Method for recording cooking food and cooking equipment

Abstract

A method for detecting food placed on a cooking surface (14) to be heated uses a light marker projector (36) spaced apart from at least one sensor (32) to determine the properties of the food. Furthermore, a cooking device (10) is proposed.

Description

[0001] The invention relates to a method for detecting food to be cooked which is placed on a frying surface to be heated, as well as to a cooking appliance.

[0002] Various concepts are being considered to monitor and detect the food placed on professional cooking appliances with an essentially flat cooking surface.

[0003] For example, the cooking status, degree of doneness, size, or even the type of food placed on the food should be detected. This data can be used, for example, to instruct the operator or to automatically control the cooking process.

[0004] However, the environment for optical sensors is extremely unfavorable due to the heat, steam or fumes, which make it difficult to see the food being cooked and very quickly lead to contamination of the optics.

[0005] WO 2010 / 135478 A2 discloses a control system for a household appliance in which the user interface is projected onto a kitchen surface. Furthermore, a light marker projector is shown that helps determine the shape of an object and its outline on the user interface.

[0006] DE 10 2014 210 672 A1 describes a cooking appliance with a closed cooking chamber equipped with a light pattern projector and a camera. This allows the three-dimensional shape of the food to be determined.

[0007] DE 10 2019 204 531 A1 shows another cooking appliance with a so-called sample light.

[0008] DE 10 2010 039 371 A1 describes a control device for a household appliance in which the operating processes as well as the position within a detection range are detected by means of an optical detection unit.

[0009] The object of the invention is therefore to provide a method for detecting food that is characterized by advantageous detection properties. Furthermore, a cooking appliance is to be provided that allows reliable detection of the properties of the food despite heat, steam, and vapors.

[0010] The invention provides a method for detecting food to be cooked which is placed on a frying surface to be heated, characterized by the following steps: Providing a light marking projector laterally above the frying surface, Providing at least one sensor laterally above the cooking surface and away from the light marking projector for detecting light markings projected onto the food, Providing evaluation electronics coupled to the light marking projector and the at least one sensor, Activating the light marking projector and the at least one sensor by means of the evaluation electronics, wherein the light marking projector projects light markings towards the frying surface, and Determining food properties based on the data detected by at least one sensor using the evaluation electronics.

[0011] The light marker projector is capable of projecting light markers, i.e., a predetermined, particularly evenly distributed pattern, onto the cooking surface and thus onto the food. It has been shown that by limiting the emitted light using light stripes or, more generally, light patterns, high data accuracy is possible despite the aforementioned problematic external influences. This projection, as mentioned above, allows for a very comprehensive determination of properties of the food, e.g., its dimensions and degree of doneness or its cooking state, using the evaluation electronics.

[0012] The pattern itself can be irregular so that the spatial position can be determined based on the local individual pattern characteristics. For example, stripes could have small, individual bulges that define a coordinate. However, these stripes are evenly distributed.

[0013] In particular, numerous light markers, possibly even intersecting light stripes, are projected onto the cooking surface and thus onto the food placed there. This means that the entire cooking surface is covered with spaced-apart light markers (i.e., a light pattern). The light marker projector can optionally be a stripe projector.

[0014] The distance between the light markers on the projected surface is preferably less than 5 mm to obtain accurate 3-dimensional location and volume information.

[0015] For example, the light marking projector can emit infrared light stripes or infrared light patterns in the near-IR spectrum, preferably with a wavelength in the range of 800-1000 nm.

[0016] This spectral range is barely visible to the human eye, or even invisible. Furthermore, it has proven advantageous in vapor environments.

[0017] Additionally or alternatively, light patterns with a visible wavelength in the range of 400-800 nm are generated.

[0018] The projected light markings can represent a time-constant or time-variable, predefined pattern.

[0019] An additional improvement in the data results can be achieved if the light marking projector also emits infrared light stripes or infrared light patterns with a wavelength in the range of 3-4 µm (i.e. in the far-IR spectrum) and at least one sensor or another sensor detects these light markings on the food being cooked.

[0020] Here, too, numerous light markers, possibly even intersecting light stripes, are projected onto the cooking surface and thus onto the food being cooked. These light markers can be congruent with the aforementioned light markers in the near-IR range or offset from them.

[0021] The process can be simplified if the sensor or another sensor optically detects the food without light markings. The evaluation unit compares the acquired data with and without light markings, and based on this, data on the three-dimensionality of the food is determined. Simply put, the image content with and without projected illumination is subtracted from one another to obtain the pure image content from the light marking projection. This allows three-dimensional information to be determined very reliably and precisely. Furthermore, the sensor effort is reduced. The 3-dimensional shape, including the caliber of the food, can be determined very precisely.

[0022] In some cases, it may be sufficient to use only one sensor.

[0023] If data is collected with and without light markers, the food can be detected alternately with and without light markers by at least one sensor, particularly at a time interval of less than 0.5 seconds or even 0.2 seconds. This has the advantage, among other things, that if the light is minimally detected by the user, they will not be disturbed by the brief activation of the light markers. Furthermore, the short time sequence ensures that the situation on the cooking surface and the surface of the food is identical for both measurements, i.e., that the food has not been noticeably further cooked and has not been moved or removed.

[0024] The temporal sequences of such alternating scanning processes can last several seconds; for example, data with and without light markings are recorded at short intervals of 10 seconds, for example, for less than one second. This reduces the amount of data and also potentially disrupts the user due to the light markings, which may be barely visible.

[0025] An additional, simple sensor independent of the camera system, for example based on time-off light or radar, can be used to start scanning the cooking area using the above-mentioned system sensor in the event of changes in the area of ​​the cooking appliance due to operator intervention.

[0026] In order to adjust the spectrum of light used more precisely, one or more optical filters can be used in front of the detecting sensor to reduce the radiation spectrum outside the detection wavelength.

[0027] The accuracy of the data is increased if a distance measuring system is also provided to record the distance to the food. The data thus acquired is used to determine the properties of the food, in this case the dimensions of the food, as it allows the nonlinear progression of the light stripes or patterns on the food to be more accurately evaluated with regard to the topography of the food.

[0028] In this context, optical color sensors or TOF sensors, for example, can be advantageous because they allow a color or monochrome image to be provided, thus providing additional information that can be processed to determine the properties of the food. Certain TOF sensors also allow distance measurement, so these sensors can even provide two types of information.

[0029] The use of radar sensors is also possible.

[0030] Furthermore, the temperature of the food being cooked can optionally be measured via at least one sensor to determine the cooking progress and control the cooking process. Such temperature measurement can be achieved, for example, using a microbolometer.

[0031] If the frying surface is so large that it cannot be detected by a single sensor, several sensors are provided next to each other, covering the area they detect, so that the entire frying surface can be compiled from the individual pieces of information and thus detected.

[0032] A variant of the invention provides that a detection system structure in the form of a structural unit is used for the complete data acquisition, in which a single sensor or all sensors in the case of several sensors are accommodated.

[0033] To capture the entire frying surface using a camera or just a single sensor, an optically distorting (aspherical) lens, e.g., made of plastic, can optionally be used. This lens is positioned in front of the preferably single sensor. Alternatively, an aspherical mirror can be provided in the optical beam path to correct the geometric distortion caused by the camera positioning. Such an optically corrected data image field can also be numerically processed as a basis for further data processing.

[0034] The sensor data can be evaluated using statistical calculations or artificial intelligence. Output data obtained through testing is stored in the evaluation electronics and serves as reference or learning output values.

[0035] The above-mentioned object is further achieved by a cooking appliance, in particular for carrying out the aforementioned method according to the invention. The cooking appliance has a cooking surface to be heated and a housing edge surrounding the cooking surface, as well as an upwardly projecting tube attached to the cooking appliance side, to which at least one optical sensor is fastened, the cabling of which runs within the tube to evaluation electronics accommodated on or in the cooking appliance, wherein a light marking projector is connected to the cooking appliance side and spaced from the at least one sensor. A light marking projector can in particular be firmly connected to the cooking appliance, in particular to its housing, and spaced from the at least one sensor, such that the alignment of the sensor and its light marking projector to the cooking surface and to one another is fixed, which prevents readjustment when the cooking appliance is moved.Furthermore, initial installation and alignment are significantly simplified.

[0036] Attaching the sensor to the cooking appliance via the tube ensures both stable and simple positioning above and to the side of the cooking surface, allowing it to scan the surface from the side and thus enable 3D detection of the food surface. It's also important that the tube allows for easy cleaning, meaning that vapors don't pose a permanent problem for data acquisition or put strain on the wiring or contacts.

[0037] The cooking appliance is, in particular, a device with a pan, the bottom of which forms the cooking surface. The edge of the housing, to which the light marker projector is attached, is the edge of the pan.

[0038] The light marking projector can also be attached to a housing of a base part on which the tile is pivotably mounted.

[0039] The evaluation electronics can be arranged next to the frying surface, i.e. at a distance from it to the side.

[0040] The sensor and the tube are preferably provided in a corner area, namely a rear corner area of ​​the housing edge.

[0041] Alternatively, this pipe can be mounted remotely from the cooking surface, attached to a control unit that is mechanically connected to the side of the cooking surface. The greater distance from the steam, heat, and vapors generated during the cooking process reduces the environmental impact and the likelihood of contamination of the pipe unit.

[0042] The light marker projector is attached either on or in the same tube but laterally offset from the sensor or on or in another upwardly projecting tube attached to the cooking appliance side, in particular a tube at the opposite edge area or opposite corner area.

[0043] The light marking projector is designed in such a way that, according to one variant, it can emit infrared light markings with a wavelength in the range of 800-1000 nm.

[0044] The light marking projector is designed in such a way that, according to one variant, it can emit light markings in a visible wavelength in the range of 400-800 nm.

[0045] Another variant provides that the light marking projector can also emit this aforementioned infrared light marking or another infrared light marking with a wavelength in the range of 3-4 µm.

[0046] The at least one sensor detects the infrared light in the near range specified above or in the near-field and far-field IR range specified.

[0047] The sensor tube and / or the light-marking sensor tube are mounted on the housing edge or on a control unit or base, with the control unit or base being mechanically connected to the side of the cooking surface. The control unit / base comprises an outer housing that forms the mechanical support for the tube(s).

[0048] Further features and advantages of the invention will become apparent from the following descriptions and the following drawings, to which reference is made. Fig. 1 shows a schematic representation of a cooking appliance according to the invention for carrying out the method according to the invention.

[0049] In Fig. 1 shows a cooking appliance 10 which, in the variant shown, which is not to be understood as limiting, comprises a pan 12.

[0050] The pan 12 has a base that can be heated and forms a frying surface 14 on which food 16 can be fried.

[0051] The base is surrounded by a side wall 18, which extends upwards to a surrounding housing edge 20. The housing edge 20 is also referred to as the crucible edge.

[0052] Optionally, the pan 12 can be pivoted about a pivot axis A, preferably by motor, so that its front edge can be lowered, for example to pour free-flowing food 16 out of the pan 12.

[0053] The pan 12 is attached to a base part 22 for supporting the pan 12 and, if necessary, for accommodating a pivot bearing. Depending on whether the cooking appliance 10 is a tabletop cooking appliance or a floor-standing cooking appliance, the base part 22 can be short in height or extend all the way to the floor.

[0054] The base part 22 contains a control unit with evaluation electronics 24, which is part of the control unit. Reference 26 denotes a display and control unit. This evaluation electronics 24 is positioned next to the frying surface 41.

[0055] In this case, the base part 22 forms a control unit because its housing 25 contains evaluation electronics 24. Therefore, the housing 25 also belongs to the control unit.

[0056] A tube 28 is attached to a corner region of the housing edge 20, on which a camera 30 with one or more optical sensors 32 is provided in the region of its upper end.

[0057] At the opposite corner, also in the rear section of the housing edge 20, a second tube 34 is provided, which carries a light-marking projector 36, which may be a stripe projector, for example. This light-marking projector 36 can be located on or in the tube 34.

[0058] Alternatively, a crossbar is attached to the tube 28 so that the light marking projector 36 and camera 30 can be mounted at a distance from each other.

[0059] The cabling 38 of the camera 30 and the light marking projector 36 each runs through the interior of the pipe and through a chamber below the housing edge 20 to the evaluation electronics 24.

[0060] Alternatively, the tube 34 or the tube 28, including the devices attached thereto, can also be attached to the control unit, more precisely to its housing 25, preferably at the upper rear edge portion near the rear corner region of the housing edge 20. If the control unit is not housed in the illustrated housing 25 but elsewhere, the housing 25 is still present because it supports the crucible 12. In this case, the tube 28 and / or 34 is optionally attached to the housing 25 of the base part 22.

[0061] The light marking projector 36 is capable of projecting preferably parallel, minimally spaced light patterns or light markings 40, for example in the form of stripes, onto the entire frying surface 14, some of which are shown only as examples in order to maintain clarity.

[0062] The projected light markings 40 form a temporally constant or temporally variable, defined pattern. This pattern is, in particular, an optically uniformly distributed pattern. Optionally, when using light stripes, these can run not only parallel but also crosswise, as outlined.

[0063] Some of the light markers 40 or all of the light markers 40 are light markers with a wavelength of light in the range of 800-1000 nm or 400-800 nm.

[0064] These light markers 40 may additionally include light with a wavelength in the range of 3-4 µm or there are other light markers defined by light in this other IR frequency range.

[0065] The light of the light markings 40 is preferably, and this is not intended to be limiting, detected exclusively by the camera 30 and, in this case, preferably only by one sensor 32. Alternatively, several different sensors can be provided in the camera 30.

[0066] To ensure that only light in this near-IR range or in both IR ranges reaches the sensor(s) 32, one or more infrared filters 42 are provided in front of the sensors 32.

[0067] If the sensor(s) 32 cannot detect the entire frying surface, an optically distorting lens 44 can be mounted, for example, directly in front of the sensor(s) 32, via which light on the entire frying surface 14 can then be detected by the sensor(s) 32.

[0068] The singular sensor 32 is one or more sensors 32 comprising a TOF sensor. This can optionally not only provide distance information but also allows for the creation of a monochrome image of the situation on the frying surface 14.

[0069] In addition, other optical sensors can of course also be used, which may also provide colour information and thus allow conclusions to be drawn about the degree of browning of the food 16.

[0070] Furthermore, a temperature sensor and / or a radar sensor may also be present.

[0071] Using the data obtained by the sensor(s) 32, the evaluation electronics 24 determines properties of the food being cooked. For example, the type of food 16 itself, its cooking state, the position of the food on the cooking surface 14, the temperature of the food 16, and / or the caliber of the food 16 can be determined. This is done, for example, through a statistical evaluation and / or an evaluation using artificial intelligence.

[0072] The information obtained allows the cooking process to be controlled, commands to be given to the user or errors to be indicated.

[0073] The caliber of the food 16 is recorded very precisely thanks to the lateral arrangement of the camera 30; this is achieved by the combination of 3-dimensional recording by means of the perspective displacement of the light markings and their evaluation and visual image capture.

[0074] The quality of the data can be improved by having the sensor(s) 32 not only acquire data when light markers are projected, but also when data is acquired without light markers, which are then compared with the data with light markers. To separate these different measurement situations, the projection of the light markers is switched off or prevented, and during this time the cooking surface 14 and the surface of the food 16 are sensed. Shortly thereafter, light stripes or, more generally, light markers 40 are projected again, and by means of these, the cooking surface 14 and the surface of the food 16 are sensed again.

[0075] The time interval between these two different measurements can be less than 0.5 seconds, in particular less than 0.2 seconds. Simply put, the image contents thus captured are subtracted from each other to calculate three-dimensional information about the surface structure and, in turn, the dimensions of the food 16, including its thickness. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] WO 2010 / 135 478 A2

[0005] DE 10 2014 210 672 A1

[0006] DE 10 2019 204 531 A1

[0007] DE 10 2010 039 371 A1

[0008]

Claims

[1] Method for detecting food (16) to be cooked, which is placed on a frying surface (14) to be heated, characterized by the steps: A) providing a light marking projector (36) laterally above the frying surface (14), B) providing at least one sensor (32) laterally above the frying surface (14) and away from the light marking projector (36) for detecting light markings (40) projected onto the food (16), C) providing evaluation electronics (24) coupled to the light marking projector (36) and the at least one sensor (32), D) activating the light marking projector (36) and the at least one sensor (32), wherein the light marking projector (36) projects light markings (40) towards the frying surface (14), and E) Determining food properties based on the data sensed by at least one sensor (32). [2] Method according to claim 1, characterized bythat the light marking projector (36) generates light markings (40) with a wavelength in the range of 800-1000 nm. [3] Method according to claim 1 or 2, characterized by that the light marking projector (36) generates light markings (40) with a visible wavelength in the range of 400-800 nm. [4] Method according to one of the preceding claims, characterized by that the projected light markings (40) represent a temporally constant or temporally variable, defined pattern. [5] Method according to one of the preceding claims, characterized by that the light marking projector (36) additionally emits infrared light strips with far infrared light, in particular with a wavelength in the range of 3-4 µm, and the at least one sensor (32) or a further sensor detects this infrared light strip. [6] Method according to one of the preceding claims, characterized bythat the 3-dimensional shape, in particular the caliber of the food (16) to be cooked, is determined by means of the data recorded in at least one sensor (32). [7] Method according to one of the preceding claims, characterized by that the sensor (32) or another sensor detects the food (16) to be cooked optically without light stripes, and in the evaluation unit (24) the recorded data with and without light markings are compared and, based on this, data on the three-dimensionality of the food (16) are determined. [8] Method according to one of the preceding claims, characterized by that the food (16) is detected by at least one sensor (32) alternately with and without light marking, in particular at time intervals of less than 0.5 seconds. [9] Method according to one of the preceding claims, characterized by that an infrared filter (42) is positioned in front of the sensor (32) to reduce the radiation spectrum outside the detection wavelength. [10] Method according to one of the preceding claims, characterized by that the distance to the food (16) is detected by means of a distance measuring sensor and the data thus detected are used to determine the properties of the food. [11] Method according to one of the preceding claims, characterized by that a detection system structure is used in which the only or all sensors (32) are accommodated. [12] Method according to one of the preceding claims, characterized by that an optically distorting lens or an aspherical optical mirror is used in front of the at least one sensor (32) in order to be able to sense the entire frying surface (14). [13] Cooking appliance, in particular for carrying out the method according to one of the preceding claims, characterized bythat the cooking appliance (10) has a frying surface (14) to be heated, a housing edge (20) surrounding the frying surface (14) and a tube (28) attached to the cooking appliance side and projecting upwards relative to the housing edge (20), to which at least one sensor (32) is fastened, the wiring (38) of which runs inside the tube (28) to an evaluation electronics unit (24) accommodated on or in the cooking appliance (10), and that a light marking projector (36) is connected to the cooking appliance side and spaced apart from the at least one sensor (32). [14] Cooking appliance according to claim 13, characterized by that the evaluation electronics (24) is arranged next to the frying surface (41). [15] Cooking appliance according to claim 13 or 14, characterized by that the light marking projector (36) is firmly connected to the housing edge (20). [16] Cooking appliance according to claim 15, characterized bythat the light marking projector (36) is located on or in the tube (28) for the at least one sensor (32) or on or in a further tube (34) which is attached to the cooking appliance side, in particular to the housing edge (20), and projects upwards. [17] Cooking appliance according to one of claims 13 to 16, characterized by that the light marking projector (36) can emit infrared light strips with a wavelength in the range of 800-1000 nm and / or in the range of 400-800 nm, and in particular also infrared light markings with a wavelength in the range of 3-4 µm, and that the at least one sensor (32) can detect the infrared light. [18] Cooking appliance according to one of claims 13 to 17, characterized by that the tube, one of the or all of the tubes (28) is or are attached to the housing edge (20) or to a control unit or a base part (22), wherein the control unit or the base part (22) is mechanically connected laterally to the frying surface (14).

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