JPH08194680A - Distributed simulator for discrete event - Google Patents

Abstract

PURPOSE: To provide the device with which centralized management synchronous distributed simulation using various simulators is enabled. CONSTITUTION: Concerning the distributed simulator for discrete event with which the centralized management synchronous distributed simulation is performed by combining plural simulators 2-4 and a supervisor 5 connected on a network 1, on the respective simulators 2-4, data, converting transforming mechanisms 2b-4b for transforming the data which are transmitted/received among the respective simulators 2-4 together with the control information of simulation in the case of performing communication processing between the respective simulators 2-4 and the supervisor 5, into any prescribed format.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discrete event distributed simulation apparatus for performing simulation by combining a plurality of discrete event simulators.

[0002]

2. Description of the Related Art For example, various simulation methods have been proposed for simulating production in a factory, and one of them is a centralized management synchronous system in which a plurality of simulators are controlled by a control device called a supervisor. There is a simulation method.

As a centralized management synchronous type simulation method, each time a simulator executes a simulation execution command, each simulator performs a simulation at fixed time intervals, and when the simulation for that time interval is completed, the simulation is signaled to the supervisor. A time bucket method is devised in which the simulation is advanced while repeating the operation of returning.

A simulation method employing this time bucket method is, for example, Fujii et al .: "A BASI".
C STUDY ON A DISTRIBUTED
SIMULATION FOR VIRTUAL MA
NUFACTURING ”, International Conference of OR Society of Japan SI
M94 Lecture Collection T-94-1, pp. 277-281
It is described in.

FIG. 4 shows a conceptual diagram of a simulation method that employs this time bucket method. Here, two simulators are shown being managed by one supervisor. Before starting the simulation of the period ΔT1, the data 11 from the simulator 1 to the simulator 2 via the supervisor and the data 21 from the simulator 2 to the simulator 1 via the supervisor 2
Will be sent. When the simulation for ΔT is completed on each simulator, the data is exchanged and the simulation proceeds as in the above.

For communication between the simulator and the supervisor, as shown in FIGS. 5 and 6, two types of routines, SOURCE and SINK, are embedded in the simulation model, and these are processed in accordance with the synchronization signal on the supervisor. Has been achieved by
In FIG. 5, SOURCE performs a process of receiving a simulation start command for Δt and data from another simulator from the supervisor. If there are data to be sent to other simulators during the simulation process, they are stored in variables in SINK and sent to the supervisor together with the simulation end signal after the end of the simulation for Δt.

List 1 shows an example of the actual description of the above-mentioned simulation.

List 1 GEN ,,,,, N, N ,,,, 72; LIMIT, 2,2,200; NETWORK; SOUR EVENT, 4; ENTER, 1; INSP QUEUE (1); ACT (2) / 1, UNIFORM (6., 12.); GOON; ACT, 85, DPRT; ACT, 15, ADJT; ADJT QUEUE (2); ACT / 2, UNFRM (20., 40.), INSP; DPRT COLCT, INT (1), TIME IN SYSTEM; SINK EVENT, 1; TERM; BUKT CREATE, 100, 100, 3, 3; EVENT, 3; TERM; END; INIT, 0, 300; FIN; In this example, simulation The content is a simulation language (QUIC) called SLAM. k Refer
ence Manual, PritskerCor
p. , 1990)). In Listing 1, SOUR is the above-mentioned SOURCE routine, and “EVENT, 4” here is an event for fetching data input from another simulator sent via the supervisor, and the data is as follows. Captured in the variable specified by the ENTER event in the row. Also, SINK is the above SINK routine,
“EVENT, 1” here is an event for transmitting data to another simulator via the supervisor. The EVENT and ENTER described here are event functions provided by the simulation language and are part of the specifications of the simulation language. In the supervisor, the data collected from each simulator is sent together when the Δt processing start command shown in FIG. 6 is sent, and the data sent from each simulator is received when the end signal is received from each simulator.

[0009]

The above-mentioned conventional technique has a problem that it is difficult to perform a distributed simulation by combining a plurality of different discrete event simulators, because it is strongly bound to the specifications provided by the simulation language. That is, when performing a distributed simulation, for example, when performing a simulation of a production factory, a simulator that is easy to express job shop type work on a processing line, and a simulator that is easy to express flow shop type work on an assembly line, Furthermore, FMS (flexible manufactu
Although it is possible to increase the efficiency of model creation by using various simulators depending on the purpose, such as using a simulator having a robot interference check function in the ring system line, the above-mentioned conventional technique is not suitable for distributed simulation. Requires a dedicated simulator, there is a problem that it is not possible to select a simulator that suits each purpose.

The present invention has been made in view of the above circumstances, and an object of the present invention is to solve the above-mentioned problems in the prior art and to provide an apparatus capable of a centralized management synchronous distributed simulation using various simulators. To provide.

[0011]

DISCLOSURE OF THE INVENTION The present invention provides a distributed simulation apparatus for discrete events which performs a centralized management synchronous distributed simulation by combining a plurality of discrete event simulators connected on a network and one distributed simulation control apparatus. On each discrete event simulator, a mechanism for converting the data transmitted and received between each discrete event simulator into a predetermined format together with the control information of the simulation when performing the communication processing between each discrete event simulator and the distributed simulation control device. It is characterized by being provided.

Further, the present invention is characterized in that a mechanism for rearranging the data sent from each of the simulators for each destination is provided on the distributed simulation control device.

[0013]

In the distributed simulation apparatus according to the present invention, data is sent from the supervisor, which is the distributed simulation control apparatus, to each simulator in the same format. When the simulation for one simulation time interval is completed on each simulator, the data to be transmitted from each simulator to another single or a plurality of simulators via the data conversion mechanism are collectively transmitted to the supervisor. The supervisor distributes each data to the destination simulator and then sends the data again to the specified simulator.In each simulator that receives the data, the data conversion mechanism converts the data into a format that can be imported. Capture it inside the simulator. As described above, by providing a data conversion mechanism on each simulator and sharing the data transmission / reception between the simulators, it is possible to use various forms of the simulator.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration example for implementing the distributed simulation apparatus of the present invention. Here, a case of performing a simulation of a processing process, an assembly process, and a transfer process in a production factory will be described as an example.

On the network 1 such as Ethernet (registered trademark), three simulators 2 to 4 and one supervisor 5 for controlling and controlling these three simulators 2 to 4 are connected. The simulators 2 to 4 respectively perform discrete event simulations of a machining process, an assembling process, and a carrying process. Each of the simulators 2 to 4 has a simulation model description section 2
a to 4a, data conversion mechanisms 2b to 4b, communication processing unit 2c
4c and communication ports dc to 4d. Further, the supervisor 5 includes a simulation control unit 5a, a data processing unit 5b, a communication processing unit 5c, communication ports 5d to 5f,
The input means 5g and the display means 5h are provided.

In the present embodiment, for example, the supervisor 5 and the three simulators 2 to 4 are each composed of a commercially available computer, but it is not necessary that all computers have the same hardware and software. . For example, Supervisor 5 is Sma
The first simulator 2 configured by UNIX (registered trademark) computer that uses lltalk (registered trademark) and performing a simulation of a machining process is Extend2.
The second simulator 3 that is configured by a Macintosh (registered trademark) computer that uses 0 (registered trademark) and that simulates the assembly process is configured by a UNIX (registered trademark) computer that uses C ++ (registered trademark). The third simulator 2 for simulating is a Visual Basic (registered trademark)
It is composed of a DOS / V (registered trademark) computer.

Communication between the respective simulators 2 to 4 of the supervisor 5 is carried out by a socket using a communication protocol TCP / IP widely used in the UNIX (registered trademark) BSD system.

The supervisor 5 is provided with as many communication ports as the number of simulators to be combined, and different port numbers are assigned to them. Here, the three communication ports 5d to correspond to the three simulators 2 to 4
5f is provided. The socket on the supervisor 5 is a server process and can respond to connection requests from the simulators 2-4. Unique port numbers are also assigned to the communication ports (socket ports) 5d to 5f on the simulators 2 to 4 side, respectively.

The data transmitted and received from the communication ports 5d to 5f for the simulators 2 to 4 of the supervisor 5 are converted into the format shown in FIG. 2 by the data processing unit 5b. This data is treated as a 1024-byte frame for communication through the socket.
The part without data is filled with null code 00h.
First, a simulation control command (control (CTL) command) given by a 4-byte character string and the number of simulation data (simulation (SIM) command number) sent accompanying this are described.

The simulation control command includes an initialization command INIT, a simulation execution command SIMS, sent from the supervisor 5 to each of the simulators 2-4.
Also, there is a simulation end command SIME and an end signal ENDI of each command sent from each simulator 2 to 4 to the supervisor 5. The number of simulation data is given by a 2-byte unsigned binary number.

Next, a block is provided which gives the start position (position of SIM command N) from the head of the simulation data and its size (size of SIM command N). Both of them are described by a 2-byte unsigned binary number. By referring to this, the receiving side can easily retrieve each simulation data.

Further to this, the simulation data to be sent is listed (arrangement of simulation data). The simulation data is data for exchanging the simulation data with other simulators, and is generated in the data conversion mechanisms 2b-4b of the respective simulators 2-4. The internal structure of the simulation data has a format as shown in FIG. 3, and the SIM command indicating the processing content, the request destination, the request source,
Information such as the buffer name, the variable name you want to access, and the quantity, which are described consecutively. The variable name is a 4-byte ASCII code and the quantity is a 2-byte unsigned binary number so that it can be easily processed by the simulator. SI
The M command is given by a character string of 4-byte alphabetic characters, and includes a carry-in request MOVI and a carry-out request MOVO. The requestee and requester are the names given to the individual simulators,
It is represented by a 4-byte character string. The destination and source of the data is revealed by looking at this information on supervisor 5. All buffer names and variables are also given as alphanumeric 4-byte character strings starting with alphabetic characters. The quantity is given as a 2-byte unsigned binary number. With such a data structure, the simulator data can be easily cut out from the transmitted / received data in the supervisor 5 and each simulator 2-4. The data formatted in this way is transmitted to the communication processing unit 5c.
Are distributed to the respective communication ports 5d to 5f and transmitted.

In the supervisor 5, before the data processing section 5b carries out the above-mentioned processing, the simulation control section 5a sends and receives simulation control commands (CTL commands) between the simulators 2 to 4, that is, the simulation data from each simulator. I / O requests are reorganized for each destination. This work is performed by looking at the request destination data included in the data and distributing the simulation data to each request destination. In addition, the simulation control unit 5a notifies each of the simulators 2 to 4 of information such as a simulation time interval and a simulation period before starting the simulation, and also performs synchronous control of the distributed simulation. That is, when the data transmission to all the simulators 2 to 4 is ready, the data is transmitted via the communication ports 5d to 5f, and then the communication ports 5d to 5f are set to the reception waiting state.

The simulation is completed in each of the simulators 2 to 4, and the end signal S is sent to all the communication ports 5d to 5f.
When the IME arrives, the data rearrangement work is instructed, and when the work is completed, a simulation execution command or a simulation end command is sent to each of the simulators 2 to 4 at the simulation end time.

In the simulation model on each of the simulators 2 to 4, a communication event responsible for communication with the supervisor 5 is described. When this event occurs, the data conversion mechanisms 2b to 4b are called, and when the data is received from the supervisor 5, the data received by the socket is converted into the data format used in the simulator, and the simulation control described there. Performs processing based on the command and sets the data required for simulation in the corresponding simulation variable.

For example, when the simulation control command is the initialization command INIT, since the simulation period and the simulation time interval are sent as ancillary data, the simulation period which is the global variable of the simulator and the communication event which is the local variable of the communication event. The occurrence interval of is set.

When the simulation control command is the simulation execution command SIMS, after executing the communication event or the command received from the supervisor 5, there is data to be sent to the other simulators 2 to 4 together with the termination signal SIME for the command. If you collect them,
These are converted into the formats shown in FIGS. 2 and 3, set in the socket port, and transmitted to the supervisor 5. Here, data input from another simulator is treated as a source on one simulator, and data output to another simulator is treated as a sink.

It is needless to say that the above embodiment shows one example of the present invention, and the present invention is not limited to this.

[0029]

As described in detail above, according to the present invention, a discrete event for performing a centralized management synchronous distributed simulation by combining a plurality of discrete event simulators connected to a network and one distributed simulation controller. When sending and receiving data on each simulator in this distributed simulation device, a mechanism for converting the sent and received data into a specified format is provided, and by sending and receiving data through this mechanism, not only the simulator dedicated to distributed processing but also the existing This produces a remarkable effect that a distributed simulation combining a simulator used alone can be easily realized.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration example for implementing a distributed simulation apparatus for discrete events according to the present invention.

FIG. 2 is an explanatory diagram showing a format of data transmitted and received on a network in this embodiment.

FIG. 3 is a diagram showing a format of simulation data in data transmitted and received on a network.

FIG. 4 is an explanatory diagram showing an outline of processing of a conventional centralized control synchronous simulation.

FIG. 5 is a flowchart showing a processing procedure on a simulator according to a conventional technique.

FIG. 6 is a flowchart showing a processing procedure of a supervisor in the conventional technique.

[Explanation of symbols]

1 ... Network, 2-4 ... Simulator, 2a-4a
... Simulation model description part, 2b-4b ... Data conversion mechanism, 2c-4c ... Communication processing part, 2d-4d ... Communication port, 5 ... Supervisor, 5a ... Simulation control part, 5b ... Data processing part, 5c ... Communication processing part 5d ~
5f ... communication port

Claims (2)

[Claims] 1. A distributed simulation device for discrete events that performs centralized management synchronous distributed simulation by combining a plurality of discrete event simulators connected to a network and one distributed simulation control device, wherein When performing a communication process between each discrete event simulator and the distributed simulation control device, a mechanism for converting the data transmitted and received between each discrete event simulator together with the simulation control information into a predetermined format is provided. Distributed event simulation device. 2. The distributed simulation of discrete events according to claim 1, wherein a mechanism for rearranging data sent from each of the simulators for each destination is provided on the distributed simulation control device. apparatus.