Simulation and optimization method for subway frame overhaul workshop process

Abstract

The invention discloses a subway frame overhaul workshop process simulation and optimization method. The method comprises the following steps: S1, determining a simulation target; s2, collecting simulation data; s3, performing simulation planning; s4, simulation modeling is carried out; s5, simulation result processing and data analysis; and S6, process optimization and the like. According to the invention, before a subway frame overhaul workshop is built, through data-driven virtual joint overhaul library simulation system project construction, coping capacities of vehicle depot frame overhaul library planning layout, logistics optimization and production maintenance optimization adjustment can be improved; according to the method, digital decision support is provided for evaluation and efficiency improvement of a vehicle depot overhaul warehouse vehicle maintenance production line, comprehensive evaluation of vehicle depot overhaul warehouse locomotive maintenance process planning is achieved through an index analysis and optimization technology, and therefore the workshop management efficiency of the depot overhaul warehouse is improved.

Description

Technical Field

[0001] The invention relates to the technical field of subway frame overhaul, and in particular to a subway frame overhaul workshop process simulation and optimization method. Background Art

[0002] With the continuous increase in the operating mileage and service life of my country's subways, subway vehicles are facing the maintenance process of overhaul. When a subway vehicle has been in operation for 5 years or has a running mileage of 500,000-600,000 kilometers, it needs to be overhauled. When a subway vehicle has been in operation for 10 years or has a running mileage of 1 million-1.2 million kilometers, it needs to be overhauled. When selecting overhaul facilities and layout plans for vehicles, subway companies must make a general design of the overhaul process.

[0003] After the civil construction and installation of electromechanical equipment are completed, the traditional overhaul depot process layout will be difficult to change in the later stage. Most of the process flow and layout refer to the relevant experience of the national railway. It is a "big and complete" design, and many details cannot be determined, resulting in many problems such as unsmooth overhaul process flow, unreasonable process layout, incomplete functions, and inefficiency. With the continuous development of informatization, before building the overhaul depot, the overhaul depot can be simulated and analyzed by computer, so as to achieve the goal of "quality maintenance, quantitative maintenance, smart maintenance, cost reduction and efficiency improvement", build an overhaul "smart workshop", open up all the blockages in the vehicle overhaul production process, realize the management and control of the entire vehicle overhaul production process, further improve the efficiency and quality of vehicle overhaul inspection and maintenance operations, and reduce the cost of vehicle overhaul maintenance, which is of great significance to the development of intelligent operation and maintenance management of urban rail transit. Summary of the invention

[0004] The purpose of the present invention is to provide a subway frame overhaul workshop process simulation and optimization method to solve the above defects.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] A subway overhaul workshop process simulation and optimization method comprises the following steps:

[0007] S1. Determine the simulation target: Evaluate the subway overhaul plant and analyze different process layout plans to determine the simulation target;

[0008] S2. Simulation data collection: According to the classification of simulation data items, it is necessary to collect and organize the technical data, organizational structure data and system loading data of the rack overhaul workshop;

[0009] S3, Simulation planning: including system modeling and virtual simulation. Based on Plant Simulation, a process simulation model of bogie maintenance with detailed process and undetailed overall part is established on the basis of existing data, and simulation analysis is performed on the main indicators.

[0010] S4, simulation modeling: according to the above simulation plan, use the Plant Simulation standard class library and the custom class library to establish a simulation model of the overhaul warehouse system; the overhaul warehouse system simulation model includes a simulation model of the wheelset frame separation station, a simulation model of the frame disassembly station, and a simulation model of the wheelset frame assembly station;

[0011] S5. Simulation result processing and data analysis: Based on the simulation model of the bogie overhaul depot system with 250 working days, simulation calculations can be performed to obtain qualitative and quantitative data on production capacity, bottleneck processes, buffer size settings, resource utilization, turnover parts analysis, bogie maintenance area congestion, waiting, and occupancy rates of each buffer;

[0012] S6. Process optimization: Based on a thorough analysis of the key production parameters of vehicle frame overhaul production efficiency and bottlenecks, the overall process layout of the frame overhaul depot is optimized in combination with genetic algorithms, and the efficiency of the proposed optimization scheme is verified, thereby providing decision support for improving the maintenance and repair efficiency of vehicle frame overhaul depots in vehicle depots and further improving the management efficiency of frame overhaul depot workshops.

[0013] Preferably, in step S1, the simulation target is determined. When simulating the overall process layout of subway overhaul, more than 30 work sites need to be simulated in detail. However, based on the analysis of the overall rhythm and bottlenecks, 8 key work sites are divided, namely, purge - air conditioning, pantograph disassembly and installation - train disassembly - car body warehouse maintenance - bogie maintenance - car weighing - train coupling - train static adjustment, so the key work sites are simulated and simulated.

[0014] Preferably, in step S2, the technical data includes workshop layout and logistics routes, working hours and equipment performance parameters, and initial settings of circulating parts; the organizational structure data includes the shift plan of the overhaul warehouse workshop, workshop production resource allocation, and workshop production organization strategy; the system loading data includes product and work-in-progress data, and assembly BOM.

[0015] Preferably, in step S3, the system modeling adopts a hierarchical, modular, object-oriented modeling method, by importing lightweight models of external products and equipment, and establishing a basic modeling resource library including a standard object library and a customized object library, and then gradually building a virtual model of the entire workshop on this basis, and the workshop modeling results can be output as a whole through a variety of integrated interfaces.

[0016] Preferably, in step S3, the virtual simulation is to realize the virtual simulation of the production process of the rack overhaul warehouse workshop based on the simulation model of the rack overhaul warehouse system and the results of the three-dimensional process planning of the rack overhaul warehouse workshop, including modeling of the logistics simulation system, logistics simulation analysis and calculation, and scheme evaluation and optimization.

[0017] Preferably, in step S4, the wheelset frame separation station includes a semi-coupling separation process, gear box boom disassembly, fixing bolt disassembly, and lifting and disassembly followed by a wheelset frame separation process, wherein the EMU has a coupling but the trailer does not, and flow control is required for diversion processing; the frame disassembly station is composed of frame logistics, empty spring disassembly, and motor disassembly processes, wherein the EMU contains a motor but the trailer does not, so flow control is used for diversion processing.

[0018] Preferably, in the process of studying the workshop layout and logistics routes, the overall layout of the workstations, the topological relationship between the workstations, and the material distribution and transfer paths are the objects of study and investigation; for working hours and equipment performance parameters, it is necessary to collect and organize the operation time of each workstation, the average operating speed of the overhead crane, the operating speed of the aerial logistics, and the capacity data of each temporary storage area, and confirm the transportation capacity of the trolleys, AGV carts, transfer platforms, and overhead cranes; for the initial setting of the turnover parts, the traction motor, braking device, and wheelset bearings need to be set separately.

[0019] Preferably, when simulating the shift plan of the overhaul warehouse workshop, using non-natural days as the simulation time can effectively simplify the simulation model; the workshop production organization strategy includes the control strategy of the production rhythm, the frame, the car body, and the wheelset transfer strategy.

[0020] Preferably, the standard object library contains general workshop modeling object resources, which can be directly used as standard models during workshop modeling; the customized object library is oriented to the specific workshop environment characteristics of the circuit breaker assembly line, customizes and configures the customized object resource model, and quickly generates a specific object model according to actual parameters; the construction of the virtual model needs to adopt hierarchical modeling, object-oriented modeling, and modular modeling methods, and has progressive modeling capabilities, which can decompose and simplify the modeling work of complex systems to improve work efficiency; the integration interface needs to provide system integration capabilities and standard interfaces, including real-time data exchange, importing tables, importing data and drawings, and online database connection to achieve communication and data exchange between workshop modeling and other application systems.

[0021] Preferably, the modeling of the logistics simulation system needs to be based on the virtual model of the workshop and the process planning data, and the logistics simulation parameters, constraints and rules and methods need to be defined according to the technical and management conditions of the actual production environment, so as to establish a logical model of logistics simulation; when performing logistics simulation analysis and calculation, it is necessary to calculate the key production parameters of production logistics, bottlenecks, efficiency, inventory, and rhythm, so as to provide support for subsequent mid-term solution evaluation and optimization.

[0022] The beneficial effects of the present invention are:

[0023] The subway frame overhaul plant process simulation and optimization method of the present invention can improve the planning and layout, logistics optimization, and production maintenance and repair optimization and adjustment capabilities of the vehicle depot frame overhaul depot through the construction of a data-driven virtual joint maintenance depot simulation system project before building a subway frame overhaul workshop, and provide digital decision support for the evaluation and efficiency improvement of the vehicle maintenance and repair production line of the vehicle depot frame overhaul depot. Through indicator analysis and optimization technology, a comprehensive evaluation of the locomotive maintenance and repair process planning of the vehicle depot frame overhaul depot can be achieved, thereby improving the management efficiency of the frame overhaul depot workshop. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 :The present invention is based on Plant Simulation to simulate the whole process flow diagram of the subway overhaul plant;

[0025] Figure 2 : The simulation process flow chart of the present invention;

[0026] Figure 3 : The shift plan diagram of the overhaul warehouse workshop simulation of the present invention;

[0027] Figure 4 : Schematic diagram of the overall modeling technology route of the overhaul warehouse workshop of the present invention;

[0028] Figure 5 : Schematic diagram of the technical route of virtual simulation of the production process of the overhaul warehouse workshop of the present invention;

[0029] Figure 6 : The overall process layout of the overhaul warehouse workshop of the present invention;

[0030] Figure 7 : The wheelset frame separation station simulation model of the present invention;

[0031] Figure 8 : The present invention's framework disassembly station simulation model;

[0032] Fig. 9 : The wheelset frame assembly station simulation model of the present invention;

[0033] Fig.10 : Annual production capacity data chart of the overhaul warehouse of the present invention. DETAILED DESCRIPTION

[0034] The present invention is further described below in conjunction with the embodiments. It should be noted that these are merely examples and illustrations of the concept of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they should be deemed to fall within the protection scope of the present invention.

[0035] Embodiment 1:

[0036] like Figure 1 As shown, a subway overhaul workshop process simulation and optimization method includes the following steps:

[0037] S1. Determine the simulation target: Evaluate the subway overhaul plant and analyze different process layout plans to determine the simulation target.

[0038] S2. Simulation data collection: According to the classification of simulation data items, it is necessary to collect and organize the technical data, organizational structure data and system loading data of the overhaul warehouse workshop.

[0039] S3. Simulation planning: including system modeling and virtual simulation. Based on Plant Simulation and existing data, a process simulation model of bogie maintenance with detailed process and undetailed overall part is established, and simulation analysis is carried out on the main indicators.

[0040] S4. Simulation modeling: According to the above simulation plan, the Plant Simulation standard class library and the custom class library are used to establish a simulation model of the overhaul warehouse system; the simulation model of the overhaul warehouse system includes a simulation model of the wheelset frame separation station, a simulation model of the frame disassembly station, and a simulation model of the wheelset frame assembly station.

[0041] S5. Simulation result processing and data analysis: Based on the simulation model of the bogie overhaul depot system with 250 working days, simulation calculations are performed to obtain qualitative and quantitative data on production capacity, bottleneck processes, buffer size settings, resource utilization, turnover parts analysis, bogie maintenance area congestion, waiting, and occupancy rates of each buffer.

[0042] S6. Process optimization: Based on a thorough analysis of the key production parameters such as vehicle frame overhaul production efficiency and bottlenecks, the overall process layout of the frame overhaul depot is optimized in combination with genetic algorithms, and the efficiency of the proposed optimization scheme is verified, thereby providing decision support for improving the vehicle maintenance and repair efficiency of the vehicle depot frame overhaul depot and further improving the management efficiency of the frame overhaul depot workshop.

[0043] Embodiment 2:

[0044] Figure 1 This is a schematic diagram of the whole process of subway overhaul plant simulation based on Plant Simulation. Figure 1 As shown, a subway overhaul workshop process simulation and optimization method includes the following steps:

[0045] S1. Determine the simulation target: Evaluate the subway overhaul plant and analyze different process layout plans to determine the simulation target.

[0046] According to the layout plan of the preliminary overhaul, the overall process layout is simulated using Plant Simulation. According to the maintenance area layout, maintenance content, maintenance process, equipment layout, scheduling instructions, on-site material transportation, maintenance hours, etc. in the process planning plan, the process layout production capacity and production efficiency are verified and optimized.

[0047] To determine the simulation target, when simulating the overall process layout of subway frame overhaul, more than 30 work sites need to be simulated in detail. However, based on the analysis of the overall rhythm and bottlenecks, 8 key work sites are divided (namely, purge - air conditioning, pantograph disassembly and installation - train unmarshalling - car body warehouse maintenance - bogie maintenance - car weighing - train coupling - train static adjustment) as black box detailed simulation, so the key work sites are simulated and simulated.

[0048] S2. Simulation data collection: According to the classification of simulation data items, it is necessary to collect and organize the technical data, organizational structure data and system loading data of the overhaul warehouse workshop.

[0049] (1) Technical data includes workshop layout and logistics routes, working hours and equipment performance parameters, and initial settings of turnover parts.

[0050] In the process of researching the workshop layout and logistics routes, the overall layout of the workstations, the topological relationship between the workstations, the material distribution and transfer paths are the key research and investigation objects, forming a set of simulation solutions such as Figure 2 As shown. Through the survey, the working hours and equipment performance required for each equipment are collected, such as the working time of the workbench: in line with the average probability distribution, unit min; the transportation capacity of the overhead crane: each overhead crane can only transport one accessory at a time; the probability of failure: considering the failure of some equipment; the flatbed truck speed: 0.2 m / s; the turntable data: 90 degrees for 3 minutes, the transportation speed is 0.2 m / s; the car transfer platform: 0.2 m / s; the overhead crane speed: 0.2 m / s; the manual forklift: 1.3 m / s; the AGV speed: 0.8 m / s. The initial setting of the turnover parts mainly includes 16 traction motors, 96 brake devices, and 288 wheel bearings.

[0051] For working hours and equipment performance parameters, it is necessary to collect and organize the operation time of each work station, the average operating speed of the overhead crane, the operating speed of the aerial logistics and the capacity data of each temporary storage area, and confirm the transportation capacity of the trolleys, AGV carts, transfer platforms and overhead cranes.

[0052] For the initial setting of the rotating parts, the traction motor, brake device and wheelset bearings need to be set separately.

[0053] (2) Organizational structure data, including the shift plan of the overhaul warehouse workshop, the allocation of workshop production resources, and the production organization strategy of the workshop.

[0054] When simulating the shift plan of the rack overhaul workshop, using non-natural days as the simulation time can effectively simplify the simulation model. The rack overhaul workshop has one shift, working from Monday to Friday, and working hours from 9:00 to 17:00 a day, a total of 8 hours. However, in order to simplify the simulation model, the simulation plan uses working days instead of natural days as the simulation timing basis, arranging Monday to Sunday without rest, working 250 days a year. This time arrangement is basically the same as the actual effective working time of the rack overhaul workshop for 365 days. Figure 3 shown.

[0055] The allocation of workshop production resources needs to take into account the quantity and constraints of workshop resources such as the purge depot, air-conditioning pantograph disassembly, train disassembly, car body maintenance depot, and wheel-off weighing.

[0056] The workshop production organization strategy includes the production rhythm control strategy, structure, car body, wheelset transfer strategy, etc. The production rhythm control strategy is based on the events that occur in actual production, driving the coordinated operation of various production resources to control the rhythm of production. The bogie transfer strategy is constrained by the track. The bogies placed on the same track must leave each station in a certain order and finally be transferred to the wheel drop weighing station or the bogie temporary storage area.

[0057] (3) The system loads data, including product and work-in-process data and assembly BOM.

[0058] S3. Simulation planning: including system modeling and virtual simulation. Based on Plant Simulation and existing data, a process simulation model of bogie maintenance with detailed process and undetailed overall part is established, and simulation analysis is carried out on the main indicators.

[0059] Schematic diagram of the overall modeling technology route of the overhaul warehouse workshop, such as Figure 4As shown in the figure, the system modeling adopts hierarchical, modular, and object-oriented modeling methods. By importing lightweight models of external products and equipment, and establishing a basic modeling resource library including standard object library and customized object library, the virtual model of the entire workshop is gradually established on this basis, and the workshop modeling results can be output as a whole through a variety of integrated interfaces.

[0060] Among them, the standard object library contains general workshop modeling object resources, which can be directly used as standard models during workshop modeling; the customized object library is oriented to the characteristics of specific workshop environments such as circuit breaker assembly lines, and customizes and configures some customized object resource models, and can quickly generate specific object models according to actual parameters; the construction of the virtual model needs to adopt hierarchical modeling, object-oriented modeling, and modular modeling methods, with progressive modeling capabilities, and can decompose and simplify the modeling work of complex systems to improve work efficiency; the integration interface needs to provide system integration capabilities and standard interfaces, including real-time data exchange, importing tables, importing data and drawings, and online database connection to achieve communication and data exchange between workshop modeling and other application systems.

[0061] Schematic diagram of the technical route of virtual simulation of the production process of the overhaul warehouse workshop, such as Figure 5 As shown in the figure, virtual simulation is based on the simulation model of the rack overhaul warehouse system and combines the results of the three-dimensional process planning of the rack overhaul warehouse workshop to realize the virtual simulation of the production process of the rack overhaul warehouse workshop, including the modeling of the logistics simulation system, logistics simulation analysis and calculation, and solution evaluation and optimization.

[0062] Among them, the modeling of the logistics simulation system needs to be based on the virtual model of the workshop and the process planning data. According to the technical and management conditions of the actual production environment, the logistics simulation parameters, constraints and rules and methods should be defined to establish a logical model of logistics simulation. When conducting logistics simulation analysis and calculation, it is necessary to calculate key production parameters such as production logistics, bottlenecks, efficiency, inventory, and rhythm to provide support for subsequent mid-term solution evaluation and optimization.

[0063] S4. Simulation modeling: Based on the above simulation plan, use the Plant Simulation standard class library and custom class library to establish a simulation model of the rack overhaul warehouse system. The overall process layout diagram is as follows: Figure 6 The simulation model of the wheel frame overhaul depot system includes a simulation model of the wheelset frame separation station, a simulation model of the frame disassembly station, and a simulation model of the wheelset frame assembly station.

[0064] From the conceptual model of the wheelset frame separation simulation, it can be seen that the wheelset frame separation station includes the semi-coupling separation process, gearbox boom disassembly, fixing bolt disassembly, lifting and disassembly to separate the wheelset frame, etc. Among them, the motor car has a coupling but the trailer has no coupling, so flow control is required for diversion processing. The transportation of the frame is carried out by the aerial logistics claw. According to the relevant process requirements, resource constraints, working environment and other conditions, the work steps and process strings of the relevant stations are operated in parallel. The simulation model is constructed as follows Figure 7 shown.

[0065] The frame disassembly station consists of frame logistics, empty spring disassembly, and motor disassembly processes. The motor car contains a motor but the trailer does not, so flow control is used for diversion. The empty spring and motor disassembly actually occupy the same work space at this station. Considering the actual situation, a linkage station is used. When the frame enters the linkage station S1, the entrance of the linkage station S1 is locked. When the frame exits the linkage station S2, the linkage station S2 unlocks the linkage station S1, thereby ensuring that only one frame can enter the station at a time. The simulation model is constructed as follows: Figure 8 shown.

[0066] The wheelset frame assembly station consists of processes such as replacing the half-coupling seal ring, installing the primary fixing bolts, installing the gearbox boom, lifting and installing, installing the half-coupling, replacing the half-coupling, and oiling the half-coupling. The close relationship between the processes and the series and parallel relationship are given by the solution provider considering factors such as process constraints, resource constraints, process rhythm and working environment. The simulation model is constructed as follows Fig. 9 shown.

[0067] S5. Simulation result processing and data analysis: Based on the simulation model of the bogie overhaul depot system, simulation calculations are performed on 250 working days (considered as one year), and qualitative and quantitative data such as production capacity, bottleneck processes, buffer size settings, resource utilization, turnover parts analysis, bogie maintenance area congestion, waiting, and occupancy rate of each buffer area can be obtained.

[0068] like Fig.10 As shown in the figure, the final simulation results show that the solution has achieved good production capacity in both bogies and train formations, and the number of re-products on the production line is small, which proves that the design of the production line has a more balanced time consumption, and the production line has less time consumption for blocking and waiting. The frame and wheelset maintenance area are reasonably separated, which effectively ensures the efficiency of material flow and optimizes the working environment of workers. From the simulation results, the distribution of parts is basically normal, and the buffer zone is also relatively normal. From the ranking list of bottleneck processes in the simulation, the processes of wheel axle cleaning, empty spring inspection, frame flaw detection, etc. in the bogie maintenance area are time-consuming, and the bottleneck risk can be alleviated by adding parallel workstations or process optimization.

[0069] S6. Process optimization: Based on a thorough analysis of the key production parameters such as vehicle frame overhaul production efficiency and bottlenecks, the overall process layout of the frame overhaul depot is optimized in combination with genetic algorithms, and the efficiency of the proposed optimization scheme is verified, thereby providing decision support for improving the vehicle maintenance and repair efficiency of the vehicle depot frame overhaul depot and further improving the management efficiency of the frame overhaul depot workshop.

[0070] The subway frame overhaul plant process simulation and optimization method of the present invention can improve the planning and layout, logistics optimization, and production maintenance and repair optimization and adjustment capabilities of the vehicle depot frame overhaul depot through the construction of a data-driven virtual joint maintenance depot simulation system project before building a subway frame overhaul workshop, and provide digital decision support for the evaluation and efficiency improvement of the vehicle maintenance and repair production line of the vehicle depot frame overhaul depot. Through indicator analysis and optimization technology, a comprehensive evaluation of the locomotive maintenance and repair process planning of the vehicle depot frame overhaul depot can be achieved, thereby improving the management efficiency of the frame overhaul depot workshop.

[0071] The above is an exemplary description of the invention. Obviously, the specific implementation of the present invention is not limited to the above-mentioned method. As long as such non-substantial improvements are made by adopting the method concept and technical solution of the present invention, or the concept and technical solution of the invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A subway overhaul workshop process simulation and optimization method, characterized in that: The steps include: S1. Determine the simulation target: Evaluate the subway overhaul plant and analyze different process layout plans to determine the simulation target; S2. Simulation data collection: According to the classification of simulation data items, it is necessary to collect and organize the technical data, organizational structure data and system loading data of the rack overhaul workshop; S3, Simulation planning: including system modeling and virtual simulation. Based on Plant Simulation, a process simulation model of bogie maintenance with detailed process and undetailed overall part is established on the basis of existing data, and simulation analysis is performed on the main indicators. S4, simulation modeling: according to the above simulation plan, use the Plant Simulation standard class library and the custom class library to establish a simulation model of the overhaul warehouse system; the overhaul warehouse system simulation model includes a simulation model of the wheelset frame separation station, a simulation model of the frame disassembly station, and a simulation model of the wheelset frame assembly station; S5. Simulation result processing and data analysis: Based on the simulation model of the bogie overhaul depot system with 250 working days, simulation calculations can be performed to obtain qualitative and quantitative data on production capacity, bottleneck processes, buffer size settings, resource utilization, turnover parts analysis, bogie maintenance area congestion, waiting, and occupancy rates of each buffer; S6. Process optimization: Based on a thorough analysis of the key production parameters of vehicle frame overhaul production efficiency and bottlenecks, the overall process layout of the frame overhaul depot is optimized in combination with genetic algorithms, and the efficiency of the proposed optimization scheme is verified, thereby providing decision support for improving the maintenance and repair efficiency of vehicle frame overhaul depots in vehicle depots and further improving the management efficiency of frame overhaul depot workshops.

2. The subway overhaul workshop process simulation and optimization method according to claim 1 is characterized in that: In step S1, the simulation target is determined. When simulating the overall process layout of subway overhaul, more than 30 work sites need to be simulated in detail. However, based on the analysis of the overall rhythm and bottlenecks, 8 key work sites are divided, namely, purge - air conditioning, pantograph disassembly and installation - train disassembly - car body warehouse maintenance - bogie maintenance - car weighing - train coupling - train static adjustment. Therefore, the key work sites are simulated and simulated.

3. The subway overhaul workshop process simulation and optimization method according to claim 1 is characterized in that: In step S2, the technical data includes workshop layout and logistics routes, working hours and equipment performance parameters, and initial settings of turnover parts; the organizational structure data includes the shift plan of the overhaul warehouse workshop, workshop production resource allocation, and workshop production organization strategy; The system loads data including product and work-in-progress data, and assembly BOM.

4. The subway overhaul workshop process simulation and optimization method according to claim 1 is characterized in that: In step S3, the system modeling adopts a hierarchical, modular, and object-oriented modeling method. By importing lightweight models of external products and equipment and establishing a basic modeling resource library including a standard object library and a customized object library, a virtual model of the entire workshop is gradually established on this basis, and the workshop modeling results can be output as a whole through a variety of integrated interfaces.

5. The subway overhaul workshop process simulation and optimization method according to claim 1 is characterized in that: In step S3, the virtual simulation is to realize the virtual simulation of the production process of the rack overhaul warehouse workshop based on the simulation model of the rack overhaul warehouse system and the results of the three-dimensional process planning of the rack overhaul warehouse workshop, including modeling of the logistics simulation system, logistics simulation analysis and calculation, and solution evaluation and optimization.

6. The subway overhaul workshop process simulation and optimization method according to claim 1 is characterized in that: In step S4, the wheelset frame separation station includes the semi-coupling separation process, gear box boom disassembly, fixing bolt disassembly, lifting and disassembly followed by the wheelset frame separation process. The EMU has a coupling but the trailer does not, so flow control is required for diversion processing; the frame disassembly station is composed of frame logistics, empty spring disassembly, and motor disassembly processes. The EMU contains a motor but the trailer does not, so flow control is used for diversion processing.

7. The subway overhaul workshop process simulation and optimization method according to claim 3 is characterized in that: In the process of studying the layout of the workshop and the logistics routes, the overall layout of the workstations, the topological relationship between the workstations, and the material distribution and transfer routes are the objects of study and investigation; for working hours and equipment performance parameters, it is necessary to collect and organize the operation time of each workstation, the average operating speed of the overhead crane, the operating speed of the aerial logistics, and the capacity data of each temporary storage area, and confirm the transportation capacity of the trolleys, AGV carts, transfer platforms, and overhead cranes; for the initial setting of the turnover parts, the traction motor, braking device, and wheelset bearings need to be set separately.

8. The subway overhaul workshop process simulation and optimization method according to claim 3 is characterized in that: When simulating the shift plan of the overhaul warehouse workshop, using non-natural days as the simulation time can effectively simplify the simulation model; the workshop production organization strategy includes the control strategy of the production rhythm, the frame, the car body, and the wheelset transfer strategy.

9. The subway overhaul workshop process simulation and optimization method according to claim 4 is characterized in that: The standard object library contains general workshop modeling object resources, which can be directly used as standard models during workshop modeling; the customized object library is oriented to the specific workshop environment characteristics of the circuit breaker assembly line, customizes and configures the customized object resource model, and quickly generates a specific object model according to actual parameters; the construction of the virtual model needs to adopt hierarchical modeling, object-oriented modeling, and modular modeling methods, and has progressive modeling capabilities, which can decompose and simplify the modeling work of complex systems to improve work efficiency; the integrated interface needs to provide system integration capabilities and standard interfaces, including real-time data exchange, importing tables, importing data and drawings, and online database connection to achieve communication and data exchange between workshop modeling and other application systems.

10. The subway overhaul workshop process simulation and optimization method according to claim 5 is characterized in that: The modeling of the logistics simulation system needs to be based on the virtual model of the workshop and the process planning data, and the logistics simulation parameters, constraints and rules and methods need to be defined according to the technical and management conditions of the actual production environment, so as to establish a logical model of logistics simulation; when performing logistics simulation analysis and calculation, it is necessary to calculate the key production parameters of production logistics, bottlenecks, efficiency, inventory, and rhythm, so as to provide support for subsequent mid-term solution evaluation and optimization.

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