Production system

• US 5,754,740 A
• Filed: 08/15/1995
• Issued: 05/19/1998
• Est. Priority Date: 11/11/1994
• Status: Expired due to Term

• Current Assignee: LD Technology LLC (Intellectual Ventures LLC)
• Original Assignee: Fujitsu Limited
• Inventors: Hikida, Satoshi, Fukuoka, Toshiyuki
• Primary Examiner(s): Downs, Robert W.
• Application Number:
  US08/518,393
• Time in Patent Office: 1,008 Days
• Field of Search: 395/68
• US Class Current: 706/58
• CPC Class Codes: G06F 3/011 Arrangements for interaction with the human body, e.g. for user immersion in virtual reality blind teaching G09B21/00
• CPC Class Codes: G06F 9/4401 Bootstrapping security arrangements therefor G06F21/57
• CPC Class Codes: G06N 3/006 based on simulated virtual individual or collective life forms, e.g. social simulations or particle swarm optimisation [PSO]

Abstract

When the system simulates changes of a virtual world and behavior of virtual creatures inhabiting it, the unit time of real time corresponding to the unit time necessary for one processing by the system is divided as time grading. Specifically, when the system is booted up, corresponding to the duration from the time the system power source is cut off previously, simulation is performed by setting the time grading in one second, one minute, one hour, one day, one week, one month, or one year, for one processing by the system. By upon starting-up of the system, introducing such concept of time grading for the time series, simulation is performed at the time grading corresponding to the duration of the period in which the system has been stopped so far, so that prompt simulation is realized.

Claims

1. A production system for time series simulation of a virtual state set therein, comprising:

a working memory storing plural variables for expressing said virtual state;

a rule base storing plural production rules which specify the change of said virtual state, and each which is composed of a condition part for specifying said variables and an execution part for changing them; and

an inference processing unit performing a matching processing for matching said variables and said production rules, and picking up a production rule which satisfies the condition part from said working memory, a conflict resolution processing for selecting one out of plural production rules having been picked up according to a predetermined condition, an execution processing for executing the execution part of one selected production rule, and a processing for changing the variables in said working memory according to the execution result;

wherein said working memory stores said variables after they are classified into plural time classes according to the lengths of unit time for simulation;

said rule base stores said production rules after they are classified into plural time classes according to the lengths of unit time for simulation; and

said inference processing unit decides a time grading so as to select one of said plural time classes and then matches a variable and a production rule belonging to the time class equal to or higher than said selected time class.

2. The production system as set forth in claim 1, wherein said inference processing unit executes said matching processing for a period of time at each end portion of said period to be simulated.

3. A production system for time series simulation of a virtual state set therein, in a period from previous stopping time till starting time, when starting, comprising:

a working memory storing plural variables for expressing said virtual state;

a rule base storing plural production rules which specify the change of said virtual state, and each of which is composed of a condition part for specifying said variables and an execution part for changing them; and

an inference processing unit performing matching processing for matching said variables and said production rules, and picking up the production rule which satisfy the condition part from said working memory, a conflict resolution processing for selecting one out of plural condition rules having been picked up according to a predetermined condition, an execution processing for executing the execution part of one selected production rule, and a processing for changing the variables in said working memory according to the execution result;

wherein said working memory stores said variables after they are classified into plural time classes according to the lengths of unit time for simulation;

said rule bases stores said production rules after they are classified into plural time classes according to the lengths of unit time for simulation; and

said inference processing unit, when starting, decides a time grading so as to select one of said plural time classes corresponding to a period of time from a previous stop until a starting point, and then matches a variable and a production rule belonging to the time class equal to or higher than said selected time class.

4. A production system for time series simulation of a virtual state, comprising:

a working memory storing a plurality of variables for expressing said virtual state stored after said plurality of variables are classified into a plurality of time classes based on a period of time set for simulation;

a rule database storing a plurality of production rules which specify the change of said virtual state stored after said plurality of production rules are classified into a plurality of time classes according to the period of time for set simulation; and

an inference processing unit determining a time grading and selecting one of said plurality of time classes and then matching a variable and a production rule belonging to the time class equal to or higher than said selected time class, executing said selected production rule, and changing the variables in said working memory according to the execution result.