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Title:
AUTONOMOUS COOKING DEVICE TO PREPARE FOOD FROM A RECIPE FILE AND METHOD FOR CREATING RECIPE FILES
Document Type and Number:
WIPO Patent Application WO/2016/160732
Kind Code:
A1
Abstract:
An automatic cooking device creates a recipe file based on an actual cooking session by an individual. The same dish can be automatically recreated on demand from the recipe file, wherein an optimal remaining cooking time is automatically determined responsive to an image analysis of real-time image sensor feedback versus reference image. In some implementations, recipe files are acquired through a network and downloaded for a fee.

Inventors:
CHOUDHARY, Prashant (749 Superior Road, Milpitas, CA, 95035, US)
Application Number:
US2016/024572
Publication Date:
October 06, 2016
Filing Date:
March 28, 2016
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
CHOUDHARY, Prashant (749 Superior Road, Milpitas, CA, 95035, US)
International Classes:
A23L1/00
Foreign References:
US20130149679A12013-06-13
US20130302483A12013-11-14
US20130101714A12013-04-25
Attorney, Agent or Firm:
CARTWRIGHT, Dorian (Law Office of Dorian Cartwright, 2130 The AlamedaSan Jose, CA, 95126, US)
Download PDF:
Claims:
I CLAIM :

1. An autonomous cooking device to automatically prepare food according to recipe files, the cooking device comprising :

an outer shell to house a cooking unit;

an input/output device accessible from the outer shell, the input/output device to receive a selection of a specific recipe file from a plurality of recipe files, the specific recipe file comprising at least image sensor data corresponding to different phases of food preparation;

a cooking unit comprising a container and a heating

element, the cooking unit initiating a cooking portion of food preparation;

an image sensor to capture images of food while cooking for comparison against reference images;

a control unit electrically coupled to the input/output device and comprising a processor and a memory device, the control unit comprising an image analyses module to compare one or more of the captured images against one or more reference images from the specific recipe file and the control unit comprises an optimal cooking time module to estimate a remaining cooking time based on the image

comparison,

wherein the cooking unit ends the cooking portion of food preparation, responsive to the remaining cooking time .

2. The autonomous cooking device of claim 1, the cooking unit ends the cooking portion of food preparation, responsive to a difference between images being within a threshold for ending the cooking portion.

3. The autonomous cooking device of claim 1, wherein the optimal cooking time module increases or decreases the cooking time, as previously determined, responsive to the image comparison.

4. The autonomous cooking device of claim 1, wherein the remaining time module performs the image

comparison by comparing color histograms of a captured image versus a reference image.

5. The autonomous cooking device of claim 1, wherein the remaining time module performs the image

comparison by comparing power spectral densities of a captured image versus a reference image, in order to compare a real- time texture of food against a reference texture.

6. The autonomous cooking device of claim 5, wherein the image analyses module generates a one-dimensional power spectral density by integrating the square of Discrete Fourier Transform of a two-dimensional image over annular rings of equal area starting from the center of the two- dimensional image.

7. The autonomous cooking device of claim 1, wherein the image sensor comprises at least one of a visual image sensor and a thermal image sensor.

8. The autonomous cooking device of claim 1, wherein the optimal cooking time module performs the image comparison by comparing aspects of a captured image versus a reference image as a whole, in addition to comparing aspects of the captured image versus the reference image as sub- portion of the whole.

9. The autonomous cooking device of claim 1, further comprising:

a temperature sensor to generate real-time temperature readings for food being prepared, wherein the cooking unit increases or decreases an intensity of the heating element, responsive to temperature data in the recipe file.

10. The autonomous cooking device of claim 1, further comprising:

a weight sensor to generate real-time weight measurements for food being prepared,

wherein the cooking unit automatically adjusts a cooking parameters, responsive to weight data in the recipe file .

11. The autonomous cooking device of claim 1, further comprising:

a recipe learning module stored in the memory device and executed by the processor, the recipe learning module to, prior to execution of the recipe file, generate the recipe file by recording manual steps associated with the plurality of ingredient containers, the manual steps comprising a time for adding contents of each container to the cooking unit, and a temperature of the heating unit, wherein the control unit automatically adds the contents to the cooking unit at the time and automatically sets the temperature of the heating unit, according to the recipe file.

12. The autonomous cooking device of claim 1, further comprising:

a stirrer located proximate to the cooking unit to stir ingredients contained within the cooking unit; and a recipe learning module stored in the memory device and executed by the processor, the recipe learning module to, prior to execution of the recipe file, generate the recipe file by recording manual steps associated with the stirrer, the manual steps comprising at least a time and intensity for stirring ingredients in the cooking unit, and a temperature of the heating unit,

wherein the control unit automatically stirs ingredients with the stirrer, according to the recipe file.

13. The autonomous cooking device of claim 1, wherein the control unit manipulates contents of the cooking unit with at least three degrees of freedom, including axial rotation of the stirrer, up and down positioning of the stirrer, and rotation of the cooking unit.

14. The autonomous cooking device of claim 1, further comprising: a plurality of ingredient containers located proximate to a cooking unit and storing a plurality of ingredients that are automatically added to the cooking unit and heated by a heating unit, according to the control unit.

15. The autonomous cooking device of claim 1, further comprising:

a temperature sensor electrically coupled to the control unit, the temperature sensor to feedback an actual temperature of contents within the cooking unit in substantially real-time,

wherein the control unit automatically adjusts the

temperature responsive to the temperature feedback, according to the recipe file .

16. The autonomous cooking device of claim 1, further comprising:

a network interface electrically coupled to the control unit, the network interface to connect to a data network for uploading the recipe file for sharing to an online community responsive to being locally created .

17. The autonomous cooking device of claim 1, further comprising:

a network interface electrically coupled to the control unit, the network interface to connect to a data network for downloading the recipe file shared in an online community responsive to being selected at the input/output device.

18. The autonomous cooking device of claim 1, further comprising:

a plurality of disposable containers configured to fit within the plurality of ingredient containers, each disposable container being pre-packaged with a specific amount of an ingredient for the food dish, according to the recipe file .

19. The autonomous cooking device of claim 1, wherein the recipe file stored in the memory device comprises source code executable by the processor.

20. The autonomous cooking device of claim 1, wherein the optimal cooking time module determines when food preparation is complete from a coarse decision and then a fine decision .

Description:
AUTONOMOUS COOKING DEVICE TO PREPARE FOOD FROM A RECIPE FILE

AND METHOD FOR CREATING RECIPE FILES

Cross-reference to Related Applications

[001] This application claims priority to U.S. Application

No. 62/138,985, filed on March 27, 2015 by Prashant Choudhary, et al . and entitled Autonomous Cooking Device to Prepare Food from a Recipe File and Method for Creating Recipe Files, the content of both being incorporated herein by reference in their entirety.

Field of the Disclosure

[002] The invention relates generally to autonomous cooking devices, and more specifically, to intelligent appliances that automatically prepare a dish by intelligently processing a recipe file.

Background of Disclosure

[003] Recipes are a general ideal set of cooking

instructions for manual food preparation. Some recipes are written down on index cards for personal reference, or published in a cook book or even online for sharing. Even with the instructions, a novice cook can find it difficult, or at least tedious, to replicate the cooking process of a professional cook. It can also be difficult to consistently recreate personal recipes.

[004] Existing cooking devices have only a basic level of automation. For example, a microwave oven cooks according to a programmed time at a programmed power level. A coffee machine can automatically brew a pot of coffee at a programmed time using water and coffee beans. However, none of these machines are able to operate in an intelligent manner. For example, these machines are unable to adapt to actual

conditions during preparation. In another example, none of these machines are able to learn new recipes.

[005] It is desirable to overcome these shortcomings.

Therefore, what is needed is a robust autonomous cooking device to automatically prepare food. The device should use computer vision and machine learning to learn new recipes, and the device should adapt to sensor feedback in real-time during preparation. Furthermore, the device should be networked for retrieving and sharing or selling recipe files within an online community. Summary of the Disclosure

[006] To meet the above-described needs, an automatic cooking device uses computer vision and intelligence in food preparation to determine optimum cooking time for different phases of cooking a dish.

[007] In one embodiment, the automatic cooking device creates a recipe file based on an actual cooking session by an individual. The same dish can be automatically recreated on demand from the recipe file, wherein an optimal remaining cooking time is automatically determined responsive to an image analysis of real-time image sensor feedback versus reference image. In some implementations, recipe files are acquired through a network and downloaded for a fee.

[008] In another embodiment, the autonomous cooking device cooks food dishes from pre-loaded ingredients. Food is prepared according to a combination of factors. The

ingredients can be automatically added by the cooking device at various milestones based not only on time or temperature, but other factors such as color, weight, volume, moisture level, recipe directions, and the like. Sensors monitor food by providing feedback to a processor. The processor

dynamically alters cooking time by intelligently comparing current sensory data with sensory data recorded in the recipe file. For example, increase cooking time of potato curry based on infrared camera input which indicates the potatoes need more time to cook from inside. Alternatively, a texture analysis of real-time images versus reference images can lead to the same or a different conclusion. Various analyses can be weighted according to a specific algorithm.

[009] Advantageously, food preparation is performed efficiently and consistently, with minimal human intervention.

BRIEF DESCRIPTION OF THE DRAWINGS

[010] In the following drawings, like reference numbers are used to refer to like elements. Although the following figures depict various examples of the invention, the

invention is not limited to the examples depicted in the figures .

[Oil] FIG. 1 is a perspective view illustrating an autonomous cooking device utilizing recipe files, according to one embodiment .

[012] FIG. 2 is a bottom perspective view illustrating a mixing blade assembly of the autonomous cooking device of FIG. 1, according to one embodiment.

[013] FIG. 3 is a perspective view illustrating a lid assembly of the autonomous cooking device of FIG. 1, according to one embodiment .

[014] FIG. 4 is an exploded view illustrating an

ingredient dispensing platform of the autonomous cooking device of FIG. 1, according to one embodiment.

[015] FIG. 5 is a perspective view illustrating a cooking unit with three degrees of freedom for mixing in the autonomous cooking device of FIG. 1, according to one

embodiment .

[016] FIG. 6 is a block diagram of a finite state machine for electronics of the autonomous cooking device, according to one embodiment .

[017] FIG. 7 is a network architecture including the autonomous cooking device for sharing recipe files, according to one embodiment .

[018] FIG. 8 is a flow diagram illustrating a method for food preparation in the autonomous cooking device, according to one embodiment .

[019] FIG. 9 is a flow diagram illustrating a step of training the autonomous cooking device in the method of claim 8, according to one embodiment.

[020] FIG. 10 is a flow diagram illustrating a step of automatically preparing dishes with the autonomous cooking device in the method of claim 8, according to one embodiment.

[021] FIG. 11 is a flow diagram illustrating a step of computing a measure of closeness between two images, in determining an end of a cooking phase in the autonomous cooking device in the automatic preparation step of claim 9, according to one embodiment.

[022] FIG. 12 is a diagram of a table illustrating a recipe file, according to one embodiment.

[023] FIG. 13 is a diagram illustrating image processing for texture analysis steps 1110, 1114 of FIG. 11, according to one embodiment .

Detailed Description of the Disclosure

[024] Autonomous cooking devices, and methods operating therein, are described. At a high-level, the device can automatically determine optimum cooking time (i.e., remaining cooking time) for different phase of cooking for various types of food cuisines such as American, Indian, Chinese, or others. Cooking tasks include boiling eggs, brewing tea or coffee, making yogurt, preparing curries and the like. The design is intuitive and optimized for mass production. Aspects of intelligence are easily trainable and components require minimal cleaning. A compact form factor helps for easy storage and deployment.

[025] Many other aspects of the system are possible within the spirit of the present invention, as will be apparent to one of ordinary skill in the art. The techniques can be implemented in any suitable computer system having network access using a combination of computer software and/ or computer hardware. Accordingly, the following details are non-limiting and are set for only for the purpose of

illustration of preferred embodiments which can be varied within the spirit of the current invention by those of ordinary skill in the art. [026] I. Components of the Cooking Device

[027] FIG. 1 is a perspective view of an autonomous cooking device 100, according to one embodiment. The cooking device 100 generally includes an outer shell 110, a cooking unit 120, an ingredient container 130, and a control unit 140.

[028] A. Outer Shell

[029] The outer shell 110 covers the internal components which are affixed to a base. In FIG. 1, a door is opened or a panel is removed for access to the internal components, including the cooking unit 120 and a mixing blade shaft 105 and rotating platform 115 with a heating element. A lid 125 rests on top of side walls of the outer shell 110 and an ingredients container 130 is also integrated with the shell. The specific configuration of FIG. 1 is merely one example of numerous possible variations.

[030] The digital camera is one type of cooking sensor that provides feedback during the cooking process. A camera hole 125 can be bored in a lid 200 of the outer shell 110 in one embodiment, or on the side or other appropriate location in other embodiments. The outer shell 110 can be made of an opaque material which can block ambient lighting in order to protect the integrity of internal images captured by the digital camera during cooking. Some embodiments of the digital camera have auto-focus and calibration capabilities. An LED light provides a constant flicker-less source of light for capturing images. Captured images can be passed to an image processing unit as input to adaptations made on the fly. The captured images can also show levels of or identify ingredients. An air nozzle 135 or other device self-cleans a camera lens, for example, to remove food debris, steam or condensation.

[031] In one embodiment, a thermal imaging camera is also used to sense how well the ingredients are cooked from inside which might not be obvious from visual images in certain situations. For example, an algorithm using color histograms and power spectral densities can determine a difference between cooking food image and reference photos of fully- cooked food (or of individual cooking phases for a cooked dish) . Additional sensors that can be optionally connected to the outer shell 110 are described below. [032] The exhaust fan can also be attached to a lid to remove smoke and vapors from inside of the device. A filter can be periodically cleaned.

[033] A touch screen user interface or other display device on the outer shell shows information and receives user input. Examples of displayed information and input

mechanisms include ingredient levels and status, temperature readings and settings, cooking progress, video camera output, user instructions, recipe information, start and stop buttons, control knobs, time and the like. Input/ output interface such a USB can also be included on the outer shell.

[034] Other computer circuitry such as the processor and software can be deployed in the outer shell along with shielding for protection from the heat, fumes, moisture and other dangers to electronics .

[035] B. Ingredient Container

[036] The ingredients container 130 holds meal ingredients such as water, milk, flour, eggs, meat, vegetables, cooking oil, herbs, and seasonings. There are several equal-sized containers (e.g., 2 to 10 containers), or varying sized containers formed by splitting a standard container into sub- containers . The containers can be different shapes A total volume of the dispensers is preferably greater than the volume of the cooking unit. The containers are easily removed for loading, cleaning, and to be manipulated by the cooking device. Containers can be removed individually or the whole container unit can be removed for easy cleaning. A shutter can cover the containers in order to preserve and protect

ingredients from cooking fumes and smoke. In some

embodiments, disposable containers (e.g., available in a grocery store or by mail) can be used. In other embodiment, a cooling element refrigerates one or more of the containers.

[037] As directed by the control unit 140, the ingredients container 130 can use electrical and mechanical components to autonomously add contents to the cooking unit 120 at a particular time. A weight sensor or volume sensor can manage adding, for example, half a container of flour at a first time and the other half of the container at a second time.

[038] The ingredients container 130 shown in FIG. 1 is disposed near the cooking unit 120. A container 410 rests on a container base 405 which connects to a container platform 420. A motor 425 turns a bearing 430 connected to the container platform 420. A solenoid 440 pulls down a spring loaded ferrous container lock 450 to release container base 405. The controller unit 140, having knowledge of which ingredients are in which containers, can rotate the

ingredients container 130 similar to a carousel until the appropriate container reaches a position for dispensing. A solenoid 440 pulls container lock down.

[039] In one embodiment, a water supply is connected for dispensing into the cooking process. In another embodiment a water dispenser is integrated with the device.

[040] C. Cooking Unit

[041] A detail of the cooking unit 120 with the mixing blade 105 and the rotating platform 115 is shown in FIG. 5. An underside of the lid 125 with a connection to the mixing blade shaft 105 is shown in FIG. 2. A mixing blade mount 145 affixes the mixing blade shaft 105 to a mixing wheel 155. Other components of the cooking unit 120 (not shown in pictures) include a heating element and an optional cooling unit. The heating element could be an inductive coil, a resistive heating coil or any other means.

[042] As shown in FIG. 3, a removable cooking lid 330 is attached to a heavy lid holder base 320 which can be moved up or down using three steel cables 350. A cooking lid slides over the mixing blade shaft 105. A mixing blade motor 340 turns a mixing blade rotator 310 connected to the mixing blade shaft 105 which turns a spring loaded mixing blade 360, in the current embodiment.

[043] The mixing blade 360 can be a general purpose mixing blade that works across different phases of cooking (e.g., similar blade to Kitchen-Aid stand mixer) . The mixing blade 360 is strong enough to mix viscous cookie dough as well as delicate ones. The mixing blade 360 is removable for cleaning or switching out different sizes. In some embodiments, more than one mixing blade is provided. A stepper motor or DC servo motor 340 drives the mixing blade 360 using electric power to spin a mixing blade rotator 310.

[044] In one embodiment, the mixing blade 360 can also move vertically up or down to allow for mashing of

ingredients. The cooking unit 120 can be independently rotated in addition to rotation and up and down traversal of the mixing blade 360 to give more degrees of freedom in mixing compared to a stand-mixer mechanism. Using camera feedback or other sensors, the motor can rotate the main cooking utensil to necessary positions. A dual motor mixing mechanism can rotate the blades and the cooking platform. The mixing blade shaft 105 is mounted to the lid 125 in FIG. 1 but can alternatively be attached to a base. A paddle or scooper serves as the main cooking utensil in this embodiment. Parts can be interchangeable in order to substitute the mixing blade with a mixer or other tool. Additional variations are possible .

[045] In one embodiment, a cooling unit refrigerates dishes after preparation. The cooling unit can be combined with or independent of ingredient refrigeration. The cooling unit can also reduce temperatures for various phases of cooking .

[046] D. Control Unit

[047] The control unit 140 includes and cooperates with several components as the brains of the cooking device 110, an example of which is shown in the block diagram of FIG. 6.

Generally, a processor, a memory, an input/output device, and various electronic sensors automate food preparation. The control unit 140 can be isolated from the harsh cooking environment in order to protect sensitive electronics by using insulation, shields, or the outer shell 110. Based on input from sensors 605A-695E, a finite state machine and control logic 640 determines outputs for controller/ driver circuitry 650 in adjusting components 695A-695F. [048] A touch display and user interface 620 can receive instructions by a user performing manual steps during a training phase. For example, while training for preparation of brownies, contents of the ingredient containers 130 can be found in a local or networked database (e.g., recipe and ingredient database 610) and associated with the recipe file for brownies. Besides preparation instructions, some

embodiments also save nutritional information and images to the recipe file. The input/output device can also display real-time information from sensors (e.g., temperature, predicted finish time, and other data) .

[049] Sensors 605A-605E provide real-time feedback about current conditions of the food being prepared. This allows for sensor levels to be recorded during training, and to make sure the food being prepared according to a recipe file is cooking as expected. For example, a temperature sensor 605C measures a temperature of meat being cooked or soup being prepared. In another example, the thermal imaging camera 605A can be used to ensure food is perfectly cooked and not undercooked or over-cooked, using infrared technology. In yet another example, a video camera coupled to video recognition capabilities as another form of monitoring. The video camera can also stream to a remote online resource for processing. In still another example, one or more weight sensors 605D aids administration of ingredients as well as serving to monitor cooking (e.g., monitoring change in weight as an indication of cooking progress) . A position sensor 605E and many other types of sensors are possible. The user interface can be used to view sensor parameters, and for manual input or updates to sensor data.

[050] In more detail, a visual imaging camera 605B is one type of cooking sensor that provides feedback during the cooking process. The visual imaging camera 605B can be attached to a lid of the outer shell 110 in one embodiment, or on the side or other appropriate location in other

embodiments. The outer shell 110 can be made of an opaque material which can block ambient lighting in order to protect the integrity of internal images captured by the digital camera 605A during cooking. Some embodiments of the digital camera have auto-focus and calibration capabilities. An LED light provides a constant flicker-less source of light for capturing images. Captured images can be passed to an image processing unit as input to calculate remaining cooking time by comparing current images of food to reference images, as described further below with respect to FIG. 11. The captured images can also show levels of or identify ingredients. An air nozzle or other device self-cleans a camera lens, for example, to remove food debris, steam or condensation. [051] A recipe file 1200 is shown in the table of FIG. 12.

The table shows sensor data from a camera, a thermometer, and a scale. Reference images can be stored within the recipe file 1200, in memory, or online. Real-time data can be plotted on the table to identify a corresponding time. In some cases, such as depending on a type of dish being

prepared, the camera data is weighted more than the scale data, when plotting to a particular row on the table. Many implementation-specific algorithms are possible. Ingredients along with amounts are also described in the recipe file 1200. Instructions can be grouped by the different cooking phases I- IV 1202, 1204, 1206, 1208 because settings may need automatic adjustment in between phases. Rows of sensor data are shown for vimageData or visual image sensor data 1212, timageData or thermal image sensor data 1214, Wt or weight sensor data 1216 and Temp or temperature sensor data 1218. In other

embodiments, commands and computer instructions are also included in the receipt file 1200.

[052] The central processing unit can comprise a standard

PC processor, a mobile processor, or a specialized processor or ASIC. In one embodiment, a connected mobile device or online server performs processing used in the cooking process. An image processing unit 630 implemented in hardware and/ or software is available to the finite state machine and control logic 640 captures and processes data from multiple sensors and creates a recipe file. During autonomous cooking process, the data in the recipe file is used as a reference to compare with current sensor data and decide optimal cooking time to get same results as during training process. An optimal cooking time module 660 determines how much cooking time remains using output from the image processing unit 630 which determines a difference between real-time and reference images. Additional data inputs can optionally take into consideration the other sensor data versus the other reference sensor data concerning weight, temperature, and the like. The remaining cooking time can be in reference to individual phases, or in reference to the dish as a whole.

Advantageously, individual cooking phases can be automatically detected and additional ingredients added, or cooking

temperature be changed as examples automated responsive actions using components 695A-695F.

[053] The memory device can store multiple recipe files and source code executable during operation of the cooking device 110, as described herein. [054] E. Network Interface

[055] External resources can be accessed by the cooking device as shown in the example of FIG. 7. A network interface such as a MAC card, IEEE 802.11 interface, or cellular network interface connects the cooking device to a central server 710, search engines, and other external resources. A mobile app 720A, 720B can be used as a proxy for network communications and then connected in communication with the cooking device for data transfer.

[056] In one embodiment, a user generates recipe files at a recipe creator machine 730A which can be the cooking device 100 or some other device such as a personal computer or smart phone. Manual steps can be actual steps that are recorded while preparing a food dish, or can be instructional steps that are entered to a tablet computer, in order to generate recipe files. The uploaded recipe file can be stored

privately at a user profile (e.g., Dropbox account), shared privately, sold to the public, or the like. Other users, or the same user at a different cooking device can download recipe files to a recipe user machine 730B.

[057] In another embodiment, food preparation can be controlled remotely through network connections and local cameras and other sensors. The central server 710 or a user can get remote feedback and send commands in response, to affect food preparation.

[058] III. Methods of Operation in the Cooking Device

[059] One high-level method 800 of operation is

illustrated in the flow diagram of FIG. 8. The cooking device is trained by creating recipe files which contain processed sensory data captured during training for various phases of cooking a recipe (step 810) . In one embodiment, the recipe files are uploaded to an online community for sharing.

Training details are discussed further in reference to FIG. 9 below .

[060] When ready to make a particular dish, an appropriate recipe file is selected and loaded into the cooking device (step 820) . In an embodiment, the recipe file can be

downloaded from the online community, for example, responsive to a database query. A user can be guided to load ingredients (step 830) . Visual feedback, or audio instructions can be given to a user, and sensors can verify when ingredients are loaded, and make sure adequate amounts are supplied. [061] Finally, the cooking device automatically prepares the dish with loaded ingredients, according to phases of the recipe file (step 840) . Sensors are used to monitor cooking and feedback a state such as how much cooking time remains or when a new phase of cooking should begin, as set forth in FIG. 10.

[062] FIG. 9 shows one example of the training step 810 from FIG. 8. A user enters recipe ingredient information

(step 902) . The ingredients are grouped in to batches (step 904) and are ordered for loading into a cooking device (step 906) . Feedback from the cooking device displays how to best allocate ingredients for loading into containers of an ingredient dispenser unit (steps 908 and 910) . For some recipes, the cooking device starts with preheating a cooking unit (step 912 ) .

[063] The process of cooking a recipe can be divided into phases where a phase is a period of cooking with same set of ingredients and no change in set control knobs. For example, boil milk at 180F while constantly stirring till user adds tea leaves is one phase of tea recipe. In another example, cooking onions at medium stove settings till they are

caramelized is one phase. During training process, a phase is terminated by a user action like change in stove setting or adding the next batch of ingredients etc. End of current cooking phase automatically starts the next phase of cooking. During training process, as shown in FIG. 9, user controls the device by monitoring through a display and the cooking device continues storing sensor data from including temperature, weight and images (loop with step 914, 916, 924, 926) until the user determines that a phase is complete or that the dish is fully prepared (step 918) . Before commencing the next phase, the user adds the next batch of ingredients and adjusts settings as needed (step 920) . The cooking device continues recording sensor data for the phase (step 922) . Once the phases are complete (step 918), the cooking device extracts useful statistics for time, temperature and weight for storage in the recipe file (step 928) .

[064] FIG. 10 shows one example of the automatic cooking step 840 from FIG. 8. A number of phases is set (step 1002) . Sensory data from one or more sensors is compared with recorded sensory data from (step 1004) to determine when a phase has ended (step 1006) . More specifically, cooking process in encapsulated into a recipe file by breaking up the process into phases. For example, tea preparation can be represented in five phases: phase 1 to pre-heat utensils for a fixed amount of time and adds water to the cooking utensil; phase 2 boils water and adds additional ingredients such as tea, cardamoms and ginger; phase 3 boils the ingredients for a certain amount of time and then adds milk; phase 4 continues boiling; and phase continues to cook at a lower heat.

Different instructions from the recipe files can be executed within different phases, or specified for the beginning or end of a phase. Other instructions include mixing, opening or closing lids, stirring, and the like.

[065] As such, one main task of the device during

autonomous cooking mode is to replicate decision making ability of an expert cook and decide when a particular phase is completed. This is accomplished in a two-step process. The first step is a coarse decision step (step 1002, 1004, 1006, 1008, 1024, 1022) where the current sensory data is compared with recorded sensory data at all time points of ongoing cooking phase. Coarse decision step ends when current sensory data is closest to the last time point of ongoing cooking phase at-least K times. To further improve the accuracy of cooking timing, a second fine decision step (1010, 1012, 1014, 1016) follows the coarse decision step. In fine decision step sensory data from last M time points is

correlated with a moving window of M time points in recorded data to determine the optimal time T finish to end the current cooking phase. Subsequently, ongoing cooking phase proceeds for a period of T finish seconds before moving to next phase of cooking.

[066] In one embodiment, cooking errors for a phase are recognized by analyzing sensor data (step 1024) and in some cases cooking may be ended (step 1022) . For e.g., if the statistical distance between current image at start of a cooking phase and recorded image at start of the same phase is more than a pre-defined threshold, the ingredients are likely very different from recommended ingredients for the recipe and error is flagged to the user. In another example, if the weight of the ingredients in cooking unit is significantly off the weight in recorded recipe file, error is flagged to the user .

[067] FIG. 11 shows one example of the sensory comparison step of FIG. 10, for images. A current thermal or visual is received (step 1102) . The image is resized to NxN (step 1104) and formed into M sub-images of NxN size (step 1106) . In other words, a 500x500 pixel image is reduced for processing efficiency and processed as a 100x100 image in step 1102. The 500x500 image is also broken into 25 sub-images of 100x100 in step 1104. As a result, the algorithm considers the overall image comparison as well as sub-image comparisons. In some embodiments, sub-images can be unequally weighted to reduce the influence of background colors and to increase the influence of the middle of a turkey, for example .

[068] Next, the dual paths of image comparison (i.e., steps 1104 and 1106) each perform two separate analyses: a first analysis is based on colors through a color histogram; and a second analysis is a texture analysis that is devoid of color and instead relying on a PSD (power spectral density) . The PSD comparison is directed towards a texture of the food. For example, frozen chicken has a texture that is distinct from thawed chicken, as well as from fully cooked chicken. Therefore, texture analysis can indicate the progress of a particular phase.

[069] The first of dual path analyses (i.e., histogram analysis) is based on colors. In more detail, the images are extracted into image histograms for different colors (steps 1108, 1112) so that a statistical distance can be computed with a histogram vector of at least one reference image (steps 1116, 1120) .

[070] The second of dual path analyses (i.e., texture analysis) is preferably based on a black and white image rather than colors. As shown in FIG. 13, a black and white image 1310 showing texture of either food being prepared a reference food in preparation, is represented as:

The square-shaped, black and white image 1310 is integrated over concentric circles of equal area 1320, 1330 to calculate a PSD (steps 1110, 1114) and are represented as: i!JM · · J for 1320; and

In turn, a statistical distance is computed with respect to a PSD vector of at least one reference image (steps 1118, 1122) . As a result, a one-dimensional PSD is computed for a two- dimensional image. Each element of one-dimensional PSD is obtained by integrating a square of Discrete Fourier Transform of the two-dimensional image over annular rings of equal area starting from the center, using, for example, the following formula :

This method of computing PSD allows comparison of texture for two images independent of orientation (e.g., a real-time image can be rotated 40 degrees within its frame and relative to a reference image) . Other embodiments can have one, two, or more paths for analyses, using the histogram and texture analysis of the present example, or other types of image analysis .

[071] In combination with weights Wl, W2 , W3 and W4 , a statistical measure of the distance between the current image and the reference image is determined (step 1124) for

determining a state of a phase or cooking process. The value of the weights can be fixed across all recipes, or it can be determined for a phase of recipe during post-processing of recipe data. For example, if for one cooking phase, the end of phase is better indicated with color histograms, then Wl and W3 can have higher weight than W2 and W4. Weightings can be adjusted per recipe file, per type of dish, be manually set, or be otherwise adjusted as appropriate. Thus, the two separate analyses for each of the dual paths of image

comparison, can be individually weighted. Further, the resized image of step 1104 and the sub images of step 1106 can be weighted separately, between each other and between the dual paths of analysis.

[072] As will be understood by those familiar with the art, the invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Likewise, the particular naming and division of the portions, modules, agents, managers, components, functions, procedures, actions, layers, features, attributes,

methodologies, data structures and other aspects are not mandatory or significant, and the mechanisms that implement the invention or its features may have different names, divisions and/or formats. The foregoing description, for purpose of explanation, has been described with reference to specific embodiments. However, the illustrative discussions above are not intended to be exhaustive or limiting to the precise forms disclosed. Many modifications and variations are possible in view of the above teachings. The embodiments were chosen and described in order to best explain relevant principles and their practical applications, to thereby enable others skilled in the art to best utilize various embodiments with or without various modifications as may be suited to the particular use contemplated.