Method for operating a coffee grinder and coffee grinder

Abstract

Method for operating a coffee grinder in which coffee beans are ground into a powder by means of a grinding mechanism of the coffee grinder, characterized in that: - during grinding, the coffee powder resulting from the grinding is weighed using a scale in the coffee grinder, whereby several measured values ​​(M1) of the weight of the coffee powder resulting from the grinding are recorded successively over time; - by means of an electronic computing device, depending on the measured values ​​(M1), a future, first time point (t1) is predicted at which the weight will have a predetermined target value (16); - depending on the predicted first time (t1), the mill and thus the grinding is stopped at a second time (t2), which is a predetermined time interval (Z) before the predicted first time (t1).

Description

[0001] The invention relates to a method for operating a coffee grinder according to the preamble of claim 1. Furthermore, the invention relates to a coffee grinder.

[0002] Such coffee grinders and methods for operating such coffee grinders are already well known in the general prior art. Each coffee grinder has a grinding mechanism by which coffee beans are ground into coffee powder. This means that the coffee beans can be ground by means of the grinding mechanism because the aforementioned coffee powder is produced by grinding the coffee beans. A coffee beverage can then be prepared from the coffee powder, in particular by brewing it. US Patent 2021 / 0145215 A1 discloses a method and a device for grinding a product. EP Patent 3158902 A1 discloses a weighing unit for a coffee bean grinder, a coffee bean grinder with an integrated weighing unit, and a method for operating a coffee bean grinder. EP Patent 3097831 A1 discloses a calibration method for electronic grinding and dosing devices for coffee beans.WO 2012 / 138327 A1 discloses a coffee grinder. EP 3409154 A1 discloses an electronic device for grinding and precisely dosing coffee beans. EP 3167782 A1 discloses a method and a device for grinding and dosing coffee beans with automatic and continuous dosing calibration. US 5386944 A discloses a method for grinding coffee beans to produce a selected weight of ground coffee. US 2022 / 0000314 A1 discloses a coffee grinder with a device for weight control of a dose of ground coffee. US 2023 / 0017236 A1 discloses a system for processing a desired quantity of particles for further processing.

[0003] The object of the present invention is to provide a method for operating a coffee grinder and a coffee grinder itself, such that coffee beans can be ground particularly advantageously.

[0004] This problem is solved by a method with the features of claim 1 and by a coffee grinder with the features of claim 7. Advantageous embodiments with expedient further developments of the invention are specified in the remaining claims.

[0005] A first aspect of the invention relates to a method for operating a coffee grinder. In this method, coffee beans, also referred to simply as beans, are ground into a powder, also referred to as coffee powder, by means of a grinding mechanism in the coffee grinder, which is also simply called a mill. This means that in this method, the coffee beans are ground by means of the grinding mechanism, thereby producing the aforementioned coffee powder. In particular, the coffee grinder has a motor, preferably designed as an electric motor, by means of which the grinding mechanism is driven in order to grind the coffee beans into powder.

[0006] To grind coffee beans particularly efficiently, the invention provides that the resulting coffee powder is weighed during the grinding process using a scale in the coffee grinder. This allows for the sequential recording of multiple weight measurements of the resulting coffee powder, particularly at several successive measurement points. In other words, the weight is measured, or recorded, at the specified measurement points. Since the measurement points are sequential, the measured values ​​are recorded one after the other.

[0007] By means of an electronic computing device, in particular the coffee grinder, a future first point in time, specifically in relation to the measurement times, is predicted, particularly during grinding, based on the measured values. This first point in time indicates when the weight will have a predetermined target value. Furthermore, the method according to the invention provides that, particularly by means of the electronic computing device and especially during grinding, the grinding mechanism and thus the grinding process are stopped, i.e., terminated, at a second point in time, i.e., a predetermined time interval before the predicted first point in time, depending on the predicted first point in time. The grinding mechanism and the grinding process are stopped, in particular, by the electronic computing device stopping, i.e., deactivating, the motor at the second point in time.This means that in the inventive method, the grinder, and thus the grinding of the coffee beans, is stopped, i.e., terminated, before a current weight value corresponding to the target value is measured using the scale. The background of the invention is, in particular, that the coffee powder must travel a certain distance from the grinder in order to be measured by the scale, and the coffee powder requires a certain amount of time to travel this distance. This time is also referred to as the settling time, which is, for example, the aforementioned predetermined time period.By predicting the first time point, and by stopping the grinding at the second time point, and by ensuring that the predetermined time interval, in particular the fall time, lies between the second time point and the first time point, especially such that the beginning of the time interval coincides with the second time point and the end of the time interval coincides with the first time point, the aforementioned distance and thus the fall time are taken into account, so that after stopping the grinding, the actual value of the weight of the coffee powder produced by the method according to the invention, in particular automatically, corresponds to the target value or deviates only slightly from the target value.

[0008] For example, the coffee powder produced by grinding is collected in this process using a collection element. This collection element could be, for instance, a portafilter. The scale can then measure, or record, the weight of the produced coffee powder via the collection element. Thus, after grinding, the coffee powder must travel the aforementioned distance, also known as the "fall distance," from the grinder to the collection element. Therefore, the scale can only measure the weight of the produced coffee powder once the coffee powder is in the collection element and has thus completed the journey from the grinder to the collection element.If the grinder, and thus the grinding process, were to stop at the point when the scale registers the target weight via the collection element, coffee grounds still being produced by the grinder would fall into the collection element after grinding has finished. This means they would travel the distance from the grinder to the collection element, resulting in the actual weight of the coffee grounds in the collection element being greater than the desired target weight. Therefore, the collection element would contain an excessive amount of coffee grounds.

[0009] One aspect of the invention is that the ratio of the amount of ground coffee powder to the amount of water used to brew the coffee powder plays a crucial role in the taste of the coffee beverage. Furthermore, the inventive method enables the automatic grinding of coffee beans and thus the automatic production of coffee powder, particularly in such a way that, for example, a person can specify the target value, especially by having the person make at least one input to the coffee grinder, particularly via an operating interface of the coffee grinder.While the person may be notified that the grinding process has finished, particularly by means of a warning signal emitted near the coffee grinder and perceptible to someone in the vicinity visually, audibly, and / or haptically, and / or the person may recognize that the grinding has stopped due to the grinding mechanism pausing, they are not informed of the actual weight of the coffee grounds in the collection container, as measured by scales. Therefore, the person assumes that the actual weight of the coffee grounds in the collection container corresponds to the target weight specified by them.However, because the grinding process is only stopped at the aforementioned point in time, when the target weight of the coffee powder collected in the container is measured by the scale, and because ground coffee powder also falls from the grinder into the container at that time, the actual weight of the coffee powder in the container can be greater than the target weight. If, for example, the person then uses an amount of water that matches the target weight to prepare the coffee, the weight or amount of coffee powder in the container is too great for the amount of water, which can result in an undesirable taste in the coffee. This can be avoided by the inventive method, which stops the grinding process at the second point in time, and thus before the aforementioned first point in time.At the second point in time, the weight of the coffee powder is (still) less than the target value. However, since more coffee powder, already ground or produced by the grinder, falls into the collection area after the second point in time, the actual weight of the coffee powder collected, especially in the collection element, corresponds to the target value, or deviates only very slightly from the target value. If the person then uses the aforementioned amount of water, adjusted to the target value, to prepare a coffee beverage from the water and the coffee powder ground by the process, the resulting coffee beverage will have a desirable, favorable taste.The process thus enables, for example, automatic, in particular fully automatic, grinding of the coffee beans and thus automatic, in particular fully automatic, production, i.e., manufacture, of the coffee powder, especially after the person has specified the target value.

[0010] The process, that is, weighing the coffee powder and thus recording the measured values, predicting the first time point and stopping the grinder and thus the grinding process depending on the predicted first time point, takes place within the grinding process itself, that is, within the same grinding process.

[0011] To produce the coffee powder particularly advantageously, especially in such a way that the actual value does not deviate from the target value or deviates only very slightly, one embodiment of the invention provides that the second set of measured values, following the first set of measured values, is weighted more heavily than the first set of measured values ​​when predicting the first point in time. This allows, for example, any change in the grind setting of the grinder to be taken into account. In other words, the grinder can have an adjustable, i.e., variable, grind setting, so that, for example, the coffee beans can be ground finer or finer using the grinder. For example, the currently set grind setting cannot be detected, so that a change in the grind setting of the grinder that occurs, for example, during grinding cannot be detected, at least not directly.The grind size, and in particular any change in the grind size during grinding, affects the increase in the weight of the resulting coffee powder as measured by scales over time. Therefore, by giving greater weight to the second measurements, which follow the first measurements and are thus, so to speak, younger than the first measurements, the first point in time can be predicted precisely, especially if the grind size changes during grinding.

[0012] The second measurements are consecutive measurements in time, wherein the, in particular all, second measurements follow the first measurements, which follow each other in time.

[0013] The characteristic that the second measurements, which follow the first measurements in time, are weighted more heavily than the first measurements when predicting the first time point means that the influence of the second measurements on predicting the first time point is greater than the influence of the first measurements on predicting the first time point. In other words, the second measurements are given more weight than the first measurements when predicting the first time point.

[0014] The feature that the second measurements are weighted more heavily than the first measurements for predicting the first time point means, for example, that both the first and second measurements are taken into account for predicting the first time point, with the second measurements being weighted for predicting the first time point, and with the first measurements not being weighted for predicting the first time point, or with the first measurements each being weighted by a factor of 1.Furthermore, it is conceivable that the first and second measurements are considered when predicting the first time point, with both being weighted, specifically such that the first and second measurements are each weighted by a factor other than 1, but the second measurements are weighted more heavily, i.e., with a higher factor, than the first measurements. It is also conceivable that, for example, only the second measurements are considered when predicting the first time point with respect to the first and second measurements, so that the first measurements are effectively weighted with a factor of 0.Since the second measurements are weighted more heavily than the first measurements for predicting the first time point, the first measurements are, so to speak, forgotten or hidden for predicting the first time point, which allows the first time point to be determined particularly precisely.

[0015] Another embodiment is characterized in that the first time point is predicted, i.e., forecasted, by linear interpolation, particularly of the measured values, thereby enabling a particularly precise prediction of the first time point. In a further embodiment of the invention, it is provided that the first time point is predicted, i.e., forecasted, by linear interpolation, particularly of the measured values, using the least squares method, thereby enabling a particularly precise prediction of the first time point.

[0016] In order to be able to predict the first time point with particular precision, a further embodiment of the invention provides that the first time point is predicted by linear interpolation using the least squares method with a forgetting factor.

[0017] The specified time period is stored, for example, in a data storage device, particularly an electrical or electronic one, of the electronic computing device.

[0018] It has proven particularly advantageous to weigh the powder after grinding has stopped, thereby recording at least one further measurement of the powder's weight. For example, this further measurement could be the actual weight. Specifically, the powder is weighed after grinding has stopped and after a certain time interval, and particularly at a specific measurement point in time, thus recording the further measurement of the powder's weight at that measurement point. It is preferably provided that the measurement point follows the second measurement point in such a way that at least a certain time interval, preferably a longer measurement interval, lies between the second measurement point and the measurement point. In this way, for example, the further measurement point characterizes the weight of all the coffee powder produced by or through the process.Preferably, the time interval is corrected based on at least one additional measured value. For example, the additional measured value is compared with the target value. If, for instance, a difference between the target value and the additional measured value, determined by comparing the additional measured value with the target measured value, exceeds a predefined or predetermined threshold, the time interval is corrected, i.e., changed. This prevents, for example, an excessive difference between the target value and the actual value or the additional measured value during a future grinding process in which coffee beans are ground using the grinder, thus enabling the coffee powder to be produced particularly efficiently.In particular, the method according to the invention enables automatic, and especially fully automatic, grinding of the coffee beans, thus producing the coffee powder, so that the coffee powder can be prepared easily and conveniently for the aforementioned person. Furthermore, undesirable flavor variations in coffee beverages made from coffee powder ground using the method according to the invention can be avoided, so that very good-tasting coffee beverages can be prepared easily and conveniently using the method according to the invention.

[0019] A second aspect of the invention relates to a coffee grinder configured for carrying out a method according to the first aspect of the invention. Advantages and advantageous embodiments of the first aspect of the invention are to be regarded as advantages and advantageous embodiments of the second aspect of the invention, and vice versa.

[0020] The method according to the invention enables the prediction of the behavior of the coffee grinder and of a weight, also referred to as the "fall weight," which falls from the grinding mechanism, particularly into the receiving element, after grinding has stopped and which may, for example, depend on the currently set grind setting. The prediction of the grinding behavior is achieved, in particular, by predicting the first point in time, also referred to as the switch-off time, whereby the prediction is made during the grinding of the coffee beans, also referred to as the grinding process. In particular, by weighting the second measured values ​​as described, changes such as changes in the grind setting during the grinding process can also be taken into account. Iterations from one grinding process to the next can be avoided, as can re-grinding within a grinding process.The method is based, in particular, on the assumption that the time during which ground powder continues to fall after the grinding process has stopped (also referred to as switching off) is at least nearly constant, regardless of weight or grind size. This can be explained, in particular, by the fact that the distance traveled by the grinding mechanism, or the distance it must travel, and which is measured by the scale, is always the same. Friction, especially from air, can be almost entirely disregarded. The falling speed at which the already ground powder falls from the grinding mechanism until it can be measured is therefore at least almost always the same and, in particular, independent of weight.In simplified terms, the process involves using an algorithm that, during the grinding process, predicts when the target weight will be reached, based on the current change in the measured weight (also known as weight change). Assuming a constant settling time, the grinding process is then stopped earlier, i.e., before the predicted first point in time. Since the weight change during grinding may not be constant, particularly due to changes in the grind setting, bean settling, or similar factors, more weight is given to the most recent measurements, while earlier measurements are weighted less and gradually forgotten or ignored.This means that, for example, the second measurements are weighted more heavily than the first measurements.

[0021] It is conceivable that the fall time, i.e. the time span, is a functional result or a result of a neural network, so that coffee grinders with different mechanics when the powder falls out of the grinding mechanism can also be taken into account.

[0022] The time interval can be constant, or it can be varied, i.e., changed, particularly depending on the temporal progression of the measured values, either directly or indirectly. Indirectly, the time interval can be varied, for example, by using an algorithm to predict the first time point based on the measured values. The time interval can then be varied depending on how the algorithm processes the measured values, thus indirectly varying the time interval based on the measured values. For example, the time interval can be varied, i.e., changed, from one grinding process to the next.

[0023] Further advantages, features, and details of the invention will become apparent from the following description of a preferred embodiment and from the drawing. The features and combinations of features mentioned above in the description, as well as those mentioned below in the figure description and / or shown in the single figure alone, can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the invention.

[0024] The drawing shows in the single figure a diagram to illustrate a method for operating a coffee grinder.

[0025] The following describes a method for operating a coffee grinder, also referred to simply as a mill, based on the single figure. The coffee grinder has, for example, a grinding mechanism by which coffee beans, also referred to simply as beans, can be ground to produce a powder, also referred to as coffee powder. For example, the coffee grinder has a housing with a receptacle in which a receiving element, such as a portafilter, can be inserted. The coffee grinder can have a guide device by which the coffee powder ground by the grinding mechanism can be guided to and into the receptacle, and in particular to and into the portafilter, so that the coffee powder ground by the grinding mechanism can be received in the portafilter.In this process, the coffee beans are ground into powder by means of the grinder, which is then guided by the guide device to and into the collecting element and collected in the collecting element.

[0026] For example, a coffee grinder has a motor, particularly an electric motor, which drives the grinding mechanism to grind the coffee beans. The coffee grinder also has a scale, particularly an integrated one, which, particularly via the portafilter, can determine the weight of the coffee grounds contained in the portafilter and resulting from the grinding process. This weight is recorded, i.e., measured, during the process. In particular, the coffee grinder also has an electronic control unit that can control and thus operate the grinding mechanism, especially the motor. Furthermore, the coffee grinder has, for example, a control unit, also referred to as an operator interface, which allows input from a person to be entered into the control unit and thus into the coffee grinder.

[0027] In this process, for example, at least one input from a person is recorded by means of the operating device, whereby the input describes, that is, specifies or characterizes, a target value of a weight of the coffee powder to be taken into the portafilter and resulting from the grinding process, also referred to as the grinding process.

[0028] The single figure shows a diagram on whose abscissa 10 time is plotted, which, viewed from left to right, increases, as illustrated by arrow 12. On the ordinate 14 of the diagram, values ​​for the weight of the coffee grounds are plotted, with the target value entered into the diagram and labeled 16. The scale, using the portafilter, can measure the weight of the grounds contained in the portafilter and thus determine the weight. The target value 16 is, or characterizes, a desired weight that should be contained in the portafilter as a result of the grinding process.This may be the case, in particular, if the person plans, for example, to prepare a coffee drink from the coffee powder in the portafilter, which has the target weight, and from an amount of water adjusted to the target weight.

[0029] After the person has entered and thus specified the target value and therefore the target weight into the coffee grinder via the control unit, the grinding process is started, in particular by the person making a further input into the coffee grinder via the control unit after entering the target value 16, which serves as a start input, or by inserting a portafilter into the coffee grinder.

[0030] Following the start command, the electronic control unit, for example, activates the motor, thereby activating the grinder. The activated motor drives the grinder, which grinds the coffee beans into powder. The ground coffee, especially when pure, can slide along the guide rail due to gravity and be guided to and into the portafilter. Since the scale measures the weight of the coffee powder in the portafilter via the portafilter, and since the weight of the coffee powder in the portafilter increases as the grinding process progresses, this weight can be measured by the scale via the portafilter.Thus, the method involves weighing the resulting coffee powder, collected in the portafilter, using the scale of the coffee grinder during grinding. This allows for the sequential recording of multiple measurements M1 of the coffee powder collected in the portafilter. The figure shows that the measurements M1 are recorded, i.e., measured, by the scale at specific times. Since the measurement times follow one another, the measurements M1 are also sequential. The figure clearly illustrates that as time progresses, i.e., as the grinding process progresses, the weight of the resulting coffee powder, measured by the scale via the portafilter, increases.

[0031] Using the electronic control unit of the coffee grinder, a future, first time point t1 is predicted based on the measured values ​​M1. This predicts when the weight will reach the predetermined target value 16. Based on this predicted first time point t1, the electronic control unit stops the motor, and thus the grinding mechanism and the grinding process, at a second time point t2. This second time point t2 is deactivated or switched off a predetermined time interval Z, stored, for example, in the data memory of the electronic control unit, before the predicted first time point t1. This time interval Z is also referred to as the settling time. The settling time is the time it takes for the ground coffee to fall from the grinder along the guide mechanism into the portafilter, where it is measured by the scale.If the grinding process is stopped at time t2, ground coffee powder will fall into the portafilter during time Z, so that the weight of all the coffee powder ground and collected in the portafilter after time Z, and thus from time t1 onwards, has an actual value that corresponds to the target value of 16 or deviates only very slightly from it. The person can then prepare the coffee beverage from the coffee powder in the portafilter and the corresponding amount of water, resulting in a coffee with the desired taste. In this process, time t1 is predicted, or rather predicted, by a linear prediction based on the measured values ​​M1.

[0032] The diagram shown in the figure also includes a time-dependent curve 18, which is a curve of differences between the predicted next measured value and the actual measured value. These differences are therefore prediction errors that are used to refine the prediction.

Claims

[1] Method for operating a coffee mill in which coffee beans are ground into a powder by means of a grinding mechanism of the coffee mill, characterized by , that: - during grinding, the coffee powder resulting from the grinding is weighed using a scale in the coffee grinder, whereby several measured values ​​(M1) of the weight of the coffee powder resulting from the grinding are recorded successively over time; - by means of an electronic computing device, depending on the measured values ​​(M1), a future, first time point (t1) is predicted at which the weight will have a predetermined target value (16); - depending on the predicted first time (t1), the mill and thus the grinding is stopped at a second time (t2), which is a predetermined time interval (Z) before the predicted first time (t1). [2] Method according to claim 1, characterized by, that the second measurement (M1) following the first measurement (M1) is weighted more heavily for predicting the first time point (t1) than the first measurement (M1). [3] Method according to claim 1 or 2, characterized by , that the first time point (t1) is predicted by linear interpolation. [4] Method according to claim 3, characterized by , that the first time point (t1) is predicted by linear interpolation using the method of least squares. [5] Method according to claim 4, characterized by , that the first time point (t1) is predicted by linear interpolation using the least squares method with a forgetting factor. [6] Method according to any one of the preceding claims, characterized by , that: - after grinding is stopped, the powder is weighed using scales, thereby recording at least one further measurement of the powder's weight; and - depending on at least one further measured value, the time interval (Z) is corrected. [7] Coffee grinder designed to carry out a method according to any of the preceding claims.

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