JPH024497A - Controlling device for methane producing equipment - Google Patents

Abstract

PURPOSE:To enable extremely accurate operating control by extracting the characteristics of a methane producing equipment by collation with a standard analogous type and comparing them with the knowledge data of a knowledge base to infer them and deciding a necessary operating controlling method. CONSTITUTION:In a controlling device 1, the process signal of a methane producing equipment 6 which is inputted from an input terminal 7 is stored time sequentially in a data storage part 2 and a time element is erased in an analysis part 2 while considering response time and the range of registration claim and the relation of the mutual input-output signals is calculated and the characteristics of the methane producing equipment 6 are extracted by collation with a standard analogous type. Then the obtained characteristics are compared with the knowledge data of a knowledge base 4 and inferred in an inference part 5 and a necessary operating controlling method is decided and indicated on an indicator 9 and also operation of the equipment 6 is controlled via an interface part 8 and an output terminal 10. By such a way, extremely accurate operating control can be performed.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a control device for a methane production device that anaerobically treats organic wastewater, and particularly relates to a control device for controlling time-series data of two or more types of signals. The present invention relates to a control device for a methane production device that can understand the operating state of the methane production device by analyzing interrelationships and instruct necessary operation management methods.

(Conventional technology) Anaerobically treating sewage and industrial wastewater and producing methane gas, which has high utility value as fuel, through methane fermentation is a promising method that is expected to reduce treatment costs and reduce the amount of sludge generated. It is a great technology.

In the methane fermentation that takes place, the methane bacteria that control this fermentation are highly anaerobic and therefore dislike air contamination, and the gas generated is flammable, so the entire device must be a closed system. Must be.

Therefore, it is very difficult to monitor the fermentation status compared to conventional aerobic and facultative devices.

Therefore, conventional methods have been used to detect the flow rate and organic matter concentration of wastewater flowing into the methane production equipment, the amount and composition of gas generated, and the quality of the water flowing out from the processing switch. Mathematical models have been used to analyze the state of biochemical reactions.

(Problem to be solved by the invention) However, the biochemical reactions that can be calculated using mathematical models are extremely limited, and the types of water quality factors that can be detected are also limited, such as pH and ORP. Its reliability as a process measuring instrument is considerably lower than that for aerobic processing, and the control accuracy of the control system using a mathematical model is also extremely low, making it almost impossible to put it into practical use.

For this reason, the operational management of methane production equipment has traditionally been left to management methods based on the operator's long experience, rather than the control systems described above, and manual operation has therefore been the main method. The appearance of a control device for a certain methane production facility was desired.

By the way, a reliable signal that can be obtained from a methane production device is a signal related to flow rate rather than a signal related to water quality, and among flow rate signals, the inflow flow rate of wastewater such as sewage and wastewater (hereinafter referred to as inflow amount) and the gas outflow R
(hereinafter referred to as gas flow rate) is a signal that can be easily and stably obtained for a long period of time.

Therefore, the inventor focused on a control system that uses these stably obtained flow rate signals of a methane production apparatus as an input signal, and attempted to develop it.

- Numerically speaking, the relationship between the inflow amount and the gas flow rate is an important monitoring item in the current manual management method for methane production equipment. In other words, the operators of methane production equipment (experts) have accumulated norms relating to each other regarding the characteristics of the inflow amount and the response characteristics of the gas flow rate through experience, and operate in accordance with these norms on a daily basis. is in charge of operational management.

However, the standards that experts adhere to often differ from person to person, and the terminology used may not be the same. Therefore, although conventional manual operation management is practical, it is not systematic, and although it is specialized, it lacks objectivity.

Furthermore, there was the problem that the judgment varied depending on the type of methane production equipment, the scale of the equipment, and the characteristics of the wastewater.

This invention was made in view of the problems of the conventional control device for methane production equipment, and it provides reliable and important signals in the conventional empirical management method of inflow amount and gas flow rate. Utilizing time-series data of The purpose of the present invention is to provide a control device for a methane production device that can find an optimal operation management method by comparing the following.

[Structure of the Invention] <Means for Solving the Problems] The present invention provides a control device for a methane production device that anaerobically processes organic wastewater such as urban sewage or industrial wastewater and recovers it as methane gas. a data storage unit that stores time series data of a plurality of signals including both signals related to fluid flowing into the fluid and signals related to fluid flowing out;
an analysis unit that deletes time elements from time-series data of a plurality of signals stored in the data storage unit to find mutual relationships, and extracts characteristics of the process including response delay time by comparison with a standard form of the response; a knowledge base that determines a causal relationship between characteristics of the interrelationships of the plurality of signals and an operation management method for the methane production equipment; and an inference unit that determines an operation management method based on the analysis results of the analysis unit and the knowledge base. It is equipped with the following.

(Function) In general, when input/output time-series signals of a process such as a methane production device are used in a control system that uses the experiential knowledge of experts, the time-series signal data is often processed using various methods. Characteristics are analyzed and the results of the analysis are translated into knowledge about the processes in the control system.

Therefore, in the control device for a methane production device of the present invention, the response delay time between the signal related to the fluid flowing into the methane production device and the signal related to the fluid flowing out from the methane production device is taken into account, and these inputs are controlled. The interrelationships between the output signals are determined, and the operating characteristics of the actual methane production equipment are extracted by comparing the interrelationships between the input and output signals with standard types, and the necessary operation management methods are determined based on the empirical knowledge data of experts. By finding out through comparison, we can realize I & appropriate operation management.

That is, time series data X(t) of input/output signals.

Y(t) is the time difference time series data statement (1) using the following formula, ?
It is converted to (1).

Sentence (t)=X(t)-X(t-1)...(1) Room (
t ) = Y (t) - Y (t-1)
... (2) Here, t, t-i, ... are sampling times.

Next, time series data X(t) of two types of process signals,
The correlation between Y (t) and the correlation between the first-order time difference time series data can be determined by eliminating the time element, which is a common variable for both, while taking into account the actual time delay τ between the input and output signals. Desired.

And this is on the <x, y) coordinates (X(t-τ),
It can be expressed as a figure obtained by plotting Y(t)); (sentence (t-τ), chamber (t)).

The properties of these figures reflect the response state of the process and are directly related to the operating method.

Therefore, by extracting features from the figure that also takes into account the time delay τ between input and output signals, and comparing it with the knowledge base obtained from the experiential knowledge of experts, it is possible to understand the operating status of the process, and also to understand the necessary information. Operation management methods can be automatically found.

(Example) Hereinafter, embodiments of the present invention will be explained in detail based on the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention,
The control device 1 includes a data storage section 2, an analysis section 3, a knowledge base 4, and an inference section 5.

A data input terminal 7 from the methane production device 6 supplies data to the data storage section 2. Further, the output of the inference section 5 is sent to the display device 9 via the interface section 8.
At the same time, the operating output t41 of the methane production device 6 is connected to
Connected to 0.

FIG. 2 shows a detailed internal configuration of the analysis section 3, which includes a diagramming circuit 11 and a diagramming circuit 1 as described later.
an attribute value calculation circuit 12 that calculates attribute values of the methane production device 6 corresponding to various response delay times from the diagram information obtained in step 1; It is comprised of a standard type selection circuit 13 that compares the attribute value with a standard type stored in advance, determines the delay time, and extracts a feature list.

The operation of the control device for the methane production apparatus having the above configuration will be described next.

The control device 1 takes in an inflow amount signal of waste water flowing into the methane production bag N6 from the methane production device 6 via the input @7 and a discharge amount signal of methane gas generated within the methane production device 6, and stores the signal in the data storage section. 2 as time series data of the methane production device 6.

Next, in the analysis section 3, a feature list representing the characteristics of the interrelationship between the input and output signals for the methane production device 6 is generated from the time-series data in accordance with the procedure described later.

This feature list is sent to the knowledge base 4 and modifies the knowledge data stored in the knowledge base 4.

This modified knowledge data in the knowledge base 4 is referred to by the inference unit 5 and subjected to symbolic processing to determine an appropriate operation management method for controlling the methane production device 6.

The details of the operation management method determined by the inference section 5 are provided as an output of the control device 1 to the display 9 and the operation output @10 via the interface section 8.

Through such inference operations, the optimal operation management method is automatically determined based on the time-series data taken into the control device 1. This will be explained in more detail based on the flowchart shown in FIG.

In the analysis section 3 of FIG. 2, at least two types of process signals stored in the data storage section 2 shown in FIG.
That is, the time series data (X (t), Y (t)) of the amount of inflow of waste water and the amount of discharge of methane gas is read and input to the diagramming circuit 11.

The diagramming circuit 11 calculates the time difference between two types of time series data according to the following equation to obtain first-order time difference time series data (X (t) , Y (t) ) (step S
1).

X(t)=X(t)-X(t-1>...(3)Y(
t)-Y(t)-Y(t-1)... (4) Next, normalization calculations for these process signals and first-order time difference signals are performed according to the following equations (step S2).

Process No. Formula % Formula %) 1 time difference Formula sentence (1) - Sentence 7 Large (1) ... (7) Sentence (t) = ... (8) σ sentence Here, σX, σy; σ , the σ statement is the standard deviation, XT
YT, Sentence 7. Room 7 is time series data X(t).

Y(t); sentence(t),? This is the average value during period T in (1).

Furthermore, the normalized process signal (x, y) and its first-order time difference signal (large, 9) have a response time delay τ (τ
(are varied in various ways), on the <x, y) coordinates (
x (t-τ), y(t)); (large (t-τ) 1 sentence (t
)) respectively in Figure 3(a).
, (b), it is expressed as a diagram showing the interrelationships with time elements removed (step 33). The time series data diagram in FIG. 3 uses a signal every hour for 24 hours as the period T.

The diagram obtained in this way is then transmitted to the attribute value calculation circuit 12.

The attribute value calculation circuit 12 creates a temporary feature list for each delay time by varying the delay time τ (step S4).

This temporal feature list is then transmitted to the standard form selection circuit 13, where it is compared with a pre-stored feature list of standard types, and the most similar standard type is selected (steps S5, 36>).

An example of the obtained feature list is shown in FIG.

The feature list generated in this way represents the features of the methane production device 6 during the period T as a set of pairs of attributes and attribute values, and is used in the inference unit 5 as an attribute list, that is, a set of (attributes, attribute values). It is compared with the knowledge data of the knowledge base 4 by inference calculation, and the methane production equipment 6
It is used to determine the operation management method.

Note that the knowledge base 4 stores knowledge data that predetermines the relationship between the above attribute list in the feature list of FIG. 5 and the operation management index.

The operation management index of the methane production device 6 determined by the inference of the inference unit 5 is output from the control device 1, and is based on the content of the decision in the inference unit 5, the knowledge data in the knowledge base 4 used for the inference, and the inference. The route etc. are displayed on the display unit 9 to notify the operator, and the contents of the determined operation management index are transmitted to the operation output terminal 10 of the methane production device 6.

Here, an example of a rule for determining an operation management method by inference operation based on a comparison between the attribute list of the feature list and the knowledge data in the knowledge base 4 is as follows.

RULE IGATBI: P (standard deviation ≧ level (5)), and (rotation angle xy = level (-1)), and (!! alternative form = standard form (2)), and (delay time = level (16 )) HEN (water intake game) = +20%) In other words, the standard deviation of the organic wastewater inflow i In this case, the slope of the triangle) is (-1) of the pre-truncated series, and the selected form is the standard form (2), and the delay time of the standard form (2) is long and the level (+6 ), the water intake gate will be increased by +20%.
An operational management method that requires increasing organic wastewater inflow to reduce the amount of inflow becomes a candidate during the reasoning process, and along with the other candidates, is considered a likely determining factor.

In this way, at least two types of process signals including the inflow amount signal of wastewater to the methane production device 6 and the outflow amount signal of methane gas generated in the methane production device 6 are processed while taking into account the response time delay. The correlation is determined by erasing the time element, and the correlation is determined by erasing the time element while considering the response time delay for the first-order time difference value, and from these, the pattern with the standard type stored in advance is determined. Perform matching and extract feature list.

Then, by comparing the obtained feature list with the expert's empirical knowledge data stored in the knowledge base 4 and instructing the necessary operation management method of the methane production equipment 6, it is possible to make an accurate judgment close to the expert's judgment. Operation management can be performed automatically.

In addition, in the above example, the correlation is calculated for two types of wastewater inflow and methane gas outflow, but for three or more types of process signals, their time factors are calculated while taking into account response time delays. Of course, this can be done by deleting the information, finding mutual relationships, creating a feature list, and determining the operation management method.

[Effects of the Invention] As described above, according to the present invention, the relationship between input and output signals can be determined by eliminating time elements from time-series data of process signals of a methane production device while taking into account the response time and the scope of registered claims. Ask for F! The characteristics of the methane production equipment are extracted by comparing them with the A quasi-type, and the obtained characteristics are compared with the knowledge data of the knowledge base to make inferences and determine the necessary operation management method. ) can be automatically executed, which is similar to the judgment based on experience, and extremely accurate operation management can be performed.

Furthermore, regarding the first-order time difference signal of the process signal of the methane production equipment, the time element is removed while taking into account the response time delay, and the correlation between the input and output signals is determined.
If the characteristics of the methane production equipment are extracted by comparing with the type, the obtained characteristics are compared with the knowledge data of the knowledge base, and the optimal operation management method is determined, the operating status of the methane production equipment can be determined. Operation management can be performed with good followability even when there are large changes in

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an embodiment of the present invention, Fig. 2 is a block diagram showing the detailed configuration of the analysis section in the above embodiment, and Figs. FIG. 4 is a flowchart explaining the operation of the above-mentioned analysis section, and FIG. 5 is a structural diagram of an example of a feature list obtained by the above-mentioned analysis section. 1...Control device 2...Data storage unit 3...
- Analysis section 4...Knowledge storage section 5...Inference section 6...Methane production device 11...Diagram north circuit #I 12...Attribute value calculation circuit 13...Standard form selection circuit

Claims (3)

[Claims] (1) In a control device for a methane production equipment that performs anaerobic treatment on organic wastewater such as urban sewage or industrial wastewater and recovers it as methane gas, both a signal related to the fluid flowing into the methane production equipment and a signal related to the fluid flowing out of the methane production equipment are transmitted. a data storage unit that stores time-series data of a plurality of signals including the data storage unit; an analysis unit that extracts characteristics of the process including response delay time through comparison; a knowledge base that determines a causal relationship between the characteristics of the interrelationship of the plurality of signals and the operation management method of the methane production equipment; and an analysis of the analysis unit. A control device for a methane production device, comprising a reasoning section that determines an operation management method based on the results and the knowledge base. (2) The time-series data stored in the data storage unit includes an inflow amount signal of organic wastewater and an emission amount signal of methane gas generated in the methane production device.
A control device for the methane production device described above. (3) Claim 1 or 2, wherein the time-series data is a first-order time difference signal between a signal related to fluid flowing into the methane production device and a signal related to fluid flowing out from the methane production device. A control device for the methane production device described above.