JP2013050776A - Simulation system and simulation method for carriage system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To analyze a common simulation result in a plurality of terminals from a viewpoint of each of the terminals.SOLUTION: A carriage system which carries a work between processing units is simulated. Traveling of a plurality of virtual carriages in a carriage system is simulated, and data obtained by the simulation and a background image of the carriage system are transmitted to a plurality of terminals. At each terminal, a user specifies an area and a time range in the carriage system displaying the data as an image for each terminal, and the terminal images the data within the specified range and synthesizes the imaged data with the background image of the carriage system to display a synthesized image in a monitor.

Description

  The present invention relates to a simulation of a transport vehicle system.

  In the transport vehicle system, articles are transported between load ports using an overhead traveling vehicle (OHT), an automatic guided vehicle (AGV) traveling on the ground, a stacker crane, and the like. In the case of an automatic warehouse, the load port is often referred to as a station, and the conveyed article is a semiconductor wafer, a reticle, a glass substrate, a general part, or the like.

  When the transport vehicle system is installed in a semiconductor factory, a flat panel display factory, or the like, a job of the transport vehicle system is to supply and unload workpieces in a timely manner to a processing apparatus such as a semiconductor or a flat panel display. Therefore, it is necessary to simulate whether or not the transport vehicle system can transport workpieces according to a production plan in a semiconductor factory or the like. But this simulation is difficult. If a virtual transport command is simply given to the transport vehicle and the execution result is simulated, a result different from that in the case of performing an appropriate operation is obtained, and for example, traffic congestion is likely to occur. In addition, the virtual transport vehicle frequently accelerates and decelerates to avoid interference, and the amount of calculation for simulation also increases.

  Patent Document 1 (JP2003-264216A) discloses simulating production in a semiconductor factory, and Patent Document 2 (JPH10-254545A) and Patent Document 3 (JP4306723B) simulate a transport result in a transport vehicle system. Disclosure. In particular, Patent Document 3 discloses simulating the future situation of the transport vehicle system from the current position and speed of the transport vehicle and the assigned transport command.

  The inventor considered sharing the simulation results for the transport vehicle system among a plurality of terminals, and analyzing each terminal from each viewpoint. Since there are generally a plurality of actors related to the transport vehicle system, it is preferable that analysis is possible from each viewpoint. In addition, it is necessary to analyze the same simulation result with a plurality of terminals for performance evaluation and optimization of the transport vehicle system. Furthermore, if the simulation result is distributed to each terminal as a moving image, the amount of communication is too large. The inventor studied a simulation system satisfying such a condition and arrived at the present invention.

JP2003-264216A JPH10-254545A JP4306723B

  An object of the present invention is to enable a plurality of terminals to analyze a common simulation result for a transport vehicle system from each viewpoint.

The present invention is a system for simulating a transport vehicle system that transports workpieces between processing devices,
A simulation unit that simulates the traveling of a plurality of virtual transport vehicles in the transport vehicle system;
A communication unit that is connected to the simulation unit and transmits data obtained by the simulation and a background image of the transport vehicle system to a plurality of terminals;
Each terminal has an input unit for the user to specify an area in the transport vehicle system for displaying data as an image and a time range for each terminal, and images the data in the specified range and the transport vehicle system And an image composition unit for composition with the background image, and a monitor for displaying the synthesized image.

Moreover, this invention is a method of simulating a transport vehicle system that transports workpieces between processing devices,
A step of transmitting a background image of the transport vehicle system to a plurality of terminals by a communication unit connected to the simulation unit;
A step of simulating traveling of a plurality of virtual transport vehicles in the transport vehicle system by the simulation unit;
The communication unit performs the step of transmitting data obtained by simulation to a plurality of terminals, and
In each terminal, the user designates the area in the transport vehicle system for displaying data as an image and the time range for each terminal from the input unit;
The step of image-forming data within a specified range by the image synthesis unit and the image data are synthesized with the background image of the transport vehicle system;
And a step of displaying the synthesized image on a monitor.

In this invention,
・ Simulation results for the transport vehicle system can be shared by multiple terminals.
・ Each range can be analyzed independently by selecting the range to analyze the results independently.
・ Simulation results are transmitted as data and background images, so the amount of communication is small, and only the range selected by each terminal can be displayed. In this specification, the description about the simulation system also applies to the simulation method as it is, and the description about the simulation method also applies to the simulation system as it is.

Preferably, the simulation unit
A travel plan creation unit that creates a travel plan of a virtual transport vehicle according to a virtual production plan in the processing device;
Create a travel schedule that consists of a series of speed control points that represent the position and time at which the transport vehicle accelerates or decelerates, and that specifies the position and speed of the transport vehicle as a function of time for each transport vehicle according to the travel plan that you created A travel schedule creation section;
A simulator for running a virtual transport vehicle is provided in accordance with the travel schedule and the constraints of the transport vehicle system, and so as to avoid interference between the transport vehicles.

  In this way, a reliable simulation can be performed with a relatively small amount of calculation. In addition, it can be determined by simulation whether the production plan is appropriate.

Preferably, the simulation unit includes a storage unit of a system configuration of the transport vehicle system,
The plurality of terminals include an administrator terminal and other client terminals, and the plurality of terminals can communicate with each other,
Based on the change request of the system configuration from the client terminal to the administrator terminal, the administrator terminal changes the system configuration stored in the storage unit of the system configuration and causes the simulation unit to re-execute the simulation.

If you do this,
・ Analyze simulation results from multiple viewpoints on multiple terminals,
・ Consider changing the system configuration, re-run the simulation,
・ The re-executed simulation results can be confirmed on each terminal.

The figure which shows the layout of the carrier system of an Example Block diagram of the ground controller in the embodiment The figure which shows the calculation model of required time in execution example The figure which shows the meaning of making the travel schedule to a retreat position in an Example The flowchart which shows the algorithm which produces | generates the driving schedule of the conveyance vehicle in an Example. The figure showing the meaning of VCP (speed control point) in the example, 1) shows the speed pattern, 2) shows the driving schedule that expresses the speed pattern of 1) with two VCPs, 3) , 2) An example in which each VCP is expressed by two VCPs is shown. The figure which shows the example of the driving schedule in an Example The figure which shows the driving schedule of FIG. 7 as a position and time of a conveyance vehicle The figure which shows the elimination of the interference between the driving schedules in the embodiment The flowchart which shows the algorithm which manages the state of the conveyance vehicle in an Example The figure which shows the simulation apparatus of an Example, and its periphery Main block diagram of the simulation device Block diagram of client terminal

  In the following, an optimum embodiment for carrying out the present invention will be shown. The scope of the present invention should be determined according to the understanding of those skilled in the art based on the description of the scope of the claims, taking into account the description of the specification and well-known techniques in this field.

Simulation Vehicle System FIG. 1 to FIG. 10 show a real vehicle system 2 that is a simulation target. As illustrated in FIG. 1, the transport vehicle system 2 includes an interbay route 4 and an intrabay route 6, and a plurality of transport vehicles 8 transport workpieces along routes 4 and 6. A load port 10 and a buffer 12 are provided along the routes 4 and 6. The load port 10 is a place where a workpiece is transferred between a processing device (not shown) and the transport vehicle 8. The buffer 12 temporarily places the workpiece on the transport vehicle 8. It is a place to do. There are places where exclusive control is required in the routes 4 and 6, and exclusive control is required at the junction 14 of the route, for example. Here, the exclusive control is control that reliably excludes a plurality of transport vehicles from entering a certain position on the travel route at the same time. The transport vehicle 8 travels under the control of the ground controller 20, and the ground controller 20 may directly control the transport vehicle 8, or a zone controller is provided in the middle, and the ground controller controls the transport vehicle 8 via the zone controller. You may control.

  FIG. 2 shows a configuration of the ground controller 20, and the communication interface 22 receives a transport request from a host controller such as a MES (Manufacturing Execution System) 21. In the transfer request, a load port for loading a workpiece and a load port for unloading the workpiece are specified. The transport request may specify the time at which loading can be performed, the time at which loading should be completed, the time at which unloading can be performed, and the time at which unloading should be completed. Although the influence of loading and unloading delay can be reduced by a buffer or the like in the load port, if the unloading is extremely delayed, the processing apparatus may stop because there is no work to be processed. For this reason, it is important that the transport vehicle arrives at the unloading destination load port between the time when unloading becomes possible and the time when unloading should be completed. The allocation unit 24 converts the transport request into a transport command that is a command to the transport vehicle, and allocates the transport command to the transport vehicle via the communication interface 33 or the like. In addition, a conveyance command may be transmitted to the conveyance vehicle 8 with the below-mentioned travel schedule, or only a conveyance command may be transmitted.

  The schedule creation unit 25 generates a travel schedule for each transport vehicle. The travel schedule is a travel schedule of the transport vehicle when executing the transport command, dispatching, and expulsion. Further, in this specification, a combination of a position on the travel route where the transport vehicle performs speed control for acceleration or deceleration and the time thereof is referred to as VCP (speed control point). In addition, the parts that require exclusive control such as merging sections are included in the speed control point VCP, and the unloading position and loading position are also included in the VCP because they change the speed. The driving schedule is composed of VCP columns. The scheduler 26 creates a travel schedule from the current position of the transport vehicle to the destination (retreat position) ignoring interference with other transport vehicles. The destination is, for example, an unloading position or a retreat position that is farther than the unloading position. In the case where the vehicle waits for a round run after completion of unloading, for example, a travel schedule is created until the round trip is started by starting from the unloading position. When the time when loading is possible and the time when loading should be completed or when loading is possible and when loading should be completed are specified in the transport command, according to these times A travel schedule is created so that the transport vehicle arrives at the load port. When the travel schedule according to these times cannot be created, the fact is reported to the MES 21 via the communication interface 22.

  Since the plurality of transport vehicles 8 travel on the routes 4 and 6, it is considered that interference between the transport vehicles 8 occurs. The interference exclusion unit 28 corrects the travel schedule so as to eliminate interference between the transport vehicles 8 with respect to the travel schedule newly created by the scheduler 26 and the travel schedule already stored in the storage unit 31. In the detection of interference, it is detected at the speed control point VCP whether or not the transport vehicle interferes with any of the front and rear transport vehicles. For this purpose, for example, an inter-vehicle distance greater than a distance determined by the vehicle body length of the transport vehicle 8 or the like. It is evaluated whether or not it exists between the front and rear transport vehicles. Interference occurs between the front (downstream) transport vehicle and the rear (upstream) transport vehicle. When the interference is detected, the travel schedule of the rear transport vehicle is corrected. It is not necessary to detect the interference with respect to all positions on the travel route determined by the travel schedule, and it is only necessary to detect whether or not the front and rear transport vehicles interfere with each other at the speed control point VCP. For this reason, shorten the distance or time between VCPs so that the rear transport vehicle does not overtake the front transport vehicle between VCPs, or when evaluating the presence or absence of interference with VCP, It is evaluated whether the order between transport vehicles has changed between. Note that the speed control points VCP are sequentially searched from the oldest side to the newer side with respect to the travel schedules of a plurality of transport vehicles, and the presence or absence of interference is detected in order from the oldest speed control point.

  When the interference is detected, a speed control point for deceleration and a speed control point for subsequent reacceleration are added to the rear transport vehicle to avoid the interference. For multiple transport vehicles, speed control points are sorted in order of time to detect the presence or absence of interference, and when the travel schedule is corrected, the presence or absence of interference is detected once for each speed control point VCP. Thus, interference can be eliminated. The constraint condition check unit 30 checks whether or not a constraint condition such as the maximum value of power consumption is satisfied, and if not satisfied, corrects the travel schedule. The transport vehicle 8 is supplied with power from the ground side wiring by non-contact power supply or the like, and the maximum power consumption for each power supply area, which is a unit of a power supply range, is determined. When multiple vehicles are accelerated at the same time, the maximum power consumption limit may be exceeded. Therefore, the traveling schedule is corrected so that the condition of the non-contact power supply is not satisfied by the simultaneous acceleration of a plurality of transport vehicles in the same power supply area. The constraint condition check unit 30 may not be provided.

  The storage unit 31 stores a travel schedule that has been modified to eliminate interference and satisfy the constraint conditions. For example, if there are several hundred transport vehicles 8 and, for example, several minutes are required for one transport, a travel schedule is newly created for the transport vehicles of about 100 per minute, and the travel schedule is completed. become. Therefore, the processing in the interference rejection unit 28 and the constraint condition check unit 30 is periodically performed at a predetermined time interval of, for example, about 1 second to 30 seconds, and a travel schedule stored in the storage unit 31 every time is newly added. Interference elimination and constraint conditions are checked against the created travel schedule, and the corrected travel schedule is stored in the storage unit 31.

  In the travel schedule composed of a row of speed control points VCP, the acceleration of the transport vehicle changes discontinuously. Therefore, the speed is smoothed around the speed control point VCP so that the acceleration satisfies a predetermined condition. Although this process is performed by the smoothing unit 32, the smoothing may be performed by the transport vehicle 8. The communication interface 33 transmits the smoothed travel schedule (speed pattern) to the transport vehicle 8. Since the scheduler 26 creates a travel schedule from the unloading position to the retreat position, for example, a schedule of several minutes or more is created for the transport vehicle. On the other hand, the travel schedule is corrected at a period of about 1 to 30 seconds. Therefore, the communication interface 33 transmits, for example, the travel schedule or speed pattern up to the time when the travel schedule is corrected next to the transport vehicle 8 so that the travel schedule received by the transport vehicle is not wasted.

  The transport vehicle 8 reports an event such as a position, time, speed, and state, loading and unloading, and a request for passing through the merging unit to the communication interface 33, and the state management unit 34 stores the state of the transport vehicle 8. to manage. The schedule correction unit 36 compares the actual state of the transport vehicle 8 stored in the state management unit 34 with the travel schedule stored in the storage unit 31, and if there is a deviation greater than the allowable value, the storage unit The 31 travel schedule is corrected, for example, to shift by the deviation time. This correction is used when evaluating the interference between the driving schedules next time. Regardless of whether or not there is a deviation, the travel schedule may be corrected each time the state of the transport vehicle is received.

  Exclusive control at the junction or the like can be considered to be included in the travel schedule. When it is guaranteed that the deviation from the travel schedule of each transport vehicle is small, exclusive control is realized if the vehicle travels according to the travel schedule. However, if there is a possibility that the arrival order at the junction or the like may be deviated from what is assumed in the travel schedule, the arbitrator 38 is provided to execute exclusive control individually. For example, the arbitrator 38 is requested to pass the exclusive control portion such as the junction from the transport vehicle 8, and the arbitrator 38 executes the exclusive control. Alternatively, instead of requesting the passage of the exclusive control location from the transport vehicle 8, the arbitrator 38 obtains the actual position and speed of the transport vehicle from the data of the state management unit 34, and determines the passing order of the exclusive control location, A command may be given to the transport vehicle 8.

  The dispatching unit 40 instructs, for example, an empty transport vehicle, that is, a transport command not assigned, to move to a designated position along the routes 4 and 6. This is to move the transport vehicle from an area where there is a surplus of empty transport vehicles to an area where there are not enough empty transport vehicles. A transport vehicle that has not been commanded to run, that is, a transport command that is not assigned a delivery command, is not assigned a vehicle, and is not running for maintenance or other reasons, is stopped at the retracted position. The retreat position is, for example, a designated position of the intra bay route 6.

  A transport vehicle that is stopped at the retracted position may interfere with the travel of other transport vehicles. The state management unit 34 manages the transport vehicle that is stopped at the retreat position, detects a transport vehicle that interferes with the travel of the other transport vehicles, and commands to drive out. The content of the eviction is to travel to a designated position and wait. The scheduler 26 creates a travel schedule for the transport vehicle to be dispatched or driven out, and controls the travel in the same manner as the transport vehicle that is executing the transport command. Instead of providing the eviction section 42, it may be handled that a traveling schedule with a speed of 0 is created for the transport vehicle at the retreat position. Further, instead of stopping at the retracted position, the transport vehicle 8 may travel around the routes 4 and 6.

  The log file storage unit 44 stores the completed travel schedule, and the travel time analysis unit 46 obtains a parameter for calculating the required travel time from the past travel schedule. The travel schedule of the storage unit 31 gives the predicted time when the transport vehicle arrives at the loading position and the unloading position. Therefore, in response to a request from the MES 21, the predicted time at which the transport vehicle arrives at the loading position and the unloading position is output to the MES 21 via the communication interface 22.

  FIG. 3 shows a predicted travel time. From the data stored in the log file storage unit 44, a past travel schedule that has traveled so as to include the starting point and the destination of the travel is searched. The departure point is, for example, the current position of the transport vehicle at the time when the transport command is assigned, and the destination is, for example, the retreat position. The actual time required between the departure point and destination is determined from the travel schedule. In addition, from the preceding travel schedule, the number of times the preceding transport vehicle stopped and transferred the workpiece (stop transfer count) between the departure point and the destination is obtained, and the departure point and destination are determined from the travel route map. The number of junctions between and is obtained. Then, the required travel time T is statistically processed using the stop transfer number n and the number m of the merging portions as explanatory variables. For example, T = an + bm + c is approximated, and the values of coefficients a, b, and c are obtained. Here, the constant term c is the standard required time, a is the expected value of the required time increase due to one stop transfer, and b is the expected value of the required time increase due to one junction. Then, the values of a, b, and c are stored for each combination of the starting point and the destination, for example, and the required travel time is obtained from the number of stop transfer and transfer of the preceding transport vehicle and the number of junctions. The required travel time is the travel time when the scheduler 26 creates a travel schedule. Since the time for which the travel route is blocked by stop transfer is generally longer than the waiting time for passing through the junction, the number of passes through the junction may be ignored by approximating T = an + c.

  FIG. 4 shows the meaning of creating the travel schedule up to the retreat position far from the To position. In the travel schedule in which the preceding transport vehicle A arrives at the To position at time T1, the transport vehicle B travels behind the travel schedule. The preceding transport vehicle A stops at the To position, transfers the workpiece, and further travels to the retreat position. Here, if the travel schedule is limited to the To position, it is difficult to create a reliable travel schedule for the transport vehicle B.

  5 to 9 show processing in the schedule creation unit 25. FIG. When the communication interface 22 receives a transport command from the MES 21 or the like in step 1 of FIG. 5, the assignment unit 24 searches for a transport vehicle to which the transport command can be assigned, and assigns the transport command (steps 2 and 3). Here, the conveyance command is a command to travel from the current position to the retreat position via the load port for loading and unloading. The scheduler 26 creates a traveling schedule for independent traveling, neglecting interference with other transportation vehicles, for the transportation vehicles to which a transportation instruction is newly assigned (step 4). Hereinafter, the traveling schedule is simply referred to as a schedule, and the schedule includes records such as a speed control point VCP and a next target speed, and the data of the speed control point VCP includes a position and a time. Further, since the next target speed is determined from the difference in position between the two VCPs and the time difference, the target speed need not be specified in the travel schedule.

  FIG. 6 shows the concept of the speed control point VCP. 1) in FIG. 6 shows the speed pattern of the transport vehicle, and the speed is specified as a function of time. When the speed pattern of 1) in Fig. 6 is converted into a position on the travel route as a function of time, it becomes like the solid line of 2). The speed pattern is composed of repetition of acceleration, constant speed running and deceleration. Therefore, it is assumed that the speed pattern is simplified and the speed changes abruptly as indicated by the broken line 2) in FIG. In this case, the position and time at which the speed is suddenly changed are the speed control point VCP. In 2), acceleration, constant speed driving, and deceleration are expressed by two control points. One acceleration or deceleration may be expressed by two or more speed control points VCP. For example, when acceleration and deceleration are respectively displayed by two speed control points VCP, the result is as shown in 3) of FIG.

  FIG. 7 shows an example of a travel schedule before the interference is eliminated, and each record of the travel schedule is a VCP position, its time, and the next target speed. If there are other events such as loading, joining, and unloading, the event is described. The event may be specified separately from the travel schedule. For example, in the case of FIG. 7, seven VCPs are designated, two of which are loaded and unloaded, and the target speed is zero. FIG. 8 shows the travel schedule 70 of FIG. 7 as the position and time on the travel route.

  Returning to FIG. 5, in step 5, the travel schedule is corrected so as to avoid interference between transport vehicles. This process is performed on the travel schedule stored in the storage unit 31 and the travel schedule newly created by the scheduler 26, and is performed at a time interval of about 1 to 30 seconds, for example. Then, to avoid interfering with the preceding transport vehicle, modify the schedule of the subsequent transport vehicle, search the VCP in multiple schedules in time order, and process the oldest VCP to the later VCP in order. .

  An example of interference detection and travel schedule correction is shown in FIG. Assume that there are three driving schedules, a one-dot chain line driving schedule, a solid line driving schedule, and a broken line driving schedule. When the VCP is searched in time order, the times T1 to T6 are obtained. Here, if it is checked whether or not there is any interference with the solid line travel schedule at time T5, there is a sufficient interval with the one-dot chain line travel schedule, and the dashed line travel schedule interferes. Here, since the broken line travel schedule is the schedule of the rear carriage, the VCP at time T6 of the broken line travel schedule is changed to the deceleration VCP, and then the re-acceleration VCP (time T7) is added. In these VCPs, since the acceleration changes discontinuously, the speed pattern of the transport vehicle is smoothed so that the acceleration is within an allowable range.

  In step 6, the schedule is corrected so as to satisfy a constraint condition such as maximum power, and the schedule is stored in the storage unit 31. Since the schedule disappears upon completion of the command and occurs due to a new assignment, the processing of step 5 to step 7 is repeated regularly or irregularly at intervals of about 1 to 30 seconds to eliminate interference. Repeat the correction to satisfy the constraint condition. In step 8, for example, a smoothed travel schedule for the next 1 to 30 seconds is transmitted to the transport vehicle.

  FIG. 10 shows processes other than the travel schedule creation. In step 11, the state of the transport vehicle is received via the communication interface 33 and stored in the state management unit 34. The state includes position, speed, time, and event. When an arbitrator is provided, an exclusive control request is also included. In step 12, the deviation between the travel schedule and the actual state of the transport vehicle is obtained, and the data in the storage unit 31 is overwritten so as to correct the travel schedule if the deviation is greater than or equal to an allowable value. If there is an exclusive control request, exclusive control is executed by the arbitrator (step 13). Furthermore, a transport vehicle that needs to be driven out is detected from the position of the transport vehicle, and the drive out unit 42 assigns the drive out. Further, an area where there are insufficient empty transport vehicles, an area where there is room for empty transport vehicles, and the like are detected by the vehicle allocation unit 40 based on the data of the state management unit 34, and an empty transport vehicle is allocated (step 15). Furthermore, the estimated arrival time at the loading position or the unloading position is obtained from the data in the state management unit 34 or the storage unit 31 by, for example, responding to a request from the MES 21 (step 16).

Simulation Device FIGS. 11 to 13 show a simulation device 80 of the embodiment. The same reference numerals as those in FIGS. 1 to 10 denote the same components. Further, the description relating to the simulation apparatus 80 also applies to the simulation method as it is, and conversely, the description relating to the simulation method also applies to the simulation apparatus 80 as it is. Furthermore, the simulation apparatus 80 may be realized by a plurality of computers. 72 is an operator terminal of the MES 21, and the simulation device 80 communicates with the carrier system 2 to be simulated and the MES 21 via the communication interface 81, and also with the administrator terminal 96 and the plurality of client terminals 98 via the communication interface 82. connect. The administrator terminal 96 can give an arbitrary instruction to the simulation apparatus 80 such as changing the system configuration, but instructions that can be input from the client terminal 98 to the simulation apparatus 80 are limited. In other respects, the administrator terminal 96 and the client terminal 98 are the same.

  The production plan management unit 83 stores the production plan input from the MES 21 and processes the work carried into the virtual processing device in the simulation device 80 by the virtual transport vehicle for a time determined by the type of processing. When the process is over, request to carry out. In this way, the production plan management unit 83 requests workpiece transfer according to the production plan input from the MES 21, and performs virtual production based on the workpiece transfer. The travel plan creation unit 84 creates a virtual travel plan so as to transport the workpiece according to the production plan. In the travel plan, in addition to the loading position and the unloading position, the travel route along which the virtual transport vehicle travels Is specified.

  The travel schedule creation unit 86 creates a travel schedule for executing the travel plan. The meaning of the travel schedule and the creation method are the same as those of the actual transport vehicle system 2, the travel schedule creation unit 86 has the same configuration as the schedule creation unit 25, and the difference is that the storage unit 31 and the smoothing unit 32 also create a travel schedule. This is a point included in the part 86. That is, the scheduler 26 ignores the interference, creates a travel schedule, the interference elimination unit 28 eliminates the interference between the transport vehicles, and the constraint condition check unit 30 corrects the travel schedule so that the constraint conditions of the transport vehicle system 2 are satisfied. To do.

  The simulator 87 performs a simulation so that a plurality of virtual transport vehicles travel according to the travel schedule. The transport vehicle model 88 performs virtual travel according to a travel schedule using an actual transport vehicle as a model, and here causes a plurality of transport vehicles to perform virtual travel simultaneously. Then, traveling is simulated including deceleration to avoid interference between transport vehicles, stopping at the load port, transfer and the like. The output of the simulator 87 is the position and speed of the transport vehicle, the achievement status of the travel plan, and the status of the transport vehicle system such as power consumption.

  The state management unit 34 stores and manages the state of the virtual transport vehicle system, requests the dispatch unit 40 to dispatch, and requests the eviction unit 42 to eject the transport vehicle. The state management unit 34 requests correction of the travel schedule according to the position and speed of the transport vehicle being simulated, and inputs the position and speed of the transport vehicle to the travel plan creation unit 84. Based on this, the travel plan creation unit 84 designates a travel route to the transport vehicle so as not to generate a traffic jam.

  The log file storage unit 89 stores simulation data such as a production plan and a travel schedule, and simulation results. The simulation results include the position and speed of the transport vehicle, the loading and unloading times of the workpiece, the distribution of the position and state of the transport vehicle at each time, the power consumption, and the like. The system configuration storage unit 90 stores the configuration of the virtual transport vehicle system, which includes the travel route, the number of transport vehicles, the position of the load port and the buffer, the position of the junction, the branching unit, the available power, etc. There is. In addition to this, the system configuration storage unit 90 stores operation logic of the transport vehicle system, such as dispatching, expelling, selection of a travel route, and an assignment order of travel plans to the transport vehicle. The optimization unit 92 is a tool for optimizing the transport vehicle system 2 by analyzing a simulation result. Based on the distribution of the transfer time and the like, the throughput analysis unit 93 analyzes the transfer throughput, and detects that there is a transfer delay that can delay the production plan. The traffic jam detector 94 detects the traffic jam of the transport vehicle during the simulation process. The system configuration can be changed from the administrator terminal 96, for example, but may be changed autonomously by the optimization unit 92. The background image storage unit 95 stores a 3D or pseudo 3D background image corresponding to the system configuration of the virtual transport vehicle system.

  FIG. 13 shows the configuration of the client terminal 98, and the administrator terminal 96 is the same. The communication interface 100 communicates between the terminals 96 and 98 and with the communication interface 82. The background image storage unit 102 stores the background image transmitted from the simulation device 80, and the log file storage unit 104 stores all or part of the data in the log file storage unit 89 of the simulation device 80. In accordance with an instruction from the input unit 114, the image composition unit 106 combines the image of the transport vehicle and the workpiece based on the data in the log file storage unit 104 with the background image and displays the image on the monitor 108. The image of the transport vehicle and the workpiece is stored as an image corresponding to 3D or a pseudo 3D image, and the image of the transport vehicle and the workpiece moving relative to the background image in the transport vehicle system is displayed according to the data in the log file storage unit 104. .

  Since the simulation results are stored in the log file storage unit 104 in order of time, for example, the entire image of the transport vehicle system is displayed on the monitor 108 as a moving image from the beginning of the simulation or from the time specified by the user. When the simulation is repeated, for example, an image at the time designated by the user in the area designated by the previous user may be displayed as the initial image. A user who operates the terminals 96 and 98 specifies an area to be displayed and a time range in the transport vehicle system by using the input unit 114 such as a mouse or a keyboard. The image composition unit 106 creates a composite image within a specified time range in a specified area, and this image is enlarged and detailed than the entire image of the transport vehicle system. The user can change the display mode such as a bird's-eye view and a plan view, and can switch the display such as moving image display, still image display, and data display. Further, the items to be displayed can be designated such as the distribution of empty transport vehicles, the distribution of transport vehicles that are executing transport, the time distribution from the time when transport is requested in the production plan to the completion. The display range and display item designation are independent for each of the terminals 96 and 98, and each terminal 96 and 98 analyzes the simulation result independently of the others.

  Similar to the optimization unit 92, the analysis support unit 110 analyzes the simulation result, and what kind of analysis is performed is appropriately determined for each terminal 98. In FIG. 13, in addition to the throughput analysis unit 93 and the traffic jam detection unit 94, a maintenance analysis unit 111 that predicts how equipment requiring maintenance is generated from the total travel time, travel distance, and the like for each transport vehicle, A power analysis unit 112 that analyzes power consumption in each part of the travel route and analyzes whether a facility such as non-contact power feeding can be handled is shown.

  The client terminal 98 makes a request by notifying the administrator terminal 96 of what kind of simulation is to be performed. For example, the initial state for starting the simulation and the production plan to be simulated are notified. Further, the client terminal 98 requests by notifying the administrator terminal 96 how to optimize the system configuration. The administrator terminal 96 instructs the simulation apparatus 80 to re-execute the simulation and change the system configuration in response to the request.

  The simulation apparatus 80 can simulate the conveyance result in the actual conveyance vehicle system 2 almost accurately. The travel schedule creation unit 86 creates a travel schedule that incorporates avoidance of interference between transport vehicles, and this is the same schedule as that created by the transport vehicle system 2. In addition, since the travel schedule is a realistic schedule, it is rare that the simulation result greatly deviates from the travel schedule. Accordingly, the burden on the simulator 87 is small, and an accurate simulation can be performed in a relatively short time. Since the driving schedule incorporates traffic avoidance, etc., the results for almost optimal operation can be simulated in a short time. Further, the production plan is added to the simulation, and the production plan is virtually executed based on the conveyance result, and the process proceeds to the next step of the production plan. For this reason, in principle, simulation is possible to the distant future.

  The conveyance result can be accurately simulated, and the current state of the current conveyance vehicle system 2 can be simulated as an initial value. Therefore, it is possible to simulate whether or not the workpiece can be conveyed without delaying the production plan before the MES 21 moves the production plan to execution. The simulation range is, for example, a production plan from a few minutes to a few hours later, and a simulation over a longer time is possible. The optimization unit 92 detects that there is a delay in the workpiece conveyance in the simulation, and can be dealt with by changing the production plan, introducing a spare conveyance vehicle, or changing the logic of dispatching.

  When creating a new production plan or changing a production plan, it can be verified by simulation whether the production plan is realistic in terms of workpiece transfer. When an unreasonable production plan is detected, it can be dealt with by changing the production plan or changing the operation logic. In addition, the same production plan can be simulated multiple times by changing the system configuration. Then, the carrier system can be optimized by changing the system configuration.

  Several people are involved in the design and operation of the transport vehicle system. Therefore, it is necessary to perform simulations from multiple viewpoints and analyze the results. Execution of the simulation is instructed from the administrator terminal 96, the execution result is shared by the plurality of terminals 96 and 98, and each terminal 96 and 98 analyzes from different viewpoints. Note that the operator terminal 72 may be a terminal capable of instructing simulation independently of the administrator terminal 96. Also, when sending simulation results, only log file data and background image need to be sent, only part of the log file can be sent, and the background image only sends changes from the previous image. It is also possible. For this reason, the communication amount can be reduced. Each of the terminals 96 and 98 can display different scenes with different resolutions and different screen specifications in the simulation result, and can operate the screen independently. That is, the analysis at one terminal does not impose restrictions on the analysis at other terminals. The terminals 96 and 98 can perform analysis based on a common simulation result.

  Based on the analysis at each terminal 96, 98, software to increase the number of transport vehicles, add a bypass route, add a buffer, etc., change the system configuration in terms of hardware, and change the operation logic It can be proposed to change the system configuration. The system configuration is changed based on the proposal, for example, the simulation is re-executed for the same production plan, and the effectiveness of the proposal is confirmed. Since the simulation result is shared by the plurality of terminals 96 and 98, evaluation without deviation is possible. As described above, the configuration of the transport vehicle system 2 can be optimized.

  In the embodiment, the transport of the semiconductor by the overhead traveling vehicle has been described, but the same applies to the case of transporting a workpiece or the like by an unmanned transport vehicle traveling on the ground. The workpiece is not limited to a semiconductor, but may be a reticle, a substrate for a flat panel display, a medicine, a food product, a machine part, or a raw material.

2 Transport vehicle system 4 Interbay route 6 Intrabay route 8 Transport vehicle 10 Load port 12 Buffer 14 Junction section 20 Ground controller 21 MES
22, 33 Communication interface 24 Allocation unit 25 Schedule creation unit 26 Scheduler 28 Interference elimination unit 30 Restriction condition check unit 31 Storage unit 32 Smoothing unit 34 State management unit 36 Schedule correction unit 38 Arbitrator 40 Allocation unit 42 Ejection unit 44 Log file storage Unit 46 travel time analysis unit 70 travel schedule 72 operator terminal 80 simulation device 81, 82 communication interface 83 production plan management unit 84 travel plan creation unit 86 travel schedule creation unit 87 simulator 88 carrier model 89 log file storage unit 90 system configuration storage Unit 92 optimization unit 93 throughput analysis unit 94 traffic jam detection unit 95 background image storage unit 96 administrator terminal 98 client terminal 100 communication interface 102 background image storage unit 104 log file Yl storage unit 106 the image combining unit 108 monitor 110 analyzes support portion 111 Maintenance analyzer 113 power analysis unit 114 input unit

Claims (4)

A system for simulating a transport vehicle system that transports workpieces between processing devices,
A simulation unit that simulates the traveling of a plurality of virtual transport vehicles in the transport vehicle system;
A communication unit that is connected to the simulation unit and transmits data obtained by the simulation and a background image of the transport vehicle system to a plurality of terminals;
Each terminal has an input unit for the user to specify an area in the transport vehicle system for displaying data as an image and a time range for each terminal, and images the data in the specified range and the transport vehicle system An image synthesizing unit for synthesizing with the background image and a monitor for displaying the synthesized image. The simulation unit
A travel plan creation unit that creates a travel plan of a virtual transport vehicle according to a virtual production plan in the processing device;
Create a travel schedule that consists of a series of speed control points that represent the position and time at which the transport vehicle accelerates or decelerates, and that specifies the position and speed of the transport vehicle as a function of time for each transport vehicle according to the travel plan that you created A travel schedule creation section;
The transport vehicle system according to claim 1, further comprising a simulator that travels a virtual transport vehicle in accordance with a travel schedule and restrictions of the transport vehicle system and so as to avoid interference between the transport vehicles. Simulation system. The simulation unit includes a storage unit of a system configuration of the transport vehicle system,
The plurality of terminals include an administrator terminal and other client terminals, and the plurality of terminals can communicate with each other,
Based on a system configuration change request from the client terminal to the administrator terminal, the administrator terminal is configured to change the system configuration stored in the storage unit of the system configuration and to cause the simulation unit to re-execute the simulation. The simulation system for a transport vehicle system according to claim 1, wherein the system is a simulation system. A method for simulating a transport vehicle system that transports workpieces between processing devices,
A step of transmitting a background image of the transport vehicle system to a plurality of terminals by a communication unit connected to the simulation unit;
A step of simulating traveling of a plurality of virtual transport vehicles in the transport vehicle system by the simulation unit;
The communication unit performs the step of transmitting data obtained by simulation to a plurality of terminals, and
In each terminal, the user designates the area in the transport vehicle system for displaying data as an image and the time range for each terminal from the input unit;
The step of image-forming data within a specified range by the image synthesis unit and the image data are synthesized with the background image of the transport vehicle system;
And a step of displaying the synthesized image on a monitor.

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