Process planning support system

Abstract

To provide a process plan creation support system which can clarify work having a high delay risk to avoid delay of the work.SOLUTION: A process plan creation support system comprises: a work process network device 40 which expresses work divided into a plurality of activities, as a network model showing a relation of the activities; a simulation device 50 which performs three-dimensional simulation in which a robot executes the activities and executes the work, and finds a work time required for the execution of the work by the robot; a process establishment property evaluation device 60 which evaluates establishment property of a process plan based on the work time found by the simulation device 50, and determines that the process plan is not established when the work time found by the simulation device 50 exceeds a predetermined planned time; and a work process network correction device 70 which corrects the network model when the process establishment property evaluation device 60 determines that the process plan is not established.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a system for assisting in creating a work process plan.

Background Art

[0002] In work at a plant or factory, for example, due to changes in the situation at the work site, the work may not proceed as planned. If the work does not proceed as planned, the work period may be extended, the work cost may increase, or the deadline to be observed may not be met. Therefore, it is necessary to clarify particularly the work with a high risk of delay that can become a bottleneck and review the process plan for this work.

[0003] A conventional example of a process plan creation support system for assisting in creating a work process plan is described in Patent Document 1. In the production plan formulation support device described in Patent Document 1, when work is sequentially input into production processes for each production unit according to a predetermined input plan, a first model for calculating the probability that work exists in each time period of each process is generated for each production unit, a second model obtained by overlapping all the generated first models for each production unit is generated, and based on the generated second model, the time period of the process that becomes a bottleneck is specified and displayed, thereby formulating a production plan in which no bottleneck occurs.

Prior Art Documents

Patent Documents

[0004] <s

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In plant and factory operations, higher-level processes (e.g., processes defined on a monthly basis) and lower-level processes (e.g., processes defined on a daily basis) are planned. If a lower-level process is delayed, the higher-level process cannot proceed as planned, and the planned process cannot be achieved. In order to adhere to the created process plan, it is important to clearly identify tasks that have a high risk of delay and could become bottlenecks.

[0006] Generally, there are interrelationships between tasks (activities) performed in each process that are not depicted in the process chart (for example, preparation for the next task). Conventional technologies do not take these interrelationships (interactions) into account, making it difficult to accurately identify tasks with a high risk of delay. Furthermore, in order to avoid work delays, it is necessary to present users with a highly explainable process plan by displaying the process plan or robot movements.

[0007] The objective of the present invention is to provide a process planning support system that can identify tasks with a high risk of delay and thereby avoid delays in those tasks. [Means for solving the problem]

[0008] The process planning support system according to the present invention comprises: a work process network device that represents a task divided into multiple activities using a network model that shows the relationships between the activities; a simulation device that performs a three-dimensional simulation in which a robot executes the activities to perform the task and determines the work time, which is the time required for the robot to perform the task; a process feasibility evaluation device that evaluates the feasibility of the process plan based on the work time determined by the simulation device and determines that the process plan is unfeasible if the work time determined by the simulation device exceeds a predetermined plan time; and a work process network modification device that modifies the network model if the process feasibility evaluation device determines that the process plan is unfeasible. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a process planning support system that can clarify tasks with a high risk of delay and avoid delays in those tasks. [Brief explanation of the drawing]

[0010] [Figure 1] This figure shows the overall configuration of a process planning support system according to an embodiment of the present invention. [Figure 2] This diagram shows examples of work processes stored in the process data database. [Figure 3] This is an example of a field environment model that represents the work site where a robot performs its tasks in a three-dimensional virtual environment model. [Figure 4] This figure shows an example of a network model of the processing activity in Figure 2. [Figure 5] This is an example flowchart illustrating the processes performed by the process planning support system according to this embodiment. [Figure 6] This figure shows an example of when a process feasibility evaluation device determines that the process plan is unfeasible. [Figure 7] This diagram shows an example of how a process plan can be made feasible by modifying the Petri net and revising the process plans of lower-level processes when the process plan is deemed unfeasible. [Modes for carrying out the invention]

[0011] The process planning support system according to the present invention is a system that supports the creation of process plans for work in plants and factories, and can evaluate the feasibility of the process plan, clarify tasks that have a high risk of delay and may become bottlenecks, and avoid work delays. At the work site, robots mainly carry out the work based on the created process plan. The work performed at each stage of the work site is divided into multiple work units called activities. The process planning support system according to the present invention represents the work divided into multiple activities with a network model that shows the relationships between the activities, performs a 3D simulation (physical simulation) to determine the robot's work time, and if the work time exceeds the planned work time, modifies the network model and modifies the process plan.

[0012] A successful process plan means that the estimated work time is within the predetermined planned time, and the process can proceed as planned. For example, the estimated work time of a lower-level process is consistent with the work time set for a higher-level process. Activities that cause a process plan to fail are bottleneck activities and tasks with a high risk of delay. This invention clarifies tasks with a high risk of delay by identifying activities that cause a process plan to fail.

[0013] Furthermore, the process planning support system according to the present invention may display at least one of the following: information about the bottleneck activity, a 3D video of the robot's movement obtained by performing a 3D simulation, a modified network model, and a modified process plan. In the present invention, such a display makes it possible to present a highly explainable process plan to the user.

[0014] The following describes a process planning support system according to an embodiment of the present invention, with reference to the drawings. The following embodiment describes an example in which the process planning support system assists in creating a process plan for a robot performing work in a plant. [Examples]

[0015] Figure 1 is a diagram showing the overall configuration of the process plan creation support system according to this embodiment. The process plan creation support system according to this embodiment can be configured by a computer, and includes an input device 10, a display device 20, an activity extraction device 30, a work process network device 40, a 3D simulation device 50, a process feasibility evaluation device 60, a work process network correction device 70, and a process plan correction device 90.

[0016] The input device 10 is a device for a user of the process plan creation support system to input data and instructions into the process plan creation support system.

[0017] The display device 20 is a device for displaying the calculation results (for example, the created process plan, the video of the operation of the obtained robot, etc.) of the process plan creation support system to the user.

[0018] The activity extraction device 30 extracts the activities necessary for calculation from the process data database 100 described later.

[0019] The work process network device 40 represents the work divided into activities by a network model. Specifically, the work process network device 40 extracts the data of the process network corresponding to the activities extracted by the activity extraction device 30 from the work process network database 200 described later, thereby representing the work by a network model.

[0020] The 3D simulation device 50 performs a three-dimensional simulation (physical simulation) of the robot executing activities and performing work at the work site, and obtains the time required for the robot to perform the work. The 3D simulation device 50 can also obtain the throughput (processing speed).

[0021] The process feasibility evaluation device 60 evaluates the feasibility of the process plan (whether the working time of the lower-level process is within the planned time set by the higher-level process) based on the simulation results of the 3D simulation device 50. In other words, the process feasibility evaluation device 60 evaluates the feasibility of the process plan by determining whether the robot's working time (working time of the lower-level process) obtained by the 3D simulation device 50 is within the planned time (working time predetermined by the higher-level process). Specifically, if the robot's working time exceeds the planned time, the process feasibility evaluation device 60 determines that the process plan is unfeasible.

[0022] The work process network modification device 70 modifies the process network, or network model, when the process feasibility evaluation device 60 determines that the process plan is unfeasible. The work process network modification device 70 modifies the network model if the robot's work time (work time of the lower-level process) exceeds the planned time (work time predetermined in the higher-level process), as this indicates that the process plan is unfeasible.

[0023] The process plan modification device 90 modifies the process plan of lower-level processes in accordance with the modification of the network model by the work process network modification device 70 when the process feasibility evaluation device 60 determines that the process plan is unfeasible.

[0024] When the work process network modification device 70 modifies the network model and the process plan modification device 90 modifies the process plan of a lower-level process, the work time of the lower-level process becomes within the planned time set by the higher-level process, and the process plan is established.

[0025] The 3D simulation device 50, the process feasibility evaluation device 60, and the work process network modification device 70 function together as a determination module 80 that determines the feasibility of robot motion simulation.

[0026] The process planning support system according to this embodiment further comprises a process data database 100, a work process network data database 200, an environment model database 300, a robot model database 400, and a work object model database 500.

[0027] The process data database 100 stores the work processes entered into the process planning support system as initial process data. These work processes are created in advance and saved to the process data database 100 either through user input using the input device 10 or from a higher-level system. These work processes include higher-level processes (e.g., processes defined on a monthly basis) and lower-level processes (e.g., processes defined on a daily basis), and each process includes its start and end dates and the work content.

[0028] The work process network data database 200 stores process network data for each activity (work unit) as work process network data. A process network is a network model that represents the work process in an activity, such as a Petri net in discrete event simulation. The work process network data database 200 stores process networks (e.g., Petri nets) for all activities.

[0029] The following section describes an example where the process network is a Petri net.

[0030] The Environmental Model Database 300 stores a complete on-site environmental model of the plant where the robot performs its work. The on-site environmental model is a 3D virtual representation of the robot's work environment and is pre-created by the user. The on-site environmental model also includes the modeled robot.

[0031] The robot model database 400 stores information about modeled robots. This information includes details about the 3D robot model in the field environment model, such as information about the robot's movements.

[0032] The Work Object Model Database 500 stores information about modeled work objects. This information refers to the 3D model of the work object in the field environment model, and includes, for example, information about objects that are processed by a robot.

[0033] Figure 2 shows an example of work processes (initial process data) stored in the process data database 100. As an example, Figure 2 shows a process chart (Gantt chart) that has higher-level processes 110 defined on a monthly basis and lower-level processes 120 defined on a daily basis.

[0034] The upper-level process 110 consists of a processing activity 112, a recovery activity 113, and a pre-transfer processing activity 114. The processing activity 112 is an activity (work unit) that processes the workpiece. The recovery activity 113 is an activity that places the workpiece processed in the processing activity 112 into a recovery container. The pre-transfer processing activity 114 is an activity that prepares the workpiece recovered in the recovery activity 113 for transfer, and includes tasks such as putting a lid on the recovery container containing the workpiece and placing the recovery container on a transfer robot.

[0035] The lower-level process 120 is defined for each of the activities 112 to 114 of the higher-level process 110. The higher-level process 110 provides data to the lower-level process 120, including the start and end times and the work content of the lower-level process 120. Below, as an example, the lower-level process 120 of processing activity 112 will be described. In the lower-level process 120, the work object is rubble, and the work of processing the rubble is performed.

[0036] The lower-level process 120 consists of sub-activities for carrying out the processing activity 112. Specifically, the lower-level process 120 consists of a robot placement activity 121, a rubble cutting activity 122, a rubble removal activity 123, and a rubble transport activity 124. These activities 121 to 124 are set as tasks performed in minutes or hours.

[0037] Robot deployment activity 121 is an activity in which robots that will perform the work (for example, cutting / removal robots and transport robots) are deployed to the work site. Debris cutting activity 122 is an activity in which the cutting / removal robot cuts the debris to be removed. Debris removal activity 123 is an activity in which the cutting / removal robot loads the debris cut in debris cutting activity 122 onto a transport robot and removes it. Debris transport activity 124 is an activity in which the transport robot transports the debris removed in debris removal activity 123.

[0038] Each of the activities 112-114 of the higher-level process 110 has a milestone set in the higher-level process 110 as a deadline to be met. In the example shown in Figure 2, the milestone 111 of the lower-level process 120 is set by the processing activity 112 of the higher-level process 110 to be 5 hours after the start of work.

[0039] Between activities, there are Finish to Start (FS) relationships, where the next activity begins after the previous activity has finished, and Start to Start (SS) relationships, where the next activity begins after the previous activity has started. In the example shown in Figure 2, in the lower process 120, there is an FS relationship between the robot placement activity 121 and the rubble cutting activity 122, and there are SS relationships between the rubble cutting activity 122 and the rubble removal activity 123, and between the rubble removal activity 123 and the rubble transport activity 124.

[0040] In actual work, the process progresses with multiple interactions between the various activities in the lower-level process 120. These interactions include, for example, preparatory work performed between two activities for the next activity, such as preparing the materials needed for the next activity or moving the robot that will perform the work.

[0041] In the example shown in Figure 2, there are multiple interrelationships 130 between the rubble cutting activity 122 and the rubble removal activity 123, and between the rubble removal activity 123 and the rubble transport activity 124. For example, between the rubble cutting activity 122 and the rubble removal activity 123, the cutting and removal robot places the rubble cut in the rubble cutting activity 122 into a storage container. Also, for example, between the rubble removal activity 123 and the rubble transport activity 124, the cutting and removal robot prepares a new empty storage container to replace the one containing the rubble.

[0042] These types of interaction 130 tasks take a certain amount of time to perform, but they are not depicted in the process chart (Gantt chart) and are not managed (considered) as information. Therefore, even if a formula is derived to estimate the work time in the lower-level process 120 based on the work process entered by the user (initial process data stored in the process data database 100), the work time obtained using this formula is an approximate work time and may have a large error compared to the actual work time.

[0043] Figure 3 shows an example of a field environment model 310, which represents the work site where the robot performs its tasks in a three-dimensional virtual environment model. The entire field environment model 310 of the plant is stored in the environment model database 300. Figure 3 shows an example of a field environment model 310 corresponding to the work content described in processing activity 112 in Figure 2.

[0044] The field environment model 310 includes models of a cutting / removal robot 510, a transport robot 520, a storage container 530, and a work object 550 (rubble). The field environment model 310 can represent not only the relative positions of the objects present in the field environment model 310, but also the movement and changes in posture of robots 510 and 520 over time, as well as the changes in the shape of the work object 550 due to cutting. Furthermore, if the work site has a high dose rate atmosphere, robots 510 and 520 need to be replaced according to the limit cumulative dose specified in the specifications. The field environment model 310 can represent the replacement of robots 510 and 520.

[0045] The display device 20 can display a three-dimensional field environment model 310. By displaying the field environment model 310, the user can understand the positional relationships of objects in the field environment model 310, the movement, changes in posture and exchange of robots 510 and 520 over time, and the changes in the shape of the work object 550.

[0046] In this embodiment, each activity can be associated with the three-dimensional field environment model 310, allowing for highly accurate calculation of work time and the presentation of a highly explainable process plan to the user.

[0047] Figure 4 shows an example of the network model (process network data) for machining activity 112 in Figure 2. Figure 4 also shows an example of the work process of machining activity 112 represented by a Petri net. Petri nets are a representative process network frequently used in discrete event simulations.

[0048] As mentioned above, in the process chart (Gantt chart) shown in Figure 2, even if, for example, the activities 121-124 of the lower process 120 within the machining activity 112 of the higher process 110 are depicted in detail, the multiple interrelationships 130 (interactions 130) that exist between activities 121-124 are not clearly depicted.

[0049] In this embodiment, by representing the relationship between activities in a network model using a Petri net, it is possible to consider multiple interrelationships 130 (interactions 130) that exist between activities 121 to 124, and the working time required for processing activity 112 can be determined more accurately.

[0050] Generally, a Petri net N is represented by a set P of places p representing working states, a set T of transitions t representing transitions between working states, a set F of arcs connecting transitions t and places p in a directed graph, and a set W of arc weights, where a non-negative integer number of tokens are placed inside each place p. The arrangement of tokens within place p is called a marking and represents the state of the system. The initial state of the system is represented by the set m0 of initial markings.

[0051] The set of places p P, the set of transitions t T, the set of arcs F, the set of weights W, and the set of initial markings m0 are expressed by the following equations: P={p1,p2,...,p |P|} T={t1,t2,...,t |T|} F⊆(P×T)∪(T×T) W:F→{1,2,...} m0:P→{0,1,2,...} However, |P| represents the number of place p, and |T| represents the number of transition t.

[0052] The Petri net shown in Figure 4 is a Petri net that applies the above formulation to the machining activity 112 of the higher-level process 110 shown in Figure 2, i.e., the lower-level process 120.

[0053] Place p1 represents the state in which the cutting / removal robot 510 and the transport robot 520 are positioned at the work site (robot positioning state). Place p2 represents the state in which the work object 550 (rubble) cut by the cutting / removal robot 510 is stored in the storage container 530 (storage state). Place p3 represents the state in which the storage container 530 containing the work object 550 (rubble) is placed on the transport robot 520 (loading state).

[0054] Transition t1 represents the work process (cutting) in which the cutting and removal robot 510 cuts the work object 550 (rubble) and stores the cut work object 550 in the storage container 530. Transition t2 represents the work process (removal) in which the cutting and removal robot 510 places the storage container 530 onto the transport robot 520. Transition t3 represents the work process (transport) in which the transport robot 520 carrying the storage container 530 moves. Transition t4 represents the work process (robot return) in which the transport robot 520 that transported the storage container 530 moves back to its original position.

[0055] The arc f1 connecting place p1 to transition t1 is assigned a weight w1. The weight w1 represents the speed and efficiency of the cutting and removal robot 510's work.

[0056] Tokens 251 are placed inside places p1 to p3. Tokens 251 indicate the presence of work objects 550 in the state of places p1 to p3. The number of tokens that can be processed per unit time is an indicator of work efficiency and is expressed as throughput (processing speed).

[0057] When a 3D simulation of the work process is performed in the 3D field environment model 310 shown in Figure 3, the work movements obtained from the 3D simulation can be made to correspond to each transition t1 to t4. The 3D simulation of the work process in the field environment model 310 is a physical simulation that simulates the actual work movements of robots 510 and 520 (for example, the rotation and arm movement of the cutting / removal robot 510, and the movement of the transport robot 520). This 3D simulation can generate 3D videos of the work movements of robots 510 and 520. The display device 20 can display these 3D videos.

[0058] Each of the transitions t1 to t4 can be associated with a work motion (video of the work motion) obtained from a 3D simulation. For example, the cutting transition t1 can be associated with a video of the cutting and removal robot 510 cutting the work object 550 and storing the cut work object 550 in the storage container 530. The removal transition t2 can be associated with a video of the cutting and removal robot 510 loading the storage container 530 containing the work object 550 onto the transport robot 520. By associating the transitions t1 to t4 with the work motions obtained from the 3D simulation, the number of detailed calculations involving the virtual environment can be narrowed down to a finite number.

[0059] Figure 5 is an example flowchart showing the processes performed by the process planning support system according to this embodiment.

[0060] In step 2100, the process planning support system inputs information about the process for which it wants to check the feasibility of the process plan. In this embodiment, the process planning support system inputs information about the machining activity 112 and its sub-process 120 (Figure 2). The user can operate the input device 10 to input information about the process for which they want to check the feasibility of the process plan (for example, the machining activity 112 and its sub-process 120) into the process planning support system.

[0061] The feasibility of a process plan refers to whether the plans for the lower-level processes created are consistent with the higher-level processes (i.e., whether the lower-level processes are compatible with the higher-level processes). Information about the process for which you want to check the feasibility of the process plan includes, for example, the target process, the work site, and the type of work, and defines the scope of the process for which you want to check the feasibility of the process plan.

[0062] In step 3100, the activity extraction device 30 extracts activities from the work processes (initial process data) stored in the process data database 100 for the process entered in step 2100, in order to calculate the work time, the number of workers to be assigned, and the resources to be used, such as robots. In this embodiment, the activity extraction device 30 extracts activities 121 to 124 (Figure 2) of the lower-level process 120.

[0063] In step 4100, the work process network device 40 represents the work divided into activities as a network model. The work process network device 40 represents the work divided into activities as a network model by extracting process network data corresponding to the activities extracted in step 3100 from the work process network data database 200. In this embodiment, the network model is assumed to be a Petri net. That is, the work process network device 40 extracts Petri net data (for example, the Petri net data shown in Figure 4) corresponding to the activities extracted by the activity extraction device 30.

[0064] In step 5100, the 3D simulation device 50 performs a three-dimensional simulation (physical simulation) of the robots 510 and 520 performing activities and tasks at the work site, and determines the time required for the robots 510 and 520 to perform the tasks. The 3D simulation device 50 extracts information about the work site environment model 310 of the work site where the robots 510 and 520 will perform the tasks from the environment model database 300, extracts information about the models of the robots 510 and 520 to be used from the robot model database 400, and extracts information about the model of the work object 550 from the work object model database 500. Then, using this extracted information, the 3D simulation device 50 performs a simulation of the work of the robots 510 and 520 corresponding to the transitions of the Petri net extracted in step 4100.

[0065] For example, the 3D simulation device 50 performs a simulation of a robot operation corresponding to the transition t1 of cutting the petri net shown in Figure 4. In the three-dimensional field environment model 310 shown in Figure 3, the cutting and removal robot 510 cuts the work object 550 and stores the cut work object 550 in the storage container 530.

[0066] The 3D simulation device 50 performs a three-dimensional simulation, or physical simulation, of the actions that the robots 510 and 520 actually perform at the work site for each transition of the Petri Net (for example, movement, rotation, arm movement, platform movement, cutting of the workpiece, and storage of the cut workpiece into a storage container). The 3D simulation device 50 then performs a physical simulation for all operations in the lower-level process 120 of the processing activity 112 to determine the time required for each operation. The 3D simulation device 50 can perform this simulation using existing methods.

[0067] The display device 20 can also display the 3D video obtained from this physical simulation to the user. The video obtained from the physical simulation includes 3D videos of the robots 510 and 520 actually performing tasks at the work site.

[0068] In step 6100, the 3D simulation device 50 calculates the waiting time and determines the throughput (processing speed).

[0069] First, the 3D simulation device 50 performs a conceptual simulation to determine the time required for the lower-level process 120 from the Petri net. Specifically, the 3D simulation device 50 performs a simulation (conceptual simulation) using an existing Petri net simulator on the Petri net extracted in step 4100 to determine the time required for the lower-level process 120 from the Petri net. Then, the 3D simulation device 50 subtracts the time required for the lower-level process 120 determined by the conceptual simulation from the time required for the lower-level process 120 determined by the physical simulation in step 5100, and uses the resulting time as the waiting time. This waiting time includes the waiting time for the state of the Petri net, including the placement.

[0070] Next, the 3D simulation device 50 determines the throughput (processing speed) of the operations (activities 121-124) of the lower-level process 120 from the time required for the operations of the lower-level process 120 determined by the physical simulation. By determining the throughput, for example, the speed at which the workpiece 550 is cut or removed can be determined.

[0071] In step 7100, the process feasibility evaluation device 60 evaluates the feasibility of the process plan based on the simulation results of the 3D simulation device 50, and modifies the Petri net based on the evaluation results. The feasibility of the process plan means whether the work plan of the created lower-level process is consistent with the higher-level process (i.e., whether the work time of the lower-level process is within the planned time set by the higher-level process).

[0072] The process feasibility evaluation device 60 determines whether the lower process 120 can comply with the milestone 111 set by the higher process 110, based on the time taken for the work (activities 121 to 124) of the lower process 120, which was determined by physical simulation in step 5100. In other words, the process feasibility evaluation device 60 determines, based on the results of the physical simulation, whether the work time of the lower process 120 is within the planned time given by the higher process 110. Note that the planned time given by the higher process 110 includes a delay allowance ΔT max It may be set. Delay tolerance time ΔT max If this is set, the process feasibility evaluation device 60 determines that the working time of the lower process 120 is equal to the planned time and delay allowance ΔT given by the upper process 110. max Determine whether or not it is within the total time.

[0073] Furthermore, if the working time for the lower-level process 120 of robots 510 and 520 can be determined from the operational history of robots 510 and 520, the process feasibility evaluation device 60 may use this working time to evaluate the feasibility of the process plan instead of the results of the physical simulation performed by the 3D simulation device 50.

[0074] The process feasibility evaluation device 60 fails to meet milestone 111 (the working time of the lower process 120 is equal to the planned time given by the upper process 110, or the planned time given by the upper process 110 and the allowable delay time ΔT). max If it is determined that the total time exceeds the specified time, the process plan is unsuccessful, so the work process network modification device 70 modifies the Petri net, and the process plan modification device 90 modifies the process plan of the lower process 120. The process feasibility evaluation device 60 can determine the activity (bottleneck activity) that caused the process plan to be unsuccessful.

[0075] The display device 20 can display to the user information indicating that the process feasibility evaluation device 60 has determined the process plan is unsuccessful, and information about the activities (bottleneck activities) that caused the process plan to be unsuccessful. Information about the bottleneck activities includes, for example, the work content of the activity, the performance and number of robots 510 and 520 that perform the activity, and information about the tools and containers used (for example, storage container 530).

[0076] In step 7100, the work process network modification device 70 modifies the Petri net (network model), and the process plan modification device 90 modifies the process plan of the lower process 120 in accordance with the modification of the Petri net by the work process network modification device 70. In this way, the process plan creation support system according to this embodiment establishes the process plan.

[0077] The work process network modification device 70 considers the activities that caused the process plan to fail as bottleneck tasks (tasks with a high risk of delay), and modifies the Petri net for the bottleneck tasks to shorten the work time of the bottleneck activities and eliminate the bottleneck. Activities that caused the process plan to fail include, for example, tasks with a throughput (processing speed) slower than planned, or tasks that take longer to perform than planned. The work process network modification device 70 improves throughput and shortens work time to eliminate bottlenecks by changing attributes related to transitions and places in the Petri net, such as the performance and number of robots 510 and 520, and the number of storage containers 530, so that the work time of the lower process 120 is within the planned time given by the higher process 110.

[0078] The work process network modification device 70 can modify the Petri net according to a predetermined procedure or based on instructions entered by the user using the input device 10.

[0079] The process plan modification device 90 modifies the process plan of the lower process 120 in accordance with the modification of the Petri net by the work process network modification device 70.

[0080] When the work process network modification device 70 modifies the Petri net and the process plan modification device 90 modifies the process plan of the lower process 120, the work time of the lower process 120 will be within the planned time set by the higher process 110, thus avoiding work delays and achieving a successful process plan.

[0081] In step 8100, the display device 20 displays to the user either the Petri net modified by the work process network modification device 70 or the process plan modified by the process plan modification device 90. Furthermore, the display device 20 can display to the user a video of the results of a physical simulation of the robots 510, 520 performed by the 3D simulation device 50 based on the Petri net modified by the work process network modification device 70 or the process plan modified by the process plan modification device 90 (see, for example, step 5100).

[0082] Figure 6 shows an example of a case where the process feasibility evaluation device 60 determines that the process plan is unfeasible. Figure 6 shows an example of cutting and removing rubble, which is the work object 550. Transition t1 is the work process (cutting) in which the cutting and removal robot 510 cuts the work object 550 (rubble), as explained using Figure 4. In the example shown in Figure 6, the time required for the cutting transition t1 obtained from the physical simulation is longer than the planned work time, and the throughput is lower than planned, so the process plan is unfeasible.

[0083] The 3D simulation device 50 performs a simulation (physical simulation) of the cutting and removal robot 510 cutting the work object 550 in a three-dimensional field environment model 310 as a robot operation corresponding to the cutting transition t1.

[0084] In actual work, in rubble cutting activity 122, the cutting and removal robot 510 in the physical simulation cuts the work object 550 (rubble) into units that can be stored in the storage container 530. In the example shown in Figure 6, the cutting and removal robot 510 cuts the work object 550 at three cutting positions 550a, 550b, and 550c.

[0085] In this way, the rubble cutting activity 122 is divided according to the number of cutting positions 550a, 550b, and 550c. In the example shown in Figure 6, the rubble cutting activity 122 is divided into three rubble cutting activities 122a, 122b, and 122c. The 3D simulation device 50 determines the time required for the three rubble cutting activities 122a, 122b, and 122c (cutting time) through physical simulation.

[0086] As the rubble cutting activity 122 is divided into three parts, the rubble removal activity 123 is also divided into three rubble removal activities 123a, 123b, and 123c. The 3D simulation device 50 uses physical simulation to determine the time required for each of the three rubble removal activities 123a, 123b, and 123c (removal time).

[0087] The 3D simulation device 50 determines the working time (e.g., cutting time and removal time) for each activity corresponding to each transition by performing a three-dimensional physical simulation of the work of the robots 510 and 520. In this case, for example, if the object to be worked on 550 changes shape before and after the transition, the working time of the activity may increase even if the same activity is performed before and after the transition. For example, when the object to be worked on 550 is cut, the object to be worked on 550 changes shape before and after the cutting transition. Due to the change in shape of the object to be worked on 550, the time required for the rubble cutting activity 122 may change before and after the cutting transition, and the working time may increase.

[0088] The process feasibility evaluation device 60 determines that the work time calculated by the physical simulation performed by the 3D simulation device 50 is equal to the planned time (allowable delay time ΔT) given by the higher-level process 110. max If this is set, the plan time and delay tolerance ΔT given from the higher process 110 max If the total time exceeds the planned time, the process plan is deemed unsuccessful. In the example shown in Figure 6, the time required for the cutting transition t1 is longer than the planned working time, resulting in reduced throughput, and the completion time of the rubble removal activity 123c exceeds milestone 111. Therefore, the process feasibility evaluation device 60 determines that the process plan is unsuccessful because the working time calculated by physical simulation exceeds the planned time given by the higher-level process 110. The process feasibility evaluation device 60 can then identify the activity that caused the process plan to be unsuccessful (the bottleneck activity) as the rubble cutting activity 122 (122a, 122b, 122c).

[0089] The work process network correction device 70 considers the rubble cutting activity 122 (122a, 122b, 122c) to be a bottleneck operation because it is the activity that caused the process plan to fail.

[0090] Figure 7 shows an example of a case where, in Figure 6, the process plan was deemed unsuccessful, and the Petri net was modified to revise the process plan of the lower-level process 120, thereby making the process plan successful.

[0091] The work process network modification device 70 modifies the Petri net for the bottleneck activity 122 (122a, 122b, 122c) according to a predetermined procedure or based on instructions entered by the user using the input device 10, thereby shortening the work time for activity 122 (122a, 122b, 122c).

[0092] The process plan modification device 90 modifies the process plan of the lower-level process 120 in accordance with the modification of the Petri net by the work process network modification device 70. First, the 3D simulation device 50 performs a 3D simulation (physical simulation) in which robots 510 and 520 perform activities and execute work based on the modified Petri net, and determines the time required for robots 510 and 520 to execute the work. Based on the results of this 3D simulation, the process plan modification device 90 modifies the process plan of the lower-level process 120.

[0093] The work process network modification device 70 modifies the Petri net, and the process plan modification device 90 modifies the process plan of the lower-level process 120 in accordance with the modification of the Petri net, thereby eliminating bottlenecks and enabling the process plan to be established. In the example shown in Figure 7, the process plan is established by changing the nodes (places and transitions) of the Petri net.

[0094] As shown in Figure 7, the cutting transition t1 in the Petri net shown in Figure 6, which resulted in lower throughput than planned and caused the process plan to fail, is changed to transition t5 using a different cutting and removal robot 510A with improved cutting speed. As a result, the time required for the rubble cutting activities 122a, 122b, and 122c is reduced, and rubble cutting activity 122c is completed by Δt1 earlier than the originally planned completion time for rubble cutting activity 122. Furthermore, because the time required for rubble cutting activities 122a, 122b, and 122c is reduced, rubble removal activity 123c is completed by Δt2 earlier than the planned completion time for rubble removal activity 123.

[0095] In the example shown in Figure 7, by changing transition t1, which was the cause of the process plan failure, to a new transition t5, the time required for the cutting transition is reduced compared to the originally planned work time, improving throughput and allowing the lower-level process 120 of the machining activity 112 to be completed earlier than originally planned. Similarly, if transitions t2 to t4 are determined to be the cause of the process plan failure, they can be modified to make the process plan successful by changing the node in the Petri net, just as with transition t1.

[0096] The process planning support system according to this embodiment can thus clarify tasks that are likely to cause the process plan to fail, i.e., tasks that have a high risk of delay and can become bottlenecks, thereby avoiding delays in those tasks. Furthermore, the process planning support system according to this embodiment can present a highly explainable process plan to the user by displaying a 3D video of the robot's movement obtained through 3D simulation, as well as a modified Petri net and process plan that make the process plan feasible.

[0097] It should be noted that the present invention is not limited to the embodiments described above, and various modifications are possible. For example, the embodiments described above are explained in detail to make the present invention easier to understand, and the present invention is not necessarily limited to embodiments having all the configurations described. Furthermore, it is possible to replace parts of the configuration of one embodiment with the configuration of another embodiment. It is also possible to add configurations from other embodiments to the configuration of one embodiment. Furthermore, it is possible to delete parts of the configuration of each embodiment, or to add or replace other configurations. [Explanation of Symbols]

[0098] 10...Input device, 20...Display device, 30...Activity extraction device, 40...Work process network device, 50...3D simulation device, 60...Process feasibility evaluation device, 70...Work process network modification device, 80...Decision module, 90...Process plan modification device, 100...Process data database, 110...Higher-level process, 112...Processing activity, 113...Recovery activity, 114...Transfer pre-processing activity, 120...Lower-level process, 121...Robot placement activity, 122...Debris cutting activity, 123...Debris removal activity, 124...Debris transport activity, 130...Interrelationship, 200...Work process network data database, 251...Token, 300...Environment model database, 310...Site environment model, 400...Robot model database, 500...Work object model database, 510...Cutting / removal robot, 520...Transport robot, 530...Storage container, 550...Work object.

Claims

1. A work process network device that represents a task divided into multiple activities using a network model that shows the relationships between the activities, A simulation device that performs a three-dimensional simulation in which a robot performs the activity and executes the task, and determines the work time which is the time required for the robot to execute the task, A process feasibility evaluation device evaluates the feasibility of a process plan based on the work time obtained by the simulation device, and determines that the process plan is unfeasible if the work time of a lower process obtained by the simulation device exceeds the predetermined plan time for a higher process. If the process feasibility evaluation device determines that the process plan is unfeasible, the work process network modification device modifies the network model, Equipped with, The aforementioned work process network modification device considers the activity that caused the process plan to fail as a bottleneck operation, and modifies the network model for the bottleneck operation to shorten the work time of the activity that is the bottleneck. The aforementioned higher-level process is composed of a plurality of the aforementioned activities, The aforementioned lower process is defined for each of the activities of the aforementioned higher process and consists of the activities for carrying out the activities of the aforementioned higher process. A process planning support system characterized by the following features.

2. The system includes a process plan modification device that modifies the process plan in accordance with the modification of the network model by the work process network modification device. The process planning support system according to claim 1.

3. Equipped with a display device, The display device displays information about the activity that is the bottleneck. The process planning support system according to claim 1.

4. Equipped with a display device, The display device displays a three-dimensional video of the robot's movements obtained by the simulation device performing the three-dimensional simulation. The process planning support system according to claim 1.

5. Equipped with a display device, The display device displays the network model modified by the work process network modification device. The process planning support system according to claim 1.

6. Equipped with a display device, The display device displays the process plan modified by the process plan modification device. The process planning support system according to claim 2.

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