechanism is also introduced to adjust the target acceleration to achieve smooth starting.

[0022] In another aspect of the present application, a permanent magnet synchronous motor multi-machine cooperative synchronous control system for a precision casting production line is provided, comprising sequentially connected:

[0023] The motor capability constraint extraction module is used to construct a casting process task graph according to a plurality of operation steps on the precision casting production line, and then obtain the capability parameters of each permanent magnet synchronous motor for calculating its capability value, the capability parameters including maximum rotating speed, task type weight and mechanical precision factor, and then construct a motor capability matrix according to the installation mode, load mechanism and control precision of different permanent magnet synchronous motor devices.

[0024] The task scheduling matrix generation and motor matching module is used for performing intersection calculation on the path of each task and other task paths in the casting process task graph to obtain a conflict matrix, inputting the conflict matrix and a motor capability matrix into a constructed constraint optimization model, and outputting a task scheduling matrix. The task scheduling matrix is used for determining a starting time of each task on a time axis and which permanent magnet synchronous motor to execute.

[0025] The task executability dynamic verification module is used for performing dynamic feasibility determination of task execution and structured modification of the scheduling matrix based on the task scheduling matrix, mold state data, motor operation state and a combined index function. When the value of the combined index function of any task is 0, a scheduling matrix structured modification mechanism is started, and a modified scheduling matrix is output. The modification process includes phase one and phase two. Phase one is time translation modification, and phase two is backup motor migration.

[0026] The instruction graph generation and synchronous execution module is used for generating a multi-PMSM synchronous control instruction graph based on the modified scheduling matrix. The instruction graph is a directed graph with a synchronous dependent edge. A synchronous edge is introduced to complete the cooperative start of the motors through a unified clock trigger mechanism.

[0027] Compared with the prior art, the present application has the following beneficial effects:

[0028] The application provides a permanent magnet synchronous motor multi-machine cooperative synchronization control method and system for a precision casting production line, a task graph modeling is taken as an entry to establish a unified description of task nodes and sequence dependence, a beat and a path label, a motor capacity matrix is constructed to map device speed capacity and installation precision and other elements to an adaptation degree of a task type, on the basis, a scheduling target containing a capacity matching gain, a path conflict regularization and a key process delay penalty is formed to minimize a total completion time, a time-device-task ternary scheduling matrix is generated; before execution, the matrix is subjected to a site-oriented executability judgment, a combined gate function composed of mold temperature positioning and driving end fluctuation is used to verify each task and each time point, a structured minimum disturbance strategy of time translation first and device migration later is used to complete matrix correction, a chain time sequence buffer is used to maintain task chain continuity, and it is ensured that the correction does not damage process connection; in the control layer, a control instruction graph is generated based on the corrected scheduling matrix, each scheduling unit is mapped to an instruction node containing a target displacement speed, acceleration and a trigger time, a synchronous edge based on a unified clock is introduced to realize action alignment, and an inertia buffer item proportional to time offset is set to soften the acceleration, and the impact of delay insertion on the mechanism and the mold is reduced. Through the unified modeling of the task graph and the capacity matrix, the scheduling optimization containing the conflict and the key process constraint, the structured correction oriented to executability, and the control instruction graph and the synchronous trigger mechanism isomorphic to the scheduling, the application realizes the systematic closed loop of the multi-PMSM cooperative synchronization control for the precision casting scene, can maintain beat consistency, path safety and action smoothness under complex working conditions and device heterogeneous conditions, and thus improves the production line stability and the casting quality. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 A flow chart of the permanent magnet synchronous motor multi-machine cooperative synchronization control method for the precision casting production line in the embodiment of the application is shown in the embodiment of the application.

[0030] Figure 2 A composition block diagram of the permanent magnet synchronous motor multi-machine cooperative synchronization control system for the precision casting production line in the embodiment of the application is shown in the embodiment of the application. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the application.

[0032] Please refer to Figure 1 The application provides a permanent magnet synchronous motor multi-machine cooperative synchronization control method for a precision casting production line, including the following steps:

[0033] Step one: According to the multiple operation steps on the precision casting production line, the casting process task graph is constructed, and then the ability parameters of each permanent magnet synchronous motor are obtained for calculating its ability value, including maximum speed, task type weight and mechanical precision factor, and then the motor ability matrix is constructed according to the installation mode, load mechanism and control precision of different permanent magnet synchronous motors; Specifically, it includes:

[0034] This step aims to structure the specific process flow of the precision casting production line, and establish the ability matching relationship with the actual deployment of multiple permanent magnet synchronous motors (PMSM). By constructing the task graph and device capability matrix, the basic input structure of the subsequent scheduling algorithm is formed. All output contents come from actual process data, physical device parameters or static deployment configuration, ensuring that the scheme has engineering implementability and avoiding unnecessary data stacking.

[0035] Firstly, the casting process task graph needs to be established. The task comes from multiple operation steps on the precision casting production line, usually including mold heating, mold transfer, wax injection, dewaxing, mold closing, positioning and waiting nodes. Although these processes are relatively fixed, there are significant differences in parameters such as beat length, task space position and task priority between different production lines.

[0036] Therefore, in the deployment stage, engineering technicians will extract all task nodes from the PLC control logic diagram, action timing diagram and task instruction table configured in the SCADA system of the production line, and establish the casting process task graph structure according to the actual order and dependency relationship.

[0037] Each task node contains three main information fields:

[0038] Process beat , which indicates that the task must be completed within a certain period of time, usually given by historical production line data or equipment manual. For example, the mold preheating task is usually configured for seconds, and the wax injection task is configured for seconds;

[0039] Space path label , which indicates the start and end space positions involved in the task, obtained from the production line layout, such as "mold warehouse → wax injection station";

[0040] Process type label , which indicates the operation type of the task, such as handling, heating, and mold closing, which is used to establish a mapping relationship with the motor execution ability later.

[0041] To facilitate the structured description, the above task information is organized into a casting process task graph . The task graph contains task numbers, beats, sequence dependencies, path labels, and type labels; the nodes in the graph correspond to tasks , and the edges represent that the task must be completed before the task . For example, if the task is mold heating, and the task is wax injection, then . Path information is also used to determine whether there is a spatial path conflict between tasks, i.e., whether two tasks have a cross or share a work station in space.

[0042] After the task graph is established, motor capability parameters are obtained to measure whether each PMSM can efficiently complete a certain type of task. In the context of the present invention, PMSMs are usually installed in mold handling trolleys, work station switching execution arms, mold closing mechanisms, and other devices. Different installation methods, load mechanisms, and control accuracies of different devices result in significant differences in the types of tasks they are suitable for. Therefore, a motor capability matrix is defined, where is the number of motors, is the number of task types, and each element in the matrix represents the relative adaptability of the th motor to the th task type. The motor capability matrix is used to represent the execution adaptability of each type of task on different motors, and the data has been normalized for subsequent scheduling modules.

[0043] The calculation of the capability value takes into account the following three indicators: maximum speed , which represents the highest speed of the motor under rated conditions; task type weight , which represents the sensitivity of the task type to speed; and mechanical precision factor , which is obtained from the statistical data of repeated positioning errors during the debugging process of the motor platform. After combining these three indicators, the capability value calculation formula is as follows:

[0044] ;

[0045] where is read through the motor controller parameter interface, and the data format is an integer type encoding value; is the task type coefficient, which is set during the deployment phase, for example, the handling type task is , and the wax injection type is ; The reciprocating positioning accuracy of the motor from the debugging stage is counted, reflecting the stability of the motor under the installation structure, and is normalized to the interval.

[0046] For example, if the maximum speed of the transfer trolley is , the wax arm is , the clamping platform is , and the maximum speed in the system is , the transfer task is set to , and the normalized repositioning error is , and , the capacity values of the three devices are , and , respectively. It can be seen that the transfer trolley is obviously superior to other devices.

[0047] This structural modeling method can effectively prioritize matching the most suitable motor resources for this type of task in scheduling. The final capacity matrix and task graph will be used as input for the next scheduling module to ensure the operability and efficiency of task allocation. The innovation of this modeling method is to achieve a structural connection from static process to dynamic control by introducing the task-motor capacity matching relationship, enhancing the system adaptability.

[0048] Step 2: In the casting process task graph, the intersection of each task path with other task paths is calculated to obtain a conflict matrix. The conflict matrix and the motor capacity matrix are input into the constructed constraint optimization model to output a task scheduling matrix. The task scheduling matrix is used to determine the start time of each task on the time axis and which permanent magnet synchronous motor to execute. Specifically, it includes:

[0049] This step is based on the established task graph and motor capacity matrix to generate a task scheduling matrix , which is used to determine the start time of each task on the time axis and which motor to execute. Unlike conventional scheduling systems that only allocate tasks based on priority or static rules, the present invention introduces multiple constraints and innovative items that combine the characteristics of precision casting scenarios, allowing the scheduling matrix to dynamically offset common task congestion and device heterogeneity problems in the precision casting process while considering process tempo, task path conflicts, and motor capacity differences. This matrix is not only a "task table," but also an optimized expression of the task-motor-time ternary relationship, directly determining the basis for subsequent scheduling correction and control instruction generation.

[0050] The scheduling process first resolves the dependencies and space conflicts between tasks, and then, for each task... path By calculating the intersection with other task paths, a conflict matrix is ​​obtained. If the intersection of two task paths is not empty and their execution times overlap, then Otherwise .

[0051] Based on this, a constrained optimization model for task allocation and time scheduling is constructed. The goal is to minimize the total completion time of the entire production line while satisfying task dependencies, and to maximize the matching degree between task allocation and equipment capacity. This invention adds a process delay penalty term for precision casting scenarios to suppress sequential waiting situations in critical processes (e.g., wax injection immediately after mold preheating cannot be delayed for a long time), and also adds a path conflict regularization term to automatically separate tasks that may cause spatial conflicts.

[0052] After considering the above constraints, the objective function of the optimization model is:

[0053]

[0054] in, Indicates task Is it assigned to the motor? ; These are values ​​in the motor capability matrix; This is the path conflict matrix. This indicates the interval between the start times of two tasks. This is an adjustment factor for path conflict, which automatically staggers the timing of tasks with path conflicts. Indicates critical process delays, defined as tasks The delay time that must be executed in the shortest possible time after its predecessor task is completed. Used to penalize delays in critical processes. By adjusting These three coefficients can balance total time, capacity matching, path conflicts, and critical process delays under the actual needs of different production lines.

[0055] The above model ensures through constraints that:

[0056] For each task There can only be one motor. implement;

[0057] Task start time It can only be scheduled after all its preceding tasks are completed;

[0058] If a path conflict matrix exists Then it must satisfy wherein is the safety time interval of the production line, which can be measured during system debugging (e.g., 2.0 seconds).

[0059] For example, on a production line, the task (mold carrying) is performed by a carrying trolley, and the path of the task is "mold warehouse → wax injection table", the task (mold recycling) has a path of "wax injection table → warehouse", and the system calculates and the initial value is 0, since it does not meet the requirement of , the model is automatically adjusted to , and a path conflict regularization term is added to the optimization objective to reflect the cost of this adjustment.

[0060] In addition, the present application innovatively introduces a key process delay term in the objective function, so that the scheduling system can reduce the waiting time of key tasks (such as the time between mold heating and wax injection) as much as possible while meeting all constraints. This term is particularly suitable for scenarios in which a precise casting process chain needs to be closely linked, reducing the risk of mold temperature drop or wax solidification caused by improper scheduling.

[0061] In the final constraint optimization model, the scheduling matrix output is a time-device-task three-way table, the row of the matrix represents the motor , the list represents the task , and the value represents the start time of the task under the system unified clock. If a task is not assigned, the corresponding matrix element is null and does not participate in the next step. The matrix will be directly used as the input of the next step "task execution validity evaluation and scheduling correction".

[0062] Step three: based on the task scheduling matrix, mold state data, motor running state and combined index function, the dynamic feasibility of task execution is judged and the structure of the scheduling matrix is modified. When any task passes the combined index function calculation value is 0, the scheduling matrix structure modification mechanism is started, and the output is the modified scheduling matrix. The modification process includes phase one and phase two, phase one is time translation correction, and phase two is backup motor migration; specifically including:

[0063] This step generates a scheduling matrix Based on this, dynamic feasibility assessment of task execution and structured correction of the scheduling matrix are performed. This step directly bridges the gap between the system's scheduling logic and control execution, aiming to transform "theoretically schedulable task plans" into "actually executable task behaviors," thereby avoiding task failures or production line interruptions caused by factors such as abnormal mold conditions, unstable motor conditions, and conflicting task environments. Compared to general scheduling systems that rely solely on static information for planning, this step effectively improves the execution stability and control safety of the multi-motor cooperative control system in real precision casting scenarios by constructing a dynamic executability judgment function and introducing a structure correction mechanism.

[0064] The operational data used in this step is also controlled within the necessary range for a precision casting scenario, including mold status data. Motor operating status The acquisition methods are as follows: mold temperature is obtained through an industrial thermocouple module embedded in the outer wall of the mold cavity; mold alignment deviation is obtained by comparing the stereo vision sensor with the CAD model; motor current and speed are uploaded periodically by the monitoring module of the servo driver through the Modbus protocol, with a processing cycle of 500ms.

[0065] Task feasibility is no longer judged by a single condition, but by a combined index function that integrates process safety, motor operation stability, and path occupancy. This indicates that its value is either 0 or 1. To avoid false positives, the function is designed as a product-gated function, outputting 1 only when all sub-conditions are satisfied simultaneously.

[0066] ;

[0067] in, It is a task Execution object mold at time Temperature; It is a task type The minimum temperature threshold is set according to the process, such as the requirements of the wax injection task. C; It is the deviation (in millimeters) between the current clamping position of the mold and the target. For motor exist If the standard deviation of the velocity fluctuation in the interval is greater than the threshold... (e.g., 0.3 rad / s) is considered an unstable motion state; This indicates whether the task path is occupied, determined by the path time map maintained by the scheduler. It is 1 if there is a conflict, and 0 otherwise.

[0068] When any task Judged At this time, the system initiates the structured correction mechanism of the scheduling matrix. To ensure stable system operation, the correction process follows the "minimum modification principle" to avoid disrupting the system's original scheduling cycle structure. The correction process consists of two phases: Phase 1 is time shift correction, and Phase 2 is backup motor migration.

[0069] Phase 1: On the original motor Up, the original scheduling time Delay minimum safety interval If satisfied Then update the schedule to If it still cannot be executed, proceed to stage two.

[0070] Phase Two: Finding a Backup Motor Its ability value must meet the following requirements. and in the window Memory meets The time point. The scheduling transition expression is:

[0071] ;

[0072] in, This indicates that the task is performed on the motor. The current time window is checked for path conflicts; if a conflict exists, the value is 1, and that time point is excluded. This formula represents a customized dynamic task migration decision mechanism for sophisticated scenarios, distinct from the static task binding of conventional offline scheduling systems.

[0073] In addition, to suppress task chain misalignment caused by the correction, this step also introduces a chained timing regularization term. If a task is modified and its status on the task map is altered... Orderliness in tasks (e.g., tasks) (This is its successor task), the system will automatically correct it backwards. At the initial time, the following conditions are met:

[0074] ;

[0075] in The minimum process buffer time between tasks is typically set to 3-5 seconds by the production line cycle time system; 'k' represents the index, and '*' represents a general task marker, equivalent to a placeholder. This rule ensures that the entire task chain does not become disjointed due to local modifications, adapting to the actual characteristics of precision casting processes where "actions must be continuous, and failure means setbacks."

[0076] The final output after the correction mechanism is the corrected scheduling matrix. ,and The structure is consistent, but all non-executable or conflicting tasks have been postponed or migrated, while satisfying executability, path safety, and task chain order. This matrix provides the most realistic control timing template, closest to the actual production line state, for subsequent control instruction generation.

[0077] Step 4: Generate a multi-PMSM synchronous control command graph based on the corrected scheduling matrix. The command graph is a directed graph with synchronous dependency edges. Synchronous edges are introduced to achieve coordinated starting of each motor through a unified clock triggering mechanism. Specifically, this includes:

[0078] Based on the modified scheduling matrix Generate a multi-PMSM synchronous control command diagram for the control system. The coordinated starting of each motor is achieved through a unified clock triggering mechanism. This step is a critical point in the entire system, representing the transition from "planned scheduling" to "physical execution." Its core task is to transform the structured scheduling results into standard control commands for each motor, and to ensure the synchronicity, smoothness of action, and ability to avoid anomalies under complex process conditions, so as to prevent mold damage, workstation conflicts, or production line interruptions caused by control mis-triggering or scheduling misalignment.

[0079] The input for this step is the corrected scheduling matrix output from step three. Each element Indicates task Dispatch to motor Execution time is In addition, the task map Provides task dependency constraints and parallel relationships for constructing synchronization dependency edges; motor capability matrix. Provides the capability distribution between motors and task types, providing a basis for control parameter generation; task path It originates from the modeling structure of the first task and is used to generate the spatial control trajectory of the motor.

[0080] First, each scheduling unit Mapped to control graph nodes This node contains a triplet of position control command parameters. These represent the target displacement, velocity, and acceleration, respectively, and their values ​​are obtained by parsing the task path. The start and end positions are calculated in conjunction with the physical model of the equipment. Specifically, the task... The path is from position arrive The displacement is:

[0081] ;

[0082] Target speed According to the motor capability coefficient With the rhythm of the mission Joint adjustment, with a value not exceeding The acceleration is obtained from the motor controller parameter table. This is a fixed percentage value and will be dynamically adjusted later. The node's startup time is marked as... That is, the instruction triggering time from the scheduling matrix.

[0083] Considering that multiple tasks need to be executed collaboratively between multiple motors during the precision casting process (such as pouring immediately after the mold is clamped), this step constructs the instruction diagram. It is a directed graph with synchronously dependent edges.

[0084] If tasks exist in the task graph It is a parallel cooperative relationship, and its corresponding scheduling time satisfies Then, a synchronization edge is introduced into the graph. This means that the two nodes must be controlled by a unified system synchronization trigger signal. This mechanism is based on a unified system time base (such as a master clock based on the IEEE 1588 protocol) to ensure that the motor's actions are completed within millisecond-level alignment accuracy.

[0085] To enhance the system's control stability and task flexibility during actual execution, this step further introduces an acceleration inertia buffer correction mechanism in the control parameter generation. This mechanism addresses the impact of motor inertia changes caused by delayed or advanced scheduling on control, achieving smooth start-up by dynamically adjusting the target acceleration. The specific correction formula is as follows:

[0086] ;

[0087] in It is the initial planned target acceleration. It is the original scheduling time of the task. This is the corrected scheduling time. This is the task tick time. This parameter automatically scales the acceleration by normalizing the time offset. The inertia scaling factor (e.g., 0.8–1.0) is used to prevent excessively rapid startup from impacting the mold or tooling fixture. This formula is specifically designed for the scenario described in this invention, making the motor startup process smoother and improving the system's robustness and mechanical reliability when there is significant time drift in the task (e.g., the mold has not been fully heated).

[0088] For example, task It's a mold transfer, planned execution time. After correction, it becomes Mission rhythm Original acceleration , Then we have:

[0089] ;

[0090] The system automatically generates a softened acceleration command value to prevent the motor from suddenly moving at high speed after the task is delayed, which would affect the stability of the mold.

[0091] Final generated control chart It includes all instruction nodes, inter-node synchronization edges, target motion parameters, and inertial buffer items, which are then distributed by the system to the buffers of each PMSM driver. The system starts a cycle wheel (at a fixed frame rate, such as every 20ms) to automatically scan the instruction graph for nodes that match the current system clock, and sends start commands in batches to achieve true full-production-line synchronous scheduling and control.

[0092] Please refer to Figure 2 As shown, in a second aspect of this application, a multi-machine cooperative synchronous control system for permanent magnet synchronous motors used in a precision casting production line is also proposed, comprising:

[0093] The motor capability constraint extraction module is used to construct a casting process task diagram based on multiple operation steps on the precision casting production line. Then, by acquiring the capability parameters of each permanent magnet synchronous motor, its capability value is calculated. The capability parameters include maximum speed, task type weight, and mechanical precision factor. Subsequently, a motor capability matrix is ​​constructed based on the different installation methods, load mechanisms, and control precision of the permanent magnet synchronous motors.

[0094] The task scheduling matrix generation and motor matching module is used to calculate the intersection of the path of each task with other task paths in the casting process task diagram to obtain a conflict matrix. The conflict matrix and the motor capability matrix are input into the constructed constraint optimization model to output the task scheduling matrix. The task scheduling matrix is ​​used to determine the start time of each task on the time axis and which permanent magnet synchronous motor will execute it.

[0095] The task executability dynamic verification module is used to dynamically determine the feasibility of task execution and perform structured correction of the scheduling matrix based on the task scheduling matrix, mold status data, motor operating status and combined index function. When any task has a value of 0 calculated by the combined index function, the scheduling matrix structured correction mechanism is activated and the output is the corrected scheduling matrix. The correction process includes two stages: stage one is time shift correction and stage two is backup motor migration.

[0096] The instruction graph generation and synchronous execution module is used to generate a multi-PMSM synchronous control instruction graph based on the modified scheduling matrix. The instruction graph is a directed graph with synchronous dependency edges. Synchronous edges are introduced to complete the coordinated start-up of each motor through a unified clock triggering mechanism.

[0097] The above embodiments are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for cooperative synchronous control of multiple permanent magnet synchronous motors for a precision casting production line, characterized in that, The method comprises the following steps: According to the multiple operation steps on the precision casting production line, a casting process task graph is constructed, then the capability parameters of each permanent magnet synchronous motor are obtained for calculating the capability value, the capability parameters include maximum speed, task type weight and mechanical precision factor, then a motor capability matrix is constructed according to the installation mode, load mechanism and control precision of different permanent magnet synchronous motor devices; In the casting process task graph, the path of each task is intersected with the paths of other tasks to obtain a conflict matrix, the conflict matrix and the motor capability matrix are input into the constructed constraint optimization model to output a task scheduling matrix, the task scheduling matrix is used to determine the starting time of each task on the time axis and which permanent magnet synchronous motor executes; Based on the task scheduling matrix, mold state data, motor operating state and combined index function, dynamic feasibility judgment of task execution and structured modification of the scheduling matrix are performed, when the combined index function calculation value of any task is 0, the structured modification mechanism of the scheduling matrix is started, and the output is the modified scheduling matrix, the modification process includes phase one and phase two, phase one is time translation modification, and phase two is backup motor migration; Based on the modified scheduling matrix, a multi-PMSM synchronous control instruction graph is generated, the instruction graph is a directed graph with synchronous dependent edges, and a synchronous edge is introduced to complete the cooperative start of the motors through a unified clock trigger mechanism.

2. The method for the permanent magnet synchronous motor multi-machine cooperative synchronization control of the precision casting production line according to claim 1, characterized in that, The casting process task graph construction process comprises extracting all task nodes and establishing a casting process task graph according to the actual order and dependency relationship based on the PLC control logic graph, the action timing graph of the production line and the task instruction table configured in the SCADA system.

3. The method for the permanent magnet synchronous motor multi-machine cooperative synchronization control of the precision casting production line according to claim 2, characterized in that, The task nodes comprise a process beat, a space path label and a process type label. The process beat represents the maximum completion time of the task, the space path label represents the start and end space positions involved in the task, and the process type label represents the operation type of the task.

4. The permanent magnet synchronous motor multi-machine cooperative synchronization control method for a precision casting production line according to claim 1, characterized in that, In the conflict matrix, if the intersection of two task paths is non-empty and the execution time overlaps, the value of the conflict matrix is 1, otherwise it is 0.

5. The method for the permanent magnet synchronous motor multi-machine cooperative synchronization control of the precision casting production line according to claim 4, characterized in that, In the constraint optimization model, only one permanent magnet synchronous motor can execute each task; the starting time of the task must be after the completion of all predecessor tasks; and when the value of the path conflict matrix is 1, the interval between the starting times of the two tasks must be greater than the safety time interval of the production line.

6. The permanent magnet synchronous motor multi-machine cooperative synchronization control method for a precision casting production line according to claim 1, characterized in that, The mold state data comprises mold temperature and mold alignment deviation, and the motor operating state comprises motor current and speed.

7. The permanent magnet synchronous motor multi-machine cooperative synchronization control method for a precision casting production line according to claim 1, characterized in that, The modification step of phase one comprises: for any permanent magnet synchronous motor, if the value of the combined index function is 1 after delaying the minimum safety interval at the original scheduling time, the original scheduling time is updated; if it is still not executable, phase two is entered; The modification step of phase two comprises: finding a backup permanent magnet synchronous motor, requiring that the capability value is greater than the minimum task capability value, and that there is a time point in the original scheduling time interval within the maximum safety interval time window, which satisfies the value of the combined index function, and the original scheduling time is updated.

8. The permanent magnet synchronous motor multi-machine cooperative synchronization control method for a precision casting production line according to claim 1, characterized in that, In the instruction graph generation process, first, each scheduling unit is mapped to a control graph node, and the control graph node contains a position control instruction parameter triple, which is target displacement, speed and acceleration, respectively.

9. The method for the permanent magnet synchronous motor multi-machine cooperative synchronization control of precision casting production line according to claim 1, characterized in that, In the starting process of the permanent magnet synchronous motor, an acceleration inertia buffer correction mechanism is also introduced, which is used to control the change of motor action inertia caused by the delay or advance, and to realize smooth starting by dynamically adjusting the target acceleration.

10. A permanent magnet synchronous motor multi-machine cooperative synchronous control system for a precision casting production line, characterized in that, It comprises sequentially connected: A motor capacity constraint extraction module is used to construct a casting process task graph according to a plurality of operation steps on a precision casting production line, and then to calculate the capacity value of each permanent magnet synchronous motor by obtaining the capacity parameters of the motor, including the maximum speed, task type weight and mechanical precision factor, and then to construct a motor capacity matrix according to the different installation modes, load mechanisms and control accuracies of different permanent magnet synchronous motors. A task scheduling matrix generation and motor matching module is used to calculate the intersection of each task path and other task paths in the casting process task graph to obtain a conflict matrix, input the conflict matrix and the motor capacity matrix into the constructed constraint optimization model, and output a task scheduling matrix, which is used to determine the starting time of each task on the time axis and which permanent magnet synchronous motor to execute. A task executable dynamic verification module is used to dynamically determine the feasibility of task execution and modify the structure of the scheduling matrix based on the task scheduling matrix, mold state data, motor operating state and combined index function. When the value of any task calculated by the combined index function is 0, the scheduling matrix structure modification mechanism is started, and the output is the modified scheduling matrix. The modification process includes stage one and stage two. Stage one is time translation correction, and stage two is backup motor migration. An instruction graph generation and synchronous execution module is used to generate a multi-PMSM synchronous control instruction graph based on the modified scheduling matrix, wherein the instruction graph is a directed graph with synchronous dependency edges. The synchronous edge is introduced to complete the coordinated starting of each motor through a unified clock trigger mechanism.

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