Fuzzy control system
First Claim
1. A fuzzy control system for controlling a physical object, the physical object being responsive to a control signal and producing a status signal corresponding to the status of the physical object, the fuzzy control system comprising:
- means for receiving the status signal from the physical object;
means for generating a control reference value;
means for selectively calculating a control deviation from the received status signal and the control reference value;
operation means, connected to said selective calculating means, for performing a fuzzy inference operation on the control deviation calculated by said selective calculating means and a control deviation contained in a fuzzy rule, the fuzzy rule defined by expert knowledge, to obtain a control deviation membership function;
calculating means for calculating matching between a membership function about an internal state of said physical object and a membership function about an internal state variable included in said fuzzy rule to obtain a matching point, and calculating a membership function about the control signal for said physical object and a membership function about a new internal state variable from an internal state variable membership value corresponding to the matching point;
means for storing the membership function about said new internal state variable;
and means for outputting said control signal to said physical object and controlling the physical object.
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Accused Products
Abstract
Disclosed is a fuzzy control system which calculates a membership function concerning a control value of a to-be-controlled object through a fuzzy inference operation in accordance with an input value from the to-be-controlled object and a control rule, and determines the control value from the membership function to control the to-be-controlled object. This fuzzy control system has a plurality of internal states respectively expressed by a plurality of membership functions in addition to the input value and the control value, determines the state of the to-be-controlled object using a rule for evaluating the input value, alters the internal state by fuzzy inference, stores a decision result as a new internal state, and determines the control value of the to-be-controlled object through fuzzy inference from the new internal state and the input value.
64 Citations
14 Claims
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1. A fuzzy control system for controlling a physical object, the physical object being responsive to a control signal and producing a status signal corresponding to the status of the physical object, the fuzzy control system comprising:
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means for receiving the status signal from the physical object; means for generating a control reference value; means for selectively calculating a control deviation from the received status signal and the control reference value; operation means, connected to said selective calculating means, for performing a fuzzy inference operation on the control deviation calculated by said selective calculating means and a control deviation contained in a fuzzy rule, the fuzzy rule defined by expert knowledge, to obtain a control deviation membership function; calculating means for calculating matching between a membership function about an internal state of said physical object and a membership function about an internal state variable included in said fuzzy rule to obtain a matching point, and calculating a membership function about the control signal for said physical object and a membership function about a new internal state variable from an internal state variable membership value corresponding to the matching point; means for storing the membership function about said new internal state variable; and means for outputting said control signal to said physical object and controlling the physical object. - View Dependent Claims (2, 3, 4)
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5. A fuzzy control system for controlling a physical object, the physical object responsive to a control signal and producing a feedback signal, the fuzzy control system comprising:
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means for receiving the feedback signal from the physical object; control target signal generating means for generating a control target signal; control deviation means for acquiring a control deviation from said control target signal from said control target signal generating means and the feedback signal from said physical object; first storage means for storing a plurality of fuzzy rules about fuzzy control, the fuzzy rules defined by expert knowledge regarding the physical object; second storage means for storing an internal state of said physical object; first calculating means for calculating a membership function of said control deviation in accordance with said fuzzy rules sequentially read out from said first storage means; second calculating means for calculating matching between internal state variables included in said fuzzy rules and said internal state read out from said second storage means; third calculating means for computing a confidence from said control deviation membership function acquired by said first calculating means and an internal state membership function corresponding to a matching value; means for calculating an inference result from said confidence and a control value membership function, and calculating the control signal from said inference result; and means for outputting said control signal and controlling said physical object.
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6. A method for controlling a physical object by generating a control value through a fuzzy inference operation in accordance with an input value from said physical object and a control rule defined by expert knowledge, the control value determined from a membership function to control said physical object, the method comprising the steps of:
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preparing a plurality of internal states concerning a condition of said physical object, said internal states respectively expressed by a plurality of membership functions; monitoring the input value from said physical object; determining a state of said physical object using the control rule defined by expert knowledge, the control rule for evaluating the input value; changing an internal state by fuzzy inference; storing a decision result as a new internal state; determining the control value for said physical object through fuzzy inference from said new internal state and said input value; and controlling said physical object using said control value.
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7. A system for controlling a physical object, the physical object being responsive to a control signal and producing a status signal corresponding to the status of the physical object, the system comprising:
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means for receiving the status signal from the physical object; means for storing an existing state concerning an inferred condition of the physical object; first fuzzy inference means, responsive to the status signal, a fuzzy state transition rule for determining a new state, and the existing state, for determining a new state concerning the physical object using a fuzzy inference operation; means for storing the new state; second fuzzy inference means, responsive to the status signal, a fuzzy control rule for determining a control value, and the new state, for determining a control value for the physical object using a fuzzy inference operation; and control means, responsive to the control value, for producing the control signal and controlling the physical object. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14)
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Specification