A workpiece loading and unloading control system and method for a machining tool

Abstract

This invention relates to a machine tool loading and unloading control system and method, belonging to the field of machine tool automation control technology. The system includes a group of machine tools, multiple industrial robots with dual-station end effectors, a main control unit, an information acquisition unit, a loading and unloading buffer system, and a positioning mechanism. Through an intelligent scheduling algorithm based on the dual principles of "first-in, first-out" and "process matching," robots are only scheduled to use their dual-station end effectors for collaborative loading and unloading when all machine tools within the process matching group have completed processing, maximizing hardware efficiency. Simultaneously, the information acquisition unit automatically binds workpiece identity and full-process processing data at loading and unloading nodes, achieving precise traceability. This invention effectively solves problems such as difficulty in integrating heterogeneous equipment, low scheduling efficiency, and information traceability gaps, significantly improving production cycle time, equipment utilization, and quality control levels.

Description

Technical Field

[0001] This invention relates to the field of machine tool automation control technology, specifically to a machine tool loading and unloading control system and method. Background Technology

[0002] In the flexible upgrading of automobile manufacturing, adopting multi-robot service machine tool groups is key to improving efficiency. However, existing systems often encounter communication protocol barriers when integrating processing equipment of different brands and varying ages, forming "information silos." At the same time, general multi-robot scheduling algorithms cannot fully utilize the efficiency of dedicated hardware, resulting in optimization bottlenecks in production cycle time and equipment utilization.

[0003] In existing technologies, one improvement approach focuses on optimizing multi-robot scheduling. For example, patent CN108067770A discloses a coordination scheduling method based on task weight and priority determination, aiming to improve production cycle time. While such methods can optimize task sequences, their scheduling logic is usually not deeply integrated with the specific physical layout of the production line, the strong process coupling between machine tools, and the specific form of the robot's end effector. In the multi-process flow scenario of automotive parts, this makes it impossible to proactively create working conditions that maximize the value of a single action of the dual-gripper robot (such as simultaneously serving two process-related machine tools). The scheduling optimization remains at the task allocation level and fails to address the root cause of production cycle time coordination.

[0004] Another approach focuses on building a flexible resource scheduling system. For example, patent CN115689094A proposes a method for dynamically matching mobile robots, end effectors, and processing tasks through a central server to improve system adaptability. This type of solution broadens the scope of resource scheduling, but its core lies in the universal matching and traffic management of standardized, mobile resources. For machine tool groups fixed on production lines with heterogeneous communication interfaces, especially older equipment that relies on hard-wiring for real-time signal interaction, this solution lacks deep integration and precise control capabilities. Furthermore, its resource matching model does not optimize for specific operating modes such as "simultaneous loading and unloading by dual grippers," which can significantly improve cycle time.

[0005] Traditional automated production lines reveal three inherent flaws when dealing with complex scenarios involving multiple product varieties, small batches, and the coexistence of new and old equipment: Integration barriers: Inconsistent communication protocols between new and old machine tools lead to high system integration costs, long cycles, and poor stability, resulting in "information silos".

[0006] Scheduling bottleneck: The static and rigid allocation of tasks to multiple robots cannot respond to dynamic rhythms, and cannot fully utilize the potential of high-performance hardware such as dual grippers, resulting in hidden equipment idleness.

[0007] Traceability gap: The material flow and information flow are disconnected, and process data cannot be accurately linked to specific workpieces, making it difficult to quickly trace quality problems and lacking data support for process optimization.

[0008] In summary, there is an urgent need for a machine tool loading and unloading control system and method that can maximize the utilization of the robot's hardware potential, significantly reduce the robot's idle movement and waiting time, optimize production cycle time, and significantly improve equipment utilization. Summary of the Invention

[0009] The purpose of this invention is to provide a machine tool loading and unloading control system and method that maximizes the utilization of the robot's hardware potential, significantly reduces the robot's idle movement and waiting time, optimizes production cycle time, and significantly improves equipment utilization.

[0010] The above objective is achieved through the following technical solution: a machine tool loading and unloading control system, comprising: A group of machine tools, including multiple machine tools used for machining parts; The robot execution unit includes multiple industrial robots that can work together for loading, unloading and transferring workpieces. The end effector of the industrial robot has a dual-station structure. The main control unit is used to control the machine tool group and robot execution unit, and realize the interaction of actions and information between equipment, task scheduling and data binding; The information acquisition unit is used to collect the unique identification information of the workpiece. Loading and unloading buffer system for stable conveying of workpieces; The positioning mechanism, located at the end of the feeding buffer system, is used to correct the posture of the workpiece. The scheduling module, integrated into the main control unit, is used to schedule the robot execution unit's tasks according to preset scheduling rules; the preset scheduling rules include: First-In-First-Out (FIFO) principle: The task queue is generated according to the order in which the machine tools complete their processing. Process matching principle: According to the process layout, at least two machine tools are set as a matching group. Only when all machine tools in the matching group have completed processing, the industrial robot is scheduled to perform loading and unloading operations for the matching group at the same time. If only one machine tool has completed processing, its task is placed in the queue to wait.

[0011] In practical applications, the workpieces to be processed are placed in the loading and unloading buffer system manually or by an external system, which smoothly transports the workpieces to the end. A positioning mechanism at the end corrects the workpiece's posture to ensure uniformity. Subsequently, the robot execution unit grasps the workpiece, and an information acquisition unit (such as a vision scanning system) collects the unique identification information on the workpiece. This identification information is received by the main control unit and bound as the workpiece's "digital ID card." The robot then transfers the identified workpiece to the target machine tool in the processing group for processing. During this process, the main control unit monitors the operation, completion, and fault status of each machine tool in real time through its integrated device communication interface. When a machine tool completes processing, the scheduling module begins operation. First, following the first-in, first-out principle, the system adds the machine tool's task to the processing queue in chronological order. Next, the scheduling module queries the status of other machine tools belonging to the same "matching group" based on preset process matching principles. Only when all machine tools in the matching group report processing completion will the scheduling module generate a collaborative loading and unloading instruction, dispatching an idle industrial robot to the task. The robot utilizes its dual-station end effector to simultaneously complete the unloading (removing finished products) and loading (placing workpieces to be processed) operations of multiple machine tools within the matching group in a single work cycle. If only some machine tools in the matching group complete their tasks, their tasks will remain in a waiting state in the queue, and the robot will not be triggered to take action.

[0012] After the final process is completed, the robot places the finished product into the unloading buffer system for output. Throughout the process, information such as the workpiece processing equipment, process parameters, and operation time is dynamically bound to its unique identifier by the main control unit, forming a complete data loop.

[0013] The core of the process matching principle lies in proactively creating conditions for collaborative operation. By mandating "collective action" of the matched machine tools, this solution maximizes the hardware potential of the robot's dual-station structure, enabling it to serve multiple machines in a single movement, significantly reducing the robot's idle movement and waiting time. Combined with the fairness guarantee of the first-in, first-out principle, it optimizes production cycle time and significantly improves equipment utilization (especially for high-priced robots).

[0014] By introducing the dual principles of "first-in, first-out" and "process matching," scheduling decisions not only consider the order of tasks but also proactively identify and utilize the process coupling relationships between machine tools, thereby creating working conditions that maximize the efficiency of the dual-gripper robot and significantly improving production cycle time and equipment utilization.

[0015] A further technical solution is that the main control unit is connected to the machine tool group through a hybrid communication architecture. The communication methods of the hybrid communication module include Ethernet communication and IO hard-wired communication. For machine tools that support the preset Ethernet protocol, Ethernet communication is used; for machine tools that do not support the preset Ethernet protocol, hard-wired communication is used through the digital IO points reserved by the main control unit.

[0016] The hybrid communication capabilities of the main control unit enable the integration of new devices supporting standard industrial Ethernet protocols and older devices with only basic digital interfaces into the same control network. This breaks down the "information silos" previously created by protocol barriers, significantly reducing the cost and complexity of system upgrades and transformations, while ensuring the real-time and reliable acquisition of key production signals (such as processing completion and safety door status), providing a solid data foundation for upper-level intelligent scheduling.

[0017] A further technical solution is that the industrial robot end effector has a dual-station structure, and multiple industrial robots are installed on the same linear guide rail. This configuration supports the loading and unloading operations of two machine tools in a single action, reducing the robot's idle travel and waiting time, and fully releasing the hardware efficiency of the dual grippers.

[0018] A further technical solution is that the information acquisition unit is a visual barcode scanning system, which collects the unique code of the workpiece as the workpiece ID. The main control unit dynamically binds the workpiece ID with the processing machine tool information, process parameters, timestamp, and operating robot information to form a digital product history.

[0019] By automatically acquiring workpiece identity at key logistics nodes (such as during loading and unloading), and dynamically binding information with physical entities through the main control unit, this solution ensures that data from every processing stage, from raw materials to finished products, is accurately recorded and associated with specific workpieces. This achieves transparency and digitalization of the production process. When quality issues arise, they can be quickly and accurately located to specific processes, equipment, or even batches, greatly improving the speed and accuracy of quality traceability and providing data support for process optimization and lean manufacturing.

[0020] A further technical solution is that the loading and unloading buffer system includes a loading buffer line and an unloading buffer line, and the positioning mechanism includes a positioning table. Both the loading and unloading buffer lines are servo-driven and equipped with workpiece detection sensors. The positioning table includes a lifting cylinder, a clamping cylinder, a rotary servo motor, and a laser detection sensor, used to correct the workpiece to a preset posture before the robot grasps it. This configuration ensures that the robot grasps the workpiece with consistent posture each time, improving the accuracy of grasping and transferring, and ensuring processing stability.

[0021] To achieve the above objectives, the present invention also provides a method for controlling the loading and unloading of a machine tool, which is executed based on any of the aforementioned machine tool loading and unloading control systems, and includes the following steps: S1, Loading and Positioning: The loading and unloading buffer system transports the unprocessed workpiece to the positioning mechanism and performs posture correction on the workpiece; S2, Information Acquisition and Binding: The visual recognition system acquires the unique identification information of the workpiece, and the main control unit dynamically binds the identification information with processing-related information. S3, Processing and Transfer Scheduling: The main control unit schedules the robot to perform loading and unloading tasks according to the scheduling algorithm. Here, a task queue is generated for the machine tools that have completed processing in the order of completion time. At the same time, according to the preset process pairing relationship, it is determined whether the other machine tool paired with the machine tool that has completed processing has also completed processing. If and only if both machine tools of the process pairing have completed processing, the scheduling robot uses its dual-station actuator to perform collaborative loading and unloading operations for the two machine tools at the same time. If only one of them has completed processing, its task waits in the queue. S4, Unloading: The robot execution unit transports the finished product to the loading and unloading buffer system and outputs the processed workpiece.

[0022] A further technical solution is that the loading and unloading buffer system includes a loading buffer line and an unloading buffer line, the positioning mechanism includes a positioning table, both the loading buffer line and the unloading buffer line are servo driven and are respectively equipped with workpiece detection sensors; the positioning table includes a lifting cylinder, a clamping cylinder, a rotary servo motor and a laser detection sensor, and step S1 specifically includes the following steps: S11, place the workpiece at the starting point of the loading buffer line, and the main control unit starts the servo motor to transport the workpiece at a preset speed; S12, After the workpiece detection sensor detects the workpiece, the main control unit immediately controls the feeding buffer line to decelerate and stop; S13, the lifting cylinder lifts the workpiece to the preset height, the clamping cylinder clamps the workpiece, and the lifting cylinder retracts. S14, the rotary servo motor adjusts the workpiece posture through multiple rotations, and the positioning is completed after the sensor confirms that the posture is correct.

[0023] This setup, through multi-level positioning correction, ensures that the workpiece's posture is unique and accurate, providing stable operating conditions for the robot to grasp it.

[0024] A further technical solution is that step S3 specifically includes the following steps: S31, after the machine tool completes the processing, it sends a signal to the main control unit that the processing is complete. After the main control unit confirms that the machine tool is safe and operable, it adds the machine tool information and its completion timestamp to the workpiece equipment queue. The workpiece equipment queue is sorted according to the first-in-first-out principle. S32, the main control unit continuously scans the queue and robot status, and when there is an idle robot, it extracts the machine tool information to be processed from the head of the queue; S33, query the matching group information of the machine tool to be processed, and check whether the other machine tool in the matching group is in the state of having completed processing and waiting for loading and unloading; S34. If both machine tools in the matching group meet the conditions, the main control unit generates a collaborative loading and unloading task and assigns the nearest idle robot to execute it; if not, the pending machine tool task waits in the queue until the matching conditions are met. S35, after the robot performs the loading and unloading task, it sends a completion signal to the main control unit. The main control unit updates the status of the machine tool and the robot and removes the machine tool information from the queue. This setup enables intelligent collaboration between the robot and the machine tool, reduces the robot's idle travel and waiting time, and maximizes the operational value of the dual-gripper robot.

[0025] A further technical solution is that, in step S3, the main control unit calculates the comprehensive cost based on the inter-device movement distance / time matrix, task waiting time, and robot load status, and selects the robot with the lowest comprehensive cost to execute the task.

[0026] This setup optimizes robot scheduling and allocation, further improving the overall operational efficiency of the production line.

[0027] A further technical solution is to perform at least one identification before and after the robot grasps the workpiece, and bind the successfully identified workpiece identification information with its subsequent processing machine tool, process parameters and timestamp information to form a traceable data chain.

[0028] Compared to existing technologies, this invention provides a complete solution through the systematic combination of three innovative modules: a hybrid communication integration scheme, a dual-principle intelligent scheduling algorithm, and a full-process information binding system. At the equipment level, it achieves low-cost, highly reliable heterogeneous integration; at the control level, it achieves efficient collaborative scheduling deeply coupled with the process; and at the information level, it achieves transparent, traceable, and refined management. Ultimately, these technologies work together on the production line to achieve comprehensive benefits including improved efficiency, reduced costs, guaranteed quality, and enhanced flexibility, strongly supporting the transformation and upgrading of the manufacturing industry towards intelligent manufacturing. Specifically: Efficiency Improvement: Through dual-principle scheduling and efficient dual-gripper collaboration, the robot's idle travel and waiting time can be reduced. Cost reduction: Hybrid communication solutions protect existing equipment investments and reduce integration costs and post-maintenance complexity.

[0029] Quality and Control Upgrade: Achieve 100% digital traceability throughout the entire process from raw materials to finished products, reducing the time to locate quality problems from hours to minutes, and greatly improving the level of process optimization and production management.

[0030] Enhanced flexibility: The system can quickly adapt to product changes by adjusting parameters (such as pairing relationships and queue rules) to meet the needs of flexible manufacturing. Attached Figure Description

[0031] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0032] Figure 1 This is a structural block diagram of a machine tool loading and unloading control system according to one embodiment of the present invention; Figure 2 This is a flowchart illustrating a machine tool loading and unloading control method according to one embodiment of the present invention. Detailed Implementation

[0033] The present invention will now be described in detail with reference to the accompanying drawings. This description is merely illustrative and explanatory, and should not be construed as limiting the scope of protection of the present invention. Furthermore, those skilled in the art can combine the features in the embodiments described herein and in different embodiments according to the description in this document.

[0034] To better understand the technical solution of this invention, a machine tool loading and unloading control system, such as... Figure 1 ,include: A group of machine tools, including multiple machine tools used for machining parts; The robot execution unit includes multiple industrial robots that can work together for loading, unloading and transferring workpieces. The end effector of the industrial robot has a dual-station structure. The main control unit is used to control the machine tool group and robot execution unit, and realize the interaction of actions and information between equipment, task scheduling and data binding; The information acquisition unit is used to collect the unique identification information of the workpiece. Loading and unloading buffer system for stable conveying of workpieces; The positioning mechanism, located at the end of the feeding buffer system, is used to correct the posture of the workpiece. The scheduling module, integrated into the main control unit, is used to schedule the robot execution unit's tasks according to preset scheduling rules; the preset scheduling rules include: First-In-First-Out (FIFO) principle: The task queue is generated according to the order in which the machine tools complete their processing. Process matching principle: According to the process layout, at least two machine tools are set as a matching group. Only when all machine tools in the matching group have completed processing, the industrial robot is scheduled to perform loading and unloading operations for the matching group at the same time. If only one machine tool has completed processing, its task is placed in the queue to wait.

[0035] In practical applications, the workpieces to be processed are placed in the loading and unloading buffer system manually or by an external system, which smoothly transports the workpieces to the end. A positioning mechanism at the end corrects the workpiece's posture to ensure uniformity. Subsequently, the robot execution unit grasps the workpiece, and an information acquisition unit (such as a vision scanning system) collects the unique identification information on the workpiece. This identification information is received by the main control unit and bound as the workpiece's "digital ID card." The robot then transfers the identified workpiece to the target machine tool in the processing group for processing. During this process, the main control unit monitors the operation, completion, and fault status of each machine tool in real time through its integrated device communication interface. When a machine tool completes processing, the scheduling module begins operation. First, following the first-in, first-out principle, the system adds the machine tool's task to the processing queue in chronological order. Next, the scheduling module queries the status of other machine tools belonging to the same "matching group" based on preset process matching principles. Only when all machine tools in the matching group report processing completion will the scheduling module generate a collaborative loading and unloading instruction, dispatching an idle industrial robot to the task. The robot utilizes its dual-station end effector to simultaneously complete the unloading (removing finished products) and loading (placing workpieces to be processed) operations of multiple machine tools within the matching group in a single work cycle. If only some machine tools in the matching group complete their tasks, their tasks will remain in a waiting state in the queue, and the robot will not be triggered to take action.

[0036] After the final process is completed, the robot places the finished product into the unloading buffer system for output. Throughout the process, information such as the workpiece processing equipment, process parameters, and operation time is dynamically bound to its unique identifier by the main control unit, forming a complete data loop.

[0037] The core of the process matching principle lies in proactively creating conditions for collaborative operation. By mandating "collective action" of the matched machine tools, this solution maximizes the hardware potential of the robot's dual-station structure, enabling it to serve multiple machines in a single movement, significantly reducing the robot's idle movement and waiting time. Combined with the fairness guarantee of the first-in, first-out principle, it optimizes production cycle time and significantly improves equipment utilization (especially for high-priced robots).

[0038] By introducing the dual principles of "first-in, first-out" and "process matching," scheduling decisions not only consider the order of tasks but also proactively identify and utilize the process coupling relationships between machine tools, thereby creating working conditions that maximize the efficiency of the dual-gripper robot and significantly improving production cycle time and equipment utilization.

[0039] Based on the above embodiments, in another embodiment of the present invention, the main control unit is connected to the machine tool group through a hybrid communication architecture. The communication methods of the hybrid communication module include Ethernet communication and IO hard-wired communication. For machine tools that support the preset Ethernet protocol, Ethernet communication is used; for machine tools that do not support the preset Ethernet protocol, hard-wired communication is used through the digital IO points reserved by the main control unit.

[0040] The hybrid communication capabilities of the main control unit enable the integration of new devices supporting standard industrial Ethernet protocols and older devices with only basic digital interfaces into the same control network. This breaks down the "information silos" previously created by protocol barriers, significantly reducing the cost and complexity of system upgrades and transformations, while ensuring the real-time and reliable acquisition of key production signals (such as processing completion and safety door status), providing a solid data foundation for upper-level intelligent scheduling.

[0041] Based on the above embodiments, in another embodiment of the present invention, the industrial robot end effector has a dual-station structure, and multiple industrial robots are mounted on the same linear guide rail. This configuration supports loading and unloading operations of two machine tools in a single action, reducing the robot's idle travel and waiting time, and fully releasing the hardware efficiency of the dual grippers.

[0042] Based on the above embodiments, in another embodiment of the present invention, the information acquisition unit is a visual barcode scanning system. The visual barcode scanning system acquires the unique code of the workpiece as the workpiece ID. The main control unit dynamically binds the workpiece ID with the processing machine tool information, process parameters, timestamp, and operating robot information to form a digital product history.

[0043] By automatically acquiring workpiece identity at key logistics nodes (such as during loading and unloading), and dynamically binding information with physical entities through the main control unit, this solution ensures that data from every processing stage, from raw materials to finished products, is accurately recorded and associated with specific workpieces. This achieves transparency and digitalization of the production process. When quality issues arise, they can be quickly and accurately located to specific processes, equipment, or even batches, greatly improving the speed and accuracy of quality traceability and providing data support for process optimization and lean manufacturing.

[0044] Based on the above embodiments, in another embodiment of the present invention, the loading and unloading buffer system includes a loading buffer line and an unloading buffer line, the positioning mechanism includes a positioning table, and both the loading and unloading buffer lines are servo-driven and equipped with workpiece detection sensors respectively; the positioning table includes a lifting cylinder, a clamping cylinder, a rotary servo motor, and a laser detection sensor, used to correct the workpiece to a preset posture before the robot grasps it. This configuration ensures that the robot grasps the workpiece with consistent posture each time, improving the accuracy of grasping and transferring, and ensuring processing stability.

[0045] The present invention also provides a method for controlling the loading and unloading of a machine tool, the embodiment of which is as follows, based on any of the above-described machine tool loading and unloading control systems, and includes the following steps: S1, Loading and Positioning: The loading and unloading buffer system transports the unprocessed workpiece to the positioning mechanism and performs posture correction on the workpiece; S2, Information Acquisition and Binding: The visual recognition system acquires the unique identification information of the workpiece, and the main control unit dynamically binds the identification information with processing-related information. S3, Processing and Transfer Scheduling: The main control unit schedules the robot to perform loading and unloading tasks according to the scheduling algorithm. Here, a task queue is generated for the machine tools that have completed processing in the order of completion time. At the same time, according to the preset process pairing relationship, it is determined whether the other machine tool paired with the machine tool that has completed processing has also completed processing. If and only if both machine tools of the process pairing have completed processing, the scheduling robot uses its dual-station actuator to perform collaborative loading and unloading operations for the two machine tools at the same time. If only one of them has completed processing, its task waits in the queue. S4, Unloading: The robot execution unit transports the finished product to the loading and unloading buffer system and outputs the processed workpiece.

[0046] A further technical solution is that the loading and unloading buffer system includes a loading buffer line and an unloading buffer line, the positioning mechanism includes a positioning table, both the loading buffer line and the unloading buffer line are servo driven and are respectively equipped with workpiece detection sensors; the positioning table includes a lifting cylinder, a clamping cylinder, a rotary servo motor and a laser detection sensor, and step S1 specifically includes the following steps: S11, place the workpiece at the starting point of the loading buffer line, and the main control unit starts the servo motor to transport the workpiece at a preset speed; S12, After the workpiece detection sensor detects the workpiece, the main control unit immediately controls the feeding buffer line to decelerate and stop; S13, the lifting cylinder lifts the workpiece to the preset height, the clamping cylinder clamps the workpiece, and the lifting cylinder retracts. S14, the rotary servo motor adjusts the workpiece posture through multiple rotations, and the positioning is completed after the sensor confirms that the posture is correct.

[0047] Based on the above embodiments, in another embodiment of the present invention, step S3 specifically includes the following steps: S31, after the machine tool completes the processing, it sends a signal to the main control unit that the processing is complete. After the main control unit confirms that the machine tool is safe and operable, it adds the machine tool information and its completion timestamp to the workpiece equipment queue. The workpiece equipment queue is sorted according to the first-in-first-out principle. S32, the main control unit continuously scans the queue and robot status, and when there is an idle robot, it extracts the machine tool information to be processed from the head of the queue; S33, query the matching group information of the machine tool to be processed, and check whether the other machine tool in the matching group is in the state of having completed processing and waiting for loading and unloading; S34. If both machine tools in the matching group meet the conditions, the main control unit generates a collaborative loading and unloading task and assigns the nearest idle robot to execute it; if not, the pending machine tool task waits in the queue until the matching conditions are met. S35, after the robot performs the loading and unloading task, it sends a completion signal to the main control unit. The main control unit updates the status of the machine tool and the robot and removes the machine tool information from the queue. Based on the above embodiments, in another embodiment of the present invention, in step S3, the main control unit calculates the comprehensive cost based on the inter-device movement distance / time matrix, task waiting time and robot load status, and selects the robot with the lowest comprehensive cost to perform the task.

[0048] Based on the above embodiments, in another embodiment of the present invention, at least one identification is performed before and after the robot grasps the workpiece, and the successfully identified workpiece identification information is bound to its subsequent processing machine tool, process parameters and timestamp information to form a traceable data chain.

[0049] To better understand the technical solution of this invention, a specific implementation process of the technical solution is provided, such as... Figure 2 : Hardware configuration: PLC: Siemens S7 series PLC, equipped with digital input / output modules for hardwiring.

[0050] Robots: 3 six-axis industrial robots (such as KUKA KR60), equipped with dual pneumatic / electric grippers, mounted on a 30-meter linear guide rail.

[0051] Vision system: 5-megapixel industrial camera, equipped with a ring light source and a dedicated image processor.

[0052] The buffer line and positioning stage consist of an SMC cylinder (lifting and clamping) and a Siemens servo motor (conveying and rotating).

[0053] Network: Industrial gigabit Ethernet switches; some machine tools are connected via Profinet, while others are connected to the PLC IO module via cables.

[0054] Software configuration: PLC programming: Using TIA Portal V17, write functional blocks including device communication processing, robot scheduling core algorithm (FIFO and matching logic), queue management, data binding, etc.

[0055] Robot programming: The robot's local program receives macro instructions ("GoTo_Machine_A_Pick_and_Place") from the PLC and executes standardized actions.

[0056] Vision system: Configured with barcode scanning software, it communicates with the PLC via TCP / IP and sends the workpiece ID in string format.

[0057] The specific implementation of material feeding and positioning: 1. After the workpiece is manually placed at the starting point of the buffer line, the PLC starts the servo motor to transport the workpiece to the positioning table at a preset speed.

[0058] 2. When the photoelectric sensor detects the edge of the workpiece or a specific mark (the trigger signal changes from OFF to ON), the PLC immediately responds to this rising edge signal and sends a high-priority command of "immediate deceleration and stop" to the servo driver within the next scan cycle (usually <1ms).

[0059] 3. After the PLC confirms that the conveyor line has stopped and stabilized, the solenoid valve controlling the lifting cylinder is energized, the cylinder rod extends, and the workpiece is smoothly lifted to the predetermined height, so that it is completely removed from the conveyor surface.

[0060] 4. After the lifting position sensor sends a feedback signal, the PLC controls the clamping cylinder to clamp the workpiece from both sides, eliminating the X and Y offsets and rotations caused by slight deviations in the stop position in the horizontal plane.

[0061] 5. After clamping in place, the PLC starts the rotary servo motor. The motor rotates clockwise at the first preset speed V1. After the sensor detects the signal, the motor stops rotating. Then it rotates counterclockwise at the second preset speed V2. After the sensor detects the signal, the motor stops rotating. Then it rotates clockwise at the third preset speed V3. After the sensor detects the signal, the motor stops rotating. The workpiece is corrected to a unique and correct orientation, providing the robot with a completely consistent grasping posture.

[0062] The specific implementation of the processing and transfer process: 1. Once any machine tool (M1) completes its process, it will immediately send a "processing completed" signal to the PLC.

[0063] 2. After receiving the signal, the PLC confirms that the machine tool M1 has completed processing and the door is open, and is in a safe and operable state.

[0064] 3. The PLC adds the identifier of machine tool M1 (such as machine tool number M1) and its completion timestamp to a list called "Completed Workpiece Equipment Queue". This queue is strictly ordered according to the "first-in, first-out" principle, that is, the machine tool that completes processing earliest is at the front of the queue.

[0065] 4. The PLC's scheduler continuously scans the "completed workpiece equipment queue" and checks the idle status of the robot within the work area.

[0066] 5. When a robot is found to be idle, the scheduler starts from the head of the queue (i.e., the earliest completed task) and checks whether the tasks of the devices in the queue are executable.

[0067] 6. The scheduler reads the preset "pairing device" of the target machine tool (for example, the pairing device of machine tool M1 is M2) and checks whether its pairing device (M2) is also in the "processing completed and waiting for loading and unloading" state.

[0068] 7. If the paired machine (M2) has also completed processing and is in the queue (regardless of order), the PLC determines that the "matching principle" is met. It will simultaneously generate a collaborative loading and unloading task for the two paired machine tools and assign it to the currently idle robot.

[0069] 8. If the paired device (M2) has not yet completed processing, the PLC will not dispatch a robot to the current target machine tool (M1). The task of M1 will remain in the queue and wait until its paired device M2 has also completed processing and met the matching conditions before it will be dispatched for execution together.

[0070] 9. The robot receives the task instruction from the PLC and moves to the target machine tool.

[0071] 10. The robot uses its dual grippers to complete the loading and unloading of a single machine tool in one work cycle: one gripper takes out the finished workpiece, and the other gripper simultaneously puts in the workpiece to be processed.

[0072] 11. Once completed, the robot sends a task completion signal to the PLC.

[0073] 12. After confirming that the robot has completed its task, the PLC updates the machine tool status to "Running" or "Waiting for Material" and removes it from the "Completed Workpiece Equipment Queue".

[0074] 13. The system then returns to the initial state of step 1, waits for the next "processing complete" event to be triggered, and begins a new round of scheduling loop.

[0075] The specific implementation of the scheduling algorithm: T_Completion: The absolute time of machining completion reported by each machine tool.

[0076] T_Waiting: The cumulative waiting time of the task in the queue.

[0077] M_Status[i]: Machine tool status enumeration (running, waiting for material, fault, idle).

[0078] R_Status[j]: Robot status enumeration (busy, idle, moving, faulty) and its current position coordinates (X,Y).

[0079] P_Pair: A predefined machine tool process pairing mapping table (e.g., M1→M2).

[0080] D_Matrix: The distance / time matrix between devices, used to calculate the estimated travel time T_Travel for the robot to travel from its current position (X, Y) to the target machine tool Mn.

[0081] 1. Retrieve the head task from the "Completed Workpiece Equipment Queue" by pressing T_Completion and obtain its equipment identifier M_Current.

[0082] 2. Query P_Pair to obtain its paired device M_Paired, and read the M_Status status of both.

[0083] 3. When M_Paired's M_Status is also "Completed and awaiting material", the "matching principle" condition is met.

[0084] 4. The algorithm iterates through all robots whose R_Status is "idle" or "about to be idle", combines their G_Robot load status, current position and D_Matrix to calculate a comprehensive cost function Cost = f(T_Travel, T_Waiting,G_Robot), and selects the robot with the lowest cost to perform the collaborative loading and unloading task.

[0085] 5. If the "matching principle" is not met, the system will update T_Waiting of M_Current and continue to monitor it until it times out or the condition is met.

[0086] Device layer: Adopting a hybrid communication integration solution, it seamlessly integrates new and old devices by combining Ethernet (Profinet / EtherNet / IP) with IO hardwired connections, breaking down integration barriers.

[0087] Scheduling Layer: A dual-principle scheduling algorithm based on "first-in, first-out" and "process matching" is proposed. This algorithm not only ensures task fairness, but more importantly, it actively identifies and utilizes the process coupling relationship between machine tools to intelligently generate task sequences that maximize the efficiency of the dual-gripper robot (such as "dual-gripper relay task"), thus logically solving the problem of scheduling rigidity.

[0088] Information Layer: Design a vision-triggered end-to-end information binding method. At key loading and unloading nodes, the workpiece identity is automatically collected through visual barcode scanning, and the central control system associates it with the end-to-end processing data in real time to build a complete and reliable digital twin history.

[0089] Technical Support: The above solution is strongly supported by a series of specific and implementable technical modules: With a high-performance PLC as the control core, it has multi-protocol parsing capabilities and high-speed IO processing capabilities, and is the physical basis for hybrid communication and real-time scheduling.

[0090] Parametric dynamic scheduling model: The algorithm calculates based on a real-time updated database of parameters such as equipment status, robot position, load, and process pairing table, achieving a leap from "fixed rules" to "dynamic optimization".

[0091] High-precision execution and sensing unit: including servo precise positioning, real-time sensor feedback, machine vision recognition, etc., ensures a precise and reliable closed loop from scheduling instructions to physical execution.

[0092] For those skilled in the art, various improvements and modifications can be made without departing from the principles of this invention, and these improvements and modifications should also be considered within the scope of protection of this invention.

Claims

1. A machine tool loading and unloading control system, characterized by, include: A group of machine tools, including multiple machine tools used for machining parts; The robot execution unit includes multiple industrial robots that can work together for loading, unloading and transferring workpieces. The end effector of the industrial robot has a dual-station structure. The main control unit is used to control the machine tool group and robot execution unit, and realize the interaction of actions and information between equipment, task scheduling and data binding; The information acquisition unit is used to collect the unique identification information of the workpiece. Loading and unloading buffer system for stable conveying of workpieces; The positioning mechanism, located at the end of the feeding buffer system, is used to correct the posture of the workpiece. The scheduling module, integrated into the main control unit, is used to schedule the robot to perform unit tasks according to preset scheduling rules; The preset scheduling rules include: First-In-First-Out (FIFO) principle: The task queue is generated according to the order in which the machine tools complete their processing. Process matching principle: According to the process layout, at least two machine tools are set as a matching group. Only when all machine tools in the matching group have completed processing, the industrial robot is scheduled to perform loading and unloading operations for the matching group at the same time. If only one machine tool has completed processing, its task is placed in the queue to wait.

2. The machine tool loading and unloading control system according to claim 1, characterized in that, The main control unit is connected to the machine tool group through a hybrid communication architecture. The communication methods of the hybrid communication module include Ethernet communication and I / O hard-wired communication. For machine tools that support the preset Ethernet protocol, Ethernet communication is used; for machine tools that do not support the preset Ethernet protocol, hard-wired communication is used through the digital I / O points reserved by the main control unit.

3. The machine tool loading and unloading control system of claim 1, wherein, The end effector of the industrial robot has a dual-station structure, and multiple industrial robots are installed on the same linear guide rail.

4. The machine tool loading and unloading control system according to claim 1, characterized in that, The information acquisition unit is a visual barcode scanning system. The visual barcode scanning system collects the unique code of the workpiece as the workpiece ID. The main control unit dynamically binds the workpiece ID with the machine tool information, process parameters, timestamp, and operating robot information to form a digital product history.

5. The machine tool loading and unloading control system according to claim 4, characterized in that, The loading and unloading buffer system includes a loading buffer line and an unloading buffer line. The positioning mechanism includes a positioning table. Both the loading buffer line and the unloading buffer line are servo driven and are equipped with workpiece detection sensors. The positioning table includes a lifting cylinder, a clamping cylinder, a rotary servo motor, and a laser detection sensor, which are used to correct the workpiece to a preset posture before the robot grasps it.

6. A method for controlling the loading and unloading of a machine tool, characterized in that, The machining tool loading and unloading control system according to any one of claims 1-5 includes the following steps: S1, Loading and Positioning: The loading and unloading buffer system transports the unprocessed workpiece to the positioning mechanism and performs posture correction on the workpiece; S2, Information Acquisition and Binding: The visual recognition system acquires the unique identification information of the workpiece, and the main control unit dynamically binds the identification information with processing-related information. S3, Processing and Transfer Scheduling: The main control unit schedules the robot to perform loading and unloading tasks according to the scheduling algorithm. Here, a task queue is generated for the machine tools that have completed processing in the order of completion time. At the same time, according to the preset process pairing relationship, it is determined whether the other machine tool paired with the machine tool that has completed processing has also completed processing. If and only if both machine tools of the process pairing have completed processing, the scheduling robot uses its dual-station actuator to perform collaborative loading and unloading operations for the two machine tools at the same time. If only one of them has completed processing, its task waits in the queue. S4, Unloading: The robot execution unit transports the finished product to the loading and unloading buffer system and outputs the processed workpiece.

7. The machine tool loading and unloading control method according to claim 6, characterized in that, The loading and unloading buffer system includes a loading buffer line and an unloading buffer line. The positioning mechanism includes a positioning table. Both the loading and unloading buffer lines are servo driven and are equipped with workpiece detection sensors. The positioning table includes a lifting cylinder, a clamping cylinder, a rotary servo motor, and a laser detection sensor. Step S1 specifically includes the following steps: S11, place the workpiece at the starting point of the loading buffer line, and the main control unit starts the servo motor to transport the workpiece at a preset speed; S12, After the workpiece detection sensor detects the workpiece, the main control unit immediately controls the feeding buffer line to decelerate and stop; S13, the lifting cylinder lifts the workpiece to the preset height, the clamping cylinder clamps the workpiece, and the lifting cylinder retracts. S14, the rotary servo motor adjusts the workpiece posture through multiple rotations, and the positioning is completed after the sensor confirms that the posture is correct.

8. The machine tool loading and unloading control method according to claim 7, characterized in that, Step S3 specifically includes the following steps: S31, after the machine tool completes the processing, it sends a signal to the main control unit that the processing is complete. After the main control unit confirms that the machine tool is safe and operable, it adds the machine tool information and its completion timestamp to the workpiece equipment queue. The workpiece equipment queue is sorted according to the first-in-first-out principle. S32, the main control unit continuously scans the queue and robot status, and when there is an idle robot, it extracts the machine tool information to be processed from the head of the queue; S33, query the matching group information of the machine tool to be processed, and check whether the other machine tool in the matching group is in the state of having completed processing and waiting for loading and unloading; S34. If both machine tools in the matching group meet the conditions, the main control unit generates a collaborative loading and unloading task and assigns the nearest idle robot to execute it; if not, the pending machine tool task waits in the queue until the matching conditions are met. S35 After the robot performs the loading and unloading task, it sends a completion signal to the main control unit. The main control unit updates the status of the machine tool and the robot and removes the machine tool information from the queue.

9. The machine tool loading and unloading control method according to claim 7, characterized in that, In step S3, the main control unit calculates the comprehensive cost based on the inter-device movement distance / time matrix, task waiting time, and robot load status, and selects the robot with the lowest comprehensive cost to execute the task.

10. The machining tool loading and unloading control method according to claim 7, wherein, The robot performs at least one identification before and after grasping the workpiece, and binds the successfully identified workpiece identification information with its subsequent processing machine tool, process parameters and timestamp information to form a traceable data chain.

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