Whirlpool Corporation

Panasonic Holdings Corporation

Mattia Rigo

Davide Guatta

Valeria Nocella

Raffaele Paganini

Francesco Giordano

An electromagnetic cooking device and method of controlling the same is provided herein. The cooking device has a cavity in which popcorn is placed and a plurality of RF feeds configured to introduce electromagnetic radiation into the cavity for popping the popcorn. A controller is provided and is configured to: analyze forward and backward power at the plurality of RF feeds to calculate efficiency; determine and monitor a coefficient of variation of the efficiency; detect a popping state of the popcorn based on changes in the coefficient of variation; and adjust a power level of the electromagnetic radiation in response to detection of the popping state.

Electromagnetic cooking device with automatic popcorn popping feature and method of controlling cooking in the electromagnetic device

A method for identifying a cooking level of a food load in an electromagnetic cooking device is disclosed. The method includes controlling a frequency and a phase of a first RF signal and a second RF signal and amplifying the first RF signal and the second RF signal thereby generating a first RF feed and a second RF feed. The method further includes emitting the first RF feed and the second RF feed into an enclosed cavity to heat a food load and measuring at least one reflection signal. The method further includes calculating a Q-factor for the enclosed cavity based on the reflection signal, monitoring the Q-factor, and identifying a change in the Q-factor exceeding a predetermined change threshold. In response to identifying the change exceeding the predetermined change threshold, a cooking level for the food load is identified.

System and method for detecting cooking level of food load

An electromagnetic cooking device is provided having a controller and a plurality of RF feeds configured to introduce electromagnetic radiation into an enclosed cavity to heat up a food load. The controller is configured to: select a heating target; generate a heating strategy to determine a sequence of desired heating patterns; cause the RF feeds to output an RF signal to thereby excite the enclosed cavity; monitor the created heating patterns to measure resonances in the enclosed cavity and store a map of efficiency in frequency and phase domains from which the controller identifies resonant modes and Q-factors associated therewith; continue to monitor the created heating patterns and store maps of efficiency in the frequency and phase domains until a specified change is detected in at least one Q-factor; and when the specified change in the at least one Q-factor is identified, stop cooking the food load.

Detecting changes in food load characteristics using Q-factor

An electromagnetic cooking device includes a cavity in which a food load is placed, a plurality of RF feeds for introducing electromagnetic radiation into the enclosed cavity, and a controller configured to detect asymmetries and select rotations that compensate for the asymmetries; select a heating target including a plurality of resonant modes that are rotated using the selected rotations in the preceding step; generate a heating strategy based on the heating target to determine a sequence of desired heating patterns; cause the RF feeds to output a radio frequency signal to thereby excite the enclosed cavity with a selected set of phasors for a set of frequencies; and monitor the created heating patterns based on the forward and backward power measurements at the RF feeds to use closed-loop regulation to selectively modify the sequence of resonant modes into the enclosed cavity based on the desired heating patterns as monitored.

Method and device for electromagnetic cooking using non-centered loads management through spectromodal axis rotation

An electromagnetic cooking device includes a cavity in which a food load is placed, a plurality of RF feeds for introducing electromagnetic radiation into the enclosed cavity, and a controller configured to select a heating target including a plurality of unrotated resonant modes; detect asymmetries of the food load relative to a center of the enclosed cavity and select rotations for the plurality of unrotated resonant modes that compensate for the detected asymmetries of the food load to generate a plurality of optimized resonant modes; generate a heating strategy having a selected sequence of the optimized resonant modes; cause the RF feeds to excite the enclosed cavity with a selected set of phasors for a set of frequencies corresponding to each resonant mode of the selected sequence of optimized resonant modes; and monitor the created heating patterns using closed-loop regulation to selectively modify the sequence of optimized resonant modes.

Method and device for electromagnetic cooking using non-centered loads

An electromagnetic cooking device is disclosed. The device comprises an enclosed cavity configured to receive a food load and a plurality of amplifiers configured to amplify a first RF signal and a second RF signal thereby supplying the RF signals to the enclosed cavity. A controller is in communication with the plurality of amplifiers. The controller is configured to control the first RF signal and the second RF signal along a stirring path between a first approximate resonant mode and a second approximate resonant mode of the enclosed cavity. Each of the resonance modes comprises a frequency and phase shift between the first RF signal and the second RF signal.

System and method for controlling a heating distribution in an electromagnetic cooking device

An electromagnetic cooking device includes an enclosed cavity configured to receive a food load, a plurality of high power amplifiers and RF feeds for introducing electromagnetic radiation into the cavity, and a controller for controlling the frequency, phase and amplitude of the electromagnetic radiation fed into the cavity by the RF feeds. The controller is configured to identify resonant modes, develop and implement a heating strategy based on the resonant modes, utilize an asynchronous manager to automatically detect when a variable has changed to a degree that requires an updated identification of resonant modes and an updated heating strategy, and if the asynchronous manager determines that updates are needed, repeat the steps above to determine a new heating strategy, otherwise continue with the current heating strategy.

Method and device for electromagnetic cooking using asynchronous sensing strategy for resonant modes real-time tracking

An electromagnetic cooking device and cooking method to perform zone cooking is disclosed. The method includes scanning a resonant cavity in which a food load has been placed with RF feeds that are coupled to respective high power amplifiers; identifying resonant frequencies and corresponding phases of the RF feeds; storing a resonance map; classifying symmetries in the resonant map; determining paths defining stirring routes between poles of different symmetries; determining midpoints in the paths with a maximum unbalance between reflected powers of the respective high power amplifiers; classifying the unbalance in terms of power steered to the left and right sides of the food load; synthesizing a heating strategy for zone cooking using the classified unbalance; and implementing the heating strategy by causing the plurality of high power amplifiers and RF feeds to introduce electromagnetic radiation at specific selected frequencies and phases into the cavity based on the heating strategy.

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Varese, Italy

Mattia Rigo