WO2020251514A1

WO2020251514A1 - A coffe machine and turkish coffee brewing method

Info

Publication number: WO2020251514A1
Application number: PCT/TR2020/050595
Authority: WO
Inventors: Ozkan AKGUL; Arda DONERKAYALI
Original assignee: Arcelik Anonim Sirketi
Priority date: 2019-06-12
Filing date: 2020-07-07
Publication date: 2020-12-17

Abstract

The present invention relates to a coffee machine (1) comprising a body (2); at least one brewing pot (3) which is placed into/onto the body (2) and wherein water, coffee and as per the preference additional ingredients such as sugar are put and brewed; a heater (4) which is disposed in the body (2) and which enables the brewing port (3) to be heated; a level sensor (5) which is disposed on the body (2) and which measures the level of the water-coffee mixture in the brewing pot (3); and a control unit (6) which determines a reference point by using the value measured (hölc) by the level sensor (5).

Description

A COFFE MACHINE AND TURKISH COFFEE BREWING METHOD

The present invention relates to a coffee machine wherein the coffee is brewed by mixed with water.

Coffee machines which can brew Turkish coffee are known. In this type of machines, water and coffee are transferred to a brewing pot automatically or by the user and the coffee is brewed by heating the brewing pot. In the traditional Turkish coffee brewing method, the coffee is boiled with water, thus the coffee essence comes out. During the boiling, the coffee foams and the coffee pot is removed from the cooker and served before the foam overflows from the coffee pot. In the coffee machines, while brewing Turkish coffee it is very important to detect if the coffee is ready for serving. Use of infrared or time-of-flight level sensors is known to this end, and the sensor measures the foam level to decide if the brewing is completed or not. However, the amount of foam on the coffee is affected by the amount of coffee, the miscibility of the coffee, the type of coffee (such as mastic flavored, etc.) and additional ingredients such as sugar, etc., and it becomes difficult for the coffee machines to brew the coffee in the same consistency every time. Moreover, the moisture and the steam generated in the coffee pot also cause the decision of completion of the brewing process at the wrong time. Furthermore, since the upper surface of the mixture in the coffee pot is not planar, it is very difficult to decide when the coffee is brewed. That the effect of these parameters is not equal, in other words linear, but is variable across all measurements causes a chaotic situation and adversely affects the decision of completion of the brewing process taken by the control unit of the coffee machine. In the state of the art, there are embodiments wherein a measurement is taken at the beginning of the brewing process and the decision of completion of the brewing process is taken when there is a certain amount of increase over the first measurement. In this type of coffee machines, when the sensor makes a measurement smaller than the actual height level at the beginning of the brewing process, the coffee remains uncooked, and if a higher measurement is made, the coffee is overcooked and has a bitter taste. In the state of the art International Patent Application No. W02006008583, a coffee machine is disclosed, which takes a first measurement taken by the sensor as the reference value.

In the state of the art International Patent Application No. W02008068224, a coffee machine is disclosed, which determines the brewing parameters according to the number of cups.

In the state of the art International Patent Application No. WO2018174837, a coffee machine is disclosed, wherein the sensor errors are minimized by changing the calculation of the height of completing the brewing process.

The aim of the present invention is the realization of a coffee machine which provides the brewing of Turkish coffee with the traditional consistency.

The coffee machine realized in order to attain the aim of the present invention, explicated in the claims, comprises a control unit which calculates a new reference value by using the difference between the value measured at the beginning of the brewing process and the reference value. The new reference value is calculated by multiplying said difference by a predetermined coefficient and adding the result to the reference value, and is used in the algorithm used for deciding on the completion of the brewing prcoess. By measuring the height of the coffee-water mixture at the beginning of the brewing process and calculating a new reference value depending on the ambient conditions, the basic parameter in the algorithm of the decision of completion of the brewing process is correctly determined. Thus, the small errors at the beginning are prevented from expanding and causing a erroneous decision of completion of the brewing process.

In an embodiment of the present invention, the control unit uses a different coefficient if the value measured is higher than the reference value. In a version of this embodiment, the coefficient is determined according to the magnitude of the difference. By means of this embodiment, the changes in the ambient conditions are reflected to the algorithm of the decision of completion of the brewing process in the best manner. In another embodiment of the present invention, the control unit uses a coefficient different than the above-mentioned one if the value measured is smaller than the reference value. In a version of this embodiment, the coefficient is determined according to the magnitude of the difference. The variation in the sensor data have a greater effect on the decision of completion of the brewing process if the value measured is smaller than the reference value compared to the case where the value measured is higher than the reference value, and by means of this embodiment, the effect of ambient variables is included in the calculation even in this case.

In another embodiment of the present invention, the control unit determines the reference table containing the reference values and the coefficients used depending on the time. Thus, the effect of deviations in the values measured by the sensor depending on the ambient variables is minimized, and the new reference value is determined by using said time-dependent parameters, ensuring that the decision of completion of the brewing process is taken at the correct time.

The coffee machine of the present invention is controlled by a control method which is executed by the control unit for brewing the coffee in the desired consistency and which comprises the steps of:

- measuring the level of the coffee-water mixture in the brewing pot a predetermined time after the brewing process starts and saving the value measured into the memory of the control unit,

- comparing the value measured with a predetermined reference value,

- selecting the higher coefficient for calculating the new reference value if the value measured is smaller than the reference value or selecting the smaller coefficient for calculating the new reference value if the value measured is higher than the reference value,

- calculating the new reference value by multiplying the difference between the a predetermined reference value and the value measured by the relevant coefficient and adding the result to the reference value. In the coffee machine of the present invention, the reference value used for calculating the decision of completion of the brewing process is calculated by taking into account the ambient conditions, and by taking into account small factors at the beginning of the brewing process, important changes which may affect the taste and consistency of the coffee are prevented. Thus, it becomes possible to brew coffee with the same taste and consistency under any condition.

The coffee machine realized to attain the aim of the present invention is illustrated in the attached figures, where:

Figure 1 - is the schematic view of a coffee machine.

Figure 2 - is the sideways cross-sectional view of the brewing pot in an embodiment of the present invention.

Figure 3 - is the sideways cross-sectional view of the brewing pot in another embodiment of the present invention.

The elements illustrated in the figures are numbered as follows:

1. Coffee machine

2. Body

3. Brewing pot

4. Heater

5. Level sensor

6. Control unit

The following symbols are used so that the present invention is understood better: t - predetermined time

hreft - Predetermined reference table

hrefi - Predetermined reference height value at t time

hole - Height value measured by the level sensor at t time

hreff - Newly calculated reference value D - Difference between href and hole

Ct - Predetermined coefficient

Ctk - Smaller coefficient

Ctb - Higher coefficient

The coffee machine (1) comprises a body (2); at least one brewing pot (3) which is placed into/onto the body (2) and wherein water, coffee and as per the preference additional ingredients such as sugar are put and brewed; a heater (4) which is disposed in the body (2) and which enables the brewing port (3) to be heated; a level sensor (5) which is disposed on the body (2) and which measures the level of the water-coffee mixture in the brewing pot (3); and a control unit (6) which determines a reference point by using the value measured (hole) by the level sensor (5).

In the coffee machine (1), the user puts water and coffee into the brewing pot (3) and places the same onto the body (2) or water and coffee are automatically taken into the brewing pot (3), and then the user starts the brewing process by pressing the start button (not shown in the figures). In the brewing process, the heater (4) contacts the brewing pot (3) preferably from below and provides the brewing of Turkish coffee. The level sensor (5) will be referred to as the sensor (5) hereinafter. By means of the sensor (5), the raising of the foam on the coffee is detected and it is decided if the brewing process is completed. While brewing coffee, especially brewing Turkish coffee, the control of the amount of heat transferred to the brewing receptacle (3) is very important. The control unit (6) controls the heater (4) according to the data received from the sensor (5). The value measured (hole) by the sensor (5) is used as reference, and the decision of completion of the brewing process is taken according to the reference value.

The coffee machine (1) of the present invention comprises the control unit (6) which contains a reference table (hreft) related to the amount of coffee to be brewed in the memory thereof, and which enables a new reference value (hreff) to be calculated by multiplying the difference (A=holc-hrefi) between the value measured (hole) by the level sensor (5) a certain time (t) after the beginning of the heating process and the relevant value (hrefi) in the reference table (hreft) by a coefficient (Ct) and adding the result to the value (hrefi) in the reference table (hreft) (hreff=hrefi+Ct*(holc-hrefi)). In the memory of the control unit (6), the producer saves the coffee height values obtained as a result of numerous experiments and related to the amount of coffee, hence to the number of cups as a reference table (hreft). The values (hrefi) in the reference table (hreft) can be a value or can be used to define a value range. In normal conditions, the values measured (hole) by the sensor (5) are expected to be the same as the values (hrefi) in the reference table (hreft). However, due to the factors mentioned above, differences may arise and the sensor (5) data is required to be interpreted differently.

When the value measured (hole) by the sensor (5) is different from the reference value (hrefi), the control unit (6) determines a new reference value (hreff), thus enabling the proper completion of the brewing process. The new reference value (hreff) is calculated by multiplying the difference (D) between the value measured (hole) and the reference value (hrefi) by a coefficient (Ct) and adding the result to the reference value (hrefi). Thus, the sensor (5) is calibrated according to the ambient conditions at the beginning of each brewing process, always ensuring the brewing of coffee with the same taste and consistency. By performing the sensor (5) calibration at the beginning of the brewing process, the precision of the values measured (hole) is taken under control from the first moment and erroneous decisions are prevented.

In an embodiment of the present invention, the control unit (6) uses a smaller coefficient (Ctk) than the coefficient (Ct) while calculating the new reference value (hreff) if the value measured (hole) by the sensor (5) a certain time (t) after the beginning of the brewing process is higher (holc>hrefi) than the predetermined reference value (hrefi). As a result of numerous experiments, it is found that a smaller calibration is required if the value measured (hole) is greater than the reference value (hrefi), and hence the control unit (6) uses the smaller coefficient (Ctk) while calculating the new reference value (hreff).

In a version of this embodiment, the control unit (6) determines the smaller coefficient (Ctk) in direct proportion to the difference (D) between the value measured (hole) by the sensor (5) and the predetermined reference value (hrefi). Since the effect of the changes in the ambient conditions (humidity, vapor, dirtiness of the sensor surface) is not linear, the coefficient (Ct, Ctk, Ctb) must be variable, and the coefficient (Ct, Ctk, Ctb) is determined according to the difference (D) between the value measured (hole) and the reference value (hrefi). Thus, the calculation of the new reference value (hreff) is carried out with a polynomial approach suitable for the chaotic ambient conditions.

In another embodiment of the present invention, the control unit (6) uses a higher coefficient (Ctb) than the coefficient (Ct) while calculating the new reference value (hreff) if the value measured (hole) by the sensor (5) a certain time (t) after the beginning of the brewing process is smaller (holc<hrefi) than the predetermined reference value (hrefi). It is observed that the value measured (hole) is smaller than the reference value (hrefi) especially when a small amount of coffee is desired to be brewed, and in this case, a greater calibration is required and hence the control unit (6) uses the higher coefficient (Ctb) while calculating the new reference value (hreff). In a version of this embodiment, the control unit (6) determines the higher coefficient (Ctb) in direct proportion to the difference (D) between the value measured (hole) by the sensor (5) and the predetermined reference value (hrefi).

In another embodiment of the present invention, the control unit (6) ensures that the reference table (hreft) and the coefficients (Ct, Ctk, Ctb) are calculated depending on the time. The reference table (hreft) and the values (hrefi) used in the brewing process are not dependent on the values measured (hole) instantaneously, and can be calculated according to values measured (hole) at various times. Therefore, the height of the coffee mixture brewed under the ideal conditions depending on the time is recorded in the reference table (hreft). While calculating the new reference value (hreff) by using the values measured (hole) by the sensor (5) at different times, the reference values (hrefi) related to the relevant times are used. In this case, the coefficients (Ct, Ctk, Ctb) used for calibration are determined depending on the time, and the sensitivity in the calculation of the new reference value (hreff) is maximized. For example, the values measured (hole) 20, 25 and 30 seconds after the beginning of the brewing process are compared with the reference values (hrefi) corresponding to the relevant times in the reference table (hreft) and the average of the three new different reference values (hreff) calculated by using the coefficients (Ct, Ctb, Ctk) related to said times is used as the new reference value (hreff) by the control unit (6) while deciding on the completion of the brewing process. Moreover, the control unit (6) compares the values measured (hole) by the sensor (5) throughout the brewing process with the values depending on the time in the reference table (hreft), thus controlling the entire brewing process.

In a version of this embodiment, the control unit (6) continuously takes measurements by the sensor (5) instead of taking measurements at certain times, and uses the continuously-taken measurements in the above-disclosed embodiments. The iteration method is used by using the previous measurements so that said values are constantly updated. During the cooking process, as the coffee mixture heats up, steam and moisture are generated, and hence the sensitivity of the measurements taken at high temperatures decreases. The control unit (6) reduces the effect of low sensitivity measurements by using a coefficient (Ct, Ctb, Ctk) decreasing based depending on the time while determining the new reference value (hreff), and ensures that the new time- dependent value (hreff) obtained by repeatedly using (iteration method) the calculated values is free from the sensor (5) errors. For example, the new reference value (hreff) is started to be calculated with the measurement taken at the 20th second and iterated until the 30th or 40th second, and the effect of the next measurements is decreased in proportion to the coefficient Ct, Ctb, Ctk) such that the new reference value (hreff) is obtained at the end of said time.

The Turkish coffee brewing method of the present invention comprises the following steps executed by the control unit (6) in the coffee machine (1) comprising the above- described control unit (6):

- measuring the level of the coffee- water mixture in the brewing pot (3) a predetermined time (t) after the beginning of the brewing process and saving the value measured (hole) into the memory of the control unit (6),

- comparing the value measured (hole) with a predetermined reference value (hrefi) in the reference table (hreft), - selecting the higher coefficient (Ctb) for calculating the new reference value (hreff) if the value measured (hole) is smaller (holc<hrefi) than the reference value (hrefi) or selecting the smaller coefficient (Ctk) for calculating the new reference value (hreff) if the value measured (hole) is higher (holc>hrefi) than the reference value (hrefi), - calculating the new reference value (hreff) by using the relevant reference value

(hrefi) in the reference table (hreft), the value measured (hole) and the higher coefficient (Ctb) or the smaller coefficient (Ctk).

In a version of the Turkish coffee brewing method, the new reference value (hreff) is calculated by multiplying the difference (D) between the value measured (hole) and the reference value (hrefi) in the reference table (hreft) by a coefficient (Ct, Ctb, CTk) and adding the result to the reference value (hrefi).

In the Turkish coffee machine (1) of the present invention, by measuring the height, in other words the level of the coffee-water mixture at the beginning of the brewing process, the deviation of the level sensor (5) is determined, and the decision of completion of the brewing process is calculated for every brewing process. Thus, a new reference value (hreff) is calculated by using the higher coefficient (Ctb) when the level sensor (5) makes a measurement smaller than the reference value (hrefi), preventing the coffee from being undercooked. Similarly, a new reference value (hreff) is calculated by using the smaller coefficient (Ctk) when the level sensor (5) makes a measurement higher than the reference value (hrefi), preventing the coffee from being overcooked. Moreover, by selecting the coefficients (Ct, Ctb, Ctk) depending on the time and in relation to the difference (D) between the reference value (hrefi) and the value measured (hole), the chaotic behavior profile, depending on the ambient conditions, of the real level/height of the coffee mixture is included in the calculation for the completion of the brewing process.

Claims

1 -A coffee machine (1) comprising a body (2); at least one brewing pot (3) which is placed into/onto the body (2) and wherein water, coffee and as per the preference additional ingredients such as sugar are put and brewed; a heater (4) which is disposed in the body (2) and which enables the brewing port (3) to be heated; a level sensor (5) which is disposed on the body (2) and which measures the level of the water-coffee mixture in the brewing pot (3); and a control unit (6) which determines a reference point by using the value measured (hole) by the level sensor (5), characterized by the control unit (6) which contains a reference table (hreft) related to the amount of coffee to be brewed in the memory thereof, and which enables a new reference value (hreff) to be calculated by multiplying the difference (A=holc -hrefi) between the value measured (hole) by the level sensor (5) a certain time (t) after the beginning of the heating process and the relevant value (hrefi) in the reference table (hreft) by a coefficient (Ct) and adding the result to the value (hrefi) in the reference table (hreft). 2 - A coffee machine (1) as in Claim 1, characterized by the control unit (6) which uses a smaller coefficient (Ctk) than the coefficient (Ct) while calculating the new reference value (hreff) if the value measured (hole) by the sensor (5) a certain time (t) after the beginning of the brewing process is higher (holc>hrefi) than the predetermined reference value (hrefi).

3 - A coffee machine (1) as in Claim 1 or 2, characterized by the control unit (6) which determines the smaller coefficient (Ctk) in direct proportion to the difference (D) between the value measured (hole) by the sensor (5) and the predetermined reference value (hrefi).

4 - A coffee machine (1) as in any one of the above claims, characterized by the control unit (6) which uses a higher coefficient (Ctb) than the coefficient (Ct) while calculating the new reference value (hreff) if the value measured (hole) by the sensor (5) a certain time (t) after the beginning of the brewing process is smaller (holc<hrefi) than the predetermined reference value (hrefi). 5 - A coffee machine (1) as in any one of the above claims, characterized by the control unit (6) which determines the higher coefficient (Ctb) in direct proportion to the difference (D) between the value measured (hole) by the sensor (5) and the predetermined reference value (hrefi).

6 - A coffee machine (1) as in any one of the above claims, characterized by the control unit (6) which ensures that the reference table (hreft) and the coefficients (Ct, Ctk, Ctb) are calculated depending on the time.

7 - A coffee machine (1) as in any one of the above claims, characterized by the control unit (6) which calculates the new reference value (hreff) by the iteration method by using the previous calculated value for a certain period of time.

8 - A Turkish coffee brewing method executed by the control unit (6) in the above claims and comprising the steps of

- comparing the value measured (hole) with a predetermined reference value (hrefi) in the reference table (hreft),

- selecting the higher coefficient (Ctb) for calculating the new reference value (hreff) if the value measured (hole) is smaller (holc<hrefi) than the reference value (hrefi) or selecting the smaller coefficient (Ctk) for calculating the new reference value (hreff) if the value measured (hole) is higher (holc>hrefi) than the reference value (hrefi),

- calculating the new reference value (hreff) by using the relevant reference value (hrefi) in the reference table (hreft), the value measured (hole) and the higher coefficient (Ctb) or the smaller coefficient (Ctk).

9 - A Turkish coffee brewing method as in Claim 8, characterized in that the new reference value (hreff) is calculated by multiplying the difference (A) between the value measured (hole) and the reference value (hrefi) in the reference table (hreft) by a coefficient (Ct, Ctb, CTk) and adding the result to the reference value (hrefi).