JPH0455983A - Support system for fluid related circuit development - Google Patents

Abstract

PURPOSE:To quickly and easily perform design and inspection by registering a symbol diagram and a model formula corresponding to a control element controlling a fluid related circuit as an element in a library part. CONSTITUTION:The symbol diagram of the control element as one element and its model formula are registered in a library part 4. Thus, the control element representing the control means is connected to the element turned to the element to be controlled in the fluid circuit simultaneously when preparing the diagram of the fluid related circuit in a pre-processing part 1 to enable prepare the diagram of the circuit including these. Therefore, the behavior of the fluid related circuit is analyzed while including this control element even in an analysis part 2 and a post-processing part 3. Thus, the development of the fluid related circuit can be easily performed for a short time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fluid-related circuit development support system used for designing fluid-related circuits such as hydraulic circuits and verifying their behavior.

[Conventional technology]

Conventionally, as support systems for this type of fluid circuit, in order to know the operating state of the fluid circuit in a steady state, a simulation program corresponding to the fluid circuit is generated and used for designing the fluid circuit. On the other hand, such a fluid circuit generally has a control means connected to any element within the circuit, and is operated in response to a control command from the control means. That is, when designing such a fluid circuit, it is necessary not only to design the fluid circuit itself, but also to manufacture control means corresponding to this circuit.

[Invention or problem to be solved]

However, in the above situation, if you want to verify each of the created fluid circuits and control means, you will have to actually create the actual fluid circuit and then write the control program as the control means. It was necessary to run it and see if it behaved like the target system.

If this method is adopted, the actual fluid circuit will be updated every time changes are made during the design process, such as adding or deleting individual fluid devices (elements), debugging the control program, or changing control parameters. It was necessary to manufacture the device and study its behavior, which resulted in extremely poor development efficiency.

In addition, there is a library section in which symbol diagrams corresponding to various elements as recent fluid-related equipment and model formulas showing the relationship between the input to the element and the state quantity of the element as the output from the element are registered. a preprocessing unit that combines the symbol diagrams to create a fluid-related circuit diagram in order to obtain a desired fluid-related operation; and a preprocessing unit that creates a fluid-related circuit diagram from the library unit based on the fluid-related circuit diagram. an analysis unit that calls a model formula and automatically generates a comprehensive model formula corresponding to the entire fluid-related circuit, and solves the comprehensive model formula according to input conditions; and outputs a solution of the comprehensive model formula obtained by the analysis unit. A fluid-related circuit development support system consisting of a post-processing section and the following has been proposed. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to eliminate the above-mentioned conventional drawbacks, and to provide a fluid-related circuit development support system that can quickly and easily design and verify fluid-related circuits as well as verify the control means used therein. That's true.

[Means to solve the problem]

To achieve this objective, the fluid-related circuit development support system according to the present invention has the following features: In the above-mentioned support system, symbol diagrams and model formulas corresponding to control elements that control fluid-related circuits as elements are registered in the library section. It is characterized by

[For production]

With the configuration of the present application, a fluid-related circuit diagram is created using symbol diagrams in the preprocessing section in order to obtain the desired fluid operation, and an integrated model equation is automatically generated for the entire circuit in the analysis section according to this diagram. In the configuration of this application, the symbol diagram of the control element and its model formula are stored as one element in the library section. Since it is registered, when creating a fluid-related circuit diagram in the pre-processing section mentioned above,
At the same time, it becomes possible to connect a control element representing a control means to an element to be controlled in a fluid circuit, and to create a circuit diagram including these elements. Therefore,
In this support system, the behavior of the fluid-related circuit is solved in a state where this control element is included in the analysis section and the post-processing section as well.

〔Effect of the invention〕

As a result, it becomes possible to debug the control program as a control means, change parameters, etc., change devices in fluid-related circuits while linked to the control program, and change parameters in each device, all on a computer basis. It has become possible to develop fluid-related circuits that involve such control easily, in a short time, and at low cost.

〔Example〕

Embodiments of the present application will be described below based on the drawings.

First, an outline of the hydraulic circuit development support system of the present application will be explained based on FIG. 1. As shown in the diagram, this system has four main parts (preprocessing section (1), analysis section (2)
, a post-processing section (3), and a library section (4)).

To explain the functions of each part, first, the preprocessing part (1) is a part used mainly for creating a hydraulic circuit diagram (5) intended by the user of this system, that is, a CAD means, and , creation of a symbol diagram (6) for each element used in this hydraulic related circuit diagram (5), and creation of a model formula (e1) for the model associated with this,
This is the part that also makes changes. Here, the symbol diagram (6) refers to the high-speed response valve (
15), the functions of hydraulic equipment, etc. (elements) such as relief valves (18) are expressed schematically in order to show them on the circuit diagram, and the model formula (e1) corresponds to the above-mentioned elements. It is a mathematical representation of how these circuit elements work.

Next, the function of the analysis section (2) will be explained.

This analysis section (2) is a section that automatically generates an overall model equation (E1) for the hydraulic circuit that has already been created based on the hydraulic circuit diagram (5) created by the preprocessing section (1). be. In the operation at this part (2), it is naturally necessary to select a model corresponding to each element, input part data for the model, input calculation conditions, etc.

Then, the model formula (e1) registered in the library section (4) for each model corresponding to each element, or
They are combined based on the created hydraulic-related circuit diagram (5). Furthermore, in this part (2), the overall model equation (E1) corresponding to this hydraulic pressure related circuit is solved according to the input conditions. This is the role of the analysis section (2).

Furthermore, in the post-processing section (3), the above-mentioned analysis section (2)
The solution of the hydraulic pressure-related circuit obtained in step 1 is output as a dynamic characteristic chart (8). Furthermore, in this support system, based on the model selected for each element, a bill of materials (not shown) for the parts used in this circuit is created.
is configured so that it is output. Each part mentioned above (1)
The flow of processing in (2), (3), and (4) is shown in FIG.

The general configuration of the system of the present application is as described above, but in accordance with an example in which this is used for a hydraulic circuit related to lifting and lowering operations of a three-point link mechanism, the configuration of the hydraulic circuit development support system of the present application, The functions will be explained step by step. FIG. 3 shows a mechanical schematic diagram of this system, and FIG. 4 shows a hydraulic circuit diagram of this system.

First, FIG. 3 will be explained. This work vehicle (10) is equipped with the aforementioned three-point linkage mechanism (11) at its rear.
This three-point linkage mechanism (11) serves as a load weight for a working device (II) such as a rotary.
a) It is operated to raise and lower. Here, this three-point linkage mechanism (11) is driven by a hydraulic cylinder (12). The pressure oil is supplied to the hydraulic cylinder (12) by a pump (1) mechanically connected to the engine (13).
4) is performed. Furthermore, the circuit from this pump (14) to the hydraulic cylinder (12) is provided with a high-speed response valve (15) as a lift switching valve and a falling speed control valve (16) as a flow rate control valve. . In the example of the present application, this 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) serving as a control means. The falling speed regulating valve (16) is for preventing a sudden descent during a descending operation of the working device.

This PAD control section (17) is connected to the three-point link mechanism (11).
) is obtained as control information.

Furthermore, this circuit is provided with a relief valve (18).

Users of the support system of the present application should keep in mind the hardware system described above or refer to reference drawings.
A hydraulic circuit diagram (5) related to this node system is created in the preprocessing section (1) described above. This method is similar to the conventional C
This is the same as that used in the AD system. Fourth
The figure shows a hydraulic circuit diagram (5) created in this way. In this figure, corresponding elements are labeled with the same numbers.

This hydraulic-related circuit diagram (5) will be created using a CAD system, but in the example of this application, each element includes an engine (13), a three-point linkage mechanism (11), a hydraulic system element, etc. Hydraulic related circuit diagram (5) includes mechanical elements such as and electrical elements such as PID control section (17).
or configured. That is, in this support system, in addition to hydraulic system elements such as a relief valve (18), a high-speed response valve (15), a falling speed adjustment valve (16), a hydraulic cylinder (12), and each pipe (p), the engine (1
3), three-point linkage mechanism (11), and PID control section (1
Mechanical system and electrical system elements such as 7) are adopted as objects of study, and the behavior of hydraulic-related circuits is studied.

Now, the hydraulic circuit diagram (5) obtained as above
A method for creating an integrated model equation (E1) corresponding to this circuit diagram from the following will be described below. As mentioned above, this system is equipped with a library section (4), and this section (4) stores model formulas (e) corresponding to each of the above-mentioned models.
1) is registered. In this model formula (e1), the input (external variables) system and output (state variable) system for each model are defined, and the conditions (specific constants, calculation constants) that determine the properties of the model itself are defined.
The structure has a system. For example, in the above-mentioned high-speed response valve (15), the input system includes the valve inlet (151), first, second, and third outlets (1501) shown in FIG.
(1502) (1503) flow rate, first solenoid valve (v1)
The first current signal (11) to the second solenoid valve (v2), the second current signal (■2) to the second solenoid valve (v2), and the output system is the valve inlet (15
I), first, second, third valve outlet (1501) (1502
) (1503). Examples of conditions include relief setting pressure and the like.

In each pipe (p), the input system is the flow rate at the pipe inlet and outlet, the output system is the pressure at the pipe inlet and outlet, and the condition system is the pipe diameter and pipe diameter of each pipe (p) itself. The path length, etc. When the physical quantities of mechanical elements and electrical elements are targeted as in the present application, acting force, load torque, position, speed, acceleration, angular velocity, and angular acceleration are considered as the physical quantities of mechanical elements. Here, mechanical elements are classified into rotational motion systems and linear motion systems. Furthermore, the configuration is such that current values, voltage values, etc. are taken into consideration as physical quantities of electrical elements.

Now, for elements that have different functions, their symbol diagrams, corresponding models that can be selected and their model formulas (e1), and this model formula (
The inputs, outputs and conditional systems in e1) are always stored in said library section (4). That is, in this system, each symbol diagram is associated with a model equation (e 1) determined as a result of model selection. Here, in this application, the program is F
Since it is created for the ORTRAN language TR, the model formula (e1) is written in a subroutine format, and the input/output system is written as a group of arguments in the subroutine. In this model formula (e1), an argument group is defined along with its processing method.

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

An example of the configuration of the model formula (e1) of the mechanical element and the electrical element in the present application will be introduced below. For the engine (13), which is classified as a rotary motion system as a mechanical system element, the model formula is configured to output the engine rotation speed, and based on model data regarding the engine rotation given in advance, By performing linear interpolation on this in the time domain, the rotation speed at a desired time is output. Based on the rotation speed and other conditions (fluid system conditions) delivered from the engine, the pump outputs its suction pressure and discharge pressure.

Also, load torque is transferred from the pump side to the engine.

Furthermore, a three-point linkage mechanism (1
1) and the load weight (lla), the hydraulic cylinder (
12), the system consisting of the three-point linkage mechanism (11) receives and transfers the position, moving speed, and moving acceleration of the connecting point, and the hydraulic cylinder (12) receives and transfers the load force.

On the other hand, regarding the electrical system element, the PID control section (17
) will be explained as an example. This PID pricing department (17)
The lift arm angle is detected from the three-point link mechanism, the current off time of the high speed response valve (15)-\ is calculated, and if the current time is the on time, the output current value is calculated. The formula for calculating the current off time is constructed as follows.

dTo f f (n)=Kp*dEV (n)+K
i*EV (n) 10Kd*d2EV (n) where,
dToff(n) is the current off time, Kp, Ki, Kd are proportional, integral, and differential gains, V (n) is the actual lift arm speed, RV (n) is the target speed, and EV (n
), dEV (n).

d2EV(n) is written as below.

(n indicates time step.) EV (n)=V (n)-RV (n)dEV (n
)=EV (n)-EV (n-1)d 2EV (n
) = dEV (n) - dEV (n -1) The high-speed response valve (15) is configured to receive the current value from the PID control unit (17), calculate the solenoid force, and calculate the valve speed. It is being done.

Next, in the analysis section (2), the hydraulic pressure related circuit diagram (5
), a method for automatically generating the comprehensive model equation (E1) of the entire circuit itself will be explained. In this application, a unique technique is adopted for this automatic generation method. That is, this is the comprehensive model formula automatic generation means (20) in the present application.

FIG. 5 shows the processing flow of the integrated model formula automatic generation means (20), and will be explained based on this figure. This includes element ordering means (21) and node ordering means (
22), degree-of-freedom ordering means (23), and all of these are configured to calculate each element, each node, and overall model equation (E1) for the entire specific fluid-related circuit diagram (5) that has been created. It can be said that it is a processing means for making the independent variables in the table identifiable by serial numbers. Here, a node is a connection point between each element.

The function of each means (21), (22), and (23) will be explained below. First, each element is ordered by the element ordering means (21). This ordering is performed in the order of input by CAD (approximately in accordance with the order of the flow paths of the hydraulic circuit) from the main elements to each pipe line as shown below. An example of this is shown below.

Element: 1 Motor (engine) Element: 2 Gear pump element: 3 T-type 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 Then, the node ordering means (22) orders the nodes as connection points of each element, and at the same time, the node correspondence table (T1) shown in FIG.
) is created. This node correspondence table (T1) shows the main symbol (t
1), a sub-symbol (t2) as an element connected to the main element, and the corresponding boat name (t3.t4) in these elements are made to correspond to the node number (t5). . At this stage,
The boat names (t3) (t4) of each element are displayed depending on each element. That is, for example, the inlet of an element is designated as 1 in every element, and the exit is similarly designated as 2.

Furthermore, in the present application, after the creation of the node correspondence table (TI), the degree of freedom ordering means (23) generates the degree of freedom correspondence table (T2), and then the comprehensive model equation (E1) is automatically generated. . This method will be explained below. In this application, the model formula (e 1
) are classified into state variables, external variables, intrinsic constants, calculation constants, etc. Here, the state variable is a physical quantity that the element has at each calculation step (state), and the external variable is a state variable passed from an element connected to this element. Here, of course, at the stage when this model formula (e1) is called and when the processing using this model formula (e1) is finished,
The state variables described above differ by the amount of arithmetic processing they have undergone. Furthermore, the above inherent constants and calculation constants are for each model formula (e1
) is a constant used in processing. In this application, the argument group of this model formula (e1) is described and arranged in a unique configuration. That is, each argument is expressed by one character indicating the type of variable, the boat name (up to 4 characters) of each model connected via - underscores, and the argument in each model formula (e1). , classified into state variables and external variables according to the above classification,
These are arranged in order as a state variable group and an external variable group as a subroutine argument group. An example of this is shown below.

MOTOR(W MCl state variable)! External variable heated PUMP (P 1. P 2 + state variable Q
l, Q 2. WMC)! external variable TE
E(P 1.P 2.P 3! State variable 0 1,
Q2. Q3)! External variable DENJI
(P P, P C, ·! State variable D D)! External variable REL
IEF (X RF, V RF, P IF5.P
3. l state variables Ql, Q2)
! External variable TANK (P 1)
! State variable PIPE (Q 1.Q 2.
P LPl, P2) Examples of a motor (engine), pump, T-type joint, high-speed response valve, relief valve, tank, and vibrator are shown here. Taking a motor (engine) as an example, (
W MC) indicates that the type of variable is W; it indicates angular velocity and is a variable of the MC port. After passing through such a preparatory stage, the degrees of freedom ordering means (23) converts the overall model equation (E1) using the unified variable (Y) with degrees of freedom as parameters according to the circuit diagram (5). An overall model equation (E1) is created while defining the independent variables. In this process, the above-mentioned degrees of freedom apply only to the ordered elements in the overall model equation (E1), and in the argument section of the model equation (e1) corresponding to this element, only the state variables (external variables , are not considered at first.) are determined in the order of their description. An example of this case is shown below in program form. Here, the program is created in a format that calls the model formula (e I) to the ordered elements, so
The CALL statements are written in this order.

CALL MOTOR(Y (1)> as state variable C
ALL PUMP (Y (2)Y (40).

Y (1)') CALL Y(6) TEE (Y (4).

! No external variables Y(3) ! state variable Y (43).

l external variable Y (5).

! State variables Y (44), Y (46) Y (49) ) l External variables CALL DENJI (Y (7), Y (8),
・! State variables Y (61), Y (62)) l External variables CALL RERIEF (Y (26), Y (27),
... Y (50), Y (52)) CALL TANK (Y (31)) CALL
PIPE (Y (40), Y (41) Y (42) Y (2), Y (31)) Here, first, the argument of (W MC), which is the state variable of the motor (engine), or the degree of freedom l A unified variable (Y
(1)).

In the case of this motor (engine), there are no external variables, so no further operations are performed.

Next, regarding the pump, its state variables are (P-1,
P-2) is replaced by unified variables (Y(2), Y(3)). Here, external variables (Q-1, Q2, Q
-3) cannot be replaced by a unified variable because it is not yet related to processing.

Since the external variable of the pump (W MC) is the state variable of the motor (engine) that has the same description format and is connected at node 1, this substitution is performed (Y(1)).
It will be replaced as. For example, (Y (2)), which appears for the first time in a pump, is a pipe (Y (2)) that appears at the end of the program in elements due to the node relationship.
P I PE) is replaced with an external variable (P 1). Such operations are performed throughout the entire circuit.

The above-mentioned operations have been explained on a FORTRAN basis for ease of explanation.Before such replacement operations, a table (T2), which the inventor calls a degree-of-freedom correspondence table, is created in the present application. This degree of freedom correspondence table (T2) is the unified variable (Y)
Types of variables (t
l 1) Element number (t
12) and port salt (t13), corresponding node number (
t I 4), an element number (t 15) identified as an external variable, and a port salt (t 16) as a comparison table. As can be easily understood from this table (T2), the overall model equation (E1) is described here as a unified variable with degrees of freedom as parameters based on the specific circuit system to be considered, and a unified It is now possible to process it.

Here, the initial value of the circuit is input at a predetermined step as one aspect of the above-mentioned condition system.

In this system, the overall model equation (E1) formed as described above is solved by the Runge, Footer, Gill method, etc. while following the time steps.

Below, a simulation result of a hydraulic circuit related to lifting and lowering a working device using the three-point link (11) described above will be explained. That is, the calculation results obtained by the analysis section (2) are output to a printer or illustrated in a post-processing section (3). Here, since printer output is a common output format, its explanation will be omitted. Figures 8(a) and 8(b) show the results of the graphical output. Here, in each drawing, the horizontal axis is time, and the vertical axis in Figure 8 (a) is pressure (left scale kgf/cm") and position (
Height) (right scale cm) is shown in Figure 8 (
In (b), the flow rate (left scale 1/m1n) and rotation speed (right scale rpm) are shown. The graphs of this output example in each drawing will be explained one by one. In Fig. 8 (a), the pump discharge pressure is indicated by a solid line (-), the cylinder internal pressure is indicated by a dashed line (--1--), and the height of the lower link is indicated by a long-dashed line (-1--→, The fast-response valve discharge pressure is shown as a single broken line.

On the other hand, in Figure 8 (b), the pump rotation speed is indicated by the solid line (□
), the cylinder displacement is the long dashed line (----), and the first control current (II) is the dotted line (...
. . . -), and the second control current (■2) is indicated by a dashed-dotted line (-.--.-m-.-.). In lifting and lowering the working device in this embodiment, the problem is how to control the device in a short time and without overshooting or hunting. In FIG. 8, o.

It shows the upward movement (UP) from 2.0 (sec) to 2.0 (sec). 0 to 3.0 (see)
Up to this point indicates the downward stroke (Down). moreover,
This upward stroke (UP) is divided into a first upward stroke (UPI) in which the work equipment is sufficiently far away from the target position and the first control current (If) is always on, and a first upward stroke (UPI) in which the working device is sufficiently far away from the target position and the first control current (If) is always on. 11) is approximately established from the second upward stroke (UP2), which is intermittently operated on and off. Furthermore, the downward stroke (Down) also has this configuration (Do
wn 1) (Down 2). In this first upward or downward stroke (UP I) (Down 1), the control current (II) ([2) is kept at a constant value, and the pressure, flow rate, etc. pulsate in a long period. . On the other hand, in the second ascending or descending stroke (UP2) (Down2), the high-speed response valve (15) is controlled intermittently by the P[) control section (II), and the pressure, flow rate, etc. change greatly, and the cylinder displacement and lower The link height smoothly approaches the target value (SPI) (SF3) (LRI) (LR2). This is because FIGS. 8(a) and 8(b) show operation diagrams when each element, PID control conditions, etc. are set to ideal conditions.

To compare with this example, an example in which the control conditions (proportional and integral gain) are changed in PID control is shown in Figure 9 (
b) Shown in (b).

In this case, in the second upward stroke (UP2) described above, intense vibrations occur in the pump and cylinder internal pressure, and a hunting portion (P) occurs in the cylinder displacement itself.

[Another example]

In the above embodiment, an engine and a three-point linkage mechanism have been described as mechanical elements, but as long as they respond in a typical manner to an input system of predetermined physical quantities,
These may be of any kind. The same thing can also be said about electrical elements.

Further, in the above example, the PID control method is used as the control means, but other control methods such as fuzzy control may be adopted.

In the above embodiment, for this target circuit, the PI
We have explained how the response of the system changes when the D control conditions are changed, but when designing such hydraulic circuits,
Its hard aspects (hydraulic elements, mechanical elements,
Changing the dynamic characteristics of (and electrical system elements) (changing the equipment used) is a hot topic, and changing the circuit configuration by adding or removing new hydraulic elements, etc. It is possible to consider the dynamic characteristics of the hydraulic circuits mentioned above.

Furthermore, in the analysis section, the degree of freedom correspondence table (T2) of this application
The overall model formula for the hydraulic related circuit (E
When solving 1), it is possible to use methods other than the Runge, Hutter, and Gill methods.

Incidentally, although reference numerals are written in the claims section for convenient comparison with the drawings, the present invention is not limited to the structure shown in the accompanying drawings by the reference numerals.

[Brief explanation of the drawing]

The drawings show an embodiment according to the present invention, FIG. 1 is a diagram showing the main configuration of the fluid-related circuit development support system, FIG. 2 is a diagram showing the flow of processing in each main part, and FIG. 3 is a diagram showing the support system of the present invention. Figure 4 is a diagram of the hardware system of one of the systems under consideration.
Figure 5 is a diagram showing the processing flow of the integrated model formula automatic generation means, Figure 6 is a diagram of the node correspondence table, and Figure 7 is the diagram of the degree of freedom correspondence table. Figure 8 is a diagram of the output in the optimal operating state of the system under consideration shown in Figure 3, and Figure 9 is a diagram of the output when the condition settings of the system under consideration shown in Figure 3 are inappropriate. be. (1)...Preprocessing section, (2)...Analysis section, (3)...
...Post-processing section, (4)...Library section, (5)-
... Fluid-related circuit diagram, (TI) ... Node correspondence table, (
T2)... Degrees of freedom correspondence table.

Claims (1)

[Claims] 1. Symbol diagrams corresponding to various elements as fluid-related equipment, relationships between inputs to the elements, and state quantities of the elements as outputs from the elements are represented by model formulas (e1). The library section registered in the format (4
), and a preprocessing unit (5) that combines the symbol diagrams to create a fluid-related circuit diagram (5) in order to obtain a desired fluid-related operation.
1) and the fluid-related circuit diagram (5), a model formula (e
1), automatically generates an overall model equation (E1) corresponding to the entire fluid-related circuit, and solves the overall model equation (E1) according to input conditions; The obtained comprehensive model equation (E
1); and a fluid-related circuit development support system comprising: a post-processing section (3) that outputs a solution of step 1); A fluid-related circuit development support system in which symbol diagrams and model formulas are registered. 2. The fluid-related circuit development support system according to claim 1, wherein the control element obtains an output from another element incorporated in the fluid-related circuit, and outputs a control command in response to this output.