JP2002140652A - Method and device for simulation and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform data input-output processing while synchronizing with the outside in the case of performing simulation based on a constraint type programming language. SOLUTION: In a simulating device for simulating the behavior of a system on a time based, a simulation performing part 3 performs simulation of a model described in the constraint type programming language, access an external function while performing the simulation and also changes the movements of the simulation in accordance with a returned value returned from the external function. An external function processing part 4 accesses corresponding external resource, reads data and process the external function that returns the data to the performing part 3 as a returned value while taking temporal consistency between the performing part 3 and external resource 2 in accordance with access from the performing part 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a simulation apparatus, and more particularly, to a simulation method, an apparatus, and a recording medium for simulating a behavior on a time axis of a system (system).

[0002]

2. Description of the Related Art In order for a time-dependent simulation apparatus to execute a simulation interactively by exchanging data with an external resource, the simulation apparatus outputs data to an external resource such as a file, a shared memory, and an input / output port. Therefore, means for inputting data from external resources is required.

In order for a time-dependent system to exchange data with an external resource at a specific time, an internal time managed inside the simulation apparatus and an external resource such as a timer are managed. External time must match. For this reason, such a simulation device requires a synchronization means for obtaining a time coincidence with an external resource.

[0004] By the way, as typical development languages of the conventional simulation apparatus, assembler and BASI are used.
C, Fortran, C, C ++, JAVA
(Registered trademark). The processing performed by the simulation device using these languages will be described with reference to FIG. FIG. 8 shows a simulation apparatus 101.
And an external resource 102 are shown. In the simulation device 101, an internal process 103 of the simulation,
A series of processes such as a synchronization process 104 for obtaining temporal consistency with the external resource 102 and an input / output process 105 for performing input / output with the external resource 102 are repeatedly performed.

The above-mentioned languages can easily realize reading and writing of a file, access to a memory, access to an external communication port, and the like by using standard functions and libraries, and can exchange information with external resources. It is possible. In addition, since the real time can be acquired using the timer function and the library or the standard function of the hardware, it is easy to synchronize with the time internally managed by the simulation apparatus. .

For this reason, when constructing a simulation apparatus for performing interactive input / output processing during execution of a simulation, the input / output interface function and time management function of the language itself can be used. .

On the other hand, as a device for reading separately constructed models and simulating the behavior on a time axis of a reconfigurable system, an HCC language (Hybrid Concurrent Concurrent
Text-based editable interpreter using straint programming language), add-in tool and front end for Mathematca language, Maple front end, Mat
There is an hcad front end and so on.

These languages have a function of expressing a time-dependent system using constraints such as differential equations and identities, and have a feature that a simulation model can be constructed intuitively, and a model can be easily reused. There is a feature that is. Here, such a language is called a constraint type programming language (a constraint programming language).

Some of these languages have a function of calling another language such as the C language. This function is mainly used to process mathematical functions and complicated logical operations at high speed.

[0010]

However, since the constraint-type programming language does not have a function of exchanging data with an external resource, a system for performing interactive input / output processing during execution of a simulation is required. It is impossible to build. For this reason, the constraint-based programming language has a problem that a simulation can only be executed according to a predetermined scenario when a simulation model is created.

In addition, since the constraint-type programming language does not have a function for acquiring real time, there is a problem that synchronization with the outside cannot be performed when performing data input / output processing.

The present invention has been made in view of the above situation, and has a simulation method and apparatus capable of performing data input / output processing while synchronizing with the outside while executing a simulation based on a restricted programming language.
And a recording medium.

[0013]

According to the present invention, there is provided a simulation apparatus for simulating a behavior of a system on a time axis, wherein a simulation of a model described in a constraint-type programming language is performed. Simulation execution means for calling an external function during execution of the simulation and changing the operation of the simulation in accordance with a return value returned from the external function; and executing the simulation execution means in response to a call from the simulation execution means. And external function processing means for processing an external function that accesses the external resource, reads data, and returns the data as a return value to the simulation execution means while maintaining temporal consistency with the external resource. Simulation equipment characterized by the following: There is provided.

In the above configuration, the external function processing means may process the external function at a time substantially equal to a cycle at which the simulation executing means calls the external function.

In the above configuration, the external function processing means may change a time for processing the external function in accordance with a type of call from the simulation executing means.

In the above configuration, the external function processing means may request data writing and data reading when accessing the external resource.

Further, in the above configuration, the external function may be described in C language.

In the above configuration, the constraint-type programming language may be an HCC language (Hybrid Concurrent Concurrent Language).
straint Programming Language).

According to the present invention, in a simulation method for simulating a behavior of a system on a time axis, an external function is called during execution of a simulation of a model described in a constraint programming language, and the external function is called by the external function. A method of accessing the external resource, reading data, and reflecting the data in the simulation of the model while ensuring temporal consistency between the simulation of the model and the external resource. You.

According to the present invention, in a computer-readable recording medium recording a computer program for simulating a behavior of a system on a time axis, the computer program is described in a constrained programming language. An external function is called during the execution of the simulation of the model, and the external function accesses the external resource and reads out the data while maintaining the temporal consistency between the simulation of the model and the external resource. And a step of reflecting the above in a simulation of the model.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram for explaining the concept of a simulation apparatus common to the first embodiment and the second embodiment according to the present invention.

FIG. 1 shows a simulation apparatus 1 and an external resource 2. The simulation device 1
It simulates the behavior on the time axis of the system, and includes a simulation execution unit 3 and an external function processing 4. Note that the external resource 2 may be configured to be included in the simulation device 1.

In the simulation executing section 3, an internal processing 5 of the simulation is performed, and a call 6 of an external function is performed at a time when data input / output with the external resource 2 is required.

That is, the simulation execution unit 3
Execute a simulation of a single simulation model (hereinafter referred to as a model) written in a constraint-based programming language (constrained programming language) such as the HCC language or a separately created model;
An external function is called during the execution of the simulation, and the operation of the simulation is changed according to a return value returned from the external function.

On the other hand, in the external function processing unit 4, as shown in the figure, a synchronization process 7 for obtaining temporal consistency between the simulation execution unit 3 and the external resource 2 according to the call of the external function 6 is executed. Then, data input / output processing 8 between the simulation execution unit 3 and the external resource 2 is performed.

That is, in response to the call from the simulation execution unit 3, the external function processing unit 4 accesses the external resource 2 and obtains the data while maintaining the temporal consistency between the simulation execution unit 3 and the external resource 2. And an external function that reads the data and returns the data to the simulation execution unit 3 as a return value. This function is described in a language such as the C language as an external function for a source code (program) describing the model. In particular, the external function processing unit 4 processes the external function at a time substantially equal to the period at which the simulation execution unit 3 calls the external function.

As described above, by providing the routine for performing the input / output processing and the synchronization processing in the external function and calling the routine as a part of the constraint condition, the access and the synchronization with the external resource can be realized. I have.

FIG. 2 is a block diagram showing a data flow relating to the simulation device according to the first embodiment of the present invention.

As shown in FIG. 1, a data processing device 9 and a simulation data display device 10 are connected to the simulation device 1. The data file provided in the data processing device 9 corresponds to the external resource 2 described above. Note that the simulation data display device 10 may be configured to be included in the simulation device 1.

The simulation device 1 accesses the data file of the data processing device 9 during execution of the simulation by using the function of the above-mentioned external function. The data processing device 9 reads the designated data from the data file and sends it to the simulation device 1 in response to the access from the simulation device 1. The simulation device 1 reflects the read data on a simulation program being executed. Then, the simulation device 1 causes the simulation data display device 10 to display a simulation execution result in which the data is reflected in the program.

The simulation device 1 according to the present embodiment can read data from the data file of the data processing device 9 during execution of the simulation, but changes the data to the data file of the data processing device 9 ( Data cannot be written).

FIG. 3 is a diagram for explaining input / output processing with an external device by an external function. FIG. 2 shows models A and B executed by the simulation execution unit 3, external functions processed by the external function processing unit 4, and data files held in the data processing device 9.

The model A and the model B are each HC
It is described in C language and can be executed only by a procedure specified as a source code in advance. Although these models A and B can be executed alone,
In the present embodiment, in order to simulate the behavior of the entire system, the model A and the model B are integrated (recombined) as illustrated. In the HCC language (source code, program) described in Model B,
A part for calling an external function is provided to enable input / output of data with the outside. It is assumed that a plurality of external function calling units are described here.

On the other hand, the external function is described in C language, and here, as an example, a case where a function called a getData function is used will be considered. The data in the data file, which is an external resource, is described in a text format, and described as a sequence of character strings, for example, in the order of 0, 0, 0, 0, 0, 0, 0, 1, 0, 0. I have. Each time there is a read request from the getData function, the specified data (1 or 0) is
Passed to the function. Here, the data may be stored in a shared memory that can be written from the outside.

When the simulation is performed on the model A and the model B, and the process reaches the external function calling part in the model B, the external function calling part calls the getData function by designating a predetermined argument. The getData function is
In order to synchronize, after adjusting its own execution time as necessary, it issues a read request for data corresponding to the argument to an external data processing device, and reads the specified data from the data file. The getData function determines a return value according to the read data, and returns the return value to the external function calling unit.

It is assumed that the period in which the external function is called during the simulation from the external function calling unit is set in advance so that the time during which the external function is processed is substantially equal. In this case, it is conceivable to change the processing time of the external function according to the type of call from the external function calling unit.

Also, the return value of the function corresponding to the value of the file data is set in advance (for example, if the data value is 1, the return value is 1; if the data value is 0, the return value is 0). And). The file data may be read by another application in a changed state.

In the HCC language used in this embodiment, the processing proceeds sequentially, so that no other processing is executed while the external function is being processed. Can be synchronized.

Next, referring to the flowchart of FIG.
The operation performed on the simulation execution unit 3 side will be described. The program of the model B calls the getData function with the argument being “start”, for example, during the execution of the simulation (step A1). Thereafter, it is determined whether the return value from the getData function is 1 or 0 (step A).
2) If the return value is 1, the operation of the model B is turned on (step A3). On the other hand, if the return value is 0, nothing is done.

Next, the model B program calls the getData function with the argument being “end” (step A).
4). Thereafter, it is determined whether the return value from the getData function is 1 or 0 (step A5). If the return value is 1, the operation of the model B is turned off (step A).
6). On the other hand, if the return value is 0, nothing is done.

Thereafter, the simulation is terminated, or
Alternatively, it is determined whether to continue the simulation as it is (step A7). When continuing, the processing from step A1 is repeated. Otherwise, the simulation is terminated.

Next, referring to the flowchart of FIG.
The operation performed by the external function processing unit 4 will be described. When the getData function in the external function processing unit 4 is called from the model B program, the designated argument is "start".
Is determined (step B1). If the argument is "st
If "art", the getData function considers that it is necessary to adjust its own execution time in order to maintain synchronization when performing the processing corresponding thereto, and waits for, for example, 1 second (step B2), and thereafter The designated data is read from the data file of the data processing device 9 (step B3).
If the argument is not “start” (if the argument is “end”), the getData function reads specified data from the data file of the data processing device 9 without waiting time.

Next, the getData function determines whether the data read from the data file has changed from 0 to 1 (step B4). If the data has changed from 0 to 1, the getData function sets the return value to 1 (step B5), while if the data changes from 1 to 0, the getData function sets the return value to 0. Then, this is returned to the model B program (step B6). Thus, the processing of the external function getData function ends.

In the present embodiment, when editing is performed using, for example, a text editor during execution of the simulation apparatus, the simulation execution state changes in accordance with the editing result, and the simulation data display apparatus 10
Can confirm the change. In addition, another application program can change the execution state of the simulation by editing the data.

As described above, according to the first embodiment, H
During execution of a simulation based on a constrained programming language such as the CC language, data can be read from the data processing device 9 while synchronizing with the external data processing device 9 to change the operation of the simulation.

Next, a second embodiment will be described.
FIG. 6 is a block diagram showing a data flow relating to the simulation device according to the second embodiment of the present invention.
In the following, the same reference numerals are given to the same elements as those in the above-described first embodiment, and detailed description thereof will be omitted.

In the first embodiment (FIG. 2), the case where the data is read from the data file of the data processing device 9 has been described. In the present embodiment (FIG. 6), the data is read by the access from the simulation device 1. Processing device 9
It is possible to write data to a data file. In the case of data writing, as in the case of data reading, synchronization and input / output processing are realized by using an external function.

The operation performed by the simulation execution unit 3 is substantially the same as that shown in the flowchart of FIG. 4, except that a process of passing data when an external function is called from the external function calling unit of the model B is added. Therefore, the description is omitted here.

Next, referring to the flowchart of FIG.
The operation performed by the external function processing unit 4 will be described. When the getData function in the external function processing unit 4 is called from the model B program, the designated argument is "start".
Is determined (step D1). If the argument is "st
If it is "art", the getData function considers that it is necessary to adjust its execution time to maintain synchronization when performing the processing corresponding thereto, and waits for, for example, 1 second (step D2), and then The designated data is written to the data file of the data processing device 9 (step D3), while if the argument is not “start” (if the argument is “end”),
The getData function writes specified data to the data file of the data processing device 9 without waiting time. After this, getD
The ata function reads specified data from the data file of the data processing device 9 (step D4).

Next, the getData function determines whether the data read from the data file has changed from 0 to 1 (step D5). If the data changes from 0 to 1, the getData function sets the return value to 1 (step D6), while if the data changes from 1 to 0, the getData function sets the return value to 0. Then, this is returned to the model B program (step D7). Thus, the processing of the external function getData function ends.

According to the second embodiment of the present invention, the data can be changed by writing the data file in the data processing device 9 from the simulation execution unit 3 to the data processing device 9 during the execution of the simulation. Since the operation of the simulation can be changed by reading the data from the memory 9, more complicated processing becomes possible and various simulations can be performed.

The simulation procedure described in each of the above embodiments can be recorded as a computer program on a computer-readable recording medium. By reading and executing the computer program when necessary, a simulation can be executed. In this case, as a configuration of the computer program, an external function is called during the simulation of the model described in the constraint-type programming language, and the external function uses the external function to ensure temporal consistency between the simulation of the model and external resources. While taking
A procedure of accessing the external resource, reading data, and reflecting the data in the simulation of the model.

The present invention is not limited to the above-described embodiment, but can be implemented with various modifications within the scope of the invention.

For example, in the above embodiment, the case where the HCC language is used has been described as an example. However, the present invention is not limited to this, and other constraint-based programming languages (Mathematic
a language, Maple language, Mathcad language, etc.).

[0055]

As described above in detail, according to the present invention, a simulation method and apparatus capable of performing data input / output processing while synchronizing with the outside during execution of a simulation based on a restricted programming language, And a recording medium.

[Brief description of the drawings]

FIG. 1 is a block diagram for explaining a concept of a simulation apparatus common to a first embodiment and a second embodiment according to the present invention.

FIG. 2 is a block diagram showing a data flow relating to the simulation device according to the first embodiment of the present invention.

FIG. 3 is an exemplary view for explaining input / output processing to / from the outside by an external function in the embodiment.

FIG. 4 is a flowchart for explaining an operation performed on the simulation execution unit side in the embodiment.

FIG. 5 is a flowchart for explaining an operation performed on the external function processing unit side in the embodiment.

FIG. 6 is a block diagram showing a data flow relating to a simulation device according to a second embodiment of the present invention.

FIG. 7 is a flowchart for explaining an operation performed on the external function processing unit side in the embodiment.

FIG. 8 is a diagram for explaining processing performed by a conventional simulation device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Simulation apparatus 2 ... External resource 3 ... Simulation execution part 4 ... External function processing part 5 ... External processing 6 ... External function call 7 ... Synchronization processing 8 ... Input / output processing 9 ... Data processing device 10 ... Simulation data display device

Claims (8)

[Claims] 1. A simulation device for simulating a behavior of a system on a time axis, executes a simulation of a model described in a constraint-type programming language, calls an external function during execution of the simulation, and executes a simulation from the external function. Simulation execution means for changing the operation of the simulation in accordance with the returned value returned, and in response to a call from the simulation execution means,
External function processing means for processing an external function which accesses the external resource, reads out data, and returns the data as a return value to the simulation executing means, while ensuring temporal consistency between the simulation executing means and the external resource A simulation device comprising: 2. The simulation apparatus according to claim 1, wherein the external function processing means processes the external function at a time substantially equal to a cycle at which the simulation execution means calls the external function. 3. The simulation apparatus according to claim 1, wherein the external function processing unit changes a time for processing the external function according to a type of a call from the simulation execution unit. 4. The simulation apparatus according to claim 1, wherein the external function processing means requests data writing and data reading when accessing the external resource. 5. The simulation apparatus according to claim 1, wherein the external function is described in C language. 6. The restricted programming language is HC
C (Hybrid Concurrent Constraint Programming La)
2. The simulation apparatus according to claim 1, wherein the simulation apparatus is an nguage). 7. A simulation method for simulating a behavior of a system on a time axis, wherein an external function is called during execution of a simulation of a model described in a constrained programming language, and the simulation of the model is performed by the external function. A simulation method comprising accessing the external resource, reading data, and reflecting the data in a simulation of the model while maintaining temporal consistency with the external resource. 8. A computer-readable recording medium on which a computer program for simulating a behavior of a system on a time axis is recorded, wherein the computer program executes simulation of a model described in a constraint-type programming language. During execution, an external function is called, and the external function accesses the external resource and reads data while maintaining temporal consistency between the simulation of the model and the external resource. A recording medium for executing a procedure for reflecting the information.