Wireless method and apparatus for monitoring and controlling food temperature
First Claim
1. A system for controlling refrigeration, comprising:
- at least one refrigeration case;
a temperature sensor operable to measure a temperature from said at least one refrigeration case;
a transmitter in communication with said temperature sensor and operable to wirelessly transmit data including said temperature;
a receiver adapted to receive said wirelessly transmitted data including said temperature;
a controller in communication with said receiver to receive said wirelessly transmitted data and operable to control said temperature of at least one refrigeration case based upon said wirelessly transmitted data from said at least one refrigeration case; and
a mode switch for selectively suspending said controller from control of said temperature of said at least one refrigeration case.
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Accused Products
Abstract
A system and method for controlling refrigeration including a temperature sensor operable to measure a temperature from a refrigeration case and a transceiver in communication with the temperature sensor and operable to wirelessly transmit data. A repeater receives the wirelessly transmitted data and further wirelessly transmits the data to a receiver. A controller in communication with the receiver controls the refrigeration system based upon the wirelessly transmitted data from the refrigeration case. The refrigeration case also includes a mode switch for suspending temperature reading and control for a period of time. For example, the mode switch can be used by an operator during cleaning or maintenance of the refrigerator case. Temperature control algorithms are used by the controller, and include: dead-band range (DB), proportional/integral (PI), proportional/integral/differentiation (PID) and fuzzy-logic (FL).
108 Citations
27 Claims
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1. A system for controlling refrigeration, comprising:
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at least one refrigeration case;
a temperature sensor operable to measure a temperature from said at least one refrigeration case;
a transmitter in communication with said temperature sensor and operable to wirelessly transmit data including said temperature;
a receiver adapted to receive said wirelessly transmitted data including said temperature;
a controller in communication with said receiver to receive said wirelessly transmitted data and operable to control said temperature of at least one refrigeration case based upon said wirelessly transmitted data from said at least one refrigeration case; and
a mode switch for selectively suspending said controller from control of said temperature of said at least one refrigeration case. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method for refrigeration system control, said method comprising:
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measuring a first parameter from at least one refrigeration case;
wirelessly transmitting said measured first parameter to a repeater;
transmitting a polling signal from a receiver to said repeater;
transmitting a response signal to said polling signal from said repeater to said receiver; and
communicating said response signal from said receiver to a remote controller electronically controlling said at least one refrigeration case by said remote controller to affect said measured first parameter. - View Dependent Claims (13, 14, 15, 16, 17, 18)
measuring a second parameter from another refrigeration case;
transmitting said response signal to said receiver, wherein said response signal includes said second parameter; and
electronically controlling said another refrigeration case to affect said measured second parameter.
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18. The method as defined in claim 17 wherein said at least one refrigeration case is in a first circuit and said another refrigeration case is in a second circuit.
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19. A method for refrigeration system control, said method comprising:
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setting a set point temperature for a circuit having at least one refrigerator case;
determining a temperature for said at least one refrigerator case;
wirelessly transmitting said temperature from said circuit to a system controller;
determining an error value as a function of said set point and said temperature;
determining a compressor control value as a function of said error value;
wirelessly controlling a compressor as a function of said compressor control value;
dividing upper and lower limits of a dead-band range in half; and
comparing said error value to said halves of said upper and lower limits of said dead-band range;
wherein said compressor control value is controlled off if said error value is greater than half of said upper limit and is controlled on if said error value is less than half of said lower limit. - View Dependent Claims (20, 21)
calculating a first value by multiplying said error value by a first constant;
calculating a second value as a summation of said error value over a defined time and multiplying said summation by a second constant; and
adding said first and second values to determine said compressor control value.
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21. The method of claim 20 further including the steps of:
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calculating a third value as a change is said error value over a defined time and multiplying by a third constant; and
adding said third value to said first and second values.
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22. A method for refrigeration system control, said method comprising:
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setting a set point temperature for a circuit having at least one refrigerator case;
determining a temperature for said at least one refrigerator case;
wirelessly transmitting said temperature from said circuit to a system controller;
determining an error value as a function of said set point and said temperature;
determining a compressor control value as a function of said error value;
wirelessly controlling a compressor as a function of said compressor control value;
sampling said error value over a period of time;
determining an error rate over said period of time;
determining a first set of values as a function of a specific error value and said error rate;
determining a second set of values as a function of said specific error value and said error rate; and
calculating said compressor control value as a function of said first and second sets of values. - View Dependent Claims (23, 26, 27)
calculating a first value by multiplying said error value by a first constant;
calculating a second value as a summation of said error value over a defined time and multiplying said summation by a second constant; and
adding said first and second values to determine said compressor control value.
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27. The method of claim 26 further including the steps of:
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calculating a third value as a change is said error value over a defined time and multiplying by a third constant; and
adding said third value to said first and second values.
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24. A method for refrigeration system control, said method comprising:
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setting a set point temperature for a circuit having at least one refrigerator case;
determining a temperature for said at least one refrigerator case;
wirelessly transmitting said temperature from said circuit to a system controller;
determining an error value as a function of said set point and said temperature;
determining a compressor control value as a function of said error value; and
wirelessly controlling a compressor as a function of said compressor control value;
wherein said temperature is one of either a minimum temperature, a maximum temperature or an average temperature of said refrigeration cases in a circuit of refrigeration cases. - View Dependent Claims (25)
dividing upper and lower limits of a dead-band range in half; and
comparing said error value to said halves of said upper and lower limits of said dead-band range;
wherein said compressor control valve is controlled off if said error value is greater than half of said upper limit and is controlled on if said error value is less than or equal to half of said lower limit.
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Specification