System for estimating wireless performance at manufacturing site and method therefor

The present invention relates to a system for estimating wireless performance in a manufacturing site.

In recent years, with the development of communication technology and analysis technology, the number of manufacturing sites such as factories where wireless communication is required for the progress of processes or where wireless communication is used as an aid is increasing. Various types of application programs (hereinafter simply referred to as applications) using wireless communication are being considered. One example is a system that wirelessly collects log information such as process progress information and the presence or absence of problems from sensors installed at various locations in manufacturing sites such as factories. Another example is a system that transmits video of the manufacturing site in real time using a camera, allowing production managers and skilled workers to visually check the progress of the process from a remote location or to give instructions to on-site personnel. Another example is a system that remotely controls machines such as a robot arm.

These applications can also be processed using wired communication. However, the number of devices such as sensors is expected to increase in the future, and in manufacturing sites where a wide variety of products are produced in small quantities, changes in processes can lead to frequent installation of additional equipment or movement of equipment locations. In such cases, wired communication requires rewiring every time a process is changed, which is difficult to handle. Therefore, wireless communication is expected to become the mainstream in manufacturing sites in the future.

Wireless communication can avoid the need to rewire when a process is changed (for example, when the production of one product is completed and the production of the next product begins). However, when a device is added or the location of the device is changed due to a process change, the wireless communication performance also changes.

Specifically, when radio waves used in wireless communication are placed between a transmitter and a receiver, the radio waves are attenuated by obstruction, or are reflected or scattered by devices installed near the transmitter or receiver. Therefore, adding, removing, or changing the location of devices changes the radio wave conditions in the manufacturing site, causing changes in wireless performance.

Various propagation simulation technologies have already been developed and commercialized to estimate wireless performance not only in manufacturing sites but also in business establishments (factories, offices, etc.) that use wireless communications. Patent Document 1 discloses a method that combines mining planning and network planning in a mine.

<p><patcit num="1"><text>Patent Publication No. 2019-509685</text></patcit></p>

<p>When a process is changed at a manufacturing site, the radio wave conditions in the manufacturing site change due to the installation, removal, or relocation of equipment, causing changes in wireless performance. At this time, even if various applications are operating without problems via wireless communication in the current process, the application may not operate as expected via wireless communication in the next process due to the change in wireless performance. As a result, even if the next process is started, the application required for that process may not operate, causing the process to stop, resulting in a decrease in the operating rate of the production site.</p><p>To avoid this, it is useful to estimate wireless performance in accordance with future plans by some means. Various propagation simulators that estimate wireless performance are already known. Wireless radio wave propagation simulation is a technology for estimating wireless performance, but the following problems still remain at manufacturing sites. For example, there are many small-scale manufacturing sites, and skilled wireless engineers who can use propagation simulations are not necessarily assigned to each site. On-site personnel who do not have knowledge of wireless cannot use propagation simulations well, and may not be able to estimate wireless performance correctly, or may take a long time to set up the propagation simulation.</p><p>The present invention has been made in consideration of the above-mentioned problems, and aims to assist managers and staff at manufacturing sites who do not have sufficient wireless knowledge in estimating wireless performance in each production process.</p>

<p>One aspect of the present invention is a system for estimating wireless performance at a manufacturing site, the system including one or more storage devices and one or more arithmetic devices, the one or more storage devices storing process information including information on one or more processes before the start of the processes at the manufacturing site, and management information for managing one or more wireless performance estimation methods usable for each of a plurality of applications and information for determining a processing time for each of the one or more wireless performance estimation methods, the process information including information on one or more applications used in each of the one or more processes and information on a time associated with each process, the one or more arithmetic devices referring to the process information and the management information determining one or more wireless performance estimation methods usable for each process, and referring to the process information and the management information determining whether or not the wireless performance estimation process is completed by a time associated with each process.<u style="Single">Wireless performance estimation method</u>is selected from the one or more wireless performance estimation methods available in each step.</p>

<p>According to one aspect of the present invention, it is possible to support site managers and personnel in estimating wireless performance in each production process.</p><p>Problems, configurations and effects other than those described above will become apparent from the following description of the embodiments.</p>

<figref num="1">FIG. 1 is a conceptual diagram of a manufacturing site assumed in the first embodiment.</figref><figref num="2A">This is a layout diagram of the manufacturing site for process A.</figref><figref num="2B">This is a layout diagram of the manufacturing site for process B.</figref><figref num="2C">This is a layout diagram of the manufacturing site for process C.</figref><figref num="3">FIG. 1 is a functional block diagram of a wireless performance estimation system.</figref><figref num="4">FIG.</figref><figref num="5A">FIG. 11 is a diagram showing information for calculating wireless performance.</figref><figref num="5B">FIG. 13 is a diagram of a performance estimation method table.</figref><figref num="5C">FIG. 13 is a diagram of a propagation simulation time table.</figref><figref num="5D">FIG. 13 is a diagram of an extraction condition table.</figref><figref num="5E">FIG.</figref><figref num="6">1 is a flow chart illustrating the overall operational lifecycle of one embodiment of the present disclosure.</figref><figref num="7">FIG. 13 is a flowchart showing steps for calculating wireless performance.</figref><figref num="8A">8 is a diagram of an intermediate result in the flowchart of FIG. 7 of a wireless performance calculation unit.</figref><figref num="8B">8 is a diagram of an intermediate result in the flowchart of FIG. 7 of a wireless performance calculation unit.</figref><figref num="9A">FIG. 1 is a diagram of a process output by the wireless performance estimation system and a schedule of wireless performance estimation.</figref><figref num="9B">11 is a diagram showing a wireless performance estimation result output by the wireless performance estimation system. FIG.</figref><figref num="9C">FIG. 13 is a diagram of a heat map output by the wireless performance estimation system.</figref><figref num="10">FIG. 11 is a diagram of an extraction condition table in the second embodiment.</figref><figref num="11">FIG. 13 is a diagram of an extraction condition table in the third embodiment.</figref><figref num="12A">FIG. 13 is a diagram of information for wireless performance calculation in the fourth embodiment.</figref><figref num="12B">FIG. 13 is a diagram of an application permission determination table in the fourth embodiment.</figref>

Hereinafter, several embodiments of the present invention will be described with reference to the drawings. In the following embodiments, when necessary for convenience, the description will be divided into a plurality of sections or embodiments. However, unless otherwise specified, they are not unrelated to each other, and one is related to the other in terms of partial or complete modification, details, supplementary explanation, etc. Each embodiment may be implemented individually or in combination.

In addition, in the following embodiments, when referring to the number of elements (including the number, numerical values, quantities, ranges, etc.), unless otherwise specified or clearly limited to a specific number in principle, the number is not limited to that specific number and may be more than or less than the specific number.

Furthermore, it goes without saying that in the following embodiments, the components (including element steps, etc.) are not necessarily essential unless specifically stated or considered to be clearly essential in principle.

Similarly, in the following embodiments, when referring to the shapes, positional relationships, etc. of components, unless otherwise specified or considered to be clearly different in principle, it includes those that are substantially similar or similar to the shapes, etc. The same applies to numerical values and ranges.

In the following description, expressions such as "xxx table" may be used, but the information may be data of any structure. In the following description, the structure of each table is an example, and one table may be divided into two or more tables, or two or more tables may all or partly be one table. In the following description, functions may be described using the expression "xxx part", but the function may be realized by executing one or more computer programs.

A wireless performance estimation system for use in a manufacturing site will be described below. The wireless performance estimation system facilitates advance estimation of wireless performance at a manufacturing site where an application program using wireless communication is used in the production process of a product, part, or the like.

There are many small manufacturing sites, and it is not always the case that a skilled wireless engineer who can use a propagation simulation is assigned to each site. On-site personnel who do not have knowledge of wireless may not be able to use the propagation simulation, and may not be able to estimate the wireless performance correctly, or may take a long time to set up the propagation simulation. In addition, the propagation simulation may take a long time, and as a result, the results may not be available by the time they are needed.

A wireless performance estimation system according to an embodiment of this specification adjusts the estimation accuracy of wireless performance estimation according to a process plan and application information. This allows wireless performance estimation time to be shared between processes. As a result, it is possible to select a wireless estimation method according to a process. Furthermore, in an embodiment of this specification, the wireless performance estimation system can reduce the frequency of occurrence of a situation in which wireless performance estimation is not completed before a process starts.

In the wireless performance estimation system according to an embodiment of the present specification, the information input by the user is only information on the installed equipment and information on the process plan, and knowledge of wireless is not required. Therefore, it is not necessary to deploy wireless engineers at all production sites. As a result, it is possible to perform advance verification before the start of the process and modify wireless settings as necessary, thereby improving the operation rate of the site.

&lt;First embodiment&gt; In this embodiment, an example of estimating wireless performance for three production processes before their start at one manufacturing site will be described. This manufacturing site is a multi-item, small-lot production site, and production work is carried out as a separate process for each product (product, part).

Different processes require different devices, equipment, and other installations around the production line. In this specification, these are called installations. The installations may be workers who work at designated positions beside the line. In addition, each process uses an application program that uses wireless communication to carry out or support product production. Hereinafter, the application program is also simply called an application.

Different applications may be used for different processes. Only one application may be used for some processes, while multiple applications may be used for other processes. Examples of applications used may vary depending on the manufacturing site, but in this embodiment, the following three types of applications are assumed.

The first is a log collection application. The log collection application collects log files such as the operating status of each device and the production progress status from sensors, etc. An example of the log file is a text file.

The second is an application that uses video streaming to capture the situation at the manufacturing site with a camera and display it on a monitor at a remote location in real time, and the third is an application that uses remote control to operate manufacturing equipment such as robot arms installed at the manufacturing site from a remote location.

Figure 1 is a conceptual diagram of a manufacturing site based on the above configuration. Within the manufacturing site 1, there is a production line 10 where production work is carried out, and devices that realize the above-mentioned applications are placed around it. Specifically, a sensor 12 that is a terminal for collecting logs, a camera 13 for real-time video streaming, and a remotely controlled robot arm 14 are installed.

These devices 12, 13, 14 also function as wireless communication terminals, perform wireless communication with a wireless communication base station 11, and exchange data with a remote server 15 installed in a management room 3 via a network 2. These devices performing wireless communication are wireless communication devices. A management system is installed in the management room 3, and the management system includes the server 15 and a wireless performance estimation system 100.

For example, logs collected by the sensor 12 are accumulated in a storage in the remote server 15. Images captured by the camera 13 are displayed in real time on the monitor of the remote server 15. The robot arm 14 performs work on the production line 10 according to instructions from the remote server 15. Note that there may be multiple production lines 10, devices 12, 13, 14, and base stations 11. The control room 3 may be located within the same premises as the manufacturing site (for example, the same factory) or on a different premises, and the necessary functions may be implemented on the cloud.

2A, 2B, and 2C respectively show the layout of equipment in three processes before the start at the manufacturing site 1. It is assumed that the three processes, process A, process B, and process C, are executed in this manufacturing site 1 in this order.

2A shows a layout of the equipment at the manufacturing site 1 in process A. In process A, log collection and remote control applications are not used. No sensors or robot arms are installed, and only the camera 13 performs wireless communication with the base station 11. In addition, installation objects 19A1 to 19A5, which are devices and parts that do not perform wireless communication but are necessary for process A, are also installed in the manufacturing site 1A.

FIG. 2B shows a layout of the equipment at the manufacturing site 1 in process B. In process B, real-time streaming of video and remote control applications are not used. No camera or robot arm is installed, and only the sensor 12 performs wireless communication with the base station 11. In addition, installation objects 19B1 to 19B3, which are devices and parts that do not perform wireless communication and are necessary for process B, are also installed in the manufacturing site 1B.

FIG. 2C shows a layout of the equipment at the manufacturing site 1 in process C. In process C, all three types of applications are used: log collection, real-time streaming of video, and remote control. The sensor 12, the camera 13, and the robot arm 14 all communicate wirelessly with the base station 11. In addition, installations 19C1 to 19C5, which are devices and parts that do not communicate wirelessly but are necessary for process C, are also installed in the manufacturing site 1C.

For the manufacturing site 1, the wireless performance estimation system 100 estimates wireless performance in advance before the start of each process. By estimating wireless performance in advance, measures such as changing wireless settings, changing the placement of installed objects, or changing the schedule of a process can be taken before the process starts. This makes it possible to avoid a situation in which the wireless performance after the start of a process is worse than expected and the above-mentioned application does not operate as desired. As a result, the operating rate of the entire manufacturing site can be improved.

3 is a block diagram showing a schematic configuration example of a wireless performance estimation system 100. The wireless performance estimation system 100 includes a calculation device 101 having calculation performance, and a main memory device 102 providing a storage area for storing programs executed by the calculation device 101 and data to be processed. The calculation device 101 is, for example, a CPU including one or more cores, and the main memory device 102 is, for example, a RAM including a volatile storage area.

The wireless performance estimation system 100 further includes a communication interface 106 that performs data communication with other computer devices including the remote server 15 and external storage devices, and an auxiliary storage device 103 that provides a non-volatile storage area using a hard disk drive (HDD) or a flash memory. The wireless performance estimation system 100 also includes an input device 104 that accepts operations from a user, and an output device 105 that presents the output results of each process to the user. The input device 104 includes, for example, a keyboard and a mouse, and the output device 105 includes, for example, a monitor and a printer. These components of the wireless performance estimation system 100 can communicate with each other via an internal bus 107.

3, the main memory device 102 stores programs such as a wireless performance calculation unit 121 and a propagation simulator 122. The programs executed by the arithmetic device 101 and data to be processed are loaded, for example, from the auxiliary memory device 103 to the main memory device 102. The auxiliary memory device 103 stores a process information database (DB) 131 and a wireless performance calculation information database 132.

The wireless performance estimation system 100 may be a physical computer system (one or more physical computers) or a system built on a group of computing resources (plural computing resources) such as a cloud platform. The wireless performance estimation system 100 may be a mobile device such as a smartphone or a tablet. The computer system or the group of computing resources includes one or more interface devices, one or more storage devices (including, for example, a main storage device and an auxiliary storage device), and one or more arithmetic devices.

When a function is realized by executing a program by a computing device, the defined process is performed using a storage device and/or an interface device, etc., as appropriate, and therefore the function may be considered to be at least a part of the computing device. A process described using a function as the subject may be considered to be a process performed by the computing device or a system having a processor thereof.

The program may be installed from a program source. The program source may be, for example, a program distribution computer or a computer-readable storage medium (for example, a computer-readable non-transitory storage medium). The description of each function is an example, and multiple functions may be combined into one function, or one function may be divided into multiple functions.

An overview of the software components shown in Fig. 3 will be described below. The process information database 131 holds information of a process plan received via the communication interface 106 or the input device 104. Details of the process information will be described later. The wireless performance calculation unit 121 calculates the wireless performance in each process based on the process information held in the process information database 131, using the propagation simulator 122 and wireless performance calculation information in the wireless performance calculation information database 132.

The propagation simulator 122 can use any existing technique such as a ray tracing method. The propagation simulator 122 performs a propagation simulation of wireless radio waves in the manufacturing site 1 in each process in accordance with an instruction from the wireless performance calculation unit 121, and calculates wireless performance. The wireless performance calculation information database 132 is management information that holds wireless performance calculation information such as wireless parameters used by the propagation simulator 122. The wireless performance calculation information will be described in detail later.

Fig. 4 is a diagram showing an example of a process plan 200 held in the process information database 131. As shown in Fig. 4, the process plan 200 can hold information about each process that will be executed in the future before it starts in the form of a table. The production process column 201 shows information that is common to all processes and information that is unique to each specific process. As examples, Fig. 4 shows the above-mentioned information 211A about process A, information 211B about process B, and information 211C about process C. Also shown is information 210 that is common to all processes.

The information about each process is composed of production plan information for that process and application information required for that process. The production plan information includes a product column 202, an installation object column 203, a position column 204, a size column 205, a material column 206, a start time column 207, and an end time column 208. The application information includes a required application column 209.

The product column 202 shows the products produced by the process. The installed object column 203 shows the names (types) of the installed objects (individual objects) such as devices and parts required in the process. The installed object column 203 further shows terminals that perform wireless communication. For example, in process A, a camera is a wireless terminal, in process B, a sensor is a wireless terminal, and in process C, a camera, a sensor, and a<u style="Single">sa</u>and the robot arm are wireless terminals. The wireless terminals and the base station are wireless devices.

The position column 204 indicates the position of the installation object. The size column 205 indicates the size of the installation object. The material column 206 indicates the material of the installation object. The start time column 207 indicates the scheduled start time of the process. The end time column 208 indicates the scheduled end time of the process.

The information about each process includes information about the position, size, and material of the sensor 12, camera 13, robot arm 14, etc., which are necessary for the above-mentioned application. For example, in process A, in addition to the base station, there are seven installed objects: a camera, part A1, part A2, part A3, equipment A4, and equipment A5.

The common information 210 indicates only information on the installed objects, that is, the installed object column 203, the position column 204, the size column 205, and the material column 206. The installed objects indicated by the common information 210 are used in all steps. In the example of FIG. 4, the position, size, and material of the base station 11 are included in the common information 210.

The required application column 209 holds a list of applications that perform wireless communication required for each process. In the example of Fig. 4, a video application is shown for process A. A log collection application is shown for process B. Three applications, log collection, video, and remote control, are shown for process C.

Note that the examples of process information shown throughout this specification are examples for illustrating the embodiment and do not necessarily match the process at the actual manufacturing site. Only a part of the information shown in the process plan 200 may be included, or other information may be included. For example, the size of the installation object, information on materials, and information on the end time may be omitted.

5A shows an example of wireless performance calculation information 500 held in wireless performance calculation information database 132. Wireless performance calculation information 500 includes a plurality of types of data. Specifically, wireless performance calculation information 500 includes a performance estimation method table 510, a propagation simulation time table 520, an extraction condition table 530, a material table 540, and a past performance evaluation database 550.

5B shows an example of the configuration of performance estimation method table 510. Performance estimation method table 510 indicates which performance estimation method is applicable for each application. Performance estimation method table 510 includes an application column 511 and a performance estimation method column 512. In this example, a simulation using propagation simulator 122 and database citation that cites past evaluation results in the same process are registered as methods for wireless performance calculation unit 121 to calculate wireless performance.

In this example, database citation can be used when the same process has been performed in the past. The same process is a process that manufactures the same product. Database citation can be used between processes in which the product field 202 in the process plan 200 indicates the same product. Note that similar product classification information may be prepared, and when no past analysis results for the same product exist, the analysis results for similar products may be used.

In this example, multiple types of simulations are registered. One is a high-precision simulation, and the other is a simple simulation. The high-precision simulation allows for a propagation simulation with higher accuracy than the simple simulation, and requires more computational processing. In other words, the processing time required by a computer system for the high-precision simulation is longer than the processing time required by the simple simulation on the same computer system.

In one embodiment of this specification, the high-precision simulation incorporates all installations described in the process plan 200 and executes a propagation simulation, while the simple simulation incorporates some installations extracted from all installations described in the process plan 200 and executes a propagation simulation. Although the accuracy of the simple simulation is low, it is possible to reduce the calculation time. By providing simulation methods with different accuracy based on the number of installations, it is possible to more appropriately achieve a balance between processing time and simulation performance according to the process conditions.

It should be noted that three or more types of simulation methods may be set and registered. Also, instead of the number of installed objects to be referenced in the simulation, simulation methods with different accuracies using different algorithms may be prepared.

In the example of Figure 5B, database citation, simple simulation, and high-precision simulation are all set and registered for the log collection application. The amount of data collected by the log collection is small, and there are no stringent requirements for network latency, etc. Therefore, it is considered that highly accurate wireless performance estimation is not necessary, and it is set that any method may be used.

For video, simple and high-precision simulations are set and registered. It is considered that there is a problem with accuracy in database citation, and that either simple or high-precision simulation is required. For remote control, only high-precision simulation is assigned. It is considered that the delay requirements for remote control are extremely strict and accurate wireless performance estimation is necessary, and that high-precision simulation is essential. These wireless performance estimation methods will be described later.

5C shows an example of the configuration of a propagation simulation time table 520. The propagation simulation time table 520 is information for determining the processing time for each wireless performance estimation method. The propagation simulation time table 520 shows the number of installation objects to be captured and the corresponding calculation time when performing the above-mentioned propagation simulation.

The propagation simulation time table 520 includes a number of installed objects column 521 and a propagation simulation time column 522. The values in the propagation simulation time table 520 may be empirically determined by a wireless engineer. The system may create the propagation simulation time table 520 based on past performance. In this example, it is assumed that the system creates the propagation simulation time table 520 by a wireless engineer. By defining the estimated required time in relation to the number of installed objects, a more accurate estimation of the processing time is possible.

The time required for the database citation method may be a preset constant. In one example, the time required for the database citation method is shorter than any of the propagation simulations. In a configuration in which propagation simulators with algorithms having different processing accuracy and processing time are provided, information on the respective processing times is provided, and the information may be independent of the number of installed objects.

5D shows an example of the configuration of an extraction condition table 530. The extraction condition table 530 shows conditions used to determine which installations to extract when extracting installations to be incorporated into the simulation in the above-mentioned simple simulation. It is desirable to extract those that have a large effect on wireless performance. The extraction condition table 530 includes an obstruction column 531, a parameter column 532, and a calculation exclusion condition column 533.

The shielding column 531 indicates a condition as to whether or not a target installation object is located in a position that shields radio waves between the base station 11 and a wireless terminal (devices that perform wireless communication, such as the sensor 12, the camera 13, and the robot arm 14). For example, when a virtual line connecting the positions of the wireless terminal and the base station 11 shown in the process plan 200 passes through an installation object, the installation object is determined to shield radio waves between the base station 11 and the wireless terminal.

The parameter column 532 shows parameters included in the conditions for the calculation exclusion judgment. In the example of Fig. 5D, the size of the installation and the distance between the installation and the base station or the wireless terminal are set as condition parameters. The calculation exclusion possibility condition column 533 shows the conditions for denying the exclusion from the simulation, that is, the conditions extracted for the simulation.

In the example of the extraction rule shown in Fig. 5D, if the following conditions are satisfied regarding obstruction, size, and distance, the target installation is extracted for simulation: The target installation is not in a position that obstructs radio waves between the base station and the wireless terminal ("none" in the obstruction column 531).

Furthermore, the size of the target object is equal to or larger than a threshold ThrSize. The size may be, for example, the total value of length, width, and height, or the maximum value of these. In addition, the distance between the target object and the base station or wireless terminal is equal to or smaller than a threshold ThrDist. The distance may be, for example, the minimum value of the distance from the base station or wireless terminal to the target object. The distance condition is that the target object is located within an ellipse with the coordinates of the base station and wireless terminal as its focal points.<u style="Single">Installation</u>It may be whether an object exists or not.

If the target installation is located in a position that blocks radio waves between the base station and the wireless terminal, the target installation is extracted for the simulation regardless of other conditions.

The extraction condition table does not need to include all of the above conditions. For example, the size condition may be omitted, and only the condition based on the position of the installation object may be specified, or the distance condition may be omitted. A condition different from the distance and size conditions, for example, a material condition, may be added. If the process plan does not include information on the size of the installation object, the shielding and distance conditions may be determined from only the position information.

5E shows an example of the configuration of material table 540. Material table 540 shows information on the reflectance and dielectric constant of the installation object used in the propagation simulation. This information is known information and is assumed to be set and registered in advance.

Past performance evaluation database 550 accumulates the estimation results for processes in which wireless performance estimation has already been performed by some method. A wireless engineer may register the results of calculations made in another system in past performance evaluation database 550, or the results output by wireless performance calculation unit 121 may be registered as they are. The format of past performance evaluation database 550 may be the same as the output of wireless performance calculation unit 121.

6 is a flow chart showing an overall operation cycle of an embodiment of this specification. After the management system is introduced, a maintenance cycle (602 to 609) is periodically started by a wireless engineer. In the maintenance, additions and corrections are made to various tables of the wireless performance calculation information 500 described above (603). The maintenance by the wireless engineer is longer than the on-site operation cycle (604 to 608), for example, on the order of several months.

Thereafter, the on-site operation cycle (604 to 608) begins. The on-site manager adds to or modifies the process plan 200 in accordance with the production plan, the work procedure manual, etc. (605). The wireless performance calculation unit 121 estimates wireless performance based on the wireless performance calculation information 500 and the process plan 200 (606). The remote server 15 operates the process using the estimation results (607). The on-site operation cycle (604 to 608) is relatively short, and may be on the order of one day, for example.

Fig. 7 shows an internal flowchart of step 606 in which the wireless performance calculation unit 121 estimates wireless performance following step 605 of adding/modifying the process plan 200 shown in Fig. 6. Hereinafter, this flowchart will be described with reference to the example of the process plan 200 shown in Fig. 4.

After step 605 of adding/modifying the construction plan 200, the wireless performance calculation unit 121 executes the following process for all or some of the processes scheduled to start in the near future that are registered in the construction plan 200.

First, the wireless performance calculation unit 121 executes a cycle indicated by steps 701 to 708 for each process. Specifically, the wireless performance calculation unit 121 selects (702) a candidate wireless performance estimation method applicable to the process based on the performance estimation method table 510. When multiple applications are executed in a process, a wireless performance estimation method common to all the applications can be selected as a candidate.

If the candidates include a high-precision simulation (703: YES), the wireless performance calculation unit 121 determines the simulation time of the high-precision simulation from the number of all installation objects described in the construction plan 200 and the propagation simulation time table 520 (704).

If the applicable candidates for wireless performance estimation methods include the simple simulation (705: YES), the wireless performance calculation unit 121 extracts (706) installation objects required for the simple simulation based on the extraction condition table 530. The wireless performance calculation unit 121 determines the simulation time of the simple simulation based on the number of extracted installation objects and the propagation simulation time table 520 (707).

The first interim result table 350 in FIG. 8A shows the interim results of applying the steps up to this point to each process described in the process plan 200. Specifically, the first interim result table 350 includes a process column 351 and a wireless performance estimation method column 352. The process column 351 shows each process to be estimated. The wireless performance estimation method column 352 shows candidate wireless performance estimation methods for each process. In the wireless performance estimation method column 352, the numbers in parentheses indicate the time required for each simulation. In this example, the required time is shown as a value rounded up to the next hour. The simulation required time is obtained from the propagation simulation time table 520 as a result of steps 703 to 707.

For example, since a video application is used in process A, simple simulation and high-precision simulation are selected as candidates for the performance estimation method based on the performance estimation method table 510, and database citation is not applicable. The simple simulation of process A takes 4 hours, and the high-precision simulation takes 7 hours.

On the other hand, since process B only uses a log collection application, database citation is also applicable. The time required for database citation is one hour. As shown in process plan 200, fewer objects are installed in process B than in process A. Therefore, even though they are the same high-precision simulation, process B takes less time. Since process C requires a remote control application, database citation and simple simulation are not applicable. High-precision simulation is always applied.

Next, the wireless performance calculation unit 121 verifies whether all performance estimation methods in each combination of available performance estimation methods for each process will be completed by the start time of the corresponding process, and determines the performance estimation method to be applied to each process (709). As described above, there are two, three, and one candidate wireless performance estimation methods for processes A, B, and C, respectively. There are six combinations in total. The wireless performance calculation unit 121 calculates by when the wireless performance estimation for processes A, B, and C will be completed for each combination.

In one embodiment of this specification, the estimation process for each step by the wireless performance calculation unit 121 is executed sequentially. For example, the wireless performance calculation unit 121 determines the estimated process completion time for each step by executing the estimation process sequentially starting from the step with the earliest start time. In another embodiment of this specification, the wireless performance estimation process for a plurality of steps may be executed simultaneously by different computers or computing cores. The wireless performance calculation unit 121 can determine the estimated process completion time for each step by referring to the number of estimation processes that can be executed simultaneously and information on the time required for each estimation process.

As an example of multiple operations executed simultaneously, in the process of "obtaining the second interim result table 360 by performing the process of step 709 on the first interim result table 350" described later, the second interim result table 360 is additionally obtained when process A and process B are processed sequentially by the same computer and only process C is processed simultaneously by another computer. Furthermore, it is possible to obtain second interim result tables for other combinations such as when only process A is processed sequentially by one computer and processes B and C are processed sequentially by another computer, thereby increasing the options when determining the final wireless performance estimation method. In the following, it is assumed that the processes are selected sequentially and the wireless performance estimation process is executed sequentially.

8B shows a result obtained by performing the process of step 709 on the first intermediate result table 350. Here, it is assumed that the wireless performance estimation process starts at 6 o'clock, and based on the time required for each wireless performance estimation method in each process in the first intermediate result table 350, it shows when the wireless performance calculation of each process will end for each combination of wireless performance estimation methods.

Specifically, the second interim result table 360 includes a wireless performance estimation method column 361 and a wireless performance estimation completion time column 362. The wireless performance estimation method column 361 indicates a combination of wireless performance estimation methods for each process. The wireless performance estimation completion time column 362 indicates an expected time at which the wireless performance estimation process for each process will be completed for each combination of wireless performance estimation methods.

Among these, only record 365 completes wireless performance estimation by the start times of processes A, B, and C shown in process plan 200. Record 365 applies simple simulation (indicated as "simple" in the figure) to process A, database reference ("DB") to process B, and high-precision simulation ("high precision") to process C. Wireless performance calculation unit 121 determines the combination indicated by record 365 as the combination of wireless performance estimation methods to actually apply.

When there are two or more records (combinations of estimation methods) that will be completed by the start time, one of the combinations will be selected based on a preset criterion. For example, there are the following three criteria:

(1) Select the combination that requires the shortest total calculation time for wireless performance estimation. (2) Select the combination that requires the longest total calculation time for wireless performance estimation (as a result, the combination of estimation methods with the highest accuracy within the allowable time is selected). (3) Select randomly.

In one embodiment of this specification, the wireless performance calculation unit 121 selects one combination of wireless performance estimation methods according to the judgment criterion (2). That is, the combination that requires the longest total calculation time for wireless performance estimation is selected. This makes it possible to select the combination of estimation methods with the highest accuracy within the allowable time.

If there is no combination that is completed by the start time, the wireless performance calculation unit 121 may shorten the time for the simple simulation by omitting some of the installations from the installations extracted in the simple simulation. For example, it is possible to delete the installations extracted based on specific conditions, or to change the extraction conditions to stricter ones.

Before proceeding to the process after step 709 in Fig. 7, the wireless performance calculation unit 121 may output this determined wireless estimation method on the screen of the output device 105. In the above example, the record 365 in Fig. 8 is selected. The wireless performance calculation unit 121 may output a timeline (schedule) 370 shown in Fig. 9 to, for example, a monitor.

9A shows process A, process B, and process C that are targets of the wireless performance estimation process, and a schedule 370 of the wireless performance estimation process for them. The wireless performance estimation process for process A is scheduled to start at 6:00 and end at 10:00. The estimation method is a simple simulation. Process A is scheduled to start at 10:00.

The wireless performance estimation process for process B is scheduled to start at 10:00 and end at 11:00. The estimation method is a database citation method. Process B is scheduled to start at 14:00. The wireless performance estimation process for process C is scheduled to start at 11:00 and end at 18:00. The estimation method is a high-precision simulation. Process C is scheduled to start at 19:00. By referring to the displayed schedule 370, the user can confirm that the wireless performance estimation processes required for each of all processes are expected to be completed by the corresponding process start time.

Returning to FIG. 7, next, the wireless performance calculation unit 121 sequentially executes a cycle of steps 710 to 713 for each process. Specifically, the wireless performance calculation unit 121 performs performance estimation for the corresponding process by the performance estimation method determined in step 709 (711). When applying the simple simulation or high-precision simulation as the wireless performance estimation method, the wireless performance calculation unit 121 uses a propagation simulator 122. The propagation simulation is carried out by using the material table 5 in the wireless performance calculation information 500 as necessary.<u style="Single">40</u>The dielectric constant and reflectance described in may be used.

On the other hand, when database citation is used as the wireless performance estimation method, the wireless performance calculation unit 121 cites the estimation result of the same process from the past performance evaluation database 550 in the wireless performance calculation information 500. As soon as the wireless performance estimation of one process is completed, the wireless performance calculation unit 121 outputs the result (712).

FIG. 9B shows an example of the wireless performance estimation result of the target process presented to the user. The wireless performance estimation result 380 is in a table format, and includes a process column 381,<u style="Single">line</u>9B , the wireless performance estimation result column 383 shows an attachment showing the estimation result or a link to a file showing the estimation result.

The wireless performance estimation result field 383 is similar to the output result of a conventional propagation simulation. For example, the wireless performance estimation result is expressed as a heat map showing the strength of the received power at the manufacturing site 1. The heat map is attached as a CSV file or an image file, or a link to this file is posted.

9C shows an example of a heat map of the wireless performance calculation results in process A at the manufacturing site 1. The heat map 390 displays a pattern indicating radio wave intensity together with objects installed at the manufacturing site 1. The darker the color of the pattern (closer to black), the stronger the received radio wave intensity, and the lighter the color of the pattern (closer to white), the weaker the received radio wave intensity. Note that the display mode of the heat map is arbitrary and is not limited to the example of FIG. 9C.

Furthermore, the wireless performance calculation unit 121 adds this estimation result to the past performance evaluation database 550 in the wireless performance calculation information 500, and utilizes it to reduce future calculation time. When a simple simulation is used as the wireless performance estimation method, the wireless performance calculation unit 121 may optionally output information on which installation object was extracted for the propagation simulation to the output device 105, or may store the information in the wireless performance calculation information 500.

In this embodiment, it is possible to estimate wireless performance in advance according to the future process plan to be carried out at the manufacturing site, and if a lack of wireless performance occurs, it is possible to take preventive measures such as changing wireless settings and reviewing schedules. Furthermore, the items that the site manager inputs into this system are the contents described in the production plan and work procedure manual, and do not necessarily require wireless expert knowledge.

Furthermore, if the propagation simulation for calculating wireless performance takes time and wireless performance estimation cannot be completed by the start of the process, the time required for wireless performance estimation is reduced by performing a simplified simulation in which a part of the installed object is extracted or by citing a past performance database, depending on the characteristics of the application of the process. This makes it possible to complete the performance estimation by the start time of the process. Note that, although the above example estimates wireless communication performance for a plurality of processes, it is also possible to estimate wireless communication performance for only one process. This point is similar to other embodiments.

&lt;Second embodiment&gt; In the second embodiment, when performing a simple simulation in which a part of the installation object is extracted as described in the first embodiment, a criterion for determining whether or not to extract the installation object is set for each application. The operation of this embodiment is similar to that of the first embodiment, and the differences are mainly described below.

In the first embodiment, an extraction condition table 530 showing conditions common to all applications is used. On the other hand, the extraction condition table of this embodiment shows conditions set and registered for each application. Fig. 10 shows an example of the configuration of an extraction condition table 810 of the second embodiment.

The extraction condition table 810 includes an application column 811, a shielding column 812, a parameter column 813, and a calculation exclusion condition column 814. The application column 811 indicates an identifier of the type of application to which the extraction condition is applied. The shielding column 812, the parameter column 813, and the calculation exclusion condition column 814 are similar to the shielding column 531, the parameter column 532, and the calculation exclusion condition column 533 of the extraction condition table shown in FIG. 5D.

The wireless performance calculation unit 121 determines installation objects to be extracted in the simplified simulation using extraction conditions according to the application from the extraction condition table 810. For example, for an application that requires high accuracy in wireless performance estimation, conditions are set that allow more installation objects to be extracted. For example, the number of extractions can be increased by reducing the threshold for the size of the installation objects and/or increasing the threshold for the distance. Increasing the number of extractions increases the propagation simulation time, but improves the estimation accuracy.

According to the second embodiment, it is possible to vary the accuracy of the simplified simulation depending on the type of application, and it is possible to adjust the accuracy of estimation of wireless propagation performance and the calculation time.

&lt;Third embodiment&gt; In the third embodiment, when performing a simple simulation in which a part of the installation described in the first embodiment is extracted, a criterion for determining whether or not to extract the installation is set for each wireless communication method (wireless system) (for example, Wi-Fi5, Wi-Fi6, Private-LTE, and millimeter wave Local5G). The operation of this embodiment is similar to the first embodiment, and the differences are mainly described below.

In the first embodiment, an extraction condition table 530 showing conditions common to all applications is used. On the other hand, the extraction condition table of this embodiment shows conditions set and registered for each wireless system, for example. Fig. 11 shows an example of the configuration of an extraction condition table 820 of the third embodiment.

The extraction condition table 820 includes a wireless system column 821, an obstruction column 822, a parameter column 823, and a calculation exclusion condition column 824. The wireless system column 821 indicates an identifier of the type of wireless system to which the extraction condition is applied. The obstruction column 822, the parameter column 823, and the calculation exclusion condition column 824 are similar to the obstruction column 531, the parameter column 532, and the calculation exclusion condition column 533 of the extraction condition table shown in FIG. 5D.

For example, for Wi-Fi, which has a relatively long wavelength, the number of extracted installations can be reduced by setting a larger size threshold.Also, for 5G, which uses millimeter waves, the number of extracted installations can be reduced by setting a smaller distance threshold, taking into account that 5G has a high degree of directivity.

According to the third embodiment, it is possible to vary the accuracy of the simplified simulation depending on the type of wireless system, and it is possible to adjust the accuracy of wireless propagation performance estimation and the calculation time.

&lt;Fourth embodiment&gt; In a fourth embodiment, the wireless performance estimation system outputs an output result indicating whether each application can be operated under the estimated received power conditions in addition to or instead of the heat map 390 shown in Fig. 9C. In this embodiment, the wireless performance calculation information includes information on application feasibility determination.

12A shows an example of the configuration of wireless performance calculation information 590 according to the fourth embodiment. The wireless performance calculation information 590 includes a performance estimation method table 510, a propagation simulation time table 520, an extraction condition table 530, a material table 540, a past performance evaluation database 550, and an application feasibility determination table 560. The components other than the application feasibility determination table 560 are as described in the first embodiment.

12B shows an example of the configuration of the application permission determination table 560. The application permission determination table 560 can be inputted in step 603 shown in FIG.

The application availability determination table 560 includes an application column 561, a required power (base station<u style="Single">) column</u>562, and a required power (terminal) column 563. The application column 561 indicates an identifier of the type of application.

The required power (base station) column 562 indicates the radio wave reception power (threshold) required for the base station of the wireless communication used by the application. The required power (terminal) column 563 indicates the radio wave reception power (threshold) required for the terminal of the wireless communication used by the application.<u style="Single">3</u>The power requirements in are expressed in dBm. If the power requirements of both the base station and the wireless terminal are set, it is required that both conditions are met.

After estimating the wireless performance in step 711 shown in FIG. 7, the wireless performance calculation unit 121 determines whether the estimated wireless performance satisfies the conditions required by each application.

Specifically, the wireless performance calculation unit 121 refers to the process plan shown in Fig. 4 and acquires information on the positions of the wireless base stations and wireless terminals used in each process and the applications used. The wireless performance calculation unit 121 refers to a heat map 390 indicating the distribution of the radio wave reception power and acquires the radio wave reception power strength of the wireless base stations and each wireless terminal.

The wireless performance calculation unit 121 determines whether the radio wave reception power of the base station and each wireless terminal exceeds a threshold value indicated in the application feasibility determination table 560. The wireless performance calculation unit 121 includes a determination result as to whether the estimated wireless performance satisfies the conditions required by each application in the wireless performance estimation result presented to the user.

When the radio wave reception power indicated by the heat map 390 is equal to or greater than each threshold value of the application indicated by the application feasibility determination table 560, a determination result that the application is operable is displayed. When the radio wave reception power indicated by the heat map 390 is less than any of the threshold values of the application indicated by the application feasibility determination table 560, a determination result that the application is inoperable is displayed.

According to the fourth embodiment, a site manager who obtains the output result of the wireless performance estimating system can know more directly whether the process can be operated or not.

&lt;Other embodiments&gt; In one embodiment of the present specification, the propagation simulator 122 is used in combination with another simulator. For example, a network simulator can be used in addition to the propagation simulator 122. A known network simulator can be used. The network simulator executes a simulation using the wireless performance estimation result by the propagation simulator 122. In addition to the received power information, the network simulator can also estimate the throughput, packet loss, delay, and the like of wireless communication.

In one embodiment of the present specification, an item to be input by a site manager may be added to the process plan 200, enabling customization according to the site situation. For example, the following operation may be performed.

In the first operation example, the site manager can set whether or not the wireless performance estimation calculation needs to be completed a predetermined time before the process start time. The wireless performance calculation unit 121 determines a schedule so that the wireless performance estimation process is completed by the set time for each process. As a result, it becomes possible to take some kind of measure for the time until the process start after the wireless performance estimation result is obtained.

In the second operation example, the site manager may assign priorities to the processes. The wireless performance calculation unit 121 selects processes in order from the highest priority to determine the wireless performance estimation method. If there are processes with the same priority, the process with the earliest designated time may be selected. Depending on the priorities, for example, a high-precision estimation method may be applied to a process that needs to be carried out reliably because the deadline is approaching.

In the above embodiment, the wireless communication performance estimation method for each step is determined so as to end the corresponding step before the corresponding step starts and by the time set for the corresponding step. For example, when no time is set for the step, the wireless communication estimation method may be determined under the condition that there is no requested completion time.

The present invention is not limited to the above-described embodiment, and various modified examples are included. For example, the above-described embodiment has been described in detail to clearly explain the present invention, and is not necessarily limited to those having all of the configurations described. In addition, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. In addition, it is possible to add, delete, or replace a part of the configuration of each embodiment with another configuration.

In addition, the above-mentioned configurations, functions, processing units, etc. may be realized in part or in whole by hardware, for example, by designing them as integrated circuits. In addition, the above-mentioned configurations, functions, etc. may be realized in software by a processor interpreting and executing a program that realizes each function. Information such as the program, table, file, etc. that realizes each function can be stored in a memory, a recording device such as a hard disk or SSD (Solid State Drive), or a recording medium such as an IC card or SD card.

In addition, the control lines and information lines shown are those that are considered necessary for the explanation, and not all control lines and information lines in the product are necessarily shown. In reality, it can be considered that almost all components are connected to each other.

1 Manufacturing site

2 network

11 Base Station

12 Sensors

13 camera

14 Robot Arm

15 Remote Server

100 Wireless performance estimation system

101 Calculation Unit

102 Main memory

103 Auxiliary storage device

104 Input Devices

105 Output Device

106 Communication Interface

107 Internal Bus

121 Wireless Performance Calculation Department

122 Propagation Simulator

131 Process information database

132 Wireless performance calculation information database

200 Process Planning

500 Information for wireless performance calculation