Method for controlling a kneading household appliance

Abstract

A method for controlling a kneading appliance based on the determination of the texture of a preparation (M) made in a kneading appliance (1) comprising a working tool (2a, 2b, 2c) for the preparation (M) attached to a drive output (3), said drive output (3) being rotated by a main motor, said method comprising: A step of determining a fundamental frequency (Ff) of a supply current (C) of the main motor; A step of recording the supply current (C) of the main motor; An analysis step in which an analysis quantity is determined as a function of at least one value of the amplitude (A) of a Fourier Transform of the supply current (C) for the fundamental frequency (Ff); A comparison step in which a texture parameter is determined as a function of a comparison of the analysis quantity with a comparison criterion. Figure 7

Description

Title of the invention: Method for controlling a kneading household appliance. Technical field

[0001] The invention relates to the field of kneading household appliances and more particularly to a method of controlling a kneading household appliance according to a determination of the texture of a preparation made in said kneading household appliance. Prior art

[0002] A kneading kitchen appliance includes a bowl attached to a main body. The bowl holds the ingredients necessary to prepare a food product, hereinafter referred to as a "preparation." A preparation comprises one or more ingredients and may be a mixture of dry or liquid ingredients, and may be in the form of a paste, a mousse, a powder, etc.

[0003] The kneading appliance is designed to work the preparation in such a way as to modify its texture, for example by mixing, whipping or kneading it.

[0004] Mixing means combining several ingredients together in order to obtain a homogeneous preparation.

[0005] Whisking means the action of vigorously beating the preparation in order to incorporate air and give it a light and frothy consistency.

[0006] Finally, kneading means working on the preparation to make it more elastic by developing the gluten present in said preparation.

[0007] The work on the preparation is done by specific interchangeable tools: - A kneading hook is specially designed for kneading heavy doughs, such as those used for making bread; - A mixing sheet allows for mixing lighter preparations, such as cake batters or preparations requiring a finer texture; - A whisk allows you to whip ingredients such as egg whites or cream, allowing you to create airy and frothy mixtures.

[0008] Generally, the main body comprises a foot to ensure the stability of the kneading appliance on a work surface, extended by a head that is generally movable and rotates relative to the foot, and onto which the tool is attached. More specifically, the tool is designed to be attached to a drive output located on the head of the main body. The drive output is set in rotation at by means of a main motor, positioned in the main body, for example in the foot.

[0009] Several training outings can be planned, each of which can be planned to attach different tools requiring movement at different speeds.

[0010] A user of a dough mixer is often not a pastry expert and may find it difficult to know when to stop mixing the ingredients in order to correctly follow a given recipe. Therefore, a dough mixer needs to be able to detect the texture of the mixture and determine when to stop mixing.

[0011] A known solution for detecting changes in the preparation involves a time-dependent analysis of the current or torque of the main motor of the kneading appliance. In other words, a time-dependent change in the current or torque of the main motor is compared to a threshold or slope value over time in order to determine a time-dependent change in the texture of the preparation that allows the mixing process to stop.

[0012] This solution does not give complete satisfaction, particularly for the preparation of certain doughs, such as brioche dough for example.

[0013] There is therefore a need in this regard for a reliable, inexpensive, and robust solution that can assist the user during preparation work to guarantee an optimal result, regardless of the ingredients and / or quantity used. Description of the invention

[0014] An embodiment relates to [RV1] a method of controlling a kneading household appliance according to a determination of a texture of a preparation made by said kneading household appliance, said appliance comprising at least one preparation working tool which is fixed to a drive output, said drive output being rotated by a main motor, said method being implemented by said appliance and comprising at least: - A step of determining a fundamental frequency of a supply current of the main motor; - A recording stage in which the main motor's supply current is recorded over an operating period; - An analysis step in which an analysis quantity is determined as a function of at least one value of the amplitude of a Fourier Transform of the supply current for the fundamental frequency; - A comparison step in which a texture parameter is determined based on a comparison of the analysis quantity with a comparison criterion.

[0015] The kneading appliance comprises a bowl attached to a main body. Generally, the main body is equipped with a foot extending into a head, the head being rotatable relative to the foot. The foot of the kneading appliance rests, in use, on a work surface. The head is rotatable relative to an axis extending horizontally from said work surface, in use.

[0016] The working tool is a tool designed to be fixed, preferably in a removable manner, to the drive output of the main body, and more specifically to the drive output of the head of the main body.

[0017] According to one embodiment, the kneading appliance includes a single drive output onto which each working tool can be attached alternately.

[0018] Alternatively, the kneading appliance comprises a plurality of drive outputs, each working tool being able to be attached to a single drive output. In other words, there is a pairing between a drive output and a working tool.

[0019] The drive output is rotated by means of a main motor, positioned in the main body, for example in the foot. The main motor is electrically powered by an electrical network. A user can select different operating speeds corresponding to different rotational speeds of the drive output.

[0020] According to one embodiment, each drive output of the plurality of drive outputs rotates at a different speed for the same selected operating speed. In other words, for an operating speed selected by a user, each working tool will have a different rotational speed.

[0021] The working tool can, for example, be a dough hook, a mixing sheet, or a whisk.

[0022] The method according to the invention makes it possible to determine the texture, and in particular the optimum texture for the preparation envisaged, by analyzing the amplitude of the Fourier transform of the supply current of the main motor at the fundamental frequency.

[0023] The Fourier transform is a mathematical tool that allows the main motor's supply current to be decomposed in the frequency domain. This decomposition gives the amplitude, or quantity, of each frequency in the supply current for the considered time period. Thus, the decomposition allows to analyze the frequency properties of the current, in particular to determine the value of the amplitude of the supply current at the fundamental frequency. There are several Fourier transforms such as the Discrete Fourier Transform and the Fast Fourier Transform.

[0024] The method includes a determination step in which the fundamental frequency is determined. At the end of the determination step, the fundamental frequency is known.

[0025] The fundamental frequency is a function of the rotational speed of the working tool.

[0026] According to one embodiment, the fundamental frequency is determined as a function of the working tool positioned on the drive output.

[0027] According to one embodiment, the fundamental frequency is between 0 Hz and 20 Hz, preferably between 0 Hz and 15 Hz, and in particular between 0 Hz and 12 Hz. The method also includes a recording step during which the supply current of the main motor is recorded over an operating period. In other words, when the kneading appliance is in operation, i.e., when the working tool is rotating to process a mixture, the kneading appliance records the value of the supply current, for example, by means of a Hall effect sensor placed in series on the motor's supply terminals.

[0028] The method also includes an analysis step in which an analysis quantity is determined as a function of at least one value of the amplitude of the Fourier Transform of the supply current at the fundamental frequency. During the analysis step, the kneading appliance calculates the Fourier Transform of the supply current and deduces the amplitude value at the fundamental frequency for the operating period.

[0029] According to one embodiment, the quantity of analysis is determined as a function of an average of the values ​​of the amplitude of the Fourier Transform of the supply current for the fundamental frequency over an analysis period.

[0030] Thus, after the analysis step, the analysis quantity for the fundamental frequency is known for the operating period. At each operating period, the process determines the analysis quantity. In other words, after each recording step, the process performs the analysis step.

[0031] Finally, the process includes a comparison step in which a texture parameter is determined based on a comparison of the analysis quantity with a comparison criterion.

[0032] The texture parameter can be, for example, a boolean texture parameter "non-optimal texture" / "optimal texture" or a variable parameter defining different texture states.

[0033] The comparison criterion may be a function of the fundamental frequency and / or the working tool.

[0034] The comparison criterion may be a threshold, for example, or a slope of evolution of the value of the quantity of analysis.

[0035] When the analysis quantity validates the comparison criterion, the texture of the preparation is optimal for the desired preparation.

[0036] The analytical quantity is representative of the texture of the preparation. Indeed, when ingredients are mixed, the amplitude at the fundamental frequency varies according to the viscosity and texture of the ingredients.

[0037] At the beginning of the kneading process, the amplitude at the fundamental frequency is high. This value is characteristic of the rotational speed of the working tool. Furthermore, a harmonic spectrum of the feed current, that is, the representation of the feed current amplitudes as a function of frequencies, shows fairly high amplitudes for a plurality of frequencies. These amplitudes are characteristic of an imbalance in the mixture related to the initial masses.

[0038] As mixing continues, the preparation becomes more homogeneous, and the amplitudes at the fundamental frequency, as well as at other frequencies, decrease. This is representative of the fact that the initial imbalance diminishes due to the preparation changing texture and becoming more homogeneous. When the preparation is a paste, it acquires viscoelastic properties that better absorb vibrations, thus reducing fluctuations in the supply current, particularly at the fundamental frequency. A homogeneous paste exhibits homogeneous reaction forces, reducing periodic variations in the supply current and therefore the amplitude at the fundamental frequency.

[0039] The analysis of the analysis quantity therefore makes it possible to determine the texture of the preparation, and to deduce key stages in the evolution of the preparation in order to alert the user or automatically stop the rotation of the working tool according to the expected result.

[0040] The process according to the invention has the advantage of assisting the user during preparation to guarantee an optimum result regardless of the ingredients or quantity thereof.

[0041] In some embodiments, the process includes a definition step in which at least one type of preparation is specified.

[0042] The type of preparation can be a cooking recipe, or a family of preparations such as "brioche dough", "bread dough", "whipped cream", etc.

[0043] Thus, the comparison criterion can be modified according to the type of preparation.

[0044] During the definition stage, the working tool can be detected, for example by means of a sensor, or specified by the user.

[0045] Also during the definition stage, the selected operating speed can be detected, for example by means of a sensor, or entered by the user.

[0046] Alternatively, the comparison criterion is a function of the fundamental frequency.

[0047] Preferably, the recording step, the analysis step and the comparison step are carried out continuously, that is to say at a determined frequency.

[0048] The object of this presentation may also have one or more of the following characteristics taken alone or in combination.

[0049] [RV2] In some embodiments, the frequency determination step fundamental includes at least: - a phase of recording the main motor's power supply current during an initial period of operation; - a study phase in which a plurality of amplitude-frequency sets, a set comprising an amplitude associated with a frequency, of the supply current is determined by means of a Fourier Transform of the measured supply current; - a detection phase in which the frequency of an assembly is defined as the fundamental frequency of the main motor supply current as a function of the result of a comparison of the amplitudes of said frequencies with a determination criterion.

[0050] The recording phase allows the value of the main motor's supply current to be recorded as a function of time. The first operating period is a period of time prior to that recorded during the recording step. Preferably, the first operating period is less than or equal to the operating period. During the first operating period, the kneading appliance is in operation.

[0051] The study phase consists of determining a plurality of amplitude-frequency sets, or pairs, each set comprising an amplitude associated with a frequency, by means of a Fourier Transform of the measured supply current. This corresponds to obtaining the harmonic spectrum of the supply current for at least certain frequencies, said frequencies being determined according to the possible speeds of the working tool. Alternatively, said frequencies can be determined according to the selectable operating speeds and the fixed working tool. The harmonic spectrum can also be obtained for all frequencies.

[0052] The detection phase consists of determining the fundamental frequency among the frequencies of the plurality of sets. To do this, the detection phase performs a comparison of the amplitudes of the plurality of sets with a determination criterion.

[0053] [RV3]In some embodiments, the determination criterion corresponds to the maximum amplitude taken from the plurality of amplitudes of the amplitude-frequency sets.

[0054] In other words, the amplitudes of the plurality of sets are compared with each other in order to determine the maximum amplitude. This maximum amplitude then becomes the value of the determination criterion, so that the frequency associated with this maximum amplitude becomes the fundamental frequency.

[0055] In other words, the detection phase identifies the frequency with the maximum amplitude and determines that this corresponds to the rotation speed of the working tool.

[0056] In some embodiments, the detection phase identifies the frequency having the maximum amplitude in an admissible frequency range.

[0057] According to one embodiment, the permissible frequency range is between 0Hz and 20Hz, preferably between 0Hz and 15Hz, and in particular between 0Hz and 12Hz.

[0058] In some embodiments, the determination criterion is a threshold value. Then the determination step includes a phase of reading the determination criterion from a memory.

[0059] [RV4]In some embodiments, the fundamental frequency is determined as a function of the working tool and a selected operating speed.

[0060] From the working tool and the selected operating speed it is possible to determine the rotation speed of the working tool and thus to deduce, for example by means of a reading in a lookup table, the fundamental frequency.

[0061] [RV5]In some embodiments, during the analysis step, the supply current is sampled according to a sampling time.

[0062] In some embodiments, the sampling time is between 0.5ms and 10ms, preferably between 1ms and 5ms, and in particular 2ms.

[0063] The sampling time allows the main motor supply current to be represented correctly.

[0064] [RV6] In some embodiments, the operating period is included between 10s and 1000s, preferably between 10s and 300s, and especially 150s.

[0065] The chosen operating period allows for the correct representation of the texture changes of the preparation.

[0066] [RV7] In some embodiments, the comparison step includes a reading phase of the comparison criterion in a memory.

[0067] The comparison criterion is then defined, for example, by an experiment. The comparison criterion may depend on the type of preparation carried out.

[0068] [RV8]One embodiment relates to a kneading appliance comprising at least one preparation working tool which is fixed to a drive output, said drive output being rotated by a main motor, the kneading appliance implementing the method according to any one of the preceding claims. Brief description of the drawings

[0069] The invention will be better understood from the following description, which relates to one or more embodiments according to the present invention, given by way of non-limiting examples and explained with reference to the accompanying schematic drawings, in which:

[0070] [Fig. 1] is a schematic representation of a kneading household appliance according to the invention and of two working tools;

[0071] [Fig.2] is a curve illustrating a supply current of a main motor in function of time during the preparation of brioche dough;

[0072] [Fig.3] is a harmonic spectrum of the supply current representing a signal amplitude as a function of a frequency for an operating period between 400s and 500s of the curve of [Fig.2];

[0073] [Fig.4] is the harmonic spectrum of the supply current representing the amplitude of the signal as a function of frequency for the operating period between 500s and 600s of the curve of [Fig.2];

[0074] [Fig.5] is the harmonic spectrum of the supply current representing the signal amplitude as a function of frequency for the operating period between 600s and 700s of the curve of [Fig.2];

[0075] [Fig.6] is the harmonic spectrum of the supply current representing the signal amplitude as a function of frequency for the operating period between 700s and 800s of the curve of [Fig.2];

[0076] [Fig.7] is the harmonic spectrum of the supply current representing the amplitude of the signal as a function of frequency for the operating period between 800s and 900s of the curve of [Fig.2];

[0077] [Fig.8] is the harmonic spectrum of the supply current representing the signal amplitude as a function of frequency for the operating period between 1000s and 1100s of the curve of [Fig.2]; Description of the implementation methods

[0078] Only the elements necessary for understanding the invention have been shown. To facilitate reading the drawings, the same elements bear the same reference numerals from one figure to another.

[0079] One embodiment relates to a method for determining the texture of a preparation M made in a kneading appliance 1. The preparation M comprises one or a plurality of ingredients, and may be a mixture of dry or liquid ingredients, and be in the form of a paste, a foam, a powder, etc.

[0080] The kneading appliance 1, as shown in [Fig. 1], comprises a bowl 4 which is attached to a main body 5. The main body 5 is equipped with a foot 5a extending into a head 5b, the head 5b being rotatable relative to the foot 5a. The foot 5a of the kneading appliance 1 rests, in use, on a work surface. The head 5b is rotatable relative to an axis extending horizontally from said work surface, in use.

[0081] A working tool 2a, 2b, 2c is a tool designed to be fixed, preferably in a removable manner, to the drive output 3 of the main body 5, and more specifically to the drive output 3 of the head 5b of the main body 5.

[0082] According to one embodiment, the kneading appliance 1 comprises a single drive output onto which each working tool 2a, 2b, 2c can be attached alternately.

[0083] Alternatively, the kneading appliance 1 comprises a plurality of drive outputs 3, each working tool 2a, 2b, 2c being able to be fixed to a single drive output 3. In other words, there is a pairing between a drive output 3 and a working tool 2a, 2b, 2c.

[0084] The drive output 3 is rotated by means of a main motor, positioned in the main body 5, for example in the foot 5a. The main motor is electrically powered by an electrical network. A user can select different operating speeds by means of a control element 6. Each selected operating speed corresponds to a different rotational speed of the drive output 3.

[0085] According to one embodiment, each drive output 3 of the plurality of drive outputs 3 rotates at a different speed for the same selected operating speed. In other words, for an operating speed selected by a user, each working tool 2a, 2b, 2c will have a different rotational speed.

[0086] The working tool 2a, 2b, 2c can for example be a dough hook 2a, a mixing sheet 2b, or a whisk 2c.

[0087] The table below indicates the rotational speed of the working tool 2a, 2b, 2c in the case of a plurality of drive outputs 3 rotating at different speeds thanks to different reduction ratios:

[0088] [Table 1] Selected operating speed Hook rotation speed 2a (rpm) Whip rotation speed 2b (rpm) 1 120 198 2 157 259 3 190 314 4 223 369 5 290 479 6 350 578 7 396 655 8 440 726

[0089] The method according to the invention makes it possible to determine the texture, and in particular the optimum texture for the preparation M envisaged, by analyzing an amplitude A of the Fourier transform of the supply current C of the main motor at a fundamental frequency Ff.

[0090] More specifically, the process includes a definition step in which at least one type of preparation is specified.

[0091] The type of preparation can be a cooking recipe, or a family of preparations such as "brioche dough", "bread dough", "whipped cream", etc.

[0092] During the definition step, the working tool 2a, 2b, 2c can be detected, for example by means of a sensor, or entered by the user.

[0093] Also during the definition stage, the selected operating speed can be detected, for example by means of a sensor, or entered by the user.

[0094] The method includes a determination step in which the fundamental frequency Ff of the supply current C of the main motor is determined.

[0095] According to one embodiment, the fundamental frequency Ff is determined as a function of the working tool 2a, 2b, 2c positioned on the drive output 3.

[0096] According to one embodiment, the fundamental frequency Ff is between 0Hz and 20Hz, preferably between 0Hz and 15Hz, and in particular between 0Hz and 12Hz.

[0097] In certain embodiments, the fundamental frequency Ff is determined as a function of the working tool 2a, 2b, 2c and the selected operating speed. From these two pieces of information, it is possible to determine the rotational speed. of the working tool 2a, 2b, 2c, as shown in Table 1, and thus deduce, for example by consulting a lookup table, the fundamental frequency Ff. Indeed, the fundamental frequency Ff is characteristic of the rotational speed of the working tool 2a, 2b, 2c. For example, the motor current of the dough hook 2a at a selected speed of four has a fundamental frequency Ff of 3.95 Hz. As another example, the motor current of the whisk 2c at a selected speed of five has a fundamental frequency Ff of 8 Hz.

[0098] Alternatively, the fundamental frequency determination step Ff includes a measurement phase during a first operating period Tl of the main motor's supply current C. This measurement phase records the value of the main motor's supply current C as a function of time T. The first operating period Tl is an operating period of the kneading appliance 1. The first operating period Tl is illustrated in [Fig. 2], which shows the main motor's supply current C as a function of time T during the preparation of brioche dough, using a kneading hook 2a and a selected speed of four. In [Fig. 2], the first operating period Tl is between 400 s and 500 s.

[0099] Next, the determination step includes a study phase in which a plurality of amplitude-frequency sets, that is, a set comprising an amplitude A associated with a frequency F, of the supply current C is determined by means of a Fourier Transform performed on the supply current C. The Fourier Transform is a mathematical tool that allows the supply current C of the main motor to be decomposed in the frequency domain. This decomposition gives an amplitude A, or the quantity, of each frequency F in the supply current C for the considered time period T. Thus, the decomposition allows the frequency properties of the current C to be analyzed. Several Fourier Transforms exist, such as the Discrete Fourier Transform and the Fast Fourier Transform.

[0100] The study phase consists of obtaining a harmonic spectrum of the supply current C for at least certain frequencies, said frequencies being determined according to the possible rotational speeds of the working tool 2a, 2b, 2c. Alternatively, said frequencies can be determined according to the operating speeds that can be selected and the working tool 2a, 2b, 2c fixed. The harmonic spectrum can also be obtained for all frequencies F.

[0101] Finally, the determination step includes a detection phase in which the frequency F of an assembly is defined as the fundamental frequency Ff of the main motor's supply current C as a function of the result of a comparison of the amplitudes A of said frequencies F with a determination criterion. The phase The detection process therefore consists of determining the fundamental frequency Ff among the frequencies F of the plurality of sets. To do this, the detection phase performs a comparison of the amplitudes A of the plurality of sets with a determination criterion.

[0102] In certain embodiments, the determination criterion corresponds to the maximum amplitude A taken from among the plurality of amplitudes A of the amplitude-frequency sets. In other words, the amplitudes A of the plurality of sets are compared with each other so as to determine the maximum amplitude A. This maximum amplitude then becomes the value of the determination criterion, so that the frequency F associated with this maximum amplitude A becomes the fundamental frequency Ff. In other words, the detection phase identifies the frequency F having the maximum amplitude A and determines that this corresponds to the rotational speed of the working tool 2a, 2b, 2c.

[0103] For example, [Fig. 3] illustrates the harmonic spectrum of the supply current C recorded during the measurement phase, i.e., during the first time period T1. The maximum amplitude is approximately 24 for the frequency of 3.95 Hz. Thus, for this supply current, the fundamental frequency Ff is 3.95 Hz.

[0104] In some embodiments, the detection phase identifies the frequency F having the maximum amplitude A within an admissible frequency range.

[0105] According to one embodiment, the permissible frequency range is between 0Hz and 20Hz, preferably between 0Hz and 15Hz, and in particular between 0Hz and 12Hz.

[0106] In some embodiments, the determination criterion is a threshold value. The determination step then includes a phase of reading the determination criterion from a memory. The determined amplitudes are then compared to the determination criterion.

[0107] When the fundamental frequency determination step Ff is completed, the process performs a recording step in which the supply current C of the main motor is recorded over an operating period T2, T3, T4, T5, T6. In other words, when the kneading appliance 1 is in operation, i.e. when the working tool 2a, 2b, 2c is rotating so as to work the preparation M, the kneading appliance 1 records the value of the supply current C, for example by means of a Hall effect sensor placed in series on the motor supply terminals.

[0108] In certain embodiments, the operating period T2, T3, T4, T5, T6 is between 10s and 1000s, preferably between 10s and 300s, and in particular 150s. Figure 2 illustrates several operating periods T2, T3, T4, T5, T6 corresponding to different recording stages, each of 100s. One operating period T2 is between 500s and 600s, another period operating period T3 is between 600s and 700s, another operating period T4 is between 700s and 800s, another operating period T5 is between 800s and 900s, and finally a last operating period T6 is between 1000s and 1100s.

[0109] The chosen operating period T2, T3, T4, T5, T6 allows for a correct representation of the texture evolutions of preparation M.

[0110] Next, the method includes an analysis step in which an analysis quantity is determined as a function of at least the value of the amplitude A of a Fourier Transform of the supply current C for the fundamental frequency Ff. During the analysis step, the kneading appliance 1 calculates the Fourier Transform of the supply current C and deduces the value of the amplitude A at the fundamental frequency Ff for the operating periods T2, T3, T4, T5, T6. Thus, after the analysis step, the analysis quantity for the fundamental frequency Ff is known for the operating period. At each operating period T2, T3, T4, T5, T6, the method determines the analysis quantity.

[0111] According to one embodiment, the quantity of analysis is determined as a function of an average of the values ​​of the amplitude A of the Fourier Transform of the supply current C for the fundamental frequency Ff over an analysis period.

[0112] In certain embodiments, during the analysis step, the supply current C is sampled using a sampling time, for example, which is between 0.5 ms and 10 ms, preferably between 1 ms and 5 ms, and in particular 2 ms. The sampling time makes it possible to accurately represent the supply current C of the main motor.

[0113] Figures 4 to 8 represent the harmonic spectrum of the supply current C recorded during each operating period T2, T3, T4, T5, T6. Thus, for this supply current C, the amplitudes A of the fundamental frequency Ff of 3.95 Hz for the different operating periods are listed below:

[0114] [Table 2] Figure Number Operating Period Fundamental Frequency Amplitude 4 T2 (500s-600s) 14 5 T3 (600s-700s) 15 6 T4 (700s-800s) 10, 8 7 T5 (800s-900s) 9, 8 8 T6 (1000s-1000s) 7

[0115] Finally, the process includes a comparison step in which a texture parameter is determined based on a comparison of the analysis quantity with a comparison criterion. The texture parameter can be, for example, a Boolean texture parameter "non-optimal texture" / "optimal texture" or a variable parameter defining different texture states. The comparison criterion can be a function of the fundamental frequency Ff and / or the working tool. The comparison criterion can also be an SI threshold as illustrated in Figures 4 to 7, or a slope of the change in the value of the analysis quantity. The comparison criterion can be modified depending on the type of preparation.

[0116] In some embodiments, the comparison step includes a phase of reading the comparison criterion from memory. The comparison criterion is then defined, for example, by an experiment. The comparison criterion may depend on the type of preparation performed.

[0117] When the analysis quantity validates the comparison criterion, the texture of the preparation is optimal for the desired preparation M. The analysis quantity is representative of the texture of preparation M. Indeed, when ingredients are mixed, the amplitude A at the fundamental frequency Ff varies according to the viscosity and texture of the ingredients.

[0118] At the beginning of kneading, the amplitude A at the fundamental frequency Ff is high. This value is characteristic of the rotational speed of the working tool. Furthermore, the harmonic spectrum of the supply current C shows fairly high amplitudes A for a plurality of frequencies F, as illustrated in [Fig. 3]. These amplitudes A are characteristic of an imbalance in the preparation M related to the initial masses.

[0119] As mixing continues, [Fig. 4] to 8 and Table 2, the preparation M becomes more homogeneous and the amplitudes A at the fundamental frequency Ff, as well as at other frequencies, decrease. This is representative of the fact that the initial imbalance decreases due to the preparation changing texture and becoming more homogeneous. When the preparation M is a paste, it acquires viscoelastic properties that better absorb vibrations, thus reducing fluctuations in the supply current C, particularly at the fundamental frequency Ff. A homogeneous paste exhibits homogeneous reaction forces, reducing periodic variations in the supply current C and therefore the amplitude at the fundamental frequency Ff.

[0120] For example, in Figures 4 to 8, the amplitude A at the fundamental frequency Ff decreases until it falls below the SI threshold of the comparison criterion, [Fig. 7]. In the illustrated example, the texture parameter validates the comparison criterion between 800s and 900s. Between 800s and 900s, the texture of preparation M became optimal for the brioche dough being prepared.

[0121] Analysis of the analysis quantity thus makes it possible to determine the texture of the preparation and to deduce key stages in the evolution of the preparation M in order to alert the user or automatically stop the rotation of the working tool 2a, 2b, 2c depending on the expected result. Whereas the analysis of the supply current C over time, [Fig. 2], shows no specificity.

[0122] The process according to the invention has the advantage of assisting the user during preparation to guarantee an optimum result regardless of the ingredients or quantity thereof.

[0123] Although the present invention has been described with reference to specific embodiments, it is evident that modifications and changes can be made to these examples without departing from the general scope of the invention as defined by the claims. In particular, individual features of the various embodiments illustrated / mentioned can be combined in additional embodiments. Therefore, the description and drawings should be considered in an illustrative rather than a restrictive sense.

[0124] It is also evident that all the characteristics described with reference to a process are transposable, alone or in combination, to a device, and conversely, all the characteristics described with reference to a device are transposable, alone or in combination, to a process.

Claims

1.

2. Demands Method of controlling a kneading appliance (1) based on a determination of the texture of a preparation (M) produced by said kneading appliance (1), said appliance (1) comprising at least one working tool (2a, 2b, 2c) for the preparation (M) which is fixed to a drive output (3), said drive output (3) being rotated by a main motor, said method being implemented by said appliance (1) and comprising at least: - A step of determining a fundamental frequency (Ff) of a supply current (C) of the main motor; - A recording stage in which the supply current (C) of the main motor is recorded over an operating period (T2, T3, T4, T5, T6); - An analysis step in which an analysis quantity is determined as a function of at least one value of the amplitude (A) of a Fourier Transform of the supply current (C) for the fundamental frequency (Ff); - A comparison step in which a texture parameter is determined based on a comparison of the analysis quantity with a comparison criterion. A method according to claim 1, wherein the step of determining the fundamental frequency (Ff) comprises at least: - a phase of recording over a first operating period (Tl) the supply current (C) of the main motor; - a study phase in which a plurality of amplitude-frequency sets, a set comprising an amplitude (A) associated with a frequency (F), of the supply current (C) is determined by means of a Fourier Transform of the measured supply current (C); - a detection phase in which the frequency (F) of an assembly is defined as the fundamental frequency (Ff) of the motor's supply current (C) principal as a function of a result of a comparison of the amplitudes (A) of said frequencies (F) with a determination criterion.

3. Method according to claim 2, wherein the determination criterion corresponds to the maximum amplitude (A) taken from the plurality of amplitudes (A) of the amplitude-frequency sets.

4. Method according to claim 1, wherein the fundamental frequency (Ff) is determined as a function of the working tool (2a, 2b, 2c) and a selected operating speed.

5. A method according to any one of the preceding claims, wherein during the analysis step, the supply current (C) is sampled according to a sampling time.

6. A method according to any one of the preceding claims, wherein the operating period (T2, T3, T4, T5, T6) is between 10s and 1000s, preferably between 10s and 300s, and in particular 150s.

7. A method according to any one of the preceding claims, wherein the comparison step includes a phase of reading the comparison criterion from a memory.

8. A kneading household appliance (1) comprising at least one working tool (2a, 2b, 2c) for a preparation (M) which is fixed to a drive output (3), said drive output (3) being rotated by a main motor, the kneading household appliance (1) implementing the method according to any one of the preceding claims.

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