JPS58182760A - Initial value setting system of consecutive simulation language - Google Patents

Abstract

PURPOSE:To have the correct setting of initial conditions in case two different methods coexist concerningthe direct description and expression of a differential equation when the differential equation is to be expressed in a consecutive simulation language. CONSTITUTION:All names of variables of a model obtained by translating a model which is described in a consecutive simulation language are replaced with their proper names by a simulator to produce an instruction or a region. The names of the variables emerging in the model are registered as it is in a table, and the correspondence is kept between the position and the region of the variable's name on the table. In the case of the expression with a function type integrator, the variable's name of output is registered directly at the position of the table corresponding to the region of output. While in the case of the expression in the form of an arithmetic substitution sentence with a mark attached to the variable to discriminate the stage number, an arithmetic equation, i.e., a variable's name of output is registered as it is at the position in the table corresponding to the region of the output.

Description

[Detailed Description of the Invention] 11) Technical Field of the Invention The present invention describes the setting of initial conditions when two methods of direct description and expression of a differential equation are mixed when expressing a differential equation in one word in a continuous simulation. It's about how to get it right.

(2) Background of the technology Logical models can be manipulated by computers, making it easy to conduct simulation experiments. That is, it is useful because the model can be easily modified and many factors can be combined. Continuous m simulation languages are widely used in continuous systems.
A continuous system is represented by a collection of structural statements including differential equations. In the past, the method used was to describe the integrator in functional form one by one. Recently, methods of directly describing differential equations that are easy to learn have been considered.

The expression of the functional form in an integrator is K as follows.

Oi = f (Ii, engineering (31)) 01 is the output of the first integrator 1 is the input of the first integrator IGl is the initial value of the first integrator or in the direct description of the differential equation , vvv°°=arithmetic expression, which is expressed as an arithmetic assignment statement by attaching a rank identification symbol to the variable.This expression contains the following integrator based on the functional form expression.

V Mama” = r (vvv”” s 'vl-)vY
= r(yYV, 7.)V =r(v
T, t) Generally, initial values must be given to the integrator in advance. Since the integrator is immediately specified in the functional expression, the variables to which initial values are to be given are determined during model coding. In the latter expression,
The integrator is only recognized internally by the simulator and does not appear in the coding.

For those coding the model, it is easier to understand if the variables match the coded variables.

In other words, the variables that give initial values are vYl'',...vl,
Let it be v.

(3) Conventional technology and problems Regarding model coding in the conventional method, in the description in a continuous simulation language, it is divided into the following six types of coding units: a, parameters a, variables that appear in the self-described block model, Set a numerical value directly to the variable that gives the initial value.

b. Initial condition calculation block Prior to the start of simulation, the results of calculations are set for variables that appear in the model and variables that provide initial values.

Block that defines the structure of the C6 continuous system Simulation calculations are performed by numerical integration.

Next, we will discuss the model processing format.
The simulation language @ adopts a translation method, in which a model written in a continuous simulation language is translated into an intermediate language (generally the FORTRAN language), and after compilation and linkage, the simulation becomes as shown in Figure 1. executed.

Note that the intermediate language is not limited to Photoran, but may be any other language as long as it can be used for technical calculations. The simulation processing procedure is shown below.

■ Translate a model written in a continuous simulation language, create a table of variable names that appear in the model, an area for setting values, and create a subroutine that represents the structure.

■ Decode the control statement specified in the parameter description block and set the value in the area created in ■.

■ Execute the instructions in the initial condition calculation block.

■ Execute instructions in blocks that define the structure of a continuous system.

■ Printing the area of variables that appear in the model Next, integration using the continuous simulation language is performed by continuously printing the output, input, and initial value variables for all integrators that appear in the model, as shown in the table below. - is created as a region, and integral calculations are performed using the array (continuous region) as a unit.

9- (4) Purpose of the Invention The purpose of the present invention is to develop a method for correctly setting initial conditions when two methods of direct description and expression of differential equations are mixed when expressing differential equations in a continuous simulation language. It is about providing.

(5) Structure of the Invention The structure of the present invention is to model a continuous system represented by a collection of structural statements including differential equations, and to give an initial value to an integrator representing the differential equation when performing simulation. The following processes are executed in that order, and then the instructions of the initial condition calculation block are executed.

(b) The process of translating a model written in a continuous simulation language, replacing all variable names that appear in the model with unique names in the simulator, and creating instructions and areas; , the process of registering the name as it is in the table and maintaining the correspondence between the position of the variable name on the table and the area, (/1 Expression in a functional integrator Oi = f (Ii, IC1) 01 is Output 1 of the first integrator: If the input Iol of the first integrator is the initial value of the first integrator, the output variable name is registered as is in the table position corresponding to the output area, and the input For the 7 factors, create a unique name-human formula in the block that defines the continuous system, and for the initial value, create a unique name = initial value formula at the end of the initial condition calculation block, and set the initial value. In the omitted description, the process of creating a formula with a unique name = output variable name at the end of the initial condition calculation block, 2) Adding a symbol to the variable to identify the rank, and expressing it as an arithmetic substitute for human language vYv" = = In the case of an arithmetic expression, V to vYv゛ as the output variable name.

is registered as is in the table position corresponding to the output area. Regarding inputs, create a unique input variable name for each integrator, except for the highest order integrator, and create a unique input name vv°°−■Yv°.

Name of unique input vv=vvv Name of unique input? == For the initial value to create the formula vY in the block that defines the continuous system, create a unique initial value variable name for each integrator and create a unique initial value name vv-= vvv" unique initial value. Name 7=vv Process of creating a unique initial value name =V expression at the end of the initial condition calculation block.

(E) In the parameter decoding/setting routine, when the variable specified in the parameter description block is the output of an integrator, the process of setting the value in the corresponding initial value area instead of the output area.

(f) Processing that transfers all values in the initial value area to the corresponding output area.

(6) Embodiment of the Invention FIG. 2 is an explanatory diagram showing an embodiment of the invention corresponding to FIG. 1, and the portion indicated by the thick black line has a new configuration. Further, the symbols A to A in the figure are order symbols indicating the processing procedure of the present invention. Next, an explanatory diagram of the operation following the entire flow is shown in Fig. 3. In the Plutz diagram of FIG. 3, the part indicated by the black square on the left shoulder indicates that it is a part that is new to the present invention compared to the conventional one.

Next, the sentences of each block in the model coded in the simulation language in FIG. 2 are as follows.

C1) Harameta description block sentence 1 = □ ・・・・・・・・・a1
Y2= □ ・・・・・・・・・b1Y
3 = □ ・・・・・・・・・C1Y4
vy=□ ・・・・・・・・・d11Y4ma=
・・・・・・・・・-d21Y4-
・・・・・・・・・(13102
= □ ・・・・・・・・・b2C: □
・・・・・・・・・C2D = □
......C3 (2) Initial condition calculation block statement Yl =
−−−−0, −0−a2Y2 =□ ・
・・・・・・−・b3Y3＝□ ・・・・・・
...04Y4 TV == HH
H＋＋＋＋＋ (112Y4' =□ ・・・・・・
・・・d22Y4 =□ ・・・・・・・・・d32
Gt2= □ ・・・・・・・・・b4C=
□ ・・・・・・・・・C5D =□
......C6 (3) Block statement that defines the structure of the continuous system Yl = f (Xl, ) =-=-
・-aY2 = f (Yl, 02)
Mountain ----bY5 = t (A0B, O+
D) ・・−−−−・−cY4 −I
C+F・・・・・・・・・
dFor example, ■Y1 is expressed in a functional form and the initial value is omitted,
Y2 is a variable whose initial value is 02, and Y3 indicates a case where both the input and initial value are expressed as an arithmetic expression.

Next, the correspondence between the name of the variable area in (a) and the table contents of the variable name in (b) of the process according to the present invention is as follows.

The formula created in process (c) is K as shown below.

■ Initial condition calculation block instruction W1 − □ IL2 W2 = −〜−−−−−−−b5W3=
c4 W4 = □ (X, 2 W5 = (122 W6- □<152 W20 = b4W25- □
. 5 W24= -1 to -c (5 W18=Wtl! ■ Block instructions that define the structure of the continuous system W7 = W19 W8 = 41 W9 = W21 + W22 Wl 0=W25+W26 W11=W4 W12=W5 And parameter description Block statement, calculation of initial conditions The manner in which the value of the initial value area changes depending on the presence or absence of the block statement is as follows.

Investigate each initial wJ1i1N for formulas a, b, c, and d.

Initial value of formula a Initial value of expression Initial value of 2C The sum of 1 and 2 becomes the initial value Initial value of formula d ×: The specification is invalid. ○: The specification is valid. multiple sentences specified ′ The last specified value is set.

(7) Effects of the Invention According to the present invention, the values specified and calculated in the parameter description block and the initial condition calculation block are correctly set in the initial value area.

[Brief explanation of the drawing]

FIG. 1 shows the conventional technique, and FIG. 2 shows the process according to the present invention. FIG. 3 is a flow chart of the operation of the present invention. Patent applicant Fujitsu Ltd. Attorney Eisuke Tsuchi Suzuki

Claims (1)

[Claims] When modeling and simulating a continuous system represented by a collection of structural statements including differential equations, the following processes are executed in that order in order to provide initial values in an integrator representing the differential equations. An initial value setting method in a continuous simulation language, which is characterized in that the instructions of the initial condition calculation block are executed. (b) The process of translating a model written in a continuous simulation language, replacing all variable names that appear in the model with unique names in the simulator, and creating instructions and areas; , the process of registering the name as it is in the table and maintaining the correspondence between the position of the variable name on the table and the area, (c) Expression in a functional integrator oi = r (Ii, IC1) rLoi is i- If the output Ii of the @th integrator is the input ICi of the first integrator and the initial value of the first integrator, the output variable name is registered as is in the table position corresponding to the output area, and the input Create a unique name-human formula in the block that defines the continuous system, and for the initial value, create a unique name = initial value formula at the end of the initial condition calculation block, and omit the initial value. In , the process of creating an expression for the output variable name with a unique name at the end of the calculation block of the initial condition, 2) Adding a rank identifying symbol to the variable and expressing it as an arithmetic assignment statement y TV ``'' == Arithmetic In the case of a formula, V to vtV- are registered as output variable names in the table position corresponding to the output area. For inputs, except for the highest order integrator, create a unique input variable name for each integrator (7) Input bracket name Yv" = vvv" Unique input name vv-vvv Unique input name 7 Regarding the initial value to create the formula for =vma in the block that defines the continuous system, we create a unique initial value variable name for each integral a, and create a unique initial value name mama...2vmama. Unique initial value name 7=v Ma Unique initial value name ==: Process of creating the formula for V at the end of the initial condition calculation block. (e) In the parameter decoding/setting routine, when the variable specified in the parameter description block is the output of the integrator, the value is set not in the output area but in the corresponding initial value area. (f) Processing that transfers all values in the initial value area to the corresponding output area.