FIELD OF THE INVENTION

Embodiments of the present invention generally relate to cooking process control, and particularly, to a method, apparatus, and computer program product for cooking process control based on detection of the initial status of food.

BACKGROUND OF THE INVENTION

It will be appreciated that the initial status of a certain type of food to be cooked may have some impact on the control of the cooking process. As used herein, the "initial status" refers to the status of food at or near the start of the cooking process. For example, the initial status may include whether the food is frozen or non- frozen, frozen state or degree of frozenness of the food, amount of the food, and so on forth. Generally speaking, the cooking profile or parameters should be selected at least partially based on the initial status of food. As an example, different cooking time and/or temperatures may be selected depending on whether the food is frozen.

Traditionally, the initial status of food is often judged by the human user and the cooking process is controlled based on the user selection of cooking time, cooking temperature and possibly other parameters. For example, the user may determine the initial status of a food he/she wants to cook according to some visual and/or touch cues, and then select a cooking program by operating buttons, knobs or any other mechanisms on the cooking device. However, human users especially those ordinary consumers are often incapable of accurately and quantitatively determining the initial status of various kinds of foods. As such, the cooking process would suffer from some human errors.

In order to achieve more sophisticated control to automatically select the cooking profile, several invasive or non- invasive methods have been proposed to detect the frozen/non-frozen status, for example, by sensing the initial temperature of food.

Unfortunately, either invasive or non-invasive methods have disadvantages that limit their applications. For example, the invasive methods usually require contact between the detecting tool and food, which might cause destruction or contamination of the food. Noninvasive methods generally rely on sensing technologies like infrared radiation (IR) which is only able to detect the surface temperature of the food. As a result, it is difficult to predict whether the food is volumetrically, partly or entirely frozen. Moreover, due to the

disadvantages such as high cost, inconvenient maintenance, and imprecision under harsh atmosphere (for example, cooking atmosphere), known solutions cannot satisfy the practical requirement of consumer cooking devices while supplying sufficient robustness for the cooking process control.

EP 0238022 A2 describes a heating apparatus for cooking cake comprising a gas sensor and weight sensor which are used to determine a total heating time.

EP 0001396 Al describes a method of cooking meats in a microwave oven by determining the mean internal temerature of the meat which is indicative of the internal doneness of meat as a function of sensed and sampled time dependent "in situ" humidity and temperature environemtal conditions.

US 2013/0092682 Al describes an oven comprising multiple energy sources and a cooking controller that is able to change the cooking parameters based on information received from an oven operator.

JP S58 47934 A describes a method of cooking in a high-frequency heater comprising setting a weight loss ratio based on the kind and amount of matter to be cooked, and ending cooking when the actual weight loss ratio reaches the set point.

In view of the foregoing, there is a need in the art for a more accurate and cost- effective solution for cooking process control.

SUMMARY OF THE INVENTION

In order to address the above and other potential problems, embodiments of the present invention propose a method, apparatus, and computer program product for cooking process control.

The invention is defined by the independent claims. The dependent claims define advantageous embodiments. In one aspect, embodiments of the present invention provide a method for controlling a cooking process of a food.

The method comprises the steps of: detecting a weight change of a first vaporizable component in the food over a first period of time; determining an initial status of the food at least partially based on the detected weight change of the first vaporizable component in the food; and controlling the cooking process at least partially based on the determined initial status. Other embodiments in this regard include a corresponding computer program product for cooking process control.

In another aspect, embodiments of the present invention provide an apparatus for controlling a cooking process of a food. The apparatus comprises: a detecting unit configured to detect a weight change of a first vaporizable component in the food over a first period of time, the first vaporizable component including water of the food; an initial status determining unit configured to determine an initial status of the food at least partially based on the detected weight change of the first vaporizable component in the food; and a cooking control unit configured to control the cooking process at least partially based on the determined initial status.

These embodiments of the present invention can be implemented to realize one or more of the following advantages. In accordance with embodiments of the present invention, the initial status of a food may be determined by detecting weight change of a vaporizable component(s), such as water, in the food. In this way, determination of the initial status can be done without contact with the food, thereby avoiding any destructions or contaminations. Additionally, since weight change of the vaporizable component in the food can be accurately detected with reliable, low-cost devices, it is possible to determine the initial status of food and control the cooking process with high accuracy while maintaining the costs at a relatively low level. Furthermore, exemplary embodiments of the present invention need little or no intervention of the users and can be applied in connection with various kinds of cooking devices.

Other features and advantages of embodiments of the present invention will also be understood from the following description of exemplary embodiments when read in conjunction with the accompanying drawings, which illustrate, by way of example, spirit and principles of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The details of one or more embodiments of the present invention are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages of the invention will become apparent from the description, the drawings, and the claims, wherein:

Fig. 1 is a flowchart illustrating a method for controlling cooking process of a food in accordance with exemplary embodiments of the present invention;

Figs. 2A and 2B schematic diagrams illustrating thermo-gravimetric profiles for French fries and meat balls, respectively, in accordance with an exemplary embodiment of the present invention; and

Fig. 3 is a block diagram illustrating an apparatus for controlling cooking process of a food in accordance with exemplary embodiments of the present invention.

Throughout the figures, same or similar reference numbers indicates same or similar elements.

DETAILED DESCRIPTION OF EMBODIMENTS

In general, embodiments of the present invention provide a method, apparatus, and computer program product for cooking process control. One of the core inventive ideas of the present invention is to determine the initial status of food by detecting the weight change of water or any other vaporizable components within the food during a certain period of time. Since the weight change can be measured in various reliable and low-cost manners, embodiments of the present invention provide an accurate and cost-effective manner for determining the initial status of food (for example, frozen/non- frozen, amount of the food, and so forth) and to control the cooking process accordingly.

Reference is now made to Fig. 1, where a flowchart of a method 100 for controlling the cooking process in accordance with exemplary embodiments of the present invention is shown.

At step S101, weight change of a first vaporizable component in the food is detected over a first period of time. As used herein, the "vaporizable component(s)" refers to any components that may evaporate from the food under a certain condition(s). For example, in some embodiments, the vaporizable component may be water in the food. As known, water will evaporate as the temperature increases, for example, when the food is being heated. Alternatively or additionally, it is possible to detect the weight change of any other suitable vaporizable components in the food such as vaporizable grease and the so on forth. Only for the purpose of illustration, in the following discussions, some exemplary embodiments will be described with reference to the water. However, it should be noted that the scope of the invention is not limited in this regard.

In some embodiments, weight change of the first vaporizable component in the food may be detected as a process separate to the cooking process. That is, in such embodiments, weight change of the first vaporizable component in the food and thus the initial status of food are detected before the cooking process starts. In this way, the entire cooking process may be controlled according to the determined initial status of the food, such that the food can be well cooked.

Alternatively, in some other embodiments, the detection of weight change of the first vaporizable component in the food as well as the determination of the initial status of food may be done as a portion of the cooking process. More specifically, in such

embodiments, the first period over which weight change of the first vaporizable component in the food is detected may be an initial period of cooking time for the cooking process. As an example, initially the user may select a cooking profile or program, for example, randomly or according to personal experience or some visual/touch cues. Then in an initial period (for example, several minutes) of the cooking time, weight change of the first vaporizable component may be detected, such that the initial status of food may be determined to control the remaining cooking process. This would be advantageous in terms of the cooking time since no extra time is need.

In some embodiments, in order to facilitate detecting weight change of the first vaporizable component in the food, the food may be placed into an environment with predefined configuration. For example, the food may be placed into an oven or any other suitable cooking device with predefined humidity, temperature, and so on forth. Specifically, in some embodiments, the food may be pre-heated to speed up the evaporation of the first vaporizable component.

In accordance with embodiments of the present invention, at step S101, weight change of the first vaporizable component in the food may be detected in various manners. For example, assume that during the first period of time, evaporation of the first vaporizable component is the only reason for the weight change of food. Then according to the law of conservation of mass, the weight loss of the food is quantitatively equal to the weight of the first vaporizable component that vaporizes from the food. Accordingly, in some exemplary embodiments, weight change of the first vaporizable component in the food may be detected by measuring weight change of the food per se during the first period of time. In accordance with embodiments of the present invention, weight change of the food in the first period of time may be detected in several cost-effective and accurate manners. For example, in some embodiments, the initial weight of the food is measured and recorded. Then the food weight may be sampled over time. The sampling of the food weight may be performed periodically (for example, every one or two minute), for example.

Alternatively, the sampling may be performed continuously until sufficient data have been collected to determine the initial status. The sampling of food weight may be done, for example, by use of a weight sensor(s) or electronic balance integrated with the cooking device. Based on the samples of the food weight as well as the initial weight, a set of values for the weight change of the food may be calculated.

Additionally or alternatively, in some embodiments, one or more other features related to weight change of the food may be measured. As an example, in some embodiments, elapsed time upon reaching at least one predefined amount of weight change of the food may be measured. As another example, based on the set of values for the weight change of the food, it is possible to establish a thermo-gravimetric (TG) profile that characterizes weight change of the food within the first period of time. For example, the TG profile may be embodied as a curve describing weight change of the food over time, which will be discussed below with reference to Figs. 2A and 2B. In some embodiments, the TG profile may be normalized, de-noised or otherwise processed, for example. Then at least one morphological feature may be extracted from the TG profile depending on the predication model used to identify the initial status. Examples of the morphological features may include, but not limited to, derivatives of any orders, slope, gradient, and so on forth.

It should be noted that though detecting weight change of the food is an efficient manner for detecting weight change of the first vaporizable component in the food, the scope of the present invention is not limited thereto. For example, in those embodiments where the first vaporizable component is the water in the food, at step S101, weight change of the first vaporizable component in the food may be detected by detecting the change of an environment parameter(s) during the first period time. Example of such environment parameter includes, but not limited to, humidity. It would be appreciated that in a closed environment like an oven, humidity of the surrounding air will increase as the water of the food evaporates. Thus, by monitoring the change of the environmental humidity, weight change of the water may be derived. Any suitable humidity sensors, no matter currently known or developed in the future, may be utilized to detect the humidity, and the scope of the present invention is not limited in this regard. As another example, at step S101, weight change of the first vaporizable component in the food may be detected by directly measuring the amount of the first vaporizable component that has evaporated from the food during the first period of time. For example, it is known that when the water evaporates into the air, the water molecules will rotate with alternating electromagnetic fields and transform their energy into heat.

Accordingly, radio frequency (RF) radiation with suitable frequency may be used to directly detect the amount of evaporated water. Based on the detected amount of evaporated water, weight change of the water in the food may be derived.

It should be noted that in accordance with embodiments of the present invention, different technologies for detecting weight change of the first vaporizable component in the food may be used alone. Or, alternatively, two or more of them may be combined in any suitable manners. Moreover, the scope of the present invention is not limited to the examples as discussed above. Rather, any other suitable technologies, whether currently known or developed in the future, may be used to detect or evaluate weight change of the first vaporizable component in the food.

Continuing reference to Fig. 1, the method 100 then proceeds to step SI 02 where the initial status of food is determined at least partially based on the detected weight change of the first vaporizable component in the food.

As discussed above, the "initial status" refers to the status of food at or near the start of the cooking process. For example, the initial status may include whether the food is frozen or non- frozen, frozen state or degree of the food, amount of the food, and so on forth. As an example, the frozen states may be divided as several levels, each of which is corresponding to a range of food temperatures.

In accordance with embodiments of the present invention, the correlation between weight change of the first vaporizable component in the food (or the weight of the food in some embodiments) and the initial status of food may be established in advance. For example, in some embodiment, it is possible to simply compare the weight change of the first vaporizable component in the food with a predefined threshold(s) and then determine the initial status based on the comparison. As an example, there may be two candidate initial statuses, frozen and non-frozen. If the weight change of the first vaporizable component in the food is higher than the predefined threshold within the first period of time, then the initial status of food may be determined as frozen status. Otherwise, if such weight change is below the threshold, the initial status of food may be determined as non-frozen status. In order to implement more sophisticated control of the cooking process, in some embodiments, the correlation between weight change of the first vaporizable component in the food and the initial status of food may be characterized by a prediction model(s). Generally speaking, the prediction model may be considered as a classifier for identifying the initial status of food based on one or more features related to weight change of the first vaporizable component in the food which may include, for example, one or more features representing the weight change of the food. As discussed above, the required features are collected at step S101 and may include, but not limited to, values for the weight change or its rate of the first vaporizable component in the food at one or more time instants, the time that has elapsed before reaching a pre-determined amount of weight change, or any other features extracted from the TG profile established in training. These features may be used as input to the prediction model at step SI 02 to obtain a predicted initial status of the food.

In some exemplary embodiments, the prediction model may predict the initial temperature of the food based on the input one or more features. Then the frozen status and possibly the specific frozen level of the food may be determined based on the predicted temperature. Alternatively, in some embodiments, the prediction model may directly map the extracted feature(s) to an initial status of food.

In accordance with embodiments of the present invention, any suitable prediction models may be applied to determine the initial status of food. Example of the prediction models include, but not limited to, statistical models such Hidden Markov Model (HMM) and support vector machine (SVM), artificial neural network, or any other suitable prediction models. The prediction model may be trained in advance, and in some

embodiments, may be refined in use.

Specifically, in some embodiments, the predication model may be established and trained with respect to individual types of foods. That is, different prediction models will be used for different types of foods. This would be beneficial to improve the accuracy of the initial status prediction since it is known that the evaporation properties might be different for different types of foods. Accordingly, in some embodiments, determining the initial status of food may comprise obtaining the food type. In some embodiments, the food type may be specified by the user. For example, the user may use mechanisms on the cooking device to select or otherwise specify the food type. Alternatively, the food type may be automatically identified, for example, by means of suitable sensors, machine visions, or pattern recognition technology. As an example, in some embodiments, one or more images of the food may be acquired and analyzed to recognize the shape or other features of the food to thereby determine the food type.

In those embodiments where the food type is obtained, the initial status of food may be determined from the prediction model based on the weight change of the first vaporizable component in the food as detected at step SlOl and from the obtained food type. More specifically, a prediction model that is designed for the selected food type may be selected. Then one or more features related to weight change of the first vaporizable component in the food are input to the selected prediction model to determine the initial status.

It should be noted that though obtaining and utilizing the food type would be beneficial in some embodiments, this is not necessarily performed. For example, for those special cooking device which is designed to cook similar types of foods, a single prediction model is enough and thus there is no need to obtain the food type. Therefore, in some embodiments, the step of obtaining food type may be omitted.

As shown in Fig. 1, at step SI 03, the cooking process is controlled at least partially based on the determined initial status of the food. In general, the cooking profile or one or more parameters thereof for the cooking process may be adjusted according to the determined initial status. For example, the cooking time, temperature, and/or any other relevant parameters or settings may be adapted. In some embodiments, the cooking profile for each initial status of food may be predefined. Only for the purpose of illustration, the following table shows an example.

As discussed above, in some embodiments, determination of the initial status may be performed prior to the cooking process. Accordingly, in these embodiments, the cooking process may be controlled, from the very beginning, to utilize the cooking profile corresponding to the determined initial status. Alternatively, the initial status may also be determined within cooking process. That is, the first period of time for the initial status determination is an initial period of the cooking time, such as the first several minutes. In these embodiments, if it is found that the initial cooking profile is not suitable for the determined initial status, then at step SI 03, the cooking profile or its parameter(s) for the remaining cooking process may be adjusted. On the other hand, if the initial cooking profile selected by the user is exactly the one corresponding to the determined initial status, then no adjustment is required for the remaining period of cooking time. In other words, in accordance with embodiments of the present invention, control of the cooking process includes making no change to the cooking profile.

In addition, in some embodiments, control of the cooking process at step SI 03 may further comprise automatically monitoring doneness or cooking-ready time for the food. To this end, change weight of a second vaporizable component in the food may be detected over a second period of time in the cooking process. In accordance with embodiments of the present invention, the second vaporizable component may or may not be the same as the first vaporizable component. For example, in some embodiments, the second vaporizable component may be the water in the food as well, and one or more of the following features may be detected for at least one time instant within the second period of time: moisture loss, rate of moisture loss; change of moisture loss rate, and so on forth. The weight change of the second vaporizable component in the food may be detected in similar manners as discussed above with respect to the first vaporizable component and thus will not be repeated.

Based on the detected weight change of the second vaporizable component in the food as well as the initial status as determined at step SI 02, the doneness and cooking- ready time for the food may be determined. For example, for a certain type of food in a given initial status, it may be determined that the food is well-done when the moisture loss reaches a predefined value. Furthermore, in some embodiment, the user is allowed to select the doneness level (for example, light, medium, and well-done) he/she desires. A model may be used to characterize the correlation between each of the possible doneness levels and weight change of the second vaporizable component in the food (or the weight change of the food in some embodiments). Then, based on the detected weight change of the second vaporizable component in the food over the second period of time, the cooking process may be controlled to reach the doneness level desired by the user.

Only for the purpose of illustration, an example will now be discussed. In this example, the foods to be cooked include French fries and meat balls. An electronic balance is used for weight measurement and a thermometer is used to measure initial temperature of the foods before frying. The foods are placed into a food basket and at the same time, the initial weight is recorded. As the frying proceeds, the weight of foods is detected and recorded. Conditions in this example are listed below (for both French fries and meat balls):

Initial status: frozen, non- frozen

Initial weight: 300g, 300g, 500g Frying temperature: 200°C

Total frying time: about 20 minutes

Fig. 2A shows TG profiles 201 and 202 established for frozen and non- frozen French fries when heated in Air Fryer. Specifically, in Fig. 2A, the curve 201 represents the TG profiles for French fries in frozen states, while the curve 202 represents the TG profiles for French fries in non- frozen states. As described above, a TG profile describes the weight change of the food over time. Likewise, in Fig. 2B, the curve 203 represents the TG profiles established for meat balls in frozen states, while the curve 204 represents the TG profiles for meat balls in non- frozen states. In Figs. 2A and 2B, the vertical axis represents the normalized weight in arbitrary units, and the horizontal axis represents the frying time in seconds.

In training, the TG profiles in form of weight change curves are normalized, de-noised and smoothed. It can be seen that the TG profiles are different for foods that are initially frozen and non- frozen. Therefore, the initial status (frozen or non- frozen) may be determined by using the features of the TG profile in combination with the initial weight of the foods. More specifically, in this example, the normalized remaining weight of the food at the 180th seconds of frying (denoted as RW) will be used to determine the initial status. The initial food weight (denoted as M), as an independent predictor variable, is also taken into account. In this example, the prediction model characterizes the correlation between the initial temperature (denoted as T) of foods and the two independent variables, RW and M, as follows:

T= a*RW + b*M + c*RW*M + d

where a, b, c, and d represent parameters. Through training the prediction model by linear regression based on collected training data, values of the parameters are derived as follows:

In detecting the initial status, values of the variables M and RW are detected and input into the prediction model to thereby obtain a predicted initial temperature T. Then categorization of the initial status may be done according to the pre-defined temperature intervals. For example, if the value of T is below or equal to the threshold of 0°C, the initial status of food may be determined as frozen. If the estimated value of T is higher than 0°C, the initial status of food may be determined as non- frozen. Experimental results show that the initial status of foods can be correctly identified.

Fig. 3 shows a block diagram of an apparatus for controlling cooking process of a food in accordance with embodiments of the present invention. As shown, the apparatus 300 comprises: a first detecting unit 301 configured to detect a weight change of a first vaporizable component in the food over a first period of time, the first vaporizable

component including water in the food; an initial status determining unit 302 configured to determine an initial status of the food at least partially based on the detected weight change of the first vaporizable component in the food; and a cooking control unit 303 configured to control the cooking process at least partially based on the determined initial status of the food.

In some embodiments, the first detecting unit 301 may comprise at least one of: a food weight detecting unit configured to detect a weight change of the food during the first period of time; an environmental parameter detecting unit configured to detect a change of an environmental parameter during the first period of time, the environment parameter including humidity; and a component weight detecting unit configured to detect amount of the first vaporizable component that evaporates from the food during the first period of time.

In some embodiments, the food weight detecting unit may comprise at least one of: a weight sampling unit configured to sample the weight change of the food for at least one time instant within the first period of time; a time determining unit configured to determine elapsed time upon reaching at least one predefined amount of the weight change of the food; and a feature extracting unit configured to extract at least one morphological feature from a thermo-gravimetric profile that characterizes the weight change of the food over the first period of time.

In some embodiments, the first period of time may be an initial period of cooking time for the cooking process. In these embodiments, the cooking control unit 303 may be configured to adapt, at least partially based on the determined initial status of the food, the cooking process in a remaining period of the cooking time.

In some embodiments, the food may be placed in an environment with a predefined configuration to facilitate the detecting of the weight change of the first

vaporizable component. In some embodiments, the apparatus 300 may further comprises a food type obtaining unit configured to obtain a type of the food. In these embodiments, the initial status determining unit 301 may be configured to determine the initial status of the food from a predefined prediction model based on the detected weight change of the first vaporizable component in the food and from the obtained type of the food.

In some embodiments, the apparatus 300 may further comprises: a second detecting unit configured to detect a weight change of a second vaporizable component in the food over a second period of time in the cooking process; and a doneness determining unit configured to determine doneness of the food based on the detected weight change of the second vaporizable component in the food.

It should be noted that the apparatus 300 may be implemented as hardware, software/firmware, or any combination thereof. In some embodiments, one or more units in the apparatus 300 may be implemented as software modules. For example, embodiments of the present invention may be embodied as a computer program product that is tangibly stored on a non-transient computer-readable medium. The computer program product comprises machine executable instructions which, when executed, cause the machine to perform steps of the method 100. Alternatively or additionally, some or all of the units in the apparatus 300 may be implemented using hardware modules like integrated circuits (ICs), application specific integrated circuits (ASICs), system-on-chip (SOCs), field programmable gate arrays (FPGAs), and so on forth. Moreover, in some embodiments, the apparatus 300 may be integrated into the cooking device. Alternatively, the apparatus 300 may operate as a separate device.

In general, the various exemplary embodiments may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. While various aspects of the exemplary embodiments of the present invention are illustrated and described as block diagrams, flowcharts, or using some other pictorial representation, it will be appreciated that the blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

In the context of the present invention, a machine readable medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device. The machine readable medium may be a machine readable signal medium or a machine readable storage medium. A machine readable medium may include but not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the machine readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

Computer program code for carrying out methods of the present invention may be written in any combination of one or more programming languages. These computer program codes may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program codes, when executed by the processor of the computer or other programmable data processing apparatus, cause the functions/operations specified in the flowcharts and/or block diagrams to be implemented. The program code may execute entirely on a computer, partly on the computer, as a stand-alone software package, partly on the computer and partly on a remote computer or entirely on the remote computer or server.

The above embodiments as described are only illustrative, and not intended to limit the technique approaches of the present invention. Although the present invention is described in details referring to the preferable embodiments, those skilled in the art will understand that the technique approaches of the present invention can be modified or equally displaced without departing from the spirit and scope of the technique approaches of the present invention, which will also fall into the protective scope of the claims of the present invention. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. Any reference signs in the claims should not be construed as limiting the scope.