JP2510334B2 - Support system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an assisting system used for simulating the behavior of a specific system, and more specifically, each of them is characterized by a model formula. For the purpose of simulating the system under consideration, which is composed by connecting multiple described elements, the model part of the system under consideration is called sequentially from the library section equipped with multiple model equations, and the general model equation for the system under consideration is automatically calculated. It is related to the support system to generate.

[Conventional technology]

Conventionally, when simulating a system under consideration that is configured by arbitrarily connecting multiple elements of this type,
Each element is expressed in the form of model formula, and these are
They are called and used in duplicate in any order. Each of these model formulas has a link information group. Here, these link information groups have a description format unique to this element, and the link information depending on the system under consideration is not displayed.

For example, when simulating a hydraulic circuit, the model expression corresponding to the conduit as one element is displayed as follows.

PIPE (Q 1, Q 2, P L, P 1, P 2) Here, each link information is the inlet pressure (P
1), inlet flow rate (Q 1), outlet pressure (P 2, outlet flow
Quantity (Q ) Is represented. As yet another element
The model expression corresponding to the control valve of
It is taken.

RERIEF (X RF, V RF, P 1, P 2, P 3, Q 1, Q
2) Similarly, here, the link information is the inlet pressure (P
1), inlet flow rate (Q 1), outlet pressure (P 2), exit
Flow rate (Q 2) etc. are shown.

When a plurality of these elements are arbitrarily connected in a form allowing duplication to constitute the system to be examined, the model formula must be called with the entire system-dependent variable group when the model formula is called.

That is, in the example of the hydraulic circuit described above, it is necessary to attach an identification symbol to each element such as each pipeline and each control valve, and to call the model formula of each element together with this identification symbol.

[Problems to be Solved by the Invention]

Here, in the past, the method of assigning the identification symbol was left to each individual's favorite method and was done manually, so the correspondence of the variable symbol and the correspondence relation of the link information between each model formula was , It was not done systematically. Therefore, the more complicated the system to be studied, the more time and labor it takes.
For example, when the hydraulic circuit used in a general agricultural work vehicle having the number of elements of about 30 to 50 is targeted, this work alone requires one to two weeks.

An object of the present invention is to eliminate the above-mentioned conventional drawbacks, and in the case of constructing a general model formula for simulation by sequentially and arbitrarily connecting model formulas, a support system capable of automatically forming the general model formula is provided. Is to get.

[Means for solving the problem]

To achieve this object, the support system according to the present invention classifies the link information group of the model formula into a state variable group as output information in each element and an external variable group as input information to the element, The general model formula of the system under consideration shall be described as a unified variable with the degree of freedom as a parameter, and the degrees of freedom of the unified variable shall be the order of appearance of the model formula corresponding to the elements in the general model formula, and the link information part in the model formula. It is characterized in that the order of appearance of the state variables in is decided.

[Work]

In the present application, the model formula of the system under consideration will be described as a unified variable having the degree of freedom as a parameter. That is,
Instead of assigning an identification mark to each element, the variables to be treated as independent variables in the generalized model formula are sequentially displayed as parameters (degrees of freedom) for all circuits. In the simulation of such a system, the link information group of each model formula can be classified into a state variable group as output information from the element and an external variable group to be delivered to this element. In order to obtain the solution of this examination system, only the state variables of each element should be treated as the independent variables. That is, if the examination system is fixed, the independent variable group to be handled by this examination system is also determined accordingly.

Therefore, in the case of the present application, this independent variable group is represented by a unified variable having the degree of freedom as a parameter as described above. The order of appearance of the model expressions corresponding to the elements and the order of appearance of the information variables in the link information part in the model expressions are determined.

〔The invention's effect〕

With this configuration, it is possible to set the independent variable in the generalized model formula automatically and systematically. By adopting such a method, it is possible to uniformly process the increase in the number of elements, and it becomes possible to efficiently create the general model expression.

Further, in the above configuration, the link information in the model formula is described in a form having a portion indicating the type of variable, and the correspondence between the external variable group and the state variable group between each element is connected to each element. If we take the correspondence of the variable type of the link information in the node as a point, it becomes possible to automatically create the general model formula for this whole system, considering the connection relationship of each element, It was of great help in forming a support system that could be used to verify the behavior of such systems.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First, an overview of the hydraulic circuit development support system of the present application,
It will be described with reference to FIG. As shown in the figure, this system has four main parts (a pretreatment part (1), an analysis part (2), a post-processing part (3), and a library part (4)).
It consists of

The function of each unit will be described. First, the pre-processing unit (1)
Is a part mainly used for preparing a hydraulic circuit diagram (5) intended by a user of the system, that is, a CAD means, and is used for such a hydraulic circuit diagram (5). This is a part for creating a symbol diagram (6) of each element to be created, and also creating and changing a model formula (e1) of a model associated therewith. Here, the symbol diagram (6)
High-speed response valve (1
5) The functions of hydraulic devices and other elements (elements) such as the relief valve (18) are represented in a schematic diagram in order to show them on the circuit diagram. The model formula (e1) corresponds to the above-mentioned elements. It is a mathematical expression of how these circuit elements work.

 Next, the operation of the analysis unit (2) will be described.

The analysis unit (2) is a unit that automatically generates the integrated model equation (E1) of the created hydraulic-related circuit based on the hydraulic-related circuit diagram (5) created by the above-described preprocessing unit (1). is there. In the operation at this part (2), it is naturally necessary to select a model corresponding to each element, input part data in the model, input calculation conditions, and the like. Then, the model formula (e1) registered in the library unit (4) for each model corresponding to each element is combined based on the created hydraulic circuit diagram (5).
Further, in this part (2), the general model equation (E1) corresponding to the hydraulic circuit is solved according to the input condition.
The above is the role of the analysis unit (2). Further, in the post-processing unit (3), the solution of the hydraulic pressure-related circuit obtained in the analysis unit (2) is output as a dynamic characteristic chart (8). Furthermore, in this support system, based on the model selected for each element, the parts list of the parts used in this circuit (not shown)
Is configured to be output. Each part (1)
The process flow in (2), (3) and (4) is shown in FIG.

Although the schematic configuration of the system of the present application is as described above, the configuration of the hydraulic-related circuit development support system of the present application, in accordance with an example in which this is used for the hydraulic-related circuit for raising and lowering the three-point link mechanism, The operation will be described sequentially. FIG. 3 is a mechanical schematic diagram of the system, and FIG. 4 is a hydraulic circuit diagram of the system.

First, FIG. 3 will be described. The work vehicle (10) is equipped with the above-described three-point link mechanism (11) at the rear thereof, and the working device (11a) such as a rotary as a load weight is moved up and down by the three-point link mechanism (11) as the link mechanism. It is operated. Here, the three-point link mechanism (11) is driven by the hydraulic cylinder (12). The supply of pressure oil to the hydraulic cylinder (12) is performed by a pump (14) mechanically connected to the engine (13). Further, in the circuit from the pump (14) to the hydraulic cylinder (12), a high-speed response valve (15) as a switching valve for raising and lowering and a falling speed control valve (16) as a flow control valve are provided. . The high-speed response valve (15) is for controlling the opening and closing of the high-speed response valve (15) in response to a control command from a PID control unit (17) as a control means in the example of the present application. The falling speed adjusting valve (16) is for preventing a sharp drop in the lowering operation of the working device. This PID control unit (17) is connected to the three-point link mechanism (1).
The position of 1) is obtained as control information. The circuit is further provided with a relief valve (18).

The user of the support system according to the present invention draws the hydraulic system circuit diagram (5) for the hardware system in the pre-processing unit (1) while drawing the hardware system as described above or referring to the reference drawings. Create. This approach is
It is the same as that used in the CAD system. Fourth
The figure shows a hydraulic circuit diagram (5) created in this way. In this figure, the corresponding elements are described with the same numbers.

This hydraulic circuit diagram (5) is created by a CAD system, but in the example of the present application, the hydraulic system element is used as each element, the engine (13), and the three-point link mechanism (11). The hydraulic-related circuit diagram (5) is configured so as to include the mechanical system element and the electrical system element such as the PID control unit (17). That is, in this support system, the relief valve (18), the high-speed response valve (15), the fall speed adjustment valve (1
6) In addition to the hydraulic system elements such as the hydraulic cylinder (12) and each pipeline (p), mechanical systems such as the engine (13), the three-point link mechanism (11), and the PID control unit (17),
Even the electric elements are adopted as the object of the study, and the behavior of the hydraulic circuit is examined.

Now, from the hydraulic circuit diagram (5) obtained as described above, the general model formula (E1) corresponding to this circuit diagram is obtained.
The method for creating the is described below. As described above, this system includes the library section (4), and the model formula (e1) corresponding to each model described above is registered in this section (4). In this model equation (e1), the input (external variable) system for each model,
An output (state variable) system is defined, and further, a condition (eigen constant, calculation constant) system for determining the properties of the model itself is provided. For example, in the above-described high-speed response valve (15), the input system includes a valve inlet (15I), first, second, and third outlets (15O1) (15O1) shown in FIG.
2) The flow rate of (15O3), the first current signal (I1) to the first solenoid valve (V1), and the second current signal (I2) to the second solenoid valve (V2). (15I), the fluid pressure at the first, second and third valve outlets (15O1) (15O2) (15O3).
An example of the condition system is a relief setting pressure.

In each pipeline (p), the input system is the flow rate at the pipeline inlet and outlet, the output system is the pressure at the pipeline inlet and outlet, and the condition system is the pipe diameter of each pipeline (p) itself, the pipeline. It becomes something like the length of a road. When the physical quantities of the mechanical system element and the electrical system element are targeted as in the present application, acting force, load torque, position, speed, acceleration, angular velocity, and angular acceleration are considered as the physical quantity of the mechanical system element. Here, the mechanical system elements are classified into a rotary motion system and a linear motion system. Further, as the physical quantity of the electric element, a current value, a voltage value and the like are taken into consideration.

Now, for elements having different functions, their symbol diagrams, the models that can be selected corresponding to them, their model expressions (e1), and the inputs, outputs, and conditions in these model expressions (e1). The system is determined and stored in the library section (4). That is, in this system, each symbol diagram is associated with a model expression (e1) determined as a result of model selection corresponding to the symbol diagram. Here, in this application, the program is FORTRA
Since the model expression (e1) is created using N languages, the model expression (e1) is described in a subroutine format, and the input / output system is described as an argument group in the subroutine. This model formula (e
In 1), the argument group is specified together with its processing method.

Further, a representative model is prepared corresponding to each element as described above, and the model formula (e1) of this model can be modified if necessary.

Hereinafter, examples of the configuration of the mechanical element and the model equation (e1) of the electric element in the present application will be introduced. For an engine (13) classified as a rotational motion system as a mechanical element, the model formula is configured to output the engine speed, and based on model data on the engine speed given in advance, By linearly interpolating this in the time domain, the number of rotations at a desired time is output. The pump outputs its suction pressure and discharge pressure based on the number of rotations delivered from the engine and other conditions (fluid system conditions). The load torque is transferred from the pump to the engine.

In addition, the hydraulic cylinder (12) is the partner of the three-point link mechanism (11) and the load weight (11a), which is classified as a linear motion system. The system consisting of (11) transfers the position, the moving speed and the moving acceleration of the connecting point, and the hydraulic cylinder (12) transfers the load force.

On the other hand, PID control unit (17)
Will be described as an example. The PID control unit (17) detects the lift arm angle from the three-point link mechanism, calculates the current off time to the high-speed response valve (15), and calculates the output current value if the current time is the on time. . The formula for calculating the current off time is configured as follows.

dToff (n) = Kp * qEV (n) + Ki * EV (n) + Kd * d2EV (n) where dToff (n) is the current off time, Kp, Ki, Kd are proportional, integral, differential gain, V ( n) is the actual lift arm speed, RV (n) is the target speed, and EV (n), dEV
(N) and d2EV (n) are described as follows. (N indicates a time step.) EV (n) = V (n) −RV (n) dEV (n) = EV (n) −EV (n−1) d2EV (n) = dEV (n) −dEV (N-1) In the high-speed response valve (15), the PID control unit (1
It is configured to receive the current value from 7), calculate the solenoid force, and calculate the valve speed.

Next, in the analysis unit (2), a general model expression (E1) of the entire circuit itself is obtained based on the hydraulic pressure-related circuit diagram (5).
A method for automatically generating will be described. In the present application, a unique method is adopted for this automatic generation method. That is, this is the general model automatic generation means (20) in the present application.

FIG. 5 shows the flow of the process of the integrated model formula automatic generation means (20), which will be described with reference to FIG. This is the element ordering means (21), the node ordering means (2
2), and a degree-of-freedom ordering means (23), all of which are composed of each element, each node, and the general model formula (E1) with respect to the whole of the created specific fluid-related circuit diagram (5). Can be referred to as processing means for enabling the independent variables in the to be identified by serial numbers. Here, a node is a connection point of each element.

The function of each of the means (21), (22) and (23) will be described below. First, the ordering of each element is performed by the element ordering means (21). This ordering is performed as shown below from the main element to each pipeline in the order of input by CAD (almost along the order of the flow paths of the hydraulic circuit). An example of this is shown below.

Element: 1 Motor (engine) Element: 2 Gear pump Element: 3 T-joint Element: 4 High speed response valve Element: 5 Relief valve Element: 6 Tank · · (Here, the engine is treated as a motor in the system. ) Next, the node ordering means (22) orders the nodes as connecting points of the respective elements, and together with this, the node correspondence table (T1) shown in FIG.
Is created. The node correspondence table (T1) includes a main symbol (t1) as a main element connected to each node,
It is a table in which sub-symbols (t2) as elements connected to the main elements and corresponding port names (t3, t4) in these elements are associated with node numbers (t5). At this stage, the display of the port names (t3) and (t4) of each element is dependent on each element. That is, for example, the entry of an element is described as 1 or the like in any element, and the exit is similarly designated as 2 or the like.

Further, in the present application, after the creation of the node correspondence table (T1), the degree of freedom correspondence table (T2) is generated by the degree of freedom ordering means (23), and then the general model expression (E1) is automatically generated. . This method will be described below. In the present application, the argument group as the link information group of the model formula (e1) corresponding to each element is classified into a state variable, an external variable, a unique constant, a calculation constant and the like. Where the state variables are
The element is a variable as a physical quantity that each element has in each calculation step (state), and the external variable is a state variable delivered from the element connected to this element. Here, at the stage where the model equation (e1) is called and the state where the processing of the model equation (e1) is completed, the state variables are different by the amount of the calculation processing. Further, the above-described intrinsic constants and calculation constants are constants used in the processing in each model equation (e1).

In the present application, the argument group of the model formula (e1) is described and arranged with a unique configuration. That is, each argument is represented by one character indicating the type of the variable and the port name (within four characters) of each model connected via one underscore, and the argument in each model formula (e1) is According to the above-mentioned classification, they are classified into state variables and external variables, and these are sequentially arranged as a state variable group and an external variable group as an argument group of a subroutine. An example of this is shown below.

Here, a motor (engine), a pump, a T-shaped joint,
Examples of a fast response valve, a relief valve, a tank, and a pipe are shown. For example, taking a motor (engine) as an example,
(W MC) indicates that the type of variable is W; angular velocity, and that it is a variable of the MC port. After such a preparatory step, the degree of freedom ordering means (23) uses the unified variable (Y) with the degrees of freedom as parameters according to the circuit diagram (5) described above to obtain the independent model equation (E1). An overall model expression (E1) is created while defining the variables. In this process, the degree of freedom described above is determined by the general model formula (E1)
In the ordered element order in, and in the argument part in the model expression (e1) corresponding to this element,
Only the state variables (external variables are not initially considered)
Are determined in the order described. An example in this case described in a program format is shown below. Here, the program is the model expression (e1) in the order of the ordered elements described above.
Is created in the form of calling CALL, so they are described in this order in the CALL statement.

 Here, first, the state variables of the motor (engine) are
(W The unified variable (Y) whose argument of MC) has one degree of freedom
(1)). Of this motor (engine)
If there are no external variables, do not perform any further operations.
I don't know. Next, for the pump, its state variables
(P 1, P 2) is a unified variable (Y (2), Y
(3)) will be replaced. External variable (Q
1, Q 2, Q 3) is unified because it is not related to processing yet
It cannot be replaced by a variable. And in the external variables of the pump
Yes (W MC) has the same description format that is connected at node 1.
Since this is the state variable of the motor (engine)
It will be replaced as (Y (1)).
is there. For example, it will appear for the first time with a pump (Y
(2)) is a program in element order from the node relationship.
External variable of the pipe (PIPE) (P 1) and
Has been replaced. This kind of operation is applied to all circuits
It is carried out.

Although the above-described operation has been described on a FORTRAN basis for the sake of simplicity, a table (T2) called the degree of freedom correspondence table by the inventor is created in the present application before such a replacement operation. The degree of freedom correspondence table (T2), the degree of freedom (t10) of the unified variable (Y), the variable type (t11), the element number (t12) and the port name (t13) identified as a state variable, The corresponding node number (t14), the element number (t15) identified as an external variable, and the port name (t16) are used as a reference table. As can be easily understood from this table (T2), here, the general model equation (E1) is described as a unified variable with the degree of freedom as a parameter, based on the unique circuit system to be studied, and a unified Processing is possible.

Here, the initial value of the circuit is input in a predetermined step as one mode of the condition system described above. In this system, the general model equation (E1) formed as described above is solved by the Runge, Kutta, Gil method, or the like, following the time step.

Hereinafter, a description will be given of a simulation result of a hydraulic circuit related to the lifting / lowering operation of the working device by the three-point link (11). That is, the calculation result obtained by the analysis unit (2) is output to a printer and illustrated in a post-processing unit (3). Here, the printer output is a general output format, and thus the description thereof will be omitted. FIGS. 8A and 8B show the results of the illustrated output. Here, in each drawing, the horizontal axis represents time, and the vertical axis represents pressure (left scale kgf / cm ² ) and position (height) in FIG.
(Right scale cm) is shown, and in FIG. 8 (b), the flow rate (left scale 1 / min) and the number of revolutions (right scale rpm) are shown. Graphs of this output example in each drawing will be sequentially described. In FIG. 8 (a), the pump discharge pressure is And the cylinder pressure is And the lower link height Therefore, the discharge pressure of the fast response valve is Indicated by. On the other hand, in FIG. 8B, the pump speed is And the cylinder displacement is And the first control current (I1) is And the second control current (I2) is Indicated by. In raising and lowering the working device in this embodiment, there is a problem how to control the device in a short time, without overshooting and without causing hunting or the like. In Figure 8, 0.0 to 2.0
(Sec) indicates the upward stroke (UP), and 2.0 to 3.0 (sec) indicates the downward stroke (Down). Furthermore, during this ascending stroke (UP), the work equipment is sufficiently separated from the target position, and the first control current (I1)
With the first ascending stroke (UP1) that is always in
It can be seen that the first control current (I1) is almost established from the second ascending stroke (UP2) in which the first control current (I1) is intermittently turned on and off. Furthermore, the down stroke (Down) also has such a configuration (Do
wn1) (Down2). In the first ascending or descending stroke (UP1) (Down1), the control current (I1)
(I2) is maintained at a constant value, and the pressure, the flow rate, and the like pulsate in a long cycle. On the other hand, the second ascending or descending stroke (UP
2) In (Down2), the high-speed response valve (15) is intermittently controlled by the PID control unit (17), and the pressure, flow rate, etc. change greatly, and the cylinder displacement and lower link height are smoothly changed to the target value (SP1). ) Asymptotic to (SP2) (LR1) (LR2). This is an operation diagram when each element and PID control conditions are set to an ideal state.
This is because the figures (a) and (b) show.

In order to deal with this example, an example in which this control condition (proportional and integral gain) is changed in PID control is shown in FIGS. 9 (a) and 9 (b). In this case, in the above-described second ascent stroke (UP2), intense vibration of the pump and cylinder internal pressure occurs, and a hunting portion (P) occurs in the cylinder displacement itself.

[Another embodiment]

In the above embodiment, as the mechanical system element,
Although the engine and the three-point link mechanism have been described, any type may be used as long as it responds to an input system of a predetermined physical quantity in a typical manner. The same can be said of the electric element.

Further, in the above example, the control means is based on the PID control method, but this may use another control method such as fuzzy control. In the above embodiment, the response change of the system when the condition of the PID control is changed has been described for this target circuit. However, in the design of such a hydraulic related circuit, the hardware side (each hydraulic element, mechanical It is of course not possible to change the dynamic characteristics of the system elements and electrical elements (changing the equipment used), but it is also possible to add or remove new hydraulic elements to the circuit or change this circuit configuration. hand,
It is possible to study the dynamic characteristics of the hydraulic circuit described above.

In the analysis section, the degree of freedom correspondence table of the present application (T2)
Model model (E
When solving 1), it is possible to adopt methods other than the Runge-Kutta-Gill method.

It should be noted that reference numerals are added to the claims for convenience of comparison with the drawings, but the present invention is not limited to the structures of the accompanying drawings by the entry.

[Brief description of drawings]

The drawings show an embodiment of a support system according to the present invention.
FIG. 1 is a diagram showing a main configuration of a fluid-related circuit development support system, FIG. 2 is a diagram showing a processing flow in each main part, FIG. 3 is a diagram of a hardware system of a system under consideration of the present support system, FIG. 4 is a hydraulic circuit diagram of the system under consideration shown in FIG. 3, FIG. 5 is a diagram showing the flow of processing of the general model automatic generation means, FIG. 6 is a node correspondence table diagram, and FIG. FIG. 8 is a diagram of the degree of freedom correspondence table, FIG. 8 is a diagram of the output in the optimum operating state of the system under study shown in FIG. 3, and FIG. 9 is a case where the condition setting of the system under study shown in FIG. 3 is inappropriate. FIG. (1) ... pre-processing unit, (2) ... analysis unit, (3) ... post-processing unit, (4) ... library unit, (5) ... fluid-related circuit diagram, (T1) ... Node correspondence table, (T2) …… Degree of freedom correspondence table.

Front Page Continuation (72) Inventor Koichi Onikuda 1-1-1, Hama, Amagasaki City, Hyogo Pref., Kubota Technology Development Laboratory Co., Ltd. "Hydraulic circuit design support expert system OHCS" Proceedings of the 36th Annual Conference of Information Processing Society of Japan, pp. 1565-1566, 50-2, Tomio Baba, et al. Example "

Claims (5)

(57) [Claims] 1. A library section provided with a plurality of the model formulas (e1) for the purpose of simulating a system to be examined, which is constituted by connecting a plurality of elements whose characteristics are described by the model formulas (e1), respectively. From (4), the model equation (e1) is sequentially called and the general model equation (E1) of the system under consideration
In the support system for automatically generating, the link information group of the model formula (e1) is classified into a state variable group as output information in each element and an external variable group as input information to the element, When describing the generalized model equation (E1) of the system under consideration as the unified variable (Y) having the degree of freedom as a parameter, the degree of freedom of the unified variable (Y) is defined as the element in the generalized model equation (E1). A support system which determines the appearance order of the corresponding model expression (e1) and the appearance order of the state variable in the link information part in the model expression (e1). 2. The link information in the model formula (e1) is described in a form having a portion representing a type of variable, and the correspondence between the external variable group and the state variable group between the respective elements. The support system according to claim 1, wherein is taken in correspondence with a type of a variable of the link information in a node as a connection point between the respective elements. 3. A plurality of model equations (e1) for simulating a hydraulic circuit constituted by connecting a plurality of elements whose characteristics are described by model equations (e1), respectively.
In a support system that sequentially calls the model formula (e1) from the library unit (4) including the above to obtain the general model formula (E1) of the hydraulic circuit, the link information group of the model formula (e1) is The state variable group as output information in each of the elements and the external variable group as input information to the element are described separately and described in a format having a portion indicating the type of the variable. When describing the generalized model expression (E1) of (1) with a unified variable (Y) having a degree of freedom as a parameter, the element ordering means (21) determines the calling order of the model expression (e1) of each element, The node ordering means (22) orders the nodes as connection points between the respective elements over the entire hydraulic pressure related circuit, and the degree of freedom ordering means (23) The degrees of freedom are determined in the order of calling the model equation (e1) in the generalized model equation (E1) and in the order of appearance of the state variable in the link information part in the model equation (e1), and the model equations ( The support system, wherein the correspondence between the external variable group and the state variable group between e1) is taken by the correspondence of the variable type of the link information in the node. 4. The node ordering means (22) includes a main symbol as a main element in each node, a sub-symbol as an element connected to the main element, and a corresponding port name in these elements. 4. The support system according to claim 3, wherein a node correspondence table that is a table in which is associated with the node numbers is created. 5. The degree of freedom ordering means (23) has an element having a variable represented by the degree of freedom as the state variable and its port name, and a variable represented by the degree of freedom as the external variable. The support system according to claim 3, wherein a degree-of-freedom correspondence table is created in which the owned elements and their port names are associated with the degrees of freedom.