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US 5,947,370 AGranted
Apparatus and method for real time boiling point detection and control
AssigneeArthur D. Little, Inc.
InventorsMehmet Rona, Douglas J. Ely, William E. Morgan, Steven S. Carroll, deceased
Life of this patent
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Abstract
A system for monitoring and controlling the state of a thermal process. The system applies a modulated heat input to a liquid in a vessel and a thermal response measured at the bottom of the vessel provides information for real time processing of thermal properties of the liquid as it is being heated. Detection and control of an unknown boiling point enables a steady simmer or boiling condition in the liquid to be maintained.
Claims57
In a system for monitoring and controlling the state of a thermal process, the improvement comprising:
- means for providing a fluctuating heat input to a container in response to a heat control signal;
- means for sensing temperature of said container;
- means connected to said temperature sensing means for calculating parameters based on fluctuations of temperature at said container, said parameters including a linear rate of change (.alpha.) of said temperature, an amplitude (.beta.) of said temperature fluctuations in response to said fluctuating heat input, and a phase shift (.phi.) of said temperature fluctuations relative to said fluctuating heat input;
- fuzzy logic means, having inputs connected to said .alpha., .beta., and .phi. outputs of said parameter calculating means and said heat control signal for generating a signal indicating a boiling point of said liquid;
- and
- means connected to an output of said fuzzy logic means for generating said heat control signal.
3 more elements
In a cooking appliance for heating a liquid in a vessel, the improvement comprising:
- means for setting a mode of operation for detecting and controlling a boiling point of said liquid;
- means for providing a heat input to said vessel in response to a heat control signal, said heat input including a fluctuating heat input;
- means positioned within said heat input providing means for sensing temperature of said vessel;
- means connected to said temperature sensing means for calculating parameters based on fluctuations of temperature at said vessel, said parameters including a linear rate of change (.alpha.) of said temperature, an amplitude (.beta.) of said temperature fluctuations in response to said fluctuating heat input, and a phase shift (.phi.) of said temperature fluctuations relative to said fluctuating heat input;
- fuzzy logic means, having inputs connected to said .alpha., .beta., and .phi. outputs of said parameter calculating means and said heat control signal, for generating a signal indicating a boiling point of said liquid;
- means connected to an output of said fuzzy logic means for generating said heat control signal, said heat control signal maintaining said liquid temperature in accordance with said preset mode of operation;
- and
- means coupled to said temperature sensing means for supervising said mode of operation including said calculating parameter means, said fuzzy logic means and said heat control signal generating means.
5 more elements
In a method for monitoring and controlling the state of a thermal process in a container holding a liquid, an improvement comprising the steps of:
- providing a fluctuating heat input to said container in response to a heat control signal;
- sensing temperature of said container with temperature sensing means;
- calculating parameters based on fluctuations of temperature at said container provided by said temperature sensing means, said parameters including a linear rate of change (.alpha.) of said temperature, an amplitude (.beta.) of said temperature fluctuations in response to said fluctuating heat input, and a phase shift (.phi.) of said temperature fluctuations relative to said fluctuating heat input;
- generating a signal indicating a boiling point of said liquid with fuzzy logic means, having inputs connected to said .alpha., .beta., and .phi. outputs of said parameter calculating means and said heat control signal;
- and
- generating said heat control signal with means connected to an output of said fuzzy logic means.
3 more elements
In a method for heating a liquid in a vessel on a cooking appliance, an improvement comprising the steps of:
- setting a mode of operation for detecting and controlling a boiling point of said liquid;
- providing a heat input to said vessel in response to a heat control signal, said heat input including a fluctuating heat input;
- sensing temperature of said vessel with temperature sensing means positioned within said heat input providing means;
- calculating parameters based on fluctuations of temperature at said vessel provided by said temperature sensing means, said parameters including a linear rate of change (.alpha.) of said temperature, an amplitude (.beta.) of said temperature fluctuations in response to said fluctuating heat input, and a phase shift (.phi.) of said temperature fluctuations relative to said fluctuating heat input;
- generating a signal indicating a boiling point of said liquid with fuzzy logic means connected to said .alpha., .beta., and .phi. outputs of said parameter calculating means and said heat control signal;
- generating said heat control signal with means connected to an output of said fuzzy logic means, said heat control signal maintaining said liquid temperature in accordance with said preset mode of operation;
- and
- supervising said mode of operation including said calculating parameter means, said fuzzy logic means and said heat control signal generating means with means coupled to said temperature sensing means.
5 more elements
Dependencies are inferred from the claim text.