A cross-category reconfigurable flexible numerical control assembly method and system

Abstract

This invention discloses a cross-category reconfigurable flexible CNC assembly method and system, comprising the following steps: S1: Inputting information about the product to be assembled and parsing it into assembly information; S2: Configuring assembly resources based on the assembly information; S3: Planning the assembly process based on the configured assembly resources; S4: Uploading the assembly information, assembly resources, and assembly process plan to a simulation environment, pre-running the assembly task in the simulation environment, and generating an assembly control program; S5: Distributing the assembly control program to the assembly line and running the assembly task to obtain the assembled product. This invention solves the problem of automatic assembly of any cross-category product and has extremely high reconfigurability. It does not require excessive human intervention, improves the changeover efficiency of the assembly line, and greatly reduces labor costs and workload, thus balancing reconfigurability and high efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of assembly, in particular to a cross-category reconfigurable flexible numerical control assembly method and system. BACKGROUND

[0002] The product manufacturing process has high flexibility, can meet the manufacturing process of different types of products, and has high production efficiency. In the product assembly link, for multi-variety and small-batch product assembly, currently, a man-machine mixed or all-manual assembly mode is often used to realize it, the working conditions are poor, the labor intensity is high, and the market competitiveness is lacking. However, human beings are the most flexible system, and after certain training, they can almost undertake the assembly work of various products.

[0003] Prior art 1 discloses an intelligent manufacturing production line of an electric cylinder, proposes an electric cylinder assembly unit including a semi-finished product assembly part and a finished product assembly part, realizes more rapid and stable mass production of electric cylinders, however, can only complete the assembly of electric cylinder product family.

[0004] Prior art 2 discloses a truss type flexible automatic assembly system, which can flexibly adjust the types and positions of actuators according to changes in assembly objects, and adapt to different production rhythms and assembly modes, however, the truss type structure of the system makes the reconfigurability of the whole system very poor.

[0005] Prior art 3 discloses an intelligent flexible manufacturing factory and production method, which generates production plan data by acquiring user order data, but does not give solutions such as whole line layout and resource planning, and cannot complete the customized resource management and configuration requirements of the highly reconfigurable flexible numerical control assembly center for cross-category products.

[0006] Prior art 4 discloses a reconfigurable flexible assembly system, which includes an assembly jig library, a plurality of assembly jigs are arranged in the assembly jig library, an assembly work unit, the assembly jig and the assembly tool can be installed on the assembly work unit, and the method, control system for realizing cross-category product assembly of the integrated system whole process are lacking.

[0007] In general, in the field of reconfigurable flexible assembly technology for cross-category products, there is currently no complete solution that can realize the assembly of products of any complexity and complete multi-actuator, multi-end control, and different production line level management requirements. SUMMARY

[0008] The present application aims to solve the technical problem that the prior art cannot automatically assemble any cross-category product, and provides a cross-category reconfigurable flexible numerical control assembly method and system.

[0009] To achieve the above object, the present application adopts the following technical solutions:

[0010] A cross-category reconfigurable flexible numerical control assembly method and system, comprising the following steps: S1: inputting information of a product to be assembled and parsing into assembly information; S2: configuring assembly resources according to the assembly information; S3: performing assembly process planning according to the configured assembly resources; S4: uploading the assembly information, the assembly resources and the assembly process planning to a simulation environment, pre-running an assembly task in the simulation environment, and generating an assembly control program; and S5: issuing the assembly control program to an assembly line and running the assembly task to obtain an assembled product.

[0011] In some embodiments of the present application, in step S1, the information of the product to be assembled is input to a central control computer, and the central control computer parses the information of the product to be assembled into the assembly information; the information of the product to be assembled includes at least one of a three-dimensional model of the product to be assembled, an assembly process priority relationship; the assembly information includes at least one of parts of the product to be assembled, quantities of the parts, a topological relationship of connections between the parts, a fitting relationship between the parts, dimensions of the parts, and structural features of the parts.

[0012] In some embodiments of the present application, in step S2, the assembly resources include at least one of a number of assembly lines and an assembly line layout, and the assembly line includes at least one of an assembly unit, an assembly tool, and an assembly fixture.

[0013] In some embodiments of the present application, in step S3, the assembly process planning includes assembly sequence and assembly line balancing; the assembly sequence includes a process and a step when the assembly line and the assembly unit perform the assembly task; and the assembly line balancing includes at least one of optimizing the assembly sequence, adjusting the assembly line layout, adjusting the assembly unit, adjusting the assembly tool, and adjusting the assembly fixture.

[0014] In some embodiments of the present application, in step S4, after the pre-running of the assembly task, if the assembly information, the assembly resources and the assembly process planning do not meet the requirements, step S2 is repeated or manual modification is performed; and the assembly control program includes a PLC control program, a ROS control program and an assembly language control program.

[0015] In some embodiments of the present application, in step S5, the assembly line issues the assembly control program to an assembly unit, and the assembly unit runs the assembly task; and the assembly task is monitored and fed back.

[0016] The application further provides a cross-category reconfigurable flexible numerical control assembly system, comprising a central control computer and an assembly line, wherein the central control computer is configured to receive inputted information of a product to be assembled and parse the information of the product to be assembled into assembly information; configure assembly resources according to the assembly information; and plan an assembly process according to the configured assembly resources; the central control computer is further configured to run a simulation environment, the simulation environment is configured to receive the assembly information, the assembly resources and the assembly process planning, and the central control computer is further configured to generate an assembly control program by pre-running an assembly task in the simulation environment and deliver the assembly control program to the assembly line; and the assembly line is configured to receive the assembly control program delivered by the central control computer and run the assembly task to obtain an assembled product.

[0017] In some embodiments of the application, the central control computer comprises an information parsing module, an assembly resource configuration module, an assembly process planning module and an assembly process simulation module, wherein the information parsing module is configured to receive inputted information of a product to be assembled and parse the information of the product to be assembled into assembly information; the assembly resource configuration module is configured to configure assembly resources according to the assembly information; the assembly process planning module is configured to plan an assembly process according to the configured assembly resources; and the assembly process simulation module is configured to receive the assembly information, the assembly resources and the assembly process planning and pre-run an assembly task to generate an assembly control program.

[0018] In some embodiments of the application, the assembly line comprises an assembly unit configured to execute the assembly control program, and the assembly unit comprises a PLC and an actuator.

[0019] In some embodiments of the application, the assembly unit further comprises a sensor configured to monitor the assembly task and feed back to the central control computer.

[0020] The application has the following beneficial effects:

[0021] The cross-category reconfigurable flexible numerical control assembly method and system provided by the application can solve the problem of automatic assembly of any cross-category product and have high reconfigurability, without the need for excessive human participation, thereby improving the efficiency of assembly line changeover, greatly reducing the labor cost and the workload of humans, and thus balancing reconfigurability and efficiency.

[0022] In addition, in some embodiments, the application has the following beneficial effects:

[0023] In different assembly tasks, by reusing assembly units and other assembly resources, the manufacturing management cost of developing new assembly line is greatly reduced, and the product production cycle is greatly reduced.

[0024] Other benefits of the embodiments of the present application will be further described below. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a step flow chart of the assembly method in embodiment 1;

[0026] Figure 2 is a schematic diagram of the assembly system in embodiment 1;

[0027] Figure 3 is a control center frame diagram of the assembly system in embodiment 1;

[0028] Figure 4a is an example diagram of the shuttle valve body and parts information in embodiment 1;

[0029] Figure 4b is a priority relationship diagram of the shuttle valve body in embodiment 1

[0030] Figure 4c is a schematic diagram of the installation of the shuttle valve body in embodiment 1;

[0031] Figure 5a is a schematic diagram of the layout of the assembly line 1 in embodiment 1;

[0032] Figure 5b is a schematic diagram of the layout of the assembly line 2 in embodiment 1;

[0033] Figure 6 is a schematic diagram of the different overhead structures of the assembly unit in embodiment 1;

[0034] Figure 7a is a schematic diagram of the layout of the assembly line in embodiment 1;

[0035] Figure 7b is another schematic diagram of the layout of the assembly line in embodiment 1;

[0036] Figure 8 is a schematic diagram of the jig structure in embodiment 1;

[0037] Figure 9 is a schematic diagram of the layout of the assembly unit in embodiment 1;

[0038] Figure 10 is a schematic diagram of the layout of the assembly center in embodiment 1;

[0039] Figure 11 is a schematic diagram of the assembly line in embodiment 1;

[0040] Figure 12 is the schematic diagram of the steps of the cross-category reconfigurable flexible numerical control assembly method in the embodiment of the application.

[0041] The reference signs are as follows:

[0042] Assembly unit 1, transfer unit 2, special unit 3, mobile robot 4, central tool library 5, central clamp library 6, central control computer 7, product to be assembled 8, assembly worker clamp library 56,

[0043] Part to be assembled 11, material tray 12, clamp 13, assembly unit operation executor 14, assembly unit tool cache 15, worker clamp cache rack 16, operation tool 17,

[0044] Transfer unit operation executor 21, transfer unit operation tool 22,

[0045] Special executor 31, mobile robot operation executor 41, mobile robot tool cache 42, mobile robot clamp cache 43, mobile robot part cache 44,

[0046] Shuttle valve body D1, large rubber ring D11, small rubber ring D12, steel ball D13, cylindrical plunger D14, main housing D15;

[0047] Ring assembly tool F3, position relationship assembly tool F4, positioning clamping clamp F5, threaded assembly special unit F6,

[0048] H2 is assembly line one, H3 is assembly line two, H4 is assembly line three,

[0049] Assembly unit 1-1, assembly unit 1-2, assembly unit 1-3, assembly unit 1-4, assembly unit 1-5 represent different assembly units. DETAILED DESCRIPTION

[0050] The application will be further described below with reference to the drawings and in conjunction with the preferred embodiments. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0051] It should be noted that the left, right, up, down, top, bottom and other orientation terms in the embodiments are only relative concepts or are referenced to the normal use state of the product, and should not be considered as limiting.

[0052] In the reconfigurable flexible numerical control assembly center facing cross-category products, it is necessary to realize the assembly of cross-category products with great difference in the number of product parts, great difference in product assembly process and great difference in the size range of products, which has very high requirements for the flexibility of the assembly line. In addition, in order to reduce the manufacturing cost of the assembly line, when the assembly line is reconfigured for different products, the original assembly resources can be reused to a large extent, thereby reducing the cost, in addition, the reconfiguration of the assembly line should reduce the participation of manual as much as possible, ensure its high automation, and must ensure a set of systematic control and management method.

[0053] In order to solve the assembly problem of cross-category products, the embodiment of the application expands the capability of the current flexible assembly line from product family to any product, combines the characteristics of manual assembly with efficient automatic assembly, has the characteristics of reconfigurability and high efficiency, and realizes the assembly of cross-category products.

[0054] The following embodiment of the application proposes a cross-category reconfigurable flexible numerical control assembly method, which is described with reference to Figure 12 The method comprises the following steps: S1: inputting the information of a product to be assembled 8 and parsing it into assembly information; S2: configuring assembly resources according to the assembly information; S3: planning assembly process according to the configured assembly resources; S4: uploading the assembly information, the assembly resources and the assembly process planning to a simulation environment, pre-running an assembly task in the simulation environment, and generating an assembly control program; S5: issuing the assembly control program to an assembly line and running the assembly task to obtain an assembled product.

[0055] The embodiment of the application proposes a cross-category reconfigurable flexible numerical control assembly system, which comprises a central control computer and an assembly line, wherein the central control computer is configured to receive the information of a product to be assembled and parse the information of the product to be assembled into assembly information; configure assembly resources according to the assembly information; plan assembly process according to the configured assembly resources; the central control computer is also configured to run a simulation environment, the simulation environment is configured to receive the assembly information, the assembly resources and the assembly process planning, the central control computer is also configured to pre-run an assembly task in the simulation environment to generate an assembly control program, and issue the assembly control program to the assembly line; the assembly line is configured to receive the assembly control program issued by the central control computer, and run the assembly task to obtain an assembled product.

[0056] The following embodiment is taken as an example,

[0057] Embodiment 1

[0058] The embodiment proposes a cross-category reconfigurable flexible numerical control assembly method and system, which jointly constitute an assembly center for realizing automatic assembly of different products. The embodiment includes an assembly method of the assembly center, assembly system composition, and further proposes a control method of the assembly center. The assembly method of the assembly center realizes product assembly by using assembly resources, the hardware composition is a physical carrier for assembling products in the assembly center, and the control method of the assembly center realizes the circulation, display and production scheduling of assembly information.

[0059] I. Assembly method

[0060] The assembly method of the cross-category reconfigurable flexible numerical control assembly center includes inputting product 8 information to be assembled, assembly resource configuration, assembly process planning, assembly process simulation, and assembly action execution.

[0061] S1: The product 8 information to be assembled is input into the software part of the reconfigurable flexible numerical control assembly center, i.e., a client running in a central control computer or upper computer, including three-dimensional model information of the product and assembly process priority relationship of the product. The client of the assembly center analyzes the assembly information of the product to be assembled. The analyzed assembly content includes the number of parts of the assembly body (product), the topological relationship between the parts, the fitting relationship between the parts, the size of the parts, the structural features of the parts, etc.

[0062] S2: Based on the analyzed assembly information, the client of the assembly center configures the assembly resources, including the number and layout of assembly lines, the number of assembly units 1 of each assembly line, the types and quantities of assembly tools, assembly fixtures, and material pallets on each assembly unit 1. The specific resource configuration rule is: for different products, the characteristics of the product can be obtained according to the product model information, and the product characteristics and assembly resources are matched. For example, the pen barrel of a ballpoint pen is circular in shape, so a tool for clamping a circular cylinder needs to be configured during specific tool configuration. The operation size should be greater than the diameter of the cylinder, but should not be too large, otherwise the precision will be affected.

[0063] S3: According to the configuration of the assembly resources, the process planning of the assembly center is carried out to reasonably give the processes and steps to be completed on each assembly line and assembly unit 1. Through the process planning algorithm on the client, the assembly line layout, the number of assembly units 1, and the types and quantities of fixtures on the assembly units 1 are adjusted with the assembly line balance rate and the minimum assembly time as the optimization target. In the process of repeated iteration, when the optimization target tends to be stable, i.e., the amplitude change of the optimization target is <1% in 10 iterations, the first iteration in 10 iterations is considered as the optimal planning. The efficiency of each assembly unit 1 is balanced to achieve the optimal efficiency of the entire assembly line.

[0064] S4: The assembly information, assembly resources, and process planning are imported into the simulation environment. The assembly actions and paths are manually set based on the aforementioned information. The interference check is performed. The entire assembly program is compiled in the simulation environment according to the verification actions. The simulation environment is run to achieve the predetermined assembly task.

[0065] S5: The running program, assembly resource configuration, and process planning result of the simulation environment are downloaded to the reconfigurable flexible assembly line through a network cable. The assembly line downloads specific tasks to each assembly unit 1. Each assembly unit 1 finally performs specific assembly actions and completes the monitoring of the assembly process through sensors and vision devices on the assembly unit 1. Finally, the assembly of the product is completed.

[0066] II. Assembly system

[0067] The hardware components of the cross-category reconfigurable flexible numerical control assembly system include an assembly line and a central control computer. The assembly line includes an assembly unit 1.

[0068] Preferably, the assembly line further includes a transfer unit 2, a special unit 3, a mobile robot 4, a central tool library 5, and a central clamp library 6. The assembly unit 1 completes the implementation of some assembly processes of the product. The special unit 3 implements special processes. The transfer unit 2 completes the transfer of materials between different assembly units 1. The mobile robot 4 moves throughout the assembly center to complete the transfer of materials and tools and clamps. The central tool library stores tools for implementing different process procedures. The central clamp library stores clamps for implementing different process procedures. The central control computer loads a client program to achieve the control, scheduling, monitoring, and other management of the entire line.

[0069] Preferably, the assembly unit 1, the transfer unit 2, and the special unit 3 form an assembly line according to process needs. One assembly line can implement all assembly processes. The mobile robot 4 completes the transfer of materials, tools, clamps, and the automatic configuration of other assembly resources. The tools and clamps in the central tool library and the central clamp library are managed according to a certain management mode. The types and quantities of tools and clamps can be expanded and supplemented according to the requirements of the actual assembly product.

[0070] The assembly unit 1 includes parts to be assembled, material trays, actuators, tools, clamps, and tool and clamp caches. The transfer unit 2 includes transfer unit actuators and tools. The special unit 3 includes a special actuator 31. The mobile robot 4 includes a mobile robot operation actuator 41, tool and clamp caches, and part caches. The central tool library and the central clamp library include various tools and clamps. The central control computer includes a running client and a control system.

[0071] III. Control method

[0072] The control method of the cross-category reconfigurable flexible numerical control assembly center includes a client in a central control computer, a PLC (Programmable Logic Controller) and an actuator in each assembly unit 1, each PLC controls various input and output signals such as electromagnetic valves, sensors, etc. on the assembly unit 1, and each actuator includes a robot ROS (Robot Operating System), and both the PLC control and the ROS control will realize data collection and delivery. Preferably, the sensors for input signals can be displacement sensors, pressure sensors, limit switches, probe switches, photoelectric sensors, etc., and the elements for output signals can be electromagnetic valves, relays, micro switches, motors, electric rails, buzzers, alarm lights, signal lights, etc.

[0073] The central control computer includes an information analysis module, an assembly resource configuration module, an assembly process planning module, and an assembly process simulation module. The information analysis module is used to receive the information of the product to be assembled and analyze the information of the product to be assembled into assembly information. The assembly resource configuration module is used to configure assembly resources according to the assembly information. The assembly process planning module is used to plan the assembly process according to the configured assembly resources. The assembly process simulation module is used to receive the assembly information, the assembly resources, and the assembly process planning, and pre-run the assembly task to generate an assembly control program.

[0074] The assembly line composed of the plurality of assembly units 1, the transfer unit 2, and the special unit 3 is dispatched by the central control computer of the assembly line, the assembly center composed of a plurality of assembly lines is dispatched by the central control computer, the central control computer runs a database, a whole-line client, and a Web server, can send production information to a mobile terminal, and can send commands to various units of the assembly center, mobile robots 4, and a central clamp library through a network cable and a wireless network and receive feedback signals.

[0075] After the information of the product to be assembled 8 is input, the assembly method of the assembly center is followed in sequence, and finally the central control computer sends instructions to each assembly line, mobile robots 4, an assembly clamp library, etc. Each assembly line decomposes and sends specific processes to each unit, each unit sends to the PLC and ROS, and then the PLC and ROS control specific actuators and sensor actions.

[0076] The central control computer can realize process management, production management, early warning management, quality management, report board, etc.

[0077] The central control computer completes the centralized sending and receiving of production information, manages through a unified database, and can process locally, access, query and control the entire assembly center at a remote Web end or mobile end.

[0078] The working principle of the embodiment is: given a product to be assembled, such as a shuttle valve, the product information input, assembly resource configuration, assembly process planning, assembly process simulation and assembly action execution are sequentially performed according to the steps shown in the figure to complete the assembly of the shuttle valve. Figure 1 When another product (whether across product families) such as a mobile phone needs to be assembled, the original hardware such as the assembly unit 1, the transfer unit 2 and the mobile unit can continue to be used, the tools and fixtures on the assembly unit 1 can continue to be used if they meet the assembly requirements of the mobile phone, and new tools and fixtures need to be designed and put into the central tool fixture if they cannot meet the requirements and reused in the assembly of similar products. The algorithms of various modules in the original software can be reused, such as the assembly line layout algorithm, the assembly sequence generation algorithm and the path planning algorithm. Therefore, for the assembly of different products, if the original hardware can completely achieve the predetermined assembly process requirements, no additional hardware needs to be added, and only the layout of the assembly line, the position of the tool fixture and the movement of the mechanical arm need to be adjusted according to the layout, the tool fixture list and the assembly sequence obtained from the process requirements of the new product to complete the assembly of the new product. If the original hardware cannot completely achieve the predetermined assembly process requirements, new tools and fixtures need to be designed to meet the requirements, or a special unit 3 needs to be added, for example, the assembly of the shuttle valve does not require welding, but the assembly of the mobile phone requires welding, and in the case that other hardware meets the requirements, a special welding unit 3 needs to be added to complete the assembly of the mobile phone.

[0079] For example, as shown in the figure, the assembly of the shuttle valve is completed by the assembly unit 1, the transfer unit 2 and the mobile unit, and the assembly of the mobile phone is completed by the assembly unit 1, the transfer unit 2, the mobile unit and the special unit 3. Figure 1As shown, a cross-category reconfigurable flexible numerical control assembly center is disclosed, and the assembly center working process includes A1 input product information, A2 assembly resource configuration, A3 assembly process planning, A4 assembly process simulation, A5 assembly action execution, and A6 output assembly product. The A1 input product information is mainly divided into two parts, including A11 input of the three-dimensional model of the product and A12 input of the assembly process of the product. This is the most basic and minimum input information to ensure the reconfiguration of the assembly center when assembling cross-category products. The A2 assembly resource configuration includes two parts, A21 assembly line layout and A22 fixture list. Based on the given assembly information, the layout of each assembly line, assembly unit 1, transfer unit 2, etc. in the assembly center is arranged, and the assembly fixture required by each assembly unit 1 is given. The A3 assembly process planning includes two parts, A31 assembly sequence generation and A32 assembly line balancing. Based on the given product assembly information and the assembly resource configuration, the part assembly sequence of the product is given, and the process steps of the assembly line are optimized to ensure the balance rate requirement of each assembly line assembly unit 1. The A4 assembly process simulation also includes three parts, one is A41 process planning, another is A42 resource configuration, and the other is A43 assembly program generation. This is to reproduce the A2 assembly resource configuration and A3 assembly process planning in the simulation environment again to complete the confirmation of each part. A43 assembly program generation is based on A41 and A42 assembly process simulation, and the complete assembly process simulation is completed in the simulation environment after the interference check. After the completion of the interference check, the generation of the PLC control program, the ROS control program, and the assembly language control program is directly completed in the simulation environment. The A5 assembly action execution includes two parts, A51 running assembly task and A52 product process monitoring. After the program generation, the program is issued to each assembly line through the central control computer, and is issued to the PLC and ROS controller of each assembly unit 1 of the assembly line for execution A51. Among them, the PLC controls each electrical and sensor on the assembly unit 1, and the ROS controller controls the actuator and the related electrical equipment on the actuator. Through various actuators and sensors, the A52 product process monitoring of the assembly process is completed, and the monitoring data is transmitted back to the central control computer. Finally, the output assembly completed product A6 is output.

[0080] As Figure 2As shown, the hardware components of the cross-category reconfigurable flexible CNC assembly center include assembly units 1, which complete certain process steps of the product, transfer units 2, which complete the transfer of parts and pre-assembled parts between assembly units, special units 3, which complete special processes that are difficult for assembly units to complete, mobile robots 4, which complete the picking and placing of fixtures and parts to be assembled, a central tool library 5, which stores tools needed for use in assembly units, transfer units, and special units, a central fixture library 6, which stores fixtures needed for use in assembly units and special units, and a central control computer 7, which completes the control of the assembly center. The assembly units 1 are configured with parts to be assembled 11, material pallets 12, fixtures 13, assembly unit operation executors 14, and assembly unit tool caches 15. The transfer units 2 are configured with transfer unit operation executors 21 and transfer unit operation tools 22. The special units 3 are configured with special executors 31. The mobile robots 4 are configured with mobile robot operation executors 41, mobile robot tool caches 42, mobile robot fixture caches 43, and mobile robot part caches 44. The central tool library 5 stores various tools, the central fixture library 6 stores various fixtures, and the central control computer 7 runs an assembly center client and an assembly center control system.

[0081] The special units 3 can be used to meet the needs of processes such as large-torque screwing processes, welding processes, and bending processes.

[0082] In the assembly of a simplest product, assembly units 1 are necessary. For this system, it is task-driven, and the task is simple enough to be completed with one assembly unit 1. For a complex task, such as one that requires a transfer unit 2 or a special unit 3, the units cannot be omitted.

[0083] As shown in FIG. 2, the assembly center is configured with a plurality of assembly units 1, a plurality of transfer units 2, a plurality of special units 3, a plurality of mobile robots 4, a central tool library 5, a central fixture library 6, and a central control computer 7. Figure 3As shown, the control method of the cross-category reconfigurable flexible numerical control assembly center includes three levels. The first level is the assembly center level, including a Web terminal, a mobile terminal, and a database, which can control and view the production situation of the assembly center even if it is not in the assembly center. The control system of each part in other units (such as special units, transfer units), mobile robots, central tool library, and central clamp library is implemented to realize the interaction of the central control computer and each part signal. The second level is the assembly line level. As an example, it includes assembly line 1, assembly line 2, …, and assembly line n. The actual number of assembly lines is related to the size of the assembly center. The more types of products that need to be assembled and the greater the difference between each assembly product, the larger the size of the assembly center, and the more assembly lines there are in general. However, this is not absolute and depends on process layout, assembly line balancing, tooling design, and many other factors. This is only an example of explanation. The command of the assembly central control computer is generally issued to the control system of the assembly line, and then the control system of the assembly line completes the distribution of specific instructions. It needs to be noted that depending on the size of the assembly center, a special assembly line can also constitute an assembly center, and an extremely special assembly unit can also constitute an assembly center. The third level is the assembly unit level. The assembly unit includes assembly unit 1, assembly unit 2, …, and assembly unit n. The actual number of assembly units is related to the complexity of the products to be assembled. The more parts a product has and the more complex the assembly process, the more assembly units there are in general. However, this is not absolute and depends on assembly unit process layout and tooling design and many other factors. This is only an example of explanation. The assembly unit has a client, and the system on the client is divided into a programmable logic controller (PLC) and a robot operating system (ROS). There are different signals including solenoid valves, sensors, etc. in the robot ROS, and there are different brands of operating systems. The work task of the assembly unit is issued by the assembly line, the assembly unit combines the resources of the assembly unit, sends the command to the PLC to control the corresponding solenoid valve, electric cylinder, servo motor, etc., and sends the command to the ROS to control the operation of the actuator and the tools equipped with electrical interfaces. And receive the sensor and other feedback signals obtained by the ROS and the PLC, and after integrating and processing the signals, continue to feed back to the assembly line and then to the central control computer.

[0084] As shown in Figure 4a , Figure 4b , Figure 4c As shown, the input information of the cross-category reconfigurable flexible numerical control assembly center includes a three-dimensional model of a product and an assembly process of the product, as shown in Figure 4a The three-dimensional model of the shuttle valve body D1 includes five types of parts, large rubber ring D11, small rubber ring D12, steel ball D13, cylindrical plunger D14, and main housing D15. The assembly process of the product is as shown in Figure 4cThere are three types: ① Place the large rubber ring D11 and the small rubber ring D12 into the main housing D15; ② Place the steel ball D13 into the main housing D15; ③ Place the cylindrical plug D14 into the main housing D15. To better input information into the assembly center, [the following steps are taken]. Figure 4c The assembly process in the middle is transformed into such as Figure 4b The product assembly priority diagram, where the numbers represent the constraints on the assembly order of each part.

[0085] like Figure 5a and Figure 5b As shown, the assembly line layout of the cross-category reconfigurable flexible CNC assembly center refers to the fact that, due to the extremely high degree of freedom, the reconfigurable line can accomplish the same task in many different ways. For example, to assemble the same product, Figure 5a This is the configuration of assembly line 1. Figure 5b It is an assembly line configuration 2, in which, in the assembly line, Figure 5a In the assembly line configuration, assembly units 1-1 and 1-4 run parallel to assembly unit 1-2. Assembly unit 1-5 inputs pre-assembled parts and completes the process steps of its respective assembly unit. After completing the process steps, assembly unit 1-5 transfers the pre-assembled parts to assembly unit 1-3. After completing the process steps, assembly unit 1-2 transfers some pre-assembled parts to special unit 3 to complete some operations before transferring them back to assembly unit 1-3. The remaining pre-assembled parts are directly transferred from assembly unit 1-2 to assembly unit 1-3. Finally, assembly unit 1-3 completes the process steps to achieve complete product assembly. The transfer of parts between assembly units is achieved through transfer unit 2. Figure 5b The assembly lines in the text also assemble the same products, but the difference lies in the configuration of the assembly line and the different process steps, while the assembly process is the same.

[0086] like Figure 6 As shown, the top view of the assembly unit in the cross-category reconfigurable flexible CNC assembly center is preferably circular, rectangular, square, or hexagonal. Considering the workspace of an actuator, the top view of an assembly unit is generally circular to maximize the utilization of the robotic arm's working space. However, when arranging assembly lines and assembly centers in a workshop, the overall space occupancy and utilization rate need to be considered. Different top views of assembly units will affect the layout design of the entire assembly line and the functionality of the actuators (robotic arms) on the assembly unit. Robotic arms generally have a spherical working space, and a circular top view is optimal with the robotic arm as the consideration. However, dense arrangement in space will result in waste, as there will inevitably be gaps between circles. In short, different top views will affect the allocation of assembly resources within the assembly unit, as well as the layout of the assembly line, thereby affecting process planning and even the execution of actions.

[0087] likeFigure 7a and 7b As shown in FIG. 1, the assembly line balancing schematic diagram of the cross-category reconfigurable flexible numerical control assembly center, considering two assembly line layouts, the square numbers 1', 2', 3', 4' in the layout are assembly process steps that need to be completed, wherein Figure 7a In the assembly line layout 1, process step 1' needs a long time, and steps 2' / 3' need a relatively short time, if the assembly process steps 1' / 2' are designed to be completed in assembly unit 1-1, it will cause assembly unit 1-2 to exist waiting, thereby reducing the assembly efficiency. Figure 7b In the assembly line layout, the process steps 2' / 3' are designed on the assembly unit 1-2, which can make the time of completing the assembly process of the three assembly units equal, thereby maximizing the assembly line efficiency.

[0088] As shown in FIG. 2, the jig structure schematic diagram of the cross-category reconfigurable flexible numerical control assembly center, the rubber ring assembly tool F3 is a tool specially designed to complete the rubber ring assembly, the position relationship assembly tool F4 is used to complete the clamping and placing of parts, the positioning and clamping jig F5 is used to realize the positioning and clamping of parts, and the thread assembly special unit F6 realizes the assembly requirements of large torque and special thread tightening. Figure 8 As shown in Table 1, the jig configuration list schematic of the cross-category reconfigurable flexible numerical control assembly center, the jig list is of great significance to the resource configuration of the entire assembly center, and is also an important medium for the exchange of material information of each unit. For example, the jig list of the assembly center has the following structure form, the assembly center has several assembly lines, the assembly line has several assembly units, the assembly unit completes several assembly processes, the assembly process needs what kind of tool, jig, and how many, based on this decomposition, the resource configuration of the entire assembly center is clear.

[0089] Table 1 Assembly line balancing schematic

[0090]

[0091] As shown in FIG. 3, for example, the assembly unit layout of the cross-category reconfigurable flexible numerical control assembly center is circular, including a jig buffer rack 16 for storing various tools and jigs, an operating tool 17 for executing assembly process tasks, a material tray 12 for buffering parts and parts to be assembled 11, an assembly unit operation executor 14 for executing the operation of the entire assembly unit 1, and a jig 13 for completing the positioning and clamping of parts and parts to be assembled 11.

[0092] Figure 9

[0093] As shown in FIG. 4, the assembly unit layout of the cross-category reconfigurable flexible numerical control assembly center is circular, including a jig buffer rack 16 for storing various tools and jigs, an operating tool 17 for executing assembly process tasks, a material tray 12 for buffering parts and parts to be assembled 11, an assembly unit operation executor 14 for executing the operation of the entire assembly unit 1, and a jig 13 for completing the positioning and clamping of parts and parts to be assembled 11. Figure 10 ​​As shown, the assembly center layout of the example cross-category reconfigurable flexible numerical control assembly center includes input parts, i.e. product parts 11 to be assembled input to the assembly center; H2 is assembly line one, assembly line configuration one for completing assembly of the product to be assembled 8; H3 is assembly line two, assembly line configuration two for completing assembly of the product to be assembled; H4 is assembly line three, assembly line configuration three for completing assembly of the product to be assembled, and H5 is the product completed. It also includes mobile robots 4 for completing the movement of materials, including tools, clamps, parts to be assembled, etc. throughout the assembly center; central tool library 5 (Tool Library, TLib), central clamp library 6 (Fix Library, Flib), central control computer 7 (Center Computer, CC). The assembly center uses multiple assembly lines to complete the assembly of a product, and in particular, each assembly line has a different configuration. The entire assembly center inputs parts to be assembled and outputs the final assembled product. The materials between the assembly lines are completed by mobile robots 4. Generally, there is more than one mobile robot 4, and in particular, in some cases, the assembly center may not have mobile robots, and the material transfer within the assembly line is completed by transfer units 2. The central tool library 5 and the central clamp library 6 provide tools and clamps for the entire assembly center, and the control of the entire assembly center is completed by the central control computer 7.

[0094] As shown, Figure 11 , the assembly line structure diagram of the example cross-category reconfigurable flexible numerical control assembly center includes assembly tool clamp library 56, mobile robot 4, assembly unit 1, special unit 3, and transfer unit 2. The assembly line structure layout is Figure 5a the actual layout effect.

[0095] The working principle of the above embodiment of the present application is as follows: when a product needs to be assembled, it is necessary to ensure that the central tool library 5 and the central clamp library 6 have corresponding tools and clamps, and if there is no tool and clamp, the design of the corresponding functional tool and clamp needs to be completed and supplemented to the tool and clamp. The information of the product is input into the client of the assembly center, the assembly process information is analyzed, the layout of the assembly line is realized through the algorithm, the list of tool and clamps required by each assembly unit of the assembly center is generated, generally, the generated assembly line layout needs to be confirmed. Then, the assembly sequence of each part of the product is generated, the appropriate assembly process path scheme is determined, the distribution of the assembly process scheme in the assembly center is determined through the algorithm, generally, the scheme and information need to be confirmed. Then, the whole assembly process is simulated, and the assembly program and each resource configuration scheme that can be applied to the real world are generated in the simulation environment, and are directly issued to each specific execution assembly unit 1, transfer unit 2, special unit 3, mobile robot 4, assembly tool and clamp library 56 and the like through the corresponding interface. All the information in the process is sent to the central control computer through the network, and the central control computer 7 is a server end, which is configured with a database and can send each assembly information to the mobile end and the Web end to provide query and accept the command of the mobile end and the Web to control the assembly center.

[0096] The embodiment of the present application has the following characteristics:

[0097] 1. The embodiment of the present application can realize automatic assembly of products across product families, and has extremely high reconfigurability;

[0098] 2. In different assembly tasks, each assembly unit, assembly tool and clamp, mobile robot and the like can be reused, which greatly reduces the manufacturing management cost of developing a new production line and greatly reduces the product production cycle;

[0099] 3. When assembling different products, only a small amount of product information needs to be input, and other processes are realized through corresponding algorithms, without the need for too much human intervention, which improves the equipment change efficiency and greatly reduces the labor cost;

[0100] 4. The central control computer uniformly completes the scheduling, control and management of the assembly center task, can realize the sending and receiving of commands on multiple ends, can realize the monitoring of the production task on multiple ends, and greatly improves the flexibility, numerical control and intelligent level of the reconfigurable flexible assembly field.

[0101] 5. It has the efficiency of a dedicated assembly line and the flexibility of a flexible assembly line.

[0102] The cross-category reconfigurable flexible numerical control assembly method and system disclosed by the embodiment of the present application can automatically complete assembly process planning and assembly resource configuration by inputting only a small amount of product information. After the relevant configuration is completed, full-process assembly process simulation is performed, and then the verified process and assembly resource are applied to the actual assembly line, the generated control program is downloaded to the assembly line, the actual assembly process is completed, and finally the final product is output. The embodiment of the present application can realize automatic assembly of cross-category products, greatly reducing the workload of humans. The assembly system part in the embodiment of the present application can be customized according to the specific assembly needs, thereby further realizing customized assembly tasks.

[0103] The above is a further detailed description of the present application in combination with specific preferred embodiments, and the specific implementation of the present application cannot be limited to these descriptions. For those skilled in the art to which the present application belongs, without departing from the concept of the present application, a number of equivalent substitutions or obvious modifications can be made, and the performance or use is the same, which should be regarded as belonging to the protection scope of the present application.

Claims

1. A cross-category reconfigurable flexible CNC assembly method, characterized in that, It comprises the following steps: S1: input the information of the product to be assembled and parse it into assembly information; the information of the product to be assembled includes a three-dimensional model of the product to be assembled, assembly process priority relationship; S2: configure assembly resources according to the assembly information; S3: perform assembly process planning according to the configured assembly resources; the assembly process planning includes assembly sequence and assembly line balancing; The assembly sequence includes the assembly line, the process and the step when the assembly unit performs the assembly task; The assembly line balancing includes at least one of optimization and adjustment of the assembly sequence, adjustment of the assembly line layout, adjustment of the assembly unit, adjustment of assembly tools, and adjustment of assembly fixtures by process planning algorithm, with assembly line balancing rate and minimized assembly time as optimization targets, in a repeated iterative process, when the optimization target tends to be stable, the amplitude change of the optimization target is <1%, which is the optimal planning, to achieve efficiency balance and optimal efficiency of the entire assembly line; S4: upload the assembly information, assembly resources and assembly process planning to a simulation environment, pre-run the assembly task in the simulation environment, and generate an assembly control program; S5: issue the assembly control program to the assembly line and run the assembly task to obtain the assembled product.

2. The cross-category reconfigurable flexible CNC assembly method of claim 1, wherein, In step S1, the information of the product to be assembled is input to a central control computer, which parses the information of the product to be assembled into the assembly information; The assembly information includes at least one of the parts of the product to be assembled, the number of the parts, the topological relationship between the parts, the fitting relationship between the parts, the size of the parts, and the structural features of the parts.

3. The cross-category reconfigurable flexible CNC assembly method of claim 2, wherein, In step S2, the assembly resources include at least one of the number of assembly lines and the layout of assembly lines, and the assembly line includes at least one of assembly units, assembly tools and assembly fixtures.

4. The cross-category reconfigurable flexible CNC assembly method of claim 1, wherein, In step S4, after the pre-run assembly task, if the assembly information, assembly resources and assembly process planning do not meet the requirements, repeat step S2 or manually modify them; The assembly control program includes PLC control program, ROS control program and assembly language control program.

5. The cross-category reconfigurable flexible CNC assembly method of claim 4, wherein, In step S5, the assembly line issues the assembly control program to the assembly unit, and the assembly unit runs the assembly task; It also includes monitoring and feeding back the assembly task.

6. A cross-category reconfigurable flexible CNC assembly system, characterized in that, It comprises a central control computer and an assembly line, wherein The central control computer is used to receive the input information of the product to be assembled and parse the information of the product to be assembled into assembly information, configure assembly resources according to the assembly information, and perform assembly process planning according to the configured assembly resources; The central control computer is also used to run a simulation environment, which is used to receive the assembly information, assembly resources and assembly process planning, and the central control computer is also used to pre-run the assembly task in the simulation environment to generate an assembly control program and issue the assembly control program to the assembly line; The assembly line is used for receiving the assembly control program issued by the central control computer and running the assembly task to obtain the assembled product.

7. The cross-category reconfigurable flexible CNC assembly system of claim 6, wherein, The central control computer comprises an information analysis module, an assembly resource configuration module, an assembly process planning module and an assembly process simulation module, wherein, The information analysis module is used for receiving the information of the product to be assembled and analyzing the information of the product to be assembled into assembly information; The assembly resource configuration module is used for configuring assembly resources according to the assembly information; The assembly process planning module is used for planning assembly process according to the configured assembly resources; The assembly process simulation module is used for receiving the assembly information, the assembly resources and the assembly process planning, pre-running the assembly task and generating the assembly control program.

8. The cross-category reconfigurable flexible CNC assembly system of claim 6, wherein, The assembly line comprises an assembly unit, and the assembly unit is used for executing the assembly control program, and the assembly unit comprises a PLC and an actuator.

9. The cross-category reconfigurable flexible CNC assembly system of claim 8, wherein, The assembly unit further comprises a sensor for monitoring the assembly task and feeding back to the central control computer.

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