Dynamic scheduling method based on FMS flexible production line

Abstract

The invention discloses a dynamic scheduling method based on an FMS flexible production line. The method comprises the steps that firstly, a process route and a product production plan are set according to FMS flexible line basic configuration; when the transfer mechanism is idle, judging the state of processing equipment, transferring after processing is completed, otherwise, inquiring the state of a loading station; when the loading station finishes loading, carrying out transfer judgment, otherwise, loading the materials; and the transfer judgment comprises the following steps: inquiring whether the processing equipment of the current material in the next process is idle or not, conveying the material to the processing equipment if the corresponding processing equipment is idle, and otherwise, conveying the material back to the stock bin. When the processing equipment is idle, whether the needed materials are loaded or not is analyzed, if the needed materials are loaded, the needed materials are conveyed to the processing equipment through the transfer equipment, and if the materials are not loaded or the processing equipment is in a non-idle state, the loading station is started to be idle; and when the loading station is idle, materials are added into the tray, otherwise, returning is performed to wait for the transfer mechanism to be idle. The machining efficiency of the machine tool and the operation efficiency of the flexible line are improved, and the method can adapt to complex and changeable production scenes.

Description

Technical Field

[0001] The present invention relates to the field of dynamic scheduling algorithms in the field of metal cutting intelligent manufacturing, and in particular to an automatic scheduling and control algorithm suitable for solving multi-variety small batch unmanned production scenarios (hereinafter referred to as FMS flexible lines). Background Art

[0002] With the development of industrial automation and intelligence, automated production lines have been widely used in various fields. Among them, the Flexible Manufacturing System (FMS) is an intelligent production line that can realize automated mixed production of multiple varieties and small batches in the field of metal cutting in factories. It mainly includes machine tools, transfer mechanisms, loading stations, pallets, pallet warehouses, FMS flexible production control systems, motion control technology (PLC), etc. Nowadays, with the increasing demand for customized and personalized products, the application scope of FMS flexible lines continues to expand, and its types and application scenarios are becoming increasingly diversified. With the complexity of production and manufacturing scenarios, FMS flexible lines need to adapt to and be compatible with a variety of production scenarios, and the requirements for dynamic scheduling algorithms are becoming higher and higher. The dynamic scheduling algorithm revolves around the core idea of ​​machine tool operation efficiency as the highest priority to be compatible with the dynamic scheduling of various production scenarios, so as to achieve the calculation and execution of the best production route.

[0003] The technical route for flexible line applications is a combination of multiple technical routes, mainly including: Internet of Things technology (IOT) and PLC. At present, flexible production scenarios mainly revolve around shutdown without stopping the line (failure of one or several devices in the production line will not affect the normal execution of other production operations on the entire line). At the same time, it is necessary to adapt to the changing and complex process routes and realize the loading and unloading of machine tools by means of transfer pallets. Because of the different process routes, the dynamic scheduling algorithm is required to be able to handle the changing process routes flexibly, accurately and efficiently. To achieve dynamic scheduling, the premise is to communicate with all production resources of the production line in real time, that is, the dynamic scheduling algorithm must receive the operation status of the production resources in real time, and then combine the process route, processing equipment, processing procedures and other production factors to generate an optimal solution for the next production action, and pass it to the transfer equipment for execution. Summary of the invention

[0004] In order to achieve the above technical effects, the present invention proposes a dynamic scheduling method based on FMS flexible production line. The method provides a management algorithm that integrates the Internet of Things, transfer mechanism motion control and dynamic calculation of the best production route. It senses the operating status of the machine tool and the processing status of the workpiece through real-time dynamic monitoring, combined with flexible product process routes and process parameters and the preparation of existing production resources. It dynamically analyzes the next transfer task of the transfer equipment and schedules the transfer equipment to realize the transfer of pallets and materials. In addition, it is necessary to identify various abnormal situations that occur during the production process to automatically eliminate the abnormalities without affecting the normal execution of subsequent production tasks. It improves the processing efficiency of machine tools and the operating efficiency of flexible lines, and can adapt to complex and changeable production scenarios.

[0005] The technical solution adopted by the present invention is as follows: A dynamic scheduling method based on an FMS flexible production line, the dynamic scheduling method comprises the following steps: S1. Set the process route and product production plan according to the basic configuration of the FMS flexible line; the basic configuration is used as a variable in the dynamic scheduling method. Whenever the variable changes, it will be updated to the dynamic scheduling method in real time, and the next action will be determined according to the current progress of the set process route; S2. When the transfer mechanism is idle, determine whether the processing equipment has completed processing. If the processing is completed, enter the transfer judgment logic, otherwise query the loading station status; S3. If there are already loaded materials in the queried loading station, the transfer judgment logic is entered. If there are no loaded materials, the processing equipment idle logic is started; S4, the idle logic of the processing equipment in step S3 is as follows: when the processing equipment is idle, analyze whether the material required by the current processing equipment has been loaded. If it has been loaded, it is transported to the processing equipment through the transfer equipment. If the material is not loaded or the processing equipment is not idle, the loading station idle logic is started; S5. The idle logic of the loading station in step S4 is as follows: when the loading station is idle, add materials to the pallet. If there is no idle loading station, return to step S2 and wait for the transfer mechanism to be idle; The transfer judgment logic described in step S2 and step S3 is as follows: determine whether the processing equipment of the next process of the processed material is idle. If there is corresponding idle processing equipment, transport the material to the processing equipment; otherwise, send the material back to the silo to wait for subsequent processing.

[0006] In the dynamic scheduling method as described above, the basic configuration in step S1 includes: materials, pallets, pallet warehouses, fixtures, line-side warehouses, processing equipment, loading stations, and transfer mechanisms; preferably, the processing equipment is a double turntable structure.

[0007] In the dynamic scheduling method as described above, steps S2 to S5 monitor the real-time status and production signals of each production resource of the flexible line through the Internet of Things (IOT) technology, and feed back to the dynamic scheduling method. The dynamic scheduling method dynamically mobilizes production resources through motion control technology (PLC).

[0008] The dynamic scheduling method as described above predicts the processing status of the processing equipment according to the processing rhythm of the processing equipment, and schedules the materials needed by the processing equipment in advance.

[0009] In the above-mentioned dynamic scheduling method, the process route in step S1 includes: processes and process parameters. To flexibly configure various production resources in the flexible line, the most important thing is to set the process route, specifically, including: configuring each process included in each product, setting the relevant parameters such as pallets, fixtures, production equipment, processing procedures and processing equipment required for each process.

[0010] In the dynamic scheduling method as described above, the production plan in step S1 includes: the quantity and model of products to be produced.

[0011] The dynamic scheduling method as described above includes a fault handling module.

[0012] An FMS flexible production line is also provided, which uses any of the above-mentioned dynamic scheduling methods.

[0013] The present invention has the following beneficial effects: 1. The dynamic scheduling algorithm of the present invention is different from the queue scheduling algorithm. The complexity, variability and uncertainty of the real production environment will cause the queue scheduling method to be unable to flexibly adapt to these changes, which will cause the entire FMS flexible system to be slow. However, the dynamic scheduling algorithm can generate real executable production tasks in real time according to the change signals of the real production environment, so that the entire flexible line runs more smoothly and the beat is more efficient. 2. The present invention can realize dynamic scheduling and motion control of the FMS flexible line, improve the compatible product types and production efficiency of the automated production line, and reduce waiting waste and quality defects caused by product changeover. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the main flow chart of the core algorithm logic of the present invention; Figure 2 This is a schematic diagram of notification subscription for the transfer equipment of the present invention; Figure 3 This is a schematic diagram of machine tool notification subscription of the present invention; Figure 4 This is a schematic diagram of tray notification subscription of the present invention; Figure 5This is a schematic diagram of the pallet library notification subscription of the present invention; Figure 6 This is a schematic diagram of the notification subscription of the loading station of the present invention. DETAILED DESCRIPTION

[0015] The present invention is further described below in conjunction with the accompanying drawings and specific implementation methods.

[0016] The present invention completes dynamic scheduling through the setting of process routes, monitoring of production materials and dynamic mobilization. To achieve flexible configuration of various production resources in the flexible line, the most important thing is the setting of process routes. For example: Now processing a shell requires a total of 4 operations (OP), corresponding to 4 horizontal machines. To set this process route, you need to configure OP10 corresponding to horizontal machine 1, OP20 corresponding to horizontal machine 2, OP30 corresponding to horizontal machine 3, and OP40 corresponding to horizontal machine 4. At the same time, you also need to configure the pallet and processing program required for each process. For example, for each process included in a product, set the pallet, fixture, production equipment, processing program, tool and other related parameters required for each process.

[0017] The present invention dynamically senses the operating status of production equipment and the processing status of workpieces in real time, combines flexible product process routes, process parameters and existing production resource preparation status, dynamically analyzes the next transfer task of the transfer mechanism, and dispatches the transfer mechanism to realize the transfer of pallets.

[0018] Among them, when the next production action is calculated based on the process route, if the current action is not completed, a transfer task will be generated to release the action. For example, the pallet can be put back into the pallet warehouse, and the current unfinished task can be automatically canceled. The system automatically analyzes the running status of the process route and automatically identifies whether the next process requires a pallet replacement. If no pallet replacement is required, a transfer task to other machine tools to execute the next process is directly generated, provided that the other machine tools are in an idle state.

[0019] The core priority of the dynamic scheduling algorithm in the present invention is set according to the best production efficiency of the machine tool, such as Figure 1 The main flow diagram of the dynamic scheduling algorithm logic is shown in the figure. The dynamic scheduling algorithm is used to control the loading station robot to complete the loading and unloading of the machine tool. The starting node is the robot idle. The robot's behavior is carried out in the order of machine tool processing completion, loading station loading completion, machine tool idle, and loading station idle. The following is a detailed description of each process.

[0020] Machine tool processing completion process: When a machine tool is completed, the dynamic scheduling algorithm will immediately generate a transfer task for the machine tool to unload the material, and use the robot to take out the workpiece processed in the machine tool. At this time, if the loading station is not loading, the dynamic scheduling algorithm will start the machine tool idle logic, find the pallet with materials required by the idle machine tool according to the idle machine tool, and generate the transfer task of the pallet to the idle machine tool, so as to ensure that the waiting time of the machine tool is minimized.

[0021] Loading station loading completion process: After the material at the loading station is clamped to the pallet, the dynamic scheduling algorithm automatically determines whether the machine tool that can process this material is idle. If the machine tool is idle, the dynamic scheduling algorithm will directly generate a task to transfer the pallet to the idle machine tool for processing; if there is no idle machine tool that can process this material, but other machine tools are idle, the dynamic scheduling algorithm will automatically analyze whether to deliver materials to the idle machine tool first or release the loading station first. This logic will predict and analyze the optimal solution based on factors such as processing tact, loading tact, and transfer tact, and then generate a delivery task. For example: when the processing tact is less than the loading tact, a task to deliver pallets to the loading station first is generated.

[0022] Machine tool idle process: When there is an idle machine tool, the dynamic scheduling algorithm will search all production resources and identify the materials available for the idle machine tool for distribution.

[0023] Loading station idle process: When a loading station is idle, the dynamic scheduling algorithm will generate corresponding tasks to prepare for production, such as finished product off-line transfer, rough blank on-line transfer, etc.

[0024] In order to solve the communication efficiency between the dynamic scheduling algorithm and production resources and the continuity of the entire flexible line, there are many notification subscriptions in the dynamic scheduling algorithm to monitor and process various production signals. The actions of monitoring and issuing tasks are completed through the collaboration of the dynamic scheduling algorithm, IOT and PLC, which are explained in detail below.

[0025] like Figure 2 As shown in the schematic diagram of transfer equipment notification subscription, the present invention uses the robot as a transfer equipment monitoring object, and the robot here can also be replaced by other transfer equipment, such as stackers, RGVs, trusses, etc. Transfer equipment notification subscription includes monitoring changes in the robot's own attributes. Once the robot's attributes (represented by diamond boxes) change, the dynamic scheduling algorithm will monitor this change and use the latest data for processing; when the robot completes a specific task action, the dynamic scheduling algorithm will also monitor it in time, and at the same time, it can quickly release resources or generate the next action task.

[0026] like Figure 3As shown in the machine tool notification subscription diagram, the present invention treats each machine tool as a monitoring object, including monitoring the changes of the machine tool's own attributes, such as the machine tool's shielding check. Once the dynamic scheduling algorithm monitors these attribute changes, it will use these attributes for logical operations in a timely manner. When the machine tool completes the production action, the dynamic scheduling algorithm will also monitor these signals and calculate the next production task based on the latest monitored signal.

[0027] like Figure 4 As shown in the schematic diagram of pallet notification subscription, the present invention regards each pallet as a monitoring object, and dynamically monitors the attribute changes of the pallet with respect to the pallet library, such as freezing and enabling of the pallet, binding relationship between the pallet material and the binding relationship between the pallet and the pallet library where the pallet is located, etc.

[0028] like Figure 5 The diagram of the pallet library notification subscription shown in the figure synchronizes the data changes of the pallet and the pallet library in real time to provide the latest task operation parameters for the dynamic scheduling algorithm. The dynamic scheduling algorithm dynamically adjusts the calculation of the next task according to the changes in the parameters.

[0029] like Figure 6 As shown in the loading station notification subscription diagram, the present invention regards the loading station as a monitoring object, dynamically monitors the loading and unloading completion information of the loading station, and relies on the real-time action of the loading station to calculate the next material pallet transfer path through a dynamic scheduling algorithm, and provides calculation parameters for advance material preparation and finished product offline.

[0030] The above is only the preferred solution of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

[0031] Although the above describes the specific implementation methods of the present invention, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A dynamic scheduling method based on FMS flexible production line, characterized in that: The following steps are involved: S1. Set the process route and product production plan according to the basic configuration of the FMS flexible line; S2. When the transfer mechanism is idle, determine whether the processing equipment has completed processing. If the processing is completed, enter the transfer judgment logic, otherwise query the loading station status; S3. If there are already loaded materials in the queried loading station, the transfer judgment logic is entered. If there are no loaded materials, the processing equipment idle logic is started; S4, the idle logic of the processing equipment in step S3 is as follows: when the processing equipment is idle, analyze whether the material required by the current processing equipment has been loaded. If it has been loaded, it is transported to the processing equipment through the transfer equipment. If the material is not loaded or the processing equipment is not idle, the loading station idle logic is started; S5. The idle logic of the loading station in step S4 is as follows: when the loading station is idle, add materials to the pallet. If there is no idle loading station, return to step S2 and wait for the transfer mechanism to be idle; The transfer judgment logic described in step S2 and step S3 is as follows: determine whether the processing equipment of the next process of the processed material is idle. If there is corresponding idle processing equipment, transport the material to the processing equipment; otherwise, send the material back to the silo to wait for subsequent processing.

2. The dynamic scheduling method according to claim 1, wherein: The basic configuration in step S1 includes: materials, pallets, pallet warehouses, fixtures, line warehouses, processing equipment, loading stations, and transfer mechanisms.

3. The dynamic scheduling method according to claim 1, wherein: The steps S2 to S5 monitor the real-time status and production signals of each production resource of the flexible line through the Internet of Things (IOT) technology, and feed back to the dynamic scheduling method. The dynamic scheduling method dynamically mobilizes production resources through motion control technology (PLC).

4. The dynamic scheduling method according to claim 1, wherein: The basic configuration in step S1 is used as a variable in the dynamic scheduling method. Whenever the variable changes, it will be updated in real time to the dynamic scheduling method, and the next action will be determined according to the current progress of the set process route.

5. The dynamic scheduling method according to claim 1, wherein: The dynamic scheduling method predicts the processing status of the processing equipment according to the processing rhythm of the processing equipment, and schedules the materials needed by the processing equipment in advance.

6. The dynamic scheduling method according to claim 1, wherein: The dynamic scheduling method includes a fault handling module.

7. An FMS flexible production line, characterized in that: The dynamic scheduling method described in any one of claims 1 to 6 is used.

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