JPH0644231B2 - Production system interrupt processing method - Google Patents

Description

The present invention relates to an interrupt processing system for a production system.

[Conventional technology]

As shown in FIG. 7, the production system is composed of a working memory, a production memory and an inference engine. A working memory element, which is data for inference, is stored in the working memory, and an IF-THEN format production rule is stored in the production memory. An example of working memory elements and an example of production rules are shown in FIG.

The inference engine compares the elements in the working memory with the conditional part of the production rule and finds a rule that satisfies the conditional part. Since there can be a plurality of rules that can be fired, conflicts are resolved (see, for example, Japanese Patent Laid-Open No. 61-109148), and the optimum rule is selected. Then, the execution part of the rule is executed. A flow chart of this inference engine is shown in FIG.

Since the execution unit of the fired rule changes the contents of the working memory, a new rule can be fired. In this way, a chain of rules occurs and inference proceeds. The inference engine repeats the matching-conflict resolution-execution cycle shown in FIG. 9 until a final conclusion is obtained.

During the inference period, data from outside the production system can be written only by writing an execution statement for external data input in the execution part of the rule. As a result, the external data can be input in the rule chain of inference only when the rule for inputting the external data is fired.

[Problems to be Solved by the Invention]

As described above, the conventional inference engine cannot accept data or signals from the outside unless the rule for inputting them fires. As a result, when data or a signal from the outside is generated, it is impossible to interruptly process the data or change the current inference. Inference can take a long time, and during this time, interrupt processing by external data cannot be accepted. This is a big problem when applying a production system to a real-time processing system. It is also difficult to correct the current reasoning process due to changes in external real-time data.

Incidentally, in Japanese Patent Laid-Open No. 63-47839, rules are hierarchized, and when a solution cannot be obtained, that is, due to internal factors,
Although the technology to activate other rule sets is disclosed,
Interrupt processing does not occur due to external factors.

An object of the present invention is to provide an inference engine unit with an interrupt detection function, and to add a function of interrupting inference by an asynchronous external data or signal or correcting an inference process.

[Means for Solving the Problems]

In order to detect an interrupt from the outside, an interrupt detection unit is added after the execution unit of the inference engine as shown in FIG. A flowchart of the interrupt detection unit is shown in FIG.

[Action]

The inference engine detects interrupts at the end of each match-conflict resolution-execute cycle. If the interrupt permission flag is TRUE, test the occurrence of an interrupt from the possible external input means of the system, and if an interrupt occurs, generate a working memory element for interrupt notification that is specified in advance. .
In the working memory element, information indicating the interrupt factor such as the name of the external input means that is generating the interrupt is written. At this time, the interrupt permission flag is set to FALSE so that the same interrupt is not detected again in the next inference cycle.

In the next inference cycle, the working memory element corresponding to the interrupt becomes the latest element, so the interrupt processing rule having this interrupt element in the condition part is selected and executed by conflict resolution. When this interrupt processing rule fires, the current inference is interrupted and the interrupt processing inference is started. When the interrupt processing is completed, the interrupt permission flag is set to TRUE in order to accept the next interrupt. Then, the inference interrupted by the interrupt is restarted. At this time, by changing the working memory element referenced by the restarted inference process in the interrupt processing rule, the restarted inference process can be corrected.

〔Example〕

As a specific embodiment of the present invention, an example of a production system for immediately displaying a message on an external terminal when data comes from the external terminal will be shown. This system is the fourth
As shown in the figure, it is connected to the terminal A through a communication port called comm1. The inference engine in the production system can input / output data from / to the terminal by accessing the comm1 communication port. A detailed flow chart of the interrupt detector in this example is shown in FIG.

In the interrupt detection unit, first, the interrupt permission flag is used to check that the current inference process is not in the process of interrupting. If interrupt processing is not in progress, c
Check if data is coming to the omm1 port. In this example, the data input to the comm1 port corresponds to the interrupt signal. If data comes to the comm1 port, it is assumed that an interrupt has occurred, and the corresponding working memory element (INTER) for notification of interrupts.
RUPT ^ TYPE COMM1). In this working memory element example, INTERRUPT is a class name indicating that it is an interrupt notification element, ^ TYPE is an attribute name indicating an interrupt factor, and COMM1 is a notification port name indicating an interrupt. It is an attribute value of TYPE. Finally, the interrupt permission flag is set to FALSE to indicate that the interrupt process is started.

When the working memory element for interrupt is generated, the interrupt processing rule corresponding to it is activated in the next inference cycle. FIG. 6 shows the interrupt processing rule in this embodiment. This rule defines the working memory element for interrupts (INTERRUPT ^∧ ty).
When pe COMM1) is generated, it immediately ignites
Read the data from the MM1 port and click "INTERRU
COMM the message "PT ACCEPTED"
Output to 1 port. On the terminal, the moment you enter the characters,
The above message is displayed. The interrupt processing rule erases the interrupt working memory element to indicate the end of the interrupt processing, and sets the interrupt permission flag to TRUE.

According to the interrupt processing rule of this embodiment, a message is simply displayed when an interrupt occurs, but the data is read from the external input means that generated the interrupt, and a working memory element indicating the contents of the data is generated. In this case, since the rule for matching the working memory element is fired next, it goes without saying that interrupt processing according to the content of data can be performed. Further, although only one interrupt source is handled in this embodiment, a plurality of interrupt sources can be easily dealt with by checking the presence or absence of each interrupt in the interrupt detection unit.

〔The invention's effect〕

As described above, according to the present invention in which the interrupt detection unit is added to the inference engine of the production system, the working memory element corresponding to the interrupt is generated, and the interrupt processing rule is fired, the external processing is performed during the inference. Interrupt allows you to start another inference process or modify the current inference process. In addition, the interrupt process itself has the advantage that it can be described by normal rules, which makes it easy to change or modify the interrupt process.

[Brief description of drawings]

FIG. 1 is a flow chart of an inference engine to which an interrupt detection unit of the present invention is added, FIG. 2 is a detailed flow chart of the interrupt detection unit, FIG. 3 is an example of an interrupt processing rule, and FIG. FIG. 5 is a flow chart of an interrupt detection unit in the embodiment, FIG. 6 is an interrupt processing rule of the embodiment, FIG. 7 is a configuration diagram of a production system, and FIG. 8 is a production rule. Example, No. 9
The figure is a flow chart showing the operation of a conventional inference engine. 1 ... Production system 2 ... Inference engine 3 ... Working memory 4 ... Production memory 5 ... Communication port 6 ... Terminal

Claims (1)

[Claims] 1. A working memory for storing data for inference, a production memory for storing production rules acting on the data, and a comparison between data in the working memory and rules in the production memory. In a production system consisting of an inference engine that executes a rule that can be fired, an internal interrupt detection mechanism is provided inside the inference engine, and an external interrupt is detected during an inference period based on the rule chain. ， Immediately after the execution of the rule at that point, a working
An interrupt processing method for a production system that activates rules for interrupt processing by generating memory elements.