JPH0490003A - Optimum controller - Google Patents

Abstract

PURPOSE:To output a manipulated variable, which reduces the operation cost, as an optimum controlled variable by using a superspace curved surface to obtain the operation cost in the overall aspect in consideration of operation states of individual controlled systems. CONSTITUTION:A superspace curved surface supposing means 15 supposes a curved surface formed on a superspace by relations between the manipulated variable and the operation cost. A two-dimensional curve generating means 16 estimates the position on the superspace curved surface in which the manipulated variable obtained by a quasi-optimum controller 14, namely a manipulated variable (c) from a restrictive condition confirming means 13 is placed. The means 16 projects the superspace curved surface supposed by the superspace curved surface supposing means 15 on the two-dimensional curve obtained by one manipulated variable and the operation cost based on the point on the superspace curved surface where the manipulated variable (c) is placed, and the manipulated variable to minimize the operation cost is obtained on this two-dimensional curve. Thus, the manipulated variable to reduce the operation cost is outputted as the optimum controlled variable even if individual controlled systems are inexpensively kept in the status quo.

Description

[Detailed Description of the Invention] [Industrial Fields of Application] The present invention is applicable to the optimal operation control of thermal power plants under fuel conditions, and is also intended to reduce operating costs such as nuclear power plant operation control and steel manufacturing machine operation control. This invention relates to an optimal control device used in general control systems.

[Prior Art] The configuration of a conventional optimal control device is shown in FIG. The conventional optimal control device includes a manipulated variable update direction determining means 21, a control updating means 22, a constraint checking means 23, and an optimality checking means 2.
The device operation amount update direction determining means 21 consisting of
The operating cost when the operation amount is changed by a minute amount in the "10" direction (increase direction) or the "-" direction (decrease direction) is determined, and the direction in which the operation cost becomes cheaper is determined as the update direction A. Control update means 2
2 determines the operating cost when the manipulated variable is updated by a preset amount in the update direction A determined by the manipulated variable update direction determining means 21, and compares the operating cost with the operating cost of the current manipulated variable. Then, the amount of operation is updated only when the price becomes cheaper.

The constraint checking means 23 determines whether the manipulated variable B updated by the control updating means 22 satisfies the constraint.

The optimality checking means 24 obtains the operation amount C that satisfies the constraint from the control updating means 22, judges whether the operation ff1C and the operation direction (hereinafter referred to as the operation state) are the same as the current one, and determines whether the operation ff1C and the operation direction (hereinafter referred to as the operation state) are the same. If there is, the operating state at that time is output to the controlled object as the optimal control ff1D, and if they are not the same, the process is repeated again. That is, when the manipulated variable is updated, the process for updating the operating state is performed again. On the other hand, if there is no new update, the previous operation state will be the same as the previous operation state, so the previous operation state will be output as the optimal control ff1D.

[Problems to be Solved by the Invention] Incidentally, the i-suitable control device updates the operating states of a plurality of control objects, and outputs the respective optimum control amount for each control object. Here, in the conventional optimal control device, the update by the control update means 22 is not performed, and as a result,
When there are a plurality of control targets whose operating states output as the optimum control measure are the same as the current one, there is a problem in that the operating costs are not reduced, resulting in an economic disadvantage.

That is, even if it is cheaper to maintain the status quo for each controlled object, there is still room for the cost to become cheaper when the controlled objects are considered comprehensively. However, it has not been possible to further reduce the cost using conventional optimal control devices.

The present invention has been made in view of the above points, and is an economical optimal control device that can output a manipulated variable that lowers operating costs as an optimal controlled variable even when maintaining the status quo for each controlled object is cheap. The purpose is to provide

[Means for Solving the Problems] The optimal control device according to the present invention includes: an update direction determining means for determining an update direction in which operation costs are lowered by increasing or decreasing the amount of operation; and this update direction determining means. In an optimal control device comprising: a control update means for updating the manipulated variable in the update direction determined by the control update means; and a constraint condition checking means for determining whether the manipulated variable updated by the control update means satisfies a constraint condition. , a hyperspace surface estimation means that captures the relationship between the operation amount as an input variable and the operating cost as an output variable as a hyperspace surface, and the hyperspace surface assumed by this hyperspace surface estimation means as one operation amount and operating cost. two-dimensional curve creation means for projecting onto a two-dimensional curve consisting of;
A re-optimization device that calculates an operation amount that makes the operation cost cheaper than the operation amount obtained from the constraint condition confirmation device based on the two-dimensional curve obtained by the two-dimensional curve creation means, and an operation performed by this re-optimization device. an optimality checking means for determining whether or not the amount has been updated, and returning the manipulated variable to the update direction determining means if it has been updated; and outputting the manipulated variable as an optimal control amount if the amount has not been updated; It is equipped with the following.

[Operation] According to the above configuration, it is possible to determine where on the hyperspace curved surface the manipulated variable obtained from the constraint condition confirmation means, that is, the manipulated variable obtained by the conventional optimal control device is located. Then, using the point on the hyperspace curved surface where the manipulated variable is located as a reference, 1
A two-dimensional curve consisting of the two manipulated variables and operating costs is created, and the manipulated variable that minimizes the operating cost is determined on the two-dimensional curve. As a result, operating costs can be determined from a comprehensive perspective by considering the operating status of each controlled object, and even if it is cheaper to maintain the status quo for each controlled object, the optimal control amount is the amount of operation that lowers operating costs. is output as

[Embodiment] An optimal control device according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing its configuration. This optimal control device includes a quasi-optimal control device 14, a hyperspace curved surface estimation means 1
5. Consists of two-dimensional curve creation means 16, re-optimization device 17 and optimality confirmation means 18. The semi-optimal control device 14 is
It consists of a manipulated variable update direction determining means 11, a control updating means 12, and a constraint condition checking means 13, which corresponds to a conventional optimal control device (see FIG. 3). That is, the operation amount update direction determining means 11 calculates the operating cost when the operation amount is changed by a minute amount in the "+" direction (increase direction) or the "-" direction (decrease direction), and updates the direction in which it becomes cheaper. Determine direction a. The control update means 12 calculates the operating cost when the manipulated variable is updated by a preset amount in the update direction a determined by the manipulated variable update direction determining means 11, and calculates the operating cost and the operating cost of the current manipulated variable. The amount of operation is updated only when the price becomes cheaper. The constraint checking means 13 determines whether the operation zb updated by the control updating means 12 satisfies the constraint.

On the other hand, the hyperspace curved surface estimation means 15 captures the relationship between the manipulated variable as an input variable and the operating cost as an output variable as a hyperspace curved surface d. The two-dimensional curve creation means 16 projects the hyperspace curved surface d assumed by the hyperspace curved surface estimation means 15 onto a two-dimensional curve e consisting of one operation amount and operating cost. The re-optimization device 17 calculates the operation ff obtained from the output of the semi-optimal control device 14, that is, the constraint condition confirmation device 13, based on the two-dimensional curve e obtained by the two-dimensional curve creation device 16.
Find the operation Qf that makes the operating cost cheaper than 1c. The optimality checking means 18 determines whether the manipulated variable has been updated by the re-optimization device, and if it has been updated, the manipulated variable is transmitted to the manipulated variable update direction determining means 11, that is, the sub-optimal control device 14.
If it is not updated, the manipulated variable is output to the controlled object as optimal control ff1g.

Next, the operation of this embodiment will be explained.

In this embodiment, a conventional optimal control device is used as the quasi-optimal control device 14. First, the hyperspace curved surface estimation means] 5 assumes what kind of curved surface the relationship between the operation amount and the operating cost constitutes on the hyperspace. Here, a five-dimensional hyperspace curved surface is assumed. Next, the two-dimensional curve creation means 16 estimates where on the hyperspace curved surface the manipulated variable obtained by the quasi-optimal control device 14, that is, the manipulated variable c from the constraint condition confirming means]3 is located. Then, the two-dimensional curve creation means 16 uses the point on the hyperspace curved surface where the manipulated variable C is located as a reference, and the hyperspace curved surface estimation means 15
The hyperspace surface assumed by is projected onto a two-dimensional curve consisting of one operation amount and operating cost.

Here, FIG. 2 shows a two-dimensional curve created by the two-dimensional curve creation means 16 on the five-dimensional hyperspace curved surface using the output of the quasi-optimal control device 14 as a reference.

In FIG. 2, (A) in the figure shows the manipulated variable output from the quasi-optimal control device 14. Moreover, (b) shows the manipulated variable updated by the re-optimization device 17. Re-optimization device 1
7 determines the amount of operation that minimizes the operating cost on this two-dimensional curve. That is, in FIG.
Find the amount of operation (b) that makes the operating cost cheaper.

The optimality checking means 18 determines whether the manipulated variable has been updated by the re-optimization device 17.

When updated, the re-optimization device 17 returns the manipulated variable to the semi-optimal control device 14 (operated variable update direction determining means 11). On the other hand, if it has not been updated, the re-optimization device 17 outputs the manipulated variable as the optimum control mg to the controlled object. That is, when the manipulated variable is updated, the process for updating the operating state is performed again. On the other hand, if there is no new update, the previous operation state will be the same as the previous operation state, so the previous operation state will be output as the optimal control ff1g.

In this way, by using the hyperspace curved surface, operating costs can be determined from a comprehensive perspective by considering the operating states of individual controlled objects. Note that the use of this hyperspace curved surface will be specifically explained. For example, if we assume that there are four types of objects to be controlled, we will add operating costs to these to form a five-dimensional hyperspace surface. Then, three of the operating states (outputs from the sub-optimal control device) for these four types of control objects are fixed, and the remaining operating state and operating cost are projected into two dimensions (Figure 2), and the Get cheap operating conditions.

[Effects of the Invention] As described above, according to the present invention, by using a hyperspace curved surface, operating costs can be determined from a comprehensive perspective by considering the operating states of individual controlled objects. therefore,
Even if it is cheap to maintain the status quo for each controlled object, a manipulated variable that lowers operating costs can be output as an optimal controlled variable, and economic effects can be increased.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an optimal control device according to an embodiment of the present invention, FIG. 2 is a diagram showing a two-dimensional curve created by the two-dimensional curve creation means of the same embodiment, and FIG. FIG. 1 is a block diagram showing the configuration of a conventional optimal control device. DESCRIPTION OF SYMBOLS 11... Operation amount update direction determination means, 12... Control update means, 13... Constraint condition confirmation means, 14... Quasi-optimal control device, 15... Hyperspace curved surface estimation means, 16...
- Two-dimensional curve creation means, 17... Re-optimization device, 18
...Optimality confirmation means, a...Update direction, b...Operation amount, C...Operation amount, d...Hyperspace curved surface, e...
Two-dimensional curve, f...manipulated amount, g...optimum control amount.

Claims (1)

[Scope of Claims] Update direction determining means for determining an update direction in which operating costs are lowered by increasing or decreasing the manipulated variable; and updating the manipulated variable in the update direction determined by the update direction determining means. In an optimal control device comprising a control updating means and a constraint checking means for determining whether the manipulated variable updated by the control updating means satisfies a constraint condition, the manipulated variable is used as an input variable and the operating cost is output. A hyperspace surface imagining means that captures relationships as variables as a hyperspace surface, and a two-dimensional curve creation that projects the hyperspace surface assumed by this hyperspace surface imagining means onto a two-dimensional curve consisting of one operation amount and operating cost. and a re-optimization device that calculates a manipulated variable that makes operating costs cheaper than the manipulated variable obtained from the constraint condition checking means, based on the two-dimensional curve obtained by the two-dimensional curve creating means, and this re-optimization. Optimality of determining whether the manipulated variable has been updated by the device, returning the manipulated variable to the update direction determining means if it has been updated, and outputting the manipulated variable as the optimal control variable if it has not been updated. An optimal control device characterized by comprising a confirmation means.