Distributed control system and method for flexible manufacturing unit

Abstract

The invention relates to the technical field of flexible manufacturing, and discloses a flexible manufacturing unit distributed control system and method, and the system comprises a data layer which comprises a data server and a database; the control layer comprises an upper computer control system and a lower computer control system based on distributed control; the upper computer control system is configured to execute logic operation, process data management service and three-dimensional visual monitoring, read database data, drive main logic to operate, and write back the operation state and the operation result of the main logic; the lower computer control system is configured to read database data, drive execution layer action logic operation, write back action logic operation states and operation results, read real-time states of the sensors and upload the real-time states to a database. According to the invention, the data storage capacity, the storage efficiency and the data calculation and management capability of the flexible manufacturing unit control system can be improved, and the anti-interference capability and the control real-time performance requirement when the system is applied in an industrial field environment are ensured.

Description

Technical Field

[0001] The present invention relates to the field of flexible manufacturing technology, and in particular to a distributed control system and method for a flexible manufacturing unit. Background Art

[0002] Flexible manufacturing cell is an advanced manufacturing system that integrates computer technology, automation technology, information technology and other technologies. It consists of multiple automated equipment, robots, conveying systems, detection systems, storage systems, etc. It realizes the coordinated work of equipment through computer control systems to complete various manufacturing tasks. Flexible manufacturing cells have the characteristics of high automation, flexible production, scalability, reconfigurability and high information integration. They can meet the strict requirements of modern manufacturing industry for production efficiency, product quality and production cost, and are widely used in machinery manufacturing, electronic manufacturing, automobile manufacturing, aerospace and other fields.

[0003] The control system is one of the key components of the flexible manufacturing unit and the nerve center of the entire flexible manufacturing unit. It can achieve seamless connection between logistics, manufacturing and information flow. The control system automatically adjusts the processing data and processing sequence of each device according to the product process and production plan, and produces qualified products according to the production plan and quality requirements. At present, the control systems of flexible manufacturing units at home and abroad mainly include two categories: control systems based on programmable controllers and control systems based on computers.

[0004] Programmable Logic Controller (PLC) is a digital computing and operating electronic system designed specifically for use in industrial environments. It uses programmable memory to store operating instructions such as logical operations, sequential control, timing, counting and arithmetic operations, and controls various machines and production processes through digital and analog input and output interfaces. PLC control systems have great advantages in industrial field environment applications, and have high reliability and strong anti-interference capabilities in harsh industrial production sites; they have rich digital and analog input and output interfaces and motion control functions, and can directly control relays, sensors, solenoid valves, inverters, servo drives and other electronic devices in the production site, with high real-time performance; PLCs are fast to design and install, easy to maintain, and have been widely used in small and medium-sized automation control systems. While having great advantages in field applications, control systems based on PLCs have the following problems: the hardware systems of various PLC manufacturers are incompatible, the software and programming languages, and instruction systems are different, and after replacing different brands of PLCs, the control system hardware must be changed and the software system must be redeveloped; the PLC memory is small and cannot store large amounts of data; the PLC cannot perform large and complex calculations and data management tasks.

[0005] With the development of computer hardware and software technology, computer-based flexible manufacturing unit control systems have been increasingly widely used. Computer-based flexible manufacturing unit control systems can use general relational databases to store massive amounts of manufacturing process control data and process data, can perform complex control system logic operations and data management, and are developed based on general computer platforms such as Windows. The development language is a general high-level language, and the software functions are basically not limited by hardware. However, if the computer-based flexible manufacturing unit control system is directly deployed in an industrial field environment, it is prone to various system failures due to its weak anti-interference ability. At the same time, compared with the rich digital and analog interfaces of programmable controllers, conventional computer interfaces are not suitable for the input and output requirements of industrial field equipment, and cannot directly control field electrical equipment. They must rely on intermediate input and output interfaces to control in a communication manner. Due to communication delays, there are major problems in application environments with high real-time requirements. Summary of the invention

[0006] In order to solve the above problems, the present invention proposes a distributed control system and method for a flexible manufacturing unit, which improves the data storage capacity, storage efficiency, and data calculation and management capabilities of the flexible manufacturing unit control system through collaborative control of a computer-based upper computer control system and a programmable controller (PLC)-based lower computer system, while ensuring the anti-interference ability and real-time control requirements when used in an industrial field environment.

[0007] The technical solution adopted by the present invention is as follows: In one aspect, the present invention provides a flexible manufacturing unit distributed control system, comprising: The data layer includes a data server and a database thereof, wherein the database stores physical production line status data, main logic task execution data, and production task data; The control layer includes an upper computer control system and a lower computer control system based on distributed control; the upper computer control system is configured to perform logical operations, process data management services and three-dimensional visual monitoring, read database data, drive the main logic to run, and write back the main logic running status and running results; the lower computer control system is configured to read database data, drive the execution layer action logic to run, write back the action logic running status and running results, read the real-time status of each sensor and upload it to the database.

[0008] Furthermore, the host computer control system of the control layer includes: a control subsystem configured to manage and operate the flexible production unit; A remote three-dimensional monitoring subsystem configured to remotely monitor the task execution status and unit operation status of the flexible manufacturing unit; The machining data service subsystem is configured to manage CNC machining programs, coordinate data and tool data, communicate with the CNC machine tools through a communication program developed based on the CNC system application programming interface, and upload, download and verify CNC machining programs, coordinate data and tool data.

[0009] Furthermore, the control subsystem includes: The main control module is configured to control the switching between manual and automatic operation modes, automatic operation, single-step operation, system main process reset, and reset and initialization of CNC machine tools, logistics robots, inspection workstations, loading workstations, cleaning workstations, and silos; in the automatic operation mode, the main control module reads the unit status data in the database in real time, drives the main logic operation to generate task data and writes it into the database, and then reads the database task data through the lower computer control system, drives the execution layer to execute tasks, and realizes the automated operation of the flexible manufacturing unit; The processing task management module is configured to receive the production tasks issued by the manufacturing execution system, decompose the production tasks according to the process data, and generate a processing task list of the flexible manufacturing unit; The pallet management module is configured to perform pallet monitoring, pallet binding, scheduled outbound storage, scheduled inbound storage, and modify pallet data; A machine tool management module configured to perform machine tool parameter setting, machine tool data management and machine tool status monitoring; An alarm management module is configured to perform alarm information confirmation and historical alarm information query; The system management module is configured to perform user and system authority management, basic system settings and system initialization.

[0010] Furthermore, the remote three-dimensional monitoring subsystem is built based on digital twin technology, integrating real-time data including the physical model of the flexible manufacturing unit, the status of moving parts, and the status of sensors, and completely mapping the real-time movement of the CNC machine tools and logistics robots of the flexible manufacturing unit and the real-time status of the cleaning workstation, inspection workstation, loading station, pallet, and silo in three dimensions on the remote terminal; the remote terminal can display the three-dimensional model and movement status of the flexible manufacturing unit, and display task monitoring information and efficiency monitoring information.

[0011] Furthermore, the remote three-dimensional monitoring subsystem includes: A monitoring setting module, configured to set basic parameters of the remote three-dimensional monitoring subsystem, including connection parameters, simulation parameters and sampling time; The task monitoring module is configured to display the task execution status, including the planned quantity, bound quantity and processed quantity of each production task in the current system; real-time statistics of the summary of completed and uncompleted tasks and display them on the monitoring screen in the form of statistical charts; The efficiency monitoring module is configured to collect the startup time, automatic operation time and spindle operation time of the CNC machine tool, calculate the utilization efficiency of the CNC machine tool and display it on the monitoring screen in the form of statistical charts; The status monitoring module is configured to display the physical model of the flexible manufacturing unit and rotate, enlarge and reduce it according to monitoring needs; use the real-time position data of each motion axis of the CNC machine tool and logistics robot in the database to drive the virtual machine tool and logistics robot model to realize motion simulation; read the status information of each sensor of the detection workstation, silo, loading workstation, robot fixture and machine tool fixture stored in the database, and display the status of the flexible manufacturing unit in real time; through the three-dimensional physical model, motion simulation and sensor status display, the operation process of the flexible manufacturing unit is completely mapped to realize remote monitoring.

[0012] Furthermore, the processing data service subsystem includes: The data management module is configured to manage processing data, CNC processing programs and tool data; the processing data includes the CNC processing steps and routes required for each part, the CNC processing programs used for each step, and tool information; the management of the CNC processing programs includes CNC processing program version management, program browsing, and program addition and deletion; the tool data includes the tool diameter, length, maximum processing depth and service life data installed on each machine tool of the flexible manufacturing unit; when the pallet is bound to the part, the data management module automatically checks whether the tool used in the part processing program matches the tool actually installed on the bound machine tool, and displays the matching result; The data transmission module is configured to execute the initialization, uploading and downloading of the CNC machining program and coordinate data; when the system is initialized, the data transmission module initializes the CNC machining program and coordinate data stored in the CNC machine tool; when a CNC machine tool machining data upload task occurs, the data transmission module uploads the corresponding CNC machining program and pallet coordinates according to the parts and machining task information bound to the current machine tool loading pallet; The data verification module is configured to download the CNC machining program and coordinate data on the machine tool after the machining data is uploaded, and compare and verify them with the data bound to the pallet to ensure that the uploaded data is complete and correct.

[0013] Furthermore, the lower computer control system of the control layer directly controls the main control system, CNC machine tools, cleaning workstations, loading workstations and silos of the execution layer through the digital input and output interface, and reads sensor data; directly controls the robot controller and the detection workstation through the communication interface, reads the robot status data and the detection workstation status and detection result data; uses the programmable controller to directly control the execution layer equipment and read the equipment status, and promptly feeds back the execution layer equipment status to the control layer.

[0014] Furthermore, the lower computer control system includes: A power-on initialization program module is configured to check the initial status of each device in the execution layer and perform initialization settings according to the status data of each execution device stored in the database; The main control program module is configured to map the start, stop, pause, single-step execution and reset physical buttons of the execution layer main control system to the lower computer data block, upload the data to the data layer, read the data status through the upper computer control system and perform the main logic operation; The input and output program module is configured to map the input and output interfaces of the programmable controller to the data block according to the business logic requirements; the programmable controller reads the execution layer device status into the lower computer data block through the input interface, and uploads it to the data layer for the upper computer control system to read; the output data is sent from the data layer to the lower computer data block, and according to the logical operation results of the action control program, the output interface of the programmable controller outputs the corresponding execution signal to drive the execution layer device action; The motion control program module is configured to execute the motion control logic of all execution layer devices, including the motion control logic of loading and unloading of logistics robots, the motion control logic of detection workstations to perform detection tasks, the motion control logic of cleaning workstations to perform cleaning tasks, and the motion control logic of machine tools to perform processing tasks; The automatic control program module is configured to control the automatic operation of logistics robots, CNC machine tools, testing workstations and cleaning workstations; when the upper computer control system runs the main control logic according to the current state data and generates corresponding task instruction data and uploads it to the data layer, the data layer sends the task data to the lower computer control system, and the machine control system reads the task data, drives the automatic control program to run, calls the action control program, and automatically executes the action task; The alarm control program module is configured to collect various alarm information generated during the program execution process, change the system alarm status, upload the alarm information to the data layer, and after the host control system reads the alarm data in the data layer, it executes the corresponding alarm processing program.

[0015] Furthermore, in the data layer, the physical production line status data stored in the database includes status data of CNC machine tools, logistics robots, loading workstations, inspection workstations, cleaning workstations, pallets and silos; the main logic task data stored in the database includes task commands, task execution process status and task execution result data of the main logic tasks; the production task data stored in the database is integrated with the external manufacturing execution system, receives and stores the production task data issued by the manufacturing execution system, and stores production task scheduling data, production task execution process status data and production task execution result data.

[0016] On the other hand, the present invention provides a distributed control method for a flexible manufacturing unit, comprising: System initialization: The host computer control system initializes the object instance corresponding to the execution layer; Processing task decomposition and production scheduling optimization: The host computer control system downloads the production tasks of the manufacturing execution system, calls the process data, decomposes the production tasks, generates a processing task list, and automatically schedules the processing tasks; Pallet outbound: According to the requirements of parts clamping, make an appointment to select the corresponding fixture pallet outbound, and the logistics robot will place the designated pallet on the loading station; Loading the workpiece to be processed: Install the workpiece to be processed on the pallet fixture according to the process requirements; Bind processing tasks: bind the current pallet with the task to be processed, and determine the processing machine tool, processing sequence and program number data of the current pallet; Pallet in-line: The logistics robot takes the pallet from the loading workstation; if coordinate detection is required, the logistics robot places the pallet on the detection workstation, otherwise the pallet is placed in the silo or on the machine tool; Coordinate detection: After the pallet to be detected is placed on the detection workstation, the upper computer control system issues a detection task, and the data server sends the detection task instruction data to the lower computer control system to execute the detection task. After the detection is completed, the detection task status and coordinate detection result data are fed back to the data server; Pallet temporary storage: Pallets that have completed coordinate detection are temporarily stored in the silo by the logistics robot, waiting for processing; Machine tool loading: When there is no material in the machine tool fixture, the host computer control system issues a machine tool loading task, and the logistics robot loads the pallet from the material bin to the machine tool fixture. The machine tool fixture sensor detects the material status and clamping status and uploads them to the database through the host computer control system; Processing data upload: After loading is completed on the machine tool, the data server uploads the CNC processing program and pallet coordinates bound to the pallet to the CNC machine tool system according to the instructions of the host computer control system; Processing data verification: The data server downloads the current CNC processing program and coordinate data of the machine tool and compares and verifies them with the data in the data server; Machine tool processing: According to the instructions of the upper computer control system, the lower computer control system starts the machine tool and starts processing; the CNC machine tool calls the pallet coordinates and executes the CNC processing program. After the processing is completed, the completion status is uploaded to the database through the lower computer control system; Machine tool unloading: After processing, the logistics robot moves the pallet to the cleaning workstation, and the machine tool fixture sensor detects the material status and clamping status and uploads them to the database through the host computer control system; Data initialization: After the machine tool unloading is completed, the data server starts the machine tool data initialization task, deletes the processing program, and changes the machine tool processing coordinates to safe coordinates; Pallet cleaning: After the cleaning workstation completes the pallet cleaning according to the set process, the logistics robot moves the pallet to the inspection workstation; Parts inspection: The inspection workstation completes parts inspection according to the inspection procedure bound to the pallet, and the parts inspection data and inspection results are uploaded to the database; Pallet temporary storage: The inspected parts and pallets are moved by logistics robots to the silo for temporary storage; Pallet unloading: After the pallet is scheduled to leave the warehouse, the logistics robot will move the pallet to the loading station for unloading; Task unbinding: When unloading is completed, the current pallet is unbound from the bound processing task and the task status is updated.

[0017] The beneficial effects of the present invention are: The data layer of the present invention can store a large amount of manufacturing process control data and process data by using a general relational database. At the same time, the host computer control system is decoupled from the slave computer control system through the database, and the host computer control system and the slave computer control system can be developed and debugged in parallel, thereby improving the development efficiency of the flexible manufacturing unit. When the execution layer hardware is changed, only the slave computer action control logic needs to be changed, and the host computer control system does not need to be changed, thereby reducing the system maintenance cost.

[0018] The control layer of the present invention reasonably divides the control logic level of the flexible manufacturing unit control system, adopts distributed control technology, and uses computers and programmable controllers to realize different system control functions, thereby improving the comprehensive control capabilities of the flexible manufacturing unit control system in data management, data processing and real-time control. The upper computer control system is deployed in the computer room, adopts a computer control system, and is developed based on the Windows platform. It uses its powerful data storage capacity, computing power and three-dimensional visualization interface to perform complex system control logic operations, processing data management services and three-dimensional visualization monitoring and other large computing tasks. The lower computer system is deployed in the industrial field environment, adopts a programmable controller control system, and uses its high reliability and rich input and output interfaces to directly control the field action execution logic and input and output devices, read the real-time status of the sensor, and ensure the real-time performance, high reliability and strong anti-interference ability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the overall architecture of the flexible manufacturing unit in Example 1 of the present invention.

[0020] Figure 2 This is a schematic diagram of the control layer of the flexible manufacturing unit in Example 1 of the present invention.

[0021] Figure 3 This is a flow chart of the distributed control method of the flexible manufacturing unit in Example 2 of the present invention. DETAILED DESCRIPTION

[0022] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific implementation methods of the present invention are now described. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention, that is, the embodiments described are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present invention.

[0023] Example 1 like Figure 1 The flexible manufacturing unit overall architecture schematic diagram is shown, and the flexible manufacturing unit includes a data layer, a control layer and an execution layer. This embodiment provides a flexible manufacturing unit distributed control system, including a data layer and a control layer, through which the control layer can drive the execution layer to complete various manufacturing processes.

[0024] In this embodiment, the data layer of the distributed control system of the flexible manufacturing unit includes a data server and its database, and the database stores physical production line status data, main logic task execution data and production task data; the control layer includes an upper computer control system and a lower computer control system based on distributed control; the upper computer control system is configured to perform logical operations, processing data management services and three-dimensional visual monitoring, read database data, drive the main logic operation, and write back the main logic operation status and operation results; the lower computer control system is configured to read database data, drive the execution layer action logic operation, write back the action logic operation status and operation results, read the real-time status of each sensor and upload it to the database.

[0025] Preferably, the data layer of the flexible manufacturing unit distributed control system includes a data server and a database installed thereon, which is the data core of the entire flexible manufacturing unit control system. The database mainly stores three types of data, namely, physical production line status data, main logic task execution data, and production task data. Among them, the physical production line status data is used to store the status of CNC machine tools, logistics robots, loading workstations, inspection workstations, cleaning workstations, pallets, and silos. The main logic task data stores the task commands, task execution process status, and task execution result data of the main logic task. The production task data is integrated with the external MES system (manufacturing execution system), receives and stores the production task data issued by the MES system, and stores the production task scheduling data, the production task execution process status data, and the production task execution result data. See Table 1 for details.

[0026] Table 1 - Database data types of flexible manufacturing unit distributed control system

[0027] In this embodiment, the control layer of the flexible manufacturing unit control system adopts distributed control technology, which is composed of an upper computer control system deployed in a computer room and a lower computer control system deployed at the production site. Figure 2 shown.

[0028] Among them, the upper control system based on the computer performs logical operations, processing data management services and three-dimensional visual monitoring, reads database data, drives the main logic of the control system to run, and writes back the main logic running status and running results. The lower control system based on the programmable controller PLC reads database data, drives the execution layer action logic to run, writes back the action logic running status and running results, reads the real-time status of each sensor and uploads it to the database.

[0029] Preferably, the computer-based host control system includes a control subsystem, a remote three-dimensional monitoring subsystem and a processing data service subsystem.

[0030] In this embodiment, the control subsystem of the host computer control system is used for the management and operation of the flexible production unit. More preferably, the control subsystem includes a main control module, a processing task management module, a pallet management module, a machine tool management module, an alarm management module and a system management module, as described below.

[0031] The main control module is used to control manual / automatic mode switching, automatic operation, single-step operation, system main process reset, and reset and initialize CNC machine tools, logistics robots, inspection workstations, loading workstations, cleaning workstations, and silos. In the automatic operation mode, the main control module reads the unit status data in the database in real time, drives the main logic operation to generate task data such as CNC machine tool processing, logistics robot loading and unloading, inspection, pallet loading, and cleaning, and writes it into the database. The lower computer system reads the database task data and drives the execution layer to execute tasks, realizing the automated operation of the flexible manufacturing unit.

[0032] The processing task management module is used to receive production tasks issued by the manufacturing execution system, decompose the production tasks according to the process data, generate a flexible manufacturing unit processing task list, and perform automatic or manual production scheduling. The processing task management module can add and delete production tasks, and can optimize and adjust the scheduled processing tasks.

[0033] The pallet management module includes functions such as pallet monitoring, pallet binding, scheduled outbound storage, scheduled inbound storage, and pallet data modification. At the loading station, the loader selects pallets and fixtures according to the production schedule provided by the task management module, loads the workpiece to be processed, binds the part processing process data, schedules the pallet inbound storage, and calls the logistics robot to store the pallet in the silo. The processed pallets are stored in the main silo. The scheduled outbound storage function is used to call the logistics robot to send the pallet from the silo to the loading station to unload the processed workpiece.

[0034] The machine tool management module includes machine tool settings, machine tool data management and machine tool monitoring functions. Machine tool settings are used to set basic data such as the machine tool control system model, IP address, port number, etc. Machine tool data management can manually upload processing data such as CNC programs and pallet coordinates, and can also reset and initialize the data. Machine tool monitoring can view the running processing program of the machine tool, the processing coordinate data used, the current position of each motion axis, the tool data used, the spindle speed, the feed rate, the working status of the machine tool and other information in real time on the host control system.

[0035] The alarm management module includes alarm information confirmation and historical alarm information query functions.

[0036] The system management module includes user and authority management, basic system settings and system initialization functions.

[0037] In this embodiment, the remote three-dimensional monitoring subsystem of the host control system is used to remotely monitor the task execution status and unit operation status of the flexible manufacturing unit. The remote three-dimensional monitoring subsystem is constructed using digital twin technology, integrating real-time data such as the physical model of the manufacturing unit, the status of moving parts, and the status of sensors, and fully maps the real-time movement of the manufacturing unit's CNC machine tools and logistics robots and the real-time status of the cleaning workstation, inspection workstation, loading station, pallet, and silo in a three-dimensional manner on the remote terminal. The remote terminal display can be divided into two layers. The bottom layer displays the three-dimensional model, movement, and status of the flexible manufacturing unit, which can be rotated, enlarged, and reduced according to monitoring needs; the upper layer displays task monitoring information and efficiency monitoring information.

[0038] Preferably, the remote three-dimensional monitoring subsystem includes the following modules: The monitoring setting module is used to set basic parameters of the monitoring subsystem, such as connection parameters, simulation parameters and sampling time.

[0039] The task monitoring module is used to display the execution status of each production task in the current system, including the planned quantity, bound quantity, processed quantity, etc. The summary of completed and unfinished tasks is counted in real time and displayed on the monitoring screen in the form of statistical charts.

[0040] The efficiency monitoring module is used to collect the CNC machine tool startup time, automatic operation time, and spindle operation time in real time, count the use efficiency of the CNC machine tool and display it on the monitoring screen in the form of statistical charts.

[0041] The status monitoring module is used to display the physical model of the flexible manufacturing unit in real time, which can be rotated, enlarged, or reduced according to monitoring needs. The status monitoring module uses the real-time position data of each motion axis of the CNC machine tool and logistics robot in the database to drive the virtual machine tool and logistics robot model to achieve motion simulation. The status information of each sensor of the detection workstation, silo, loading workstation, robot fixture, and machine tool fixture stored in the database is read to display the status of the flexible manufacturing unit in real time. Through the three-dimensional physical model, motion simulation, and sensor status display, the operation process of the flexible manufacturing unit is fully mapped to achieve remote monitoring function.

[0042] In this embodiment, the processing data service subsystem of the host control system is used to manage CNC processing programs, coordinate data and tool data. It communicates with the CNC machine tool through a communication program developed based on the CNC system API to upload, download and verify CNC processing programs, coordinate data and tool data.

[0043] Preferably, the processing data service subsystem includes the following modules: The data management module is used to manage processing data, CNC processing programs and tool data. Processing data includes the CNC processing steps and routes required for each part, the CNC processing programs used for each step, tools and other processing information. CNC processing program management includes CNC processing program version management, program browsing, and program addition and deletion functions. Tool data management displays the tool diameter, length, maximum processing depth, service life and other data installed on each machine tool of the flexible manufacturing unit. When the pallet is bound to the part, the system automatically verifies whether the tool used in the part processing program matches the tool actually installed on the bound machine tool, and displays the matching result.

[0044] The data transmission module is used for initialization, uploading and downloading of CNC machining programs and coordinate data. When the system is initialized, the data transmission module initializes the CNC machining programs and coordinate data stored in the CNC machine tool CNC. When a CNC machine tool machining data upload task occurs, the data transmission module uploads the corresponding CNC machining program and pallet coordinates according to the parts and machining task information bound to the current machine tool loading pallet.

[0045] The data verification module is used to download the CNC machining program and coordinate data on the machine tool after the machining data is uploaded, and compare and verify it with the data bound to the pallet to ensure that the uploaded data is complete and correct.

[0046] In this embodiment, the lower computer control system based on the programmable controller directly controls the main control system, CNC machine tools, cleaning workstations, loading workstations and silos through digital input and output interfaces, and reads sensor data. The robot controller and detection workstation are directly controlled through the communication interface to read the robot status data and the detection workstation status and detection result data. The use of a programmable controller to directly control the execution layer device and read the device status ensures the real-time execution of the control system task instructions by the execution layer device, and at the same time, the execution layer device status is fed back to the control layer in a timely manner, ensuring the timeliness of the control layer logic decision.

[0047] Preferably, the lower computer control system includes a main control program, a power-on initialization program, an input and output program, an action control program, an alarm control program and an automatic control program, which are specifically described as follows.

[0048] The power-on initialization program is used to check the initial status of each device in the execution layer and perform initialization settings based on the status data of each execution device stored in the database.

[0049] The master control program is used to map the start, stop, pause, single-step execution, and reset physical buttons of the master control system to the data block of the lower computer. The data is uploaded to the data layer, the upper computer reads the data status, and drives the master control module of the upper computer control subsystem to perform the main logic operation.

[0050] The input and output program is used to map the input and output interfaces of the programmable controller to the data block according to the business logic requirements. The programmable controller reads the execution layer device status into the data block through the input interface and uploads it to the data layer for the upper computer control system to read. The output data is sent from the data layer to the lower computer data block. According to the logical operation results of the action control program, the output interface of the programmable controller outputs the corresponding execution signal to drive the execution layer device to act.

[0051] The motion control program contains the motion control logic of all execution layer devices, including the motion control logic of loading and unloading of logistics robots, the motion control logic of detection workstations to perform detection tasks, the motion control logic of cleaning workstations to perform cleaning tasks, and the motion control logic of machine tools to perform processing tasks.

[0052] The automatic control program is used to control the automatic operation of logistics robots, CNC machine tools, inspection workstations and cleaning workstations. The main control module of the upper computer control subsystem runs the main control logic according to the current state data, generates corresponding task instruction data and uploads it to the data layer. The data layer sends the task data to the task data block of the lower computer. The lower computer reads the task data, drives the automatic control program to run, calls the action control program, and automatically executes the action task.

[0053] The alarm control program is used to collect various alarm information generated during the execution of the power-on initialization program, main control program, input and output program, motion control program and automatic control program, change the system alarm status, upload the alarm information to the data layer, and the host computer reads the alarm data in the data layer and executes the corresponding alarm processing program.

[0054] Example 2 This embodiment is based on embodiment 1: like Figure 3 As shown, this embodiment provides a distributed control method for a flexible manufacturing unit, comprising the following steps: Step 1: System initialization. The host control system reads the master control status, CNC machine tool status, logistics robot status, loading workstation status, detection workstation status, cleaning workstation status, pallet status, and silo status of the data layer, and initializes the master control, CNC machine tool, logistics robot, loading workstation, detection workstation, cleaning workstation, pallet, and silo object instances in the host control system. Start the main logic operation of the control subsystem master control module.

[0055] Step 2: Processing task decomposition and production scheduling optimization. The production task management module of the host control system downloads the production tasks of the manufacturing execution system, calls the process data of the data management module of the processing data service subsystem, decomposes the tasks, generates a processing task list, and automatically schedules the processing tasks. The scheduling results can be manually modified and optimized.

[0056] Step 3: Pallet out of the warehouse. According to the requirements of part clamping, make an appointment to select the appropriate fixture pallet out of the warehouse, and the logistics robot will place the designated pallet on the loading station.

[0057] Step 5: Load the workpiece to be processed. Install the workpiece to be processed on the pallet fixture according to the process requirements.

[0058] Step 6: Bind the processing task. In the pallet management module, bind the current pallet with the task to be processed, and determine the processing machine tool, processing sequence and program number data of the current pallet.

[0059] Step 7: Pallet in-line. The logistics robot takes the pallet from the loading station. If coordinate detection is required, the logistics robot places the pallet on the detection station, otherwise the pallet is placed on the silo or machine tool.

[0060] Step 8: Coordinate detection. After the pallet to be detected is placed on the detection workstation, the host computer control system issues a detection task, and the data server sends the detection task instruction data to the lower computer, which executes the detection automatic control program to perform the detection task. After the detection is completed, the detection task status and coordinate detection result data are fed back to the data server.

[0061] Step 9: Temporary storage of pallets. The pallets that have completed coordinate detection are temporarily stored in the silo by the logistics robot, waiting for processing.

[0062] Step 10: Loading the machine tool. When there is no material in the machine tool fixture, the host computer control system issues a machine tool loading task, and the logistics robot loads the pallet from the material bin to the machine tool fixture. The machine tool fixture sensor detects the material status and clamping status and uploads it to the database through the host computer.

[0063] Step 11: Upload processing data. After the machine tool is loaded with materials, the data server uploads the CNC processing program and pallet coordinates bound to the pallet to the CNC system of the CNC machine tool according to the instructions of the host computer.

[0064] Step 12: Processing data verification. The data server downloads the current CNC processing program and coordinate data of the machine tool, and compares and verifies it with the data in the data server to ensure that the processing data is correct.

[0065] Step 13: Machine tool processing. According to the instructions of the upper computer, the lower computer starts the machine tool and starts processing. The CNC machine tool calls the pallet coordinates and executes the CNC processing program. After the processing is completed, the completion status is uploaded to the database through the lower computer.

[0066] Step 14: Unloading from the machine tool. After processing, the logistics robot moves the pallet to the cleaning workstation, and the machine tool fixture sensor detects the material status and clamping status and uploads it to the database through the host computer.

[0067] Step 15: Data initialization. After the machine tool unloading is completed, the data server immediately starts the machine tool data initialization task, deletes the processing program, and changes the machine tool processing coordinates to safe coordinates.

[0068] Step 16: Pallet cleaning. After the cleaning workstation completes the pallet cleaning according to the set process, the logistics robot moves the pallet to the inspection workstation.

[0069] Step 17: Parts inspection. The inspection workstation completes the parts inspection according to the inspection procedure bound to the pallet, and the parts inspection data and inspection results are uploaded to the database.

[0070] Step 18: Temporary storage of pallets. The inspected parts and pallets are moved by the logistics robot to the silo for temporary storage.

[0071] Step 19: Pallet unloading. The operator makes an appointment for the pallet to be shipped out of the loading station, the logistics robot moves the pallet to the loading station, and the operator completes the unloading.

[0072] Step 20: Task unbinding. When unloading is completed, the system unbinds the current pallet from the bound processing task. The production task management module updates the task status.

[0073] It should be noted that, for the aforementioned method embodiments, for the sake of simplicity of description, they are expressed as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the order of the actions described, because according to the present application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

Claims

1. A flexible manufacturing unit distributed control system, characterized in that: include: The data layer includes a data server and a database thereof, wherein the database stores physical production line status data, main logic task execution data, and production task data; The control layer includes an upper computer control system and a lower computer control system based on distributed control; the upper computer control system is configured to perform logical operations, process data management services and three-dimensional visual monitoring, read database data, drive the main logic to run, and write back the main logic running status and running results; the lower computer control system is configured to read database data, drive the execution layer action logic to run, write back the action logic running status and running results, read the real-time status of each sensor and upload it to the database.

2. A distributed control system for a flexible manufacturing unit according to claim 1, characterized in that: The host computer control system of the control layer includes: a control subsystem configured to manage and operate the flexible production unit; A remote three-dimensional monitoring subsystem configured to remotely monitor the task execution status and unit operation status of the flexible manufacturing unit; The machining data service subsystem is configured to manage CNC machining programs, coordinate data and tool data, communicate with the CNC machine tools through a communication program developed based on the CNC system application programming interface, and upload, download and verify CNC machining programs, coordinate data and tool data.

3. A distributed control system for a flexible manufacturing unit according to claim 2, characterized in that: The control subsystem comprises: The main control module is configured to control the switching between manual and automatic operation modes, automatic operation, single-step operation, system main process reset, and reset and initialization of CNC machine tools, logistics robots, inspection workstations, loading workstations, cleaning workstations, and silos; in the automatic operation mode, the main control module reads the unit status data in the database in real time, drives the main logic operation to generate task data and writes it into the database, and then reads the database task data through the lower computer control system, drives the execution layer to execute tasks, and realizes the automated operation of the flexible manufacturing unit; The processing task management module is configured to receive the production tasks issued by the manufacturing execution system, decompose the production tasks according to the process data, and generate a flexible manufacturing unit processing task list; The pallet management module is configured to perform pallet monitoring, pallet binding, scheduled outbound storage, scheduled inbound storage, and modify pallet data; A machine tool management module configured to perform machine tool parameter setting, machine tool data management and machine tool status monitoring; An alarm management module is configured to perform alarm information confirmation and historical alarm information query; The system management module is configured to perform user and system authority management, basic system settings and system initialization.

4. A distributed control system for a flexible manufacturing unit according to claim 2, characterized in that: The remote three-dimensional monitoring subsystem is built based on digital twin technology, integrating real-time data including the physical model of the flexible manufacturing unit, the status of moving parts, and the status of sensors. It completely maps the real-time movement of the CNC machine tools and logistics robots of the flexible manufacturing unit and the real-time status of the cleaning workstation, inspection workstation, loading station, pallet, and silo in three dimensions on the remote terminal; the remote terminal can display the three-dimensional model and movement status of the flexible manufacturing unit, and display task monitoring information and efficiency monitoring information.

5. A distributed control system for a flexible manufacturing unit according to claim 2, characterized in that: The remote three-dimensional monitoring subsystem includes: A monitoring setting module, configured to set basic parameters of the remote three-dimensional monitoring subsystem, including connection parameters, simulation parameters and sampling time; The task monitoring module is configured to display the task execution status, including the planned quantity, bound quantity and processed quantity of each production task in the current system; real-time statistics of the summary of completed and uncompleted tasks and display them on the monitoring screen in the form of statistical charts; The efficiency monitoring module is configured to collect the startup time, automatic operation time and spindle operation time of the CNC machine tool, calculate the utilization efficiency of the CNC machine tool and display it on the monitoring screen in the form of statistical charts; The status monitoring module is configured to display the physical model of the flexible manufacturing unit and rotate, enlarge and reduce it according to monitoring needs; use the real-time position data of each motion axis of the CNC machine tool and logistics robot in the database to drive the virtual machine tool and logistics robot model to realize motion simulation; read the status information of each sensor of the detection workstation, silo, loading workstation, robot fixture and machine tool fixture stored in the database, and display the status of the flexible manufacturing unit in real time; through the three-dimensional physical model, motion simulation and sensor status display, the operation process of the flexible manufacturing unit is completely mapped to realize remote monitoring.

6. A distributed control system for a flexible manufacturing unit according to claim 2, characterized in that: The processing data service subsystem includes: The data management module is configured to manage processing data, CNC processing programs and tool data; the processing data includes the CNC processing steps and routes required for each part, the CNC processing programs used for each step, and tool information; the management of the CNC processing programs includes CNC processing program version management, program browsing, and program addition and deletion; the tool data includes the tool diameter, length, maximum processing depth and service life data installed on each machine tool of the flexible manufacturing unit; when the pallet is bound to the part, the data management module automatically checks whether the tool used in the part processing program matches the tool actually installed on the bound machine tool, and displays the matching result; The data transmission module is configured to execute the initialization, uploading and downloading of the CNC machining program and coordinate data; when the system is initialized, the data transmission module initializes the CNC machining program and coordinate data stored in the CNC machine tool; when a CNC machine tool machining data upload task occurs, the data transmission module uploads the corresponding CNC machining program and pallet coordinates according to the parts and machining task information bound to the current machine tool loading pallet; The data verification module is configured to download the CNC machining program and coordinate data on the machine tool after the machining data is uploaded, and compare and verify them with the data bound to the pallet to ensure that the uploaded data is complete and correct.

7. A distributed control system for a flexible manufacturing unit according to claim 1, characterized in that: The lower computer control system of the control layer directly controls the main control system, CNC machine tools, cleaning workstations, loading workstations and silos of the execution layer through the digital input and output interface, and reads sensor data; directly controls the robot controller and the detection workstation through the communication interface, reads the robot status data and the detection workstation status and detection result data; uses the programmable controller to directly control the execution layer equipment and read the equipment status, and promptly feeds back the execution layer equipment status to the control layer.

8. A distributed control system for a flexible manufacturing unit according to claim 1, characterized in that: The lower computer control system comprises: A power-on initialization program module is configured to check the initial status of each device in the execution layer and perform initialization settings according to the status data of each execution device stored in the database; The main control program module is configured to map the start, stop, pause, single-step execution and reset physical buttons of the execution layer main control system to the lower computer data block, upload the data to the data layer, read the data status through the upper computer control system and perform the main logic operation; The input and output program module is configured to map the input and output interfaces of the programmable controller to the data block according to the business logic requirements; the programmable controller reads the execution layer device status into the lower computer data block through the input interface, and uploads it to the data layer for the upper computer control system to read; the output data is sent from the data layer to the lower computer data block, and according to the logical operation results of the action control program, the output interface of the programmable controller outputs the corresponding execution signal to drive the execution layer device action; The motion control program module is configured to execute the motion control logic of all execution layer devices, including the motion control logic of loading and unloading of logistics robots, the motion control logic of detection workstations to perform detection tasks, the motion control logic of cleaning workstations to perform cleaning tasks, and the motion control logic of machine tools to perform processing tasks; The automatic control program module is configured to control the automatic operation of logistics robots, CNC machine tools, testing workstations and cleaning workstations; when the upper computer control system runs the main control logic according to the current state data and generates corresponding task instruction data and uploads it to the data layer, the data layer sends the task data to the lower computer control system, and the machine control system reads the task data, drives the automatic control program to run, calls the action control program, and automatically executes the action task; The alarm control program module is configured to collect various alarm information generated during the program execution process, change the system alarm status, upload the alarm information to the data layer, and after the host control system reads the alarm data in the data layer, it executes the corresponding alarm processing program.

9. A distributed control system for a flexible manufacturing unit according to claim 1, characterized in that: In the data layer, the physical production line status data stored in the database includes the status data of CNC machine tools, logistics robots, loading workstations, inspection workstations, cleaning workstations, pallets and silos; the main logic task data stored in the database includes the task commands of the main logic tasks, the task execution process status and the task execution result data; the production task data stored in the database is integrated with the external manufacturing execution system, receives and stores the production task data issued by the manufacturing execution system, and stores the production task scheduling data, the production task execution process status data and the production task execution result data.

10. A distributed control method for a flexible manufacturing unit, characterized in that: include: System initialization: The host computer control system initializes the object instance corresponding to the execution layer; Processing task decomposition and production scheduling optimization: The host computer control system downloads the production tasks of the manufacturing execution system, calls the process data, decomposes the production tasks, generates a processing task list, and automatically schedules the processing tasks; Pallet outbound: According to the requirements of parts clamping, make an appointment to select the corresponding fixture pallet outbound, and the logistics robot will place the designated pallet on the loading station; Loading the workpiece to be processed: Install the workpiece to be processed on the pallet fixture according to the process requirements; Bind processing tasks: bind the current pallet with the task to be processed, and determine the processing machine tool, processing sequence and program number data of the current pallet; Pallet in-line: The logistics robot takes the pallet from the loading workstation; if coordinate detection is required, the logistics robot places the pallet on the detection workstation, otherwise the pallet is placed in the silo or on the machine tool; Coordinate detection: After the pallet to be detected is placed on the detection workstation, the upper computer control system issues a detection task, and the data server sends the detection task instruction data to the lower computer control system to execute the detection task. After the detection is completed, the detection task status and coordinate detection result data are fed back to the data server; Pallet temporary storage: Pallets that have completed coordinate detection are temporarily stored in the silo by the logistics robot, waiting for processing; Machine tool loading: When there is no material in the machine tool fixture, the host computer control system issues a machine tool loading task, and the logistics robot loads the pallet from the material bin to the machine tool fixture. The machine tool fixture sensor detects the material status and clamping status and uploads them to the database through the host computer control system; Processing data upload: After loading is completed on the machine tool, the data server uploads the CNC processing program and pallet coordinates bound to the pallet to the CNC machine tool system according to the instructions of the host computer control system; Processing data verification: The data server downloads the current CNC processing program and coordinate data of the machine tool and compares and verifies them with the data in the data server; Machine tool processing: According to the instructions of the upper computer control system, the lower computer control system starts the machine tool and starts processing; the CNC machine tool calls the pallet coordinates and executes the CNC processing program. After the processing is completed, the completion status is uploaded to the database through the lower computer control system; Machine tool unloading: After processing, the logistics robot moves the pallet to the cleaning workstation, and the machine tool fixture sensor detects the material status and clamping status and uploads them to the database through the host computer control system; Data initialization: After the machine tool unloading is completed, the data server starts the machine tool data initialization task, deletes the processing program, and changes the machine tool processing coordinates to safe coordinates; Pallet cleaning: After the cleaning workstation completes the pallet cleaning according to the set process, the logistics robot moves the pallet to the inspection workstation; Parts inspection: The inspection workstation completes parts inspection according to the inspection procedure bound to the pallet, and the parts inspection data and inspection results are uploaded to the database; Pallet temporary storage: The inspected parts and pallets are moved by logistics robots to the silo for temporary storage; Pallet unloading: After the pallet is scheduled to leave the warehouse, the logistics robot will move the pallet to the loading station for unloading; Task unbinding: When unloading is completed, the current pallet is unbound from the bound processing task and the task status is updated.

Images