DESCRIPTION

[0001] The present invention relates to a washing machine or washer-dryer and a washing method, in particular a step of filling the washing machine with water.

[0002] Domestic washing machines comprise a supporting and housing structure, in which a washing tank is housed, provided with a front opening closable by a porthole door frontally hinged to the housing. A drum is rotatably housed inside the washing tank, about a horizontal or inclined axis, to receive the clothes to be washed. The drum also delimits a front opening placed at the opening of the washing tank in order to load and unload the clothes.

[0003] The washing tank is adapted to contain the washing liquid during the clothes washing steps.

[0004] A washing water filling system connectable to the water supply network is provided to allow the filling the tank with mains water and detergent substances and additives. A drainage duct associated with a drainage pump is provided at the bottom of the washing tank, which removes the washing liquid from the tank and, together with the filling system, controls the level of liquid inside the tank.

[0005] It is known to arrange a detergent tray in flow communication with the water filling system in order to add a detergent or a treatment additive to the washing liquid.

[0006] The detergent tray can be configured as a drawer which can be removed from and inserted into the housing structure and which can be filled manually for each wash with an amount of detergent and/or treatment additive sufficient for a single washing cycle.

[0007] So-called "multiple dispensing" washing machines with treatment substance dispensing and dosing systems configured to contain a sufficient amount of treatment substance for a plurality of washing cycles and to automatically dispense a controlled dose of treatment substance for each washing cycle, are also known.

[0008] An electrical resistance for heating the washing liquid contained in the washing tank is provided, the electrical resistance being arranged inside the washing tank, in the gap between the tank wall and the laundry drum.

[0009] In order to reduce the consumption of water and detergent, it is known to provide washing machines with recirculation systems which remove the washing liquid from the bottom of the tank (where it accumulates even before wetting the clothes inside the drum) and reintroduce it into the laundry drum so that a small volume of liquid is repeatedly poured on the clothes to be washed.

[0010] Recirculation systems usually comprise a recirculation duct which extends externally to the washing tank from a lower opening of the washing tank (for drawing the liquid to be recirculated) up to an upper opening of the washing tank (for reintroducing the recirculated liquid), as well as an electric or ejector recirculation pump.

[0011] Some washing machines comprise a sensor for detecting the clothes load and a control device which controls the execution of a washing program also depending on the detected clothes load.

[0012] The features described hereto in relation to washing machines of the prior art known by the Applicant can also be implemented, entirely or partially, in at least some embodiments of an improved washing machine according to the invention.

[0013] In the prior art, the clothes load is detected when performing a washing program which has already started, for example by monitoring the absorption of water in the clothes or by means of force sensors interposed between the washing tank and the housing.

[0014] Systems and methods for directly or indirectly detecting or determining the still not wet clothes mass, therefore before performing the actual clothes washing program, have also been suggested.

[0015] In the known art, the step of filling mains water in the washing tank is performed in an iterative manner, alternating the steps of opening a supply valve with rotation steps of the laundry drum and with steps of monitoring the water level in the washing tank through a pressure sensor in order to consider both a desired water level, which can be verified by detecting water pressure at the bottom of the washing tank, and the amount of water absorbed by the clothes, which in turn depends on the quantity of clothes contained in the drum.

[0016] The known iterative water filling process is performed conceptually equally for each individual washing cycle, irrespective of the quantity of clothes loaded in the laundry drum. Therefore, the individual water filling steps are selected small enough so as to avoid excessively exceeding the desired water level also in the presence of a few items of clothes. This circumstance requires an increased number of individual water filling steps alternated by corresponding steps of monitoring the water level through the pressure sensor, thus requiring undesirably lengthy filling times and undesirably increased energy consumption.

[0017] Moreover, the washing machines and washer-dryers of the known art do not allow determining clothes treatment parameters, for example the dose of detergent or other treatment substances, or the clothes drying time, in quantity ranges optimized for the type and quantity of clothes actually treated.

[0018] Therefore, it is an object of the present invention to provide an improved washing machine and washing method having features so as to shorten the time of initial filling water in the washing tank.

[0019] Further objects of the present invention relate to the provision of an improved washing machine and washing method having features so as to determine clothes treatment parameters, for example the detergent dose or the drying time, in a new and targeted manner for the type (for example, the water absorption property) and quantity (for example, the total dry and/or wet mass) of clothes actually treated.

[0020] The object of the invention is achieved by a washing machine and washing method according to the independent claims. The dependent claims relate to advantageous and preferred embodiments of the invention.

[0021] According to an aspect of the invention, there is provided a washing method by a washing machine comprising:

[0022] - a washing tank adapted to contain a washing liquid,

[0023] - a laundry drum supported inside the washing tank in rotatable manner about a rotation axis and adapted to contain clothes to be washed,

[0024] - a treatment system configured to perform, on the clothes inside the laundry drum, one or more laundry washing programs by soaking in water and detergent, [0025] wherein the washing method comprises:

[0026] - performing a program for washing the clothes contained in the laundry drum, said washing program comprising a step of filling water in the washing tank,

[0027] - performing a process of determining the mass of the still dry clothes contained in the laundry drum prior to the water filling step,

[0028] - performing the water filling step depending on the determined dry clothes mass.

[0029] This allows immediately filling the amount of water required for the clothes mass to be washed, thus obviating repeated and lengthy partial filling iterations, discontinuation and waiting for absorption of the water by the clothes, monitoring the water level, further partial filling, etc., of the known art, and therefore, obtaining a considerable decrease in the duration of the water filling step, for example in the range of 20 minutes. [0030] Similarly, a washing machine is suggested, comprising:

[0031] - a washing tank adapted to contain a washing liquid,

[0032] - a laundry drum supported inside the washing tank in rotatable manner about a rotation axis and adapted to contain clothes to be washed,

[0033] - a treatment system configured to perform, on the clothes inside the laundry drum, one or more laundry washing programs by soaking in water and detergent, [0034] wherein the treatment system is configured to:

[0035] - performing a program for washing the clothes contained in the laundry drum, said washing program comprising a step of filling water in the washing tank,

[0036] - performing a process of determining the mass of the still dry clothes contained in the laundry drum prior to the water filling step,

[0037] - performing the water filling step depending on the determined dry clothes mass.

[0038] The thus configured laundry machine allows immediately filling the washing machine with the amount of water required for the clothes mass to be washed, obviating repeated and lengthy partial filling iterations, discontinuation and waiting for absorption of the water by the clothes, monitoring the water level, further partial filling, etc., of the known art, and therefore, obtaining a considerable decrease in the duration of the water filling step, for example in the range of 20 minutes.

[0039] According to a further aspect of the invention, a washing method, indicated above, is suggested, where the water filling step depending on the determined dry clothes mass can be optional, but which also comprises the steps of:

[0040] - performing a step (41) of dispensing detergent into the washing tank (3) depending on the determined dry clothes mass (dry mass), OR

[0041] - performing a process (43) of determining the mass (wet_mass) of wet clothes contained in the laundry drum (5) after the end of the washing program,

[0042] - determining a moisture parameter indicative of an amount of water which is to be evaporated through the drying step (44) depending on the determined value of dry clothes mass (dry mass) and the determined value of wet clothes mass (wet_mass), [0043] - displaying a time duration of the drying step (44) determined depending on the determined moisture parameter.

[0044] This allows determining the detergent dose and/or the drying time in a targeted manner by the type (for example, the water absorption property) and/or quantity (for example, the total dry and/or wet mass) of clothes actually treated.

[0045] Further advantageous aspects of the invention will become apparent from the following description of some embodiments thereof, given by way of non-limiting example, with reference to the accompanying drawings, in which:

[0046] - Figure 1 is a diagrammatic sectional view of a washing machine according to an embodiment of the invention,

[0047] - Figure 2 is a block diagram of a water filling process of a washing program according to an embodiment,

[0048] - Figure 3 is a diagram showing the relation between a total required water amount (ordinate, Peak_1 [mm]) and the value of the determined dry clothes mass (abscissa, Dry mass [kg]), for determining the total required water amount (Peak_1 [mm]) depending on the determined dry clothes mass (Dry mass [kg]), according to an embodiment,

[0049] - Figure 4 is a diagram showing the relation between a water level in the washing tank after a step of absorbing water in the clothes (ordinate, abs_level_1 [mm]) and the value of the determined dry clothes mass (abscissa, Dry mass [kg]), for determining a water level value (abs_level_1 [mm]) after absorption depending on the determined dry clothes mass (Dry mass [kg]), according to an embodiment,

[0050] - Figure 5 is a diagram showing the relation between a duration of the step of absorbing water in the clothes (ordinate, abs_time_1 [s]) and the value of the determined dry clothes mass (abscissa, Dry mass [kg]), for determining a value of the duration of the water absorption step (abs_time_1 [s]) up to reaching the water level value (abs_level_1 [mm]) after absorption depending on the determined dry clothes mass (Dry mass [kg]), according to an embodiment,

[0051] - Figure 6A is a diagram showing a monitoring of the water level in the washing tank (ordinate, H2O_level [mm]) as a function of the time (abscissa, time [s]), for detecting/determining the actual duration of the water absorption step (real_time_1 [s]) up to reaching the water level value (abs_level_1 [mm]) after absorption in order to verify the correctness of the value of the determined dry clothes mass (Dry mass [kg]), according to an embodiment.

[0052] In Figure 6A, the actual duration of the water absorption step (real_time_1 = 245 s) up to reaching the water level value (abs_level_1 = 61 mm) after absorption confirms the correctness of the value of the determined dry clothes mass (Dry mass = 8 kg), in compliance with the relations in Figures 3, 4, 5.

[0053] - Figure 6B is a further diagram showing a monitoring of the water level in the washing tank (ordinate, H2O_level [mm]) as a function of the time (abscissa, time [s]), for detecting/determining the actual duration of the water absorption step (real_time_1 [s]) up to reaching the water level value (abs_level_1 [mm]) after absorption in order to verify the correctness of the value of determined dry clothes mass (Dry mass [kg]), according to an embodiment.

[0054] In Figure 6B, the actual duration of the water absorption step (real_time_1 = 103 s) up to reaching the water level value (abs_level_1 = 61 mm) after absorption shows an incorrect value of determined dry clothes mass (Dry mass = 8 kg), with respect to the more correct or revised value of clothes mass (Dry_mass_rev = 10 kg), in compliance with the relations in Figures 3, 4, 5.

[0055] - Figure 7 is a diagram showing an alternation of brief opening and closing steps of a water filling flow in a water filling sub-step with pulses, which is suitable for an improved dilution/solution and effective rinsing of powder detergent from a detergent compartment towards the washing tank, according to an embodiment.

[0056] - Figure 8 is a block diagram of a water and detergent filling process of a washing program, according to an embodiment,

[0057] - Figure 9 is a block diagram of a process for determining drying parameters of a washing program, according to an embodiment.

[0058] Detailed description of the washing machine 1

[0059] With reference to the drawings, a washing machine 1 or washer-dryer comprises a supporting and housing structure 2, in which a washing tank 3 is housed, provided with a (frontal or peripheral) opening closable by a door 4, e.g., a porthole door, hinged frontally to or on top of housing 2. A laundry drum 5 for accommodating the clothes to be washed is housed inside the washing tank 3 in a rotatable manner about a horizontal or inclined rotation axis R-R. The laundry drum 5 can also delimit a front opening at the opening of the washing tank 3, or a closable peripheral opening, for loading and unloading the clothes.

[0060] The washing machine comprises a clothes treatment system 3, 6, 7, 8, 9, 12, 13, 18, 20, 21 configured to perform one or more treatment steps on the clothes inside the laundry drum 5, in particular clothes washing steps by soaking in water and detergent and/or steps of drying clothes by forced ventilation.

[0061] The washing tank 3 is adapted to contain the washing liquid during the clothes washing steps.

[0062] A washing water filling system 6 connectable to the water mains is provided to allow filling mains water in the washing tank 3. The filling system 6 can comprise a plurality of ducts which extend from, for example, one or more, e.g., two, supply solenoid valves 7, 8, directly or through detergent compartments of a detergent tray 9, to the washing tank 3.

[0063] A drainage duct 11 with associated drainage pump 12 which removes the washing liquid from tank 3 and which, together with the supply solenoid valves 7, 8, controls the level of liquid inside tank 3, is connected to bottom 10 of the washing tank 3.

[0064] An electrical resistance 13 arranged inside tank 3, in particular at the tank bottom 10, in the gap between the wall of tank 3 and the laundry drum 5, can be provided for heating the washing liquid contained in tank 3.

[0065] The washing machine 1 can further comprise a dispensing system 18 of the “multiple dose" type for dispensing substances for treating the clothes.

[0066] In addition or alternatively to the detergent tray 9, the dispensing system 18 comprises, for example, a plurality of reservoirs 19 for containing the treatment substances, e.g., detergent for resistant white items, detergent for delicate colored items, detergent for wool, perfuming substances, enzymes, fixing substances and/or fabric softener. The plurality of reservoirs 19 can be positioned, for example, in the porthole door 4, in the detergent drawer 9, or in housing 2, and the individual reservoirs 19 are dimensioned to each contain a sufficient volume of the treatment substance for a plurality of washing cycles.

[0067] The washing machine 1 can further comprise a system 20 for recirculating the washing liquid from the bottom of tank 10 to the laundry drum 5.

[0068] The washing machine 1 can further comprise a drying system 21 , for example a drying air circuit 22 with conveying means 23, air heating means 24, and means 25 for condensing the moisture in the conveyed air.

[0069] The laundry drum 5 can be rotatably actuated by an electric motor 14 and a transmission 15, for example a belt transmission or a direct coupling of the direct drive type, in order to agitate and remix the clothes with the washing liquid.

[0070] The operation of the washing machine 1 is controlled by an electronic control system 16 in signal connection with the electric motor 14, with the treatment system 3, 6, 7, 8, 9, 12, 13, 18, 20, 21 , and with a user interface 17 for selecting a treatment program from a plurality of treatment programs.

[0071] The user interface 17 can be positioned at an outer wall or at the door 4 of housing 2, or an electronic device separate from housing 2. In response to the selections made by the user by means of the user interface 17, the control unit 16 drives the various components of the washing machine 1 to automatically wash and/or dry the clothes.

[0072] The electronic control system 16 is configured to control the electric motor 14 and the treatment system 3, 6, 7, 8, 9, 12, 13, 18, 20, 21 depending on the treatment program selected by means of the user interface.

[0073] The electronic control system 16 comprises a module 26 for determining the mass of the clothes contained in the laundry drum 5, for example by weighing or by detecting (a difference in) a mass or the weight of the washing tank-laundry drum unit or by detecting and interpreting electrical magnitudes of the electric motor 14 during a step of rotatably operating the laundry drum loaded with the still dry clothes.

[0074] Description of process 28 of determining the mass of the still dry clothes dry mass STP_1

[0075] By way of example, module 26 for determining the mass of the clothes contained in the laundry drum 5 can be configured to:

A) perform a first sequence of consecutive inrush steps, each inrush step comprising: [0076] - actuating the electric motor 14 to accelerate the laundry drum 5 to rotate from an initial speed v init equal to zero up to a predetermined maximum speed v max, with a substantially constant acceleration,

[0077] - when the predetermined maximum speed v max is reached, deactivating motor 14 so as to freely decelerate the laundry drum up to again reaching the initial speed v init equal to zero,

[0078] - in a detection time interval during the rotation acceleration of the laundry drum from the initial speed v init equal to zero up to the predetermined maximum speed v max, detecting the inrush current l inrush drawn by the electric motor 14, the rotational speed v of the electric motor 14 and time t,

B) calculate, for each individual inrush step, a rotational power parameter P generated by the electric motor 14 depending on the detected inrush current l inrush,

C) calculate, for the entire first sequence of consecutive inrush steps, an average value P_avg of the rotational power parameters P calculated for the individual inrush steps,

D) determine the mass M of the clothes in the laundry drum 5 depending on the average value P_avg of the rotational power parameters P and predetermined parameters P_0, A characterizing the washing machine 1 .

[0079] By using inrush events, i.e., events of acceleration of motor 14 (and the laundry drum 5) from a static condition to a maximum rotational speed, by means of a constant rotational acceleration ramp, the inrush current of the electric motor 14 can be considered exclusively correlated to the mass inertial moment of the assembly laundry drum 5 and clothes contained therein. This simplifies the correlation of the mass inertial moment, and thus the mass itself, with the detected current of motor 14, thus allowing a more accurate, reliable and quick determination of the clothes mass.

[0080] Description of the washing method and of the water filling method

[0081] According to an aspect of the invention, a washing method by a washing machine, for example of the type described above, comprises:

[0082] - performing a program for washing the clothes contained in the laundry drum 5, said washing program comprising a step 27 of filling water in the washing tank 3, [0083] - performing a process 28 of determining the mass dry mass of the still dry clothes contained in the laundry drum 5 prior to the water filling step 27,

[0084] - performing the water filling step 27 depending on the determined dry clothes mass dry mass.

[0085] This allows immediately filling the amount of water required for the clothes mass to be washed, thus obviating repeated and lengthy partial filling iterations, discontinuation and waiting for absorption of the water by the clothes, monitoring the water level, further partial filling, etc., of the known art, and therefore, obtaining a considerable decrease in the duration of the water filling step, for example in the range of 20 minutes.

[0086] According to an embodiment, the method comprises the steps of:

[0087] - determining a value of total required water amount Peak_1 (for example, expressed in terms of water level inside the washing tank 3 or in terms of liters) depending on the determined dry clothes mass dry mass so that the value of total required water amount Peak_1 is sufficient to wash a quantity of clothes having the determined dry clothes mass dry mass (therefore, presuming that the value dry mass was determined correctly), and

[0088] - performing an initial filling step 29 of the water filling step 27 during which initial filling step 29 the washing tank 3 is filled with the total required water amount Peak_1 (i.e., from an initial condition of still dry clothes up to reaching the total required water amount Peak ! in the washing tank 3), and where said filling occurs without discontinuations or with brief discontinuations, the total duration of which is in the range from zero to 50%, preferably in the range from zero to 30%, even more preferably in the range from zero to 10%, of the overall duration of the initial filling step 29.

[0089] The filling discontinuations, or in other words, a pulsed filling step 30 during the initial filling step 29, undesirably lengthens the overall water filling time but it can be provided to increase the dilution and rinsing effectiveness of powder detergent from a detergent tray 9 of the washing machine 1 towards the washing tank 3 (Figure 7).

[0090] Description of determining the value of total required water amount Peak_1 STP_2

[0091] Step 39 of determining the value of total required water amount Peak_1 depending on the determined dry clothes mass dry mass can comprise calculating the value of total required water amount Peak_1 using a predetermined function or table of value pairs obtained, for example, by tests performed for the washing machine 1 , for example a linear function obtained through an interpolation of discrete experimental values (Figure 3).

[0092] According to an embodiment, in order to ensure the correct and safe operation of the washing machine 1 also in the presence of very small clothes masses, for values of determined dry clothes mass dry mass below a first lower threshold value dry_mass_min_1 , e.g., below 4 kg, the corresponding value of total required water amount Peak_1 does not change, rather remains constant to value Peak_1_min calculated for the first lower threshold value dry_mass_min_1 .

[0093] In the example in Figure 3, the first lower threshold value dry_mass_min_1 of the determined dry clothes mass dry mass is 4 kg and the corresponding value of total required water amount Peak_1_min is 70 mm of water column in the washing tank 3.

[0094] Description of the initial water filling step 29 STP_3

[0095] According to an embodiment, the initial filling step 29 comprises:

[0096] - generating a water supply flow in the washing tank 3, for example by actuating a water filling system 6, for example by opening one or more supply solenoid valves 7, 8,

[0097] - monitoring the water amount H2O_level present or filled into in the washing tank 3, for example:

- by determining a water level in the washing tank 3, for example by a pressure sensor 31 or an optical sensor, or

- by detecting the flow rate and time of the water supply flow, for example by a flowmeter and a timer,

[0098] - comparing the water amount H2O_level present or filled into the washing tank 3 with the value of total required water amount Peak_1 ,

[0099] - if the water amount H2O_level present or filled into the washing tank 3 reaches or exceeds the value of total required water amount Peak_1 , discontinuing the water supply flow in the washing tank 3, for example by deactivating the water filling system 6, for example by closing the one or more supply solenoid valves 7, 8.

[00100] Thereby, the method is reliable and accurate also in the presence of different water pressures, and therefore of different supply flow rates, for example between washing machines installed on the ground floor and on the top floor of a tall building.

[00101] Description of step 32 of verifying 32 the suitability of the filled water amount STP_4

[00102] The value of total required water amount Peak_1 is an estimated value, i.e., it is an estimated value of total required water amount (Peak_1 ). This estimated value of total required water amount Peak_1 cannot always necessarily correspond to (and is not to be confused with) a total water amount filled into the washing tank since embodiments of the invention can include further step(s) 33 of corrective filling of the washing tank 3 with water so that a total amount of water filled into the washing tank can, in these cases, turn out to be the sum of the (estimated) value of total required water amount Peak_1 filled into the washing tank 3 and the further step(s) 33 of corrective filling of the washing tank 3 with water. According to an embodiment, the method comprises a step of verifying 32 the suitability of the total required water amount Peak_1 for washing the quantity of clothes actually present in the laundry drum 5, by:

[00103] - monitoring an actual absorption of the water in the clothes from reaching the value of total required water amount Peak_1 and then from the discontinuation of the water supply flow in the washing tank 3, and

[00104] - comparing the actual monitored absorption with a theoretical absorption model based (and depending) on the value of determined dry clothes mass dry mass (Figure

2, STP_4, Figures 4, 5, 6A, 6B),

[00105] - if the actual monitored absorption differs from the theoretical absorption model, performing a step 33 of corrective filling of water into the washing tank 3 and/or an (optional but advantageous) step 34 of determining a corrected value of dry clothes mass dry_mass_corr.

[00106] In case of erroneous determination of the dry clothes mass dry mass, the verification step 32 allows the method to "recognize" the error and to intervene with correction steps of both the water amount in the washing tank 3 and the value of dry clothes mass dry mass, which can also advantageously serve to determine several other parameters of the washing program.

[00107] Indeed, if a much smaller amount of water than the optimal amount is used, washing the clothes would not be very efficient or effective. For this reason, the method includes the step of verification and addition of water, if deemed suitable.

[00108] If the value of the determined dry clothes mass dry mass and, therefore the value of total required water amount Peak_1 , are (erroneously) determined to be in excess with respect to the actual clothes mass, the water amount filled into the washing tank 3 is greater than the water amount planned as optimal, but no corrective intervention is required (and the method does not include it). Indeed, a volume of excess water does not jeopardize the clothes washing results.

[00109] According to an embodiment, the verification step 32 can comprise:

[00110] - determining a theoretical value of theoretical water level abs_level_1 in the washing tank 3 after a step of absorbing water in the clothes, depending on the determined dry clothes mass dry mass (Figure 4),

[00111] - determining a theoretical value of duration abs_time_1 of the water absorption step up to reaching the theoretical value of water level abs_level_1 after the absorption step depending on the determined dry clothes mass dry mass (Figure 5),

[00112] - monitoring a water level H2O_level present in the washing tank 3, for example by a pressure sensor 31 or an optical sensor, from reaching the value of total required water amount Peak_1 , hence, from the discontinuation of the water supply flow in the washing tank 3,

[00113] - comparing the water level H2O_level in the washing tank 3 with the theoretical value of water level abs_level_1 after the step of absorbing water in the clothes, [00114] - determining the actual duration of the absorption step (by detecting the time passed) from when the value of total required water amount Peak_1 is reached (and therefore, from the discontinuation of the water supply flow in the washing tank 3) up to when the water level H2O_level in the washing tank 3 reaches the theoretical value of water level abs_level_1 after the step of absorbing water in the clothes,

[00115] - comparing the actual duration of the absorption step with the theoretical value of duration abs_time_1 of the absorption step,

[00116] - if the actual duration of the absorption step is less than the theoretical value of duration abs_time_1 of the absorption step (situation indicative of an excessive absorption and therefore, of an actual clothes mass which is greater than the determined value dry mass), performing a step 33 of corrective filling of the washing tank 3 with water and/or performing a step 34 of determining a corrected value of dry clothes mass dry_mass_corr.

[00117] Description of the step of determining the theoretical value of water level abs_level_1 after the water absorption step (Figure 4)

[00118] According to an embodiment, the step of determining the theoretical value of water level abs_level_1 after the water absorption step, depending on the determined dry clothes mass dry mass, can comprise calculating the theoretical value of water level abs_level_1 after the water absorption step using a predetermined function or table of value pairs obtained, for example, by tests performed for the washing machine 1 , for example a linear function obtained through an interpolation of discrete experimental values (Figure 4).

[00119] According to an embodiment, in order to ensure the correct and safe operation of the washing machine 1 also in the presence of relatively small clothes masses, for values of determined dry clothes mass dry mass below a second lower threshold value dry_mass_min_2, e.g., below 6 kg, the corresponding theoretical value of water level abs_level_1 does not change after the water absorption step, rather remains constant to value abs_level_1_min calculated for the second lower threshold value dry_mass_min_2.

[00120] In the example in Figure 4, the second lower threshold value dry_mass_min_2 of the determined dry clothes mass dry mass is 6 kg and the corresponding theoretical value of water level abs_level_1_min after the water absorption step is 54 mm of water column in the washing tank 3.

[00121] Description of the step of determining the theoretical value of duration abs_time_1 of the water absorption step (Figure 5)

[00122] According to an embodiment, the step of determining the theoretical value of duration abs_time_1 of the water absorption step, depending on the determined dry clothes mass dry mass, can comprise calculating the theoretical value of duration abs_time_1 of the water absorption step using a predetermined function or table of value pairs obtained, for example, by tests performed for the washing machine 1 , for example a linear function obtained through an interpolation of discrete experimental values (Figure 5). [00123] According to an embodiment, in order to ensure the correct and safe operation of the washing machine 1 also in the presence of relatively small clothes masses, for values of determined dry clothes mass dry mass below a third lower threshold value dry_mass_min_3, e.g., below 4 kg, the corresponding theoretical value of duration abs_time_1 of the water absorption step does not change, rather remains constant to value abs_time_1_min calculated for the third lower threshold value dry_mass_min_3.

[00124] In the example in Figure 5, the third lower threshold value dry_mass_min_3 of the determined dry clothes mass dry mass is 4 kg and the corresponding theoretical value of duration abs_time_1_min of the water absorption step is 138 seconds.

[00125] By way of example, consider the case in which the algorithm for determining the value of dry clothes mass dry mass makes a mistake and the determination of value dry mass, for example, is 2 kg less than the actual clothes mass. This means that the values Peak_1 and abs_level_1 would be incorrectly calculated and accordingly, the amount of water filled all at once into the washing tank 3 would be less than that required for optimal washing.

[00126] Figures 6A and 6B show the trend of the water level value H2O_level in the washing tank 3 monitored, for example by the pressure sensor 31 .

[00127] In a first case (Figure 6A), there are 8 kg of clothes in the laundry drum 5 and the determination of the value of dry clothes mass dry mass occurs correctly and, accordingly, the calculated value Peak_1 = 98 mm is consistent with the actual clothes mass and the values abs_level_1 = 61 mm and abs_time_1 = 245 s are consistent with the absorption behavior of the actual clothes mass of 8 kg.

[00128] In a second case (Figure 6B), there are 10 kg of clothes in the laundry drum 5 and the determination of the value of dry clothes mass dry mass occurs incorrectly, resulting in a value dry mass = 8 kg, and accordingly, the calculated value Peak_1 = 98 mm is not consistent with the actual clothes mass and the values abs_level_1 = 61 mm and abs_time_1 = 245 s are not consistent with the absorption behavior of the actual clothes mass of 10 kg. In the example, the calculated value Peak_1 = 98 mm would be an insufficient water filling amount for the actual clothes mass of 10 kg.

[00129] The comparison of the real time required to reach the theoretical value of water level after the absorption step abs_level_1 = 61 mm, with the theoretical value of duration of the absorption step abs_time_1 = 245 s, provides the criterion for detecting an incorrect determination of the dry clothes mass dry mass and therefore, the initial filling of an insufficient water amount. In the second case (Figure 6B), the real time of 103 s is indeed much less than the theoretical value of duration of the absorption step abs_time_1 = 245 s.

[00130] Description of the corrective water filling step 33 STP_5

[00131] According to an embodiment, the corrective water filling step 33 can comprise generating a water supply flow in the washing tank 3 up to reaching a water level in the washing tank 3 corresponding to a predetermined corrective value of water amount, for example the value of total required water amount Peak_1 determined depending on the determined dry clothes mass dry mass.

[00132] More concretely, the corrective water filling step 33 can comprise:

[00133] - generating a water supply flow in the washing tank 3, for example by actuating a water filling system 6, for example by opening one or more supply solenoid valves 7, 8,

[00134] - monitoring the water level H2O_level present in the washing tank 3, for example by a pressure sensor 31 or an optical sensor,

[00135] - comparing the water level H2O_level present in the washing tank 3 with the value of total required water amount Peak_1 ,

[00136] - if the water level H2O_level present in the washing tank 3 reaches or exceeds the value of total required water amount Peak_1 , discontinuing the water supply flow in the washing tank 3, for example by deactivating the water filling system 6, for example by closing the one or more supply solenoid valves 7, 8.

[00137] According to alternative embodiments, the corrective water filling step 33 can comprise generating a water supply flow in the washing tank 3:

[00138] - up to reaching a water level in the washing tank 3 corresponding to a predetermined corrective value of water amount, or

[00139] - where said water supply flow has predetermined total water volume, or

[00140] - where said water supply flow has a predetermined duration, for example a predetermined opening duration of a supply solenoid valve 7, 8, or

[00141] - where the water amount supplied to the washing tank 3 in the corrective water filling step 33 is determined depending on the determined corrected value of clothes mass dry_mass_corr by step 34 described above and hereinbelow.

[00142] Description of step 34 of determining the corrected value of dry clothes mass dry_mass_corr STP_6

[00143] According to an embodiment, the step of determining the corrected value of dry clothes mass dry_mass_corr can comprise:

[00144] - increasing the value of dry clothes mass dry mass by a predetermined corrective mass (dry_mass_corr = dry mass + mass_corr), for example by mass_corr = 2 kg, or

[00145] - calculating the corrected value of dry clothes mass dry_mass_corr as a function of the determined value of dry clothes mass dry mass and one or more detected water absorption parameters, for example a parameter indicative of a water level change and of a time parameter referring to the water level change, for example, so that the value dry_mass_corr increases as a speed of absorption of water in the clothes increases.

[00146] Description of step 35 of the adaptive adjustment of further treatment parameters according to the corrected value of dry clothes mass dry_mass_corr STP_10

[00147] The correction of the dry clothes mass value advantageously allows (and the method can include) a step 35 of adaptively adjusting one or more further treatment parameters, depending on the corrected value of dry clothes mass dry_mass_corr.

[00148] The parameters that are adaptively adjusted according to the corrected value of dry clothes mass dry_mass_corr (as a function of the monitored behavior of absorption of water in the clothes) are, considered individually or in any combination, the following: [00149] - amount of detergent introduced into the washing tank 3 during the washing program (or step),

[00150] - timing of introducing detergent into the washing tank 3 during the washing program (or step),

[00151] - duration of heating, for example by actuating the electrical resistance 13, of the water in the washing tank 3 during the washing program (or step),

[00152] - timing of heating, for example by actuating the electrical resistance 13, of the water in the washing tank 3 during the washing program (or step),

[00153] - duration of a clothes rinsing step during the washing program (or step),

[00154] - timing of a clothes rinsing step during the washing program (or step),

[00155] - duration of the overall washing,

[00156] - duration of ignition of the electrical resistance 13 for heating the washing liquid, [00157] - number of clothes rinsing steps,

[00158] - duration/s of the clothes rinsing step/s, [00159] - function(s) (ramp(s)) of accelerating the rotary motion of the laundry drum 5 in the clothes spinning step(s),

[00160] - maximum speed and/or duration of the individual spinning steps in case of a plurality of clothes spinning steps after the end of the clothes rinsing steps(s).

[00161] For example, in case of relatively small clothes masses, the laundry drum 5 is brought more quickly to a maximum spinning speed in the spinning steps, while in case of larger clothes masses, the rotary accelerations of the laundry drum 5 are smaller and the spinning steps are shorter to avoid an excessive accumulation of water in the tank and allow draining the water extracted from the spun clothes.

[00162] - duration of a clothes drying step at the end of the washing program (or step), [00163] - timing of a clothes drying step at the end of the washing program (or step).

[00164] Detailed description of detergent determination and dispensing (STP_11 , STP_12)

[00165] According to embodiments, the method comprises:

[00166] - using the dispensing system 10 to perform a step 41 of dispensing detergent into the washing tank 3 depending on the determined dry clothes mass dry mass.

[00167] It is particularly advantageous to determine a value of required detergent amount Detergent_1 depending on the determined dry clothes mass dry mass so that the value of required detergent amount Detergent_1 is sufficient to wash a quantity of clothes having the determined dry clothes mass dry mass.

[00168] This results in the advantage of a more targeted and effective detergent dose with reference both to the washing results and with reference to saving resources and a decrease of the environmental impact of the washing method.

[00169] According to an embodiment, the automatic multiple dose dispensing system 10 is used to perform an initial dispensing step 40 of the detergent dispensing step 41 , during which initial dispensing step 40 the required detergent amount Detergent_1 is dispensed into the washing tank 3.

[00170] This allows an automatic and versatile adjustment of the dispensable detergent amount without necessarily requiring detergent dosing interventions/decisions by the user.

[00171] According to an embodiment, the determination of the value of required detergent amount Detergent_1 can comprise calculating the value of required detergent amount Detergent_1 using a predetermined function or table of value pairs, which for example is defined by experimentation and/or according to indications of the detergent manufacturer of the detergent used.

[00172] According to a further embodiment, if the aforesaid step 32 of verifying the suitability of the value of total required water amount Peak_1 results in the actual monitored absorption differing from the theoretical absorption model, the method also includes a corrective step 42 of dispensing detergent into the washing tank 3, in addition to performing a step 33 of corrective filling of the washing tank 3 with water.

[00173] The corrective detergent dispensing step 42 comprises dispensing a corrective amount of detergent Detergent_corr, which is predetermined or determined depending on the corrected value of dry clothes mass dry_mass_corr, into the washing tank 3.

[00174] According to an embodiment, the corrective detergent dispensing step 42 comprises generating a detergent flow which is mixed with the water supply flow of the corrective water filling step 33. In other words, the corrective addition of detergent is performed simultaneously to the corrective addition of water. This allows dissolving, rinsing and transporting the corrective amount of detergent Detergent_corr directly by means of the water flow of the corrective water filling step 33.

[00175] Similarly, according to an embodiment, the initial detergent dispensing step 40 comprises generating a detergent flow which is mixed with the water supply flow of the initial water filling step 29.

[00176] Detailed description of determining drying parameters and of the drying step (STP_13)

[00177] According to an embodiment of the washing method and the washing machine 1 , where the washing machine is a washer-dryer and comprises the aforesaid drying system 21 , the method can comprise:

[00178] - performing a process 43 of determining the mass wet_mass of the wet clothes contained in the laundry drum 5 after the end of the washing and spinning steps but prior to a drying step 44,

[00179] - determining a moisture parameter indicative of an amount of water which is to be evaporated depending on the corrected value of dry clothes mass dry_mass_corr (or depending on the initial non-corrected value of dry clothes mass dry mass) and on the wet clothes mass value wet_mass,

[00180] - performing the clothes drying step 44 and displaying a drying time duration determined depending on the determined moisture parameter, or displaying a residual drying time duration determined depending on the determined moisture parameter, or [00181] - performing the clothes drying step 44 for a drying time duration determined depending on the determined moisture parameter, and displaying a determined drying time duration.

[00182] According to an embodiment, the method can comprise:

[00183] - repeatedly performing a process 43 of determining the mass wet_mass of the wet clothes contained in the laundry drum 5 after the end of the washing and spinning steps and during a successive drying step 44,

[00184] - determining a moisture parameter indicative of an amount of water which is to be evaporated depending on the corrected value of dry clothes mass dry_mass_corr (or depending on the initial non-corrected value of dry clothes mass dry mass) and on the determined wet clothes mass value wet_mass,

[00185] discontinuing the drying step 44 depending on the moisture parameter, for example when the determined value of wet clothes mass wet_mass reaches the corrected value of dry clothes mass dry_mass_corr or the initial non-corrected value of dry clothes mass dry mass (circumstance indicative of the fact that the clothes are dry again).

[00186] The wet clothes mass (wet_mass) can be determined by the methods and systems described with reference to determining the dry clothes mass dry mass.

[00187] The moisture parameter can be calculated as a function of or equal to the difference in mass delta_mass = wet_mass - dry_mass_corr or delta_mass = wet_mass - dry mass.

[00188] The drying duration can be calculated depending on the moisture contained in the clothes, i.e., the difference of wet and dry mass delta_mass = wet_mass - dry mass and of a predetermined value of drying speed, for example defined empirically or through experimentation, which can be expressed, for example, in terms of kg of water/hour.

[00189] The use of the corrected value of dry clothes mass dry_mass_corr presumes that the determination of the wet clothes mass wet_mass is systematically correct and reliable and substantially independent of the determination of the dry clothes mass dry mass.

[00190] The use of the non-corrected value of dry clothes mass dry mass presumes that the determination of the wet clothes mass wet_mass can comprise the same systematic inaccuracies as the determination of the dry clothes mass dry mass.

[00191] Description of step 38 of further verifying the water level H2O_level in the washing tank 3 STP_7

[00192] According to an embodiment, the method comprises a step 38 of further verifying the water level H20_level in the washing tank, for example by means of steps: [00193] - STP 71 determining a lower reference value fuzzy lower level and an upper reference value fuzzy upper level depending on the determined dry clothes mass dry mass and possibly depending on the ratio of the determined dry clothes mass dry mass and an upper clothes mass limit value fulljoad, for example based on a predetermined calculation or a table of value pairs, for example according to the following table:

Table - Example of table for determining reference values

[00194] - STP 72 monitoring/detecting the water level H2O_level present in the washing tank 3, for example by a pressure sensor 31 or an optical sensor,

[00195] - STP 73 comparing the water level H2O_level in the washing tank 3 with the lower reference value fuzzy lower level,

[00196] - STP 74 if the water level H2O_level present in the washing tank 3 is less than the lower reference value fuzzy lower level (situation indicative of an insufficient water level), performing a step 36 of further filling water into the washing tank 3 (STP 8, Figure 2) and, optionally, performing a step 37 of updating the current value of dry clothes mass (which can be the initial value dry mass if it was not successively corrected, otherwise the previously corrected value dry_mass_corr),

[00197] - STP 75 repeating step 32 of further verifying the water level H2O_level in the washing tank, e.g., STP 71 - STP 74, for example up to reaching a predetermined time limit, for example timejimit = 3000 s.

[00198] Description of the further water filling step 36 STP_8

[00199] According to an embodiment, the further water filling step 36 can comprise generating a water supply flow in the washing tank 3 up to reaching a water level in the washing tank 3 corresponding to a predetermined value of further water amount, for example the upper reference value fuzzy upper level determined depending on the determined dry clothes mass dry mass, corrected dry_mass_corr, or updated dry _mass_update.

[00200] More concretely, the further water filling step 36 can comprise:

[00201] - generating a water supply flow in the washing tank 3, for example by actuating a water filling system 6, for example by opening one or more supply solenoid valves 7, 8,

[00202] - monitoring the water level H2O_level present in the washing tank 3, for example by a pressure sensor 31 or an optical sensor,

[00203] - comparing the water level H2O_level present in the washing tank 3 with the upper reference value fuzzy upper level,

[00204] - if the water level H2O_level present in the washing tank 3 reaches or exceeds the upper reference value fuzzy upper level, discontinuing the water supply flow in the washing tank 3, for example by deactivating the water filling system 6, for example by closing the one or more supply solenoid valves 7, 8.

[00205] Description of step 37 of updating the value of dry clothes mass dry_mass_update STP_9

[00206] According to an embodiment, the step of updating the current value of dry clothes mass dry mass or dry_mass_update can comprise:

[00207] - increasing the value of dry clothes mass dry mass by a predetermined corrective mass (dry_mass_corr = dry mass + mass_corr), for example by mass_corr = 0.5 kg.

[00208] The method can further include updating the lower reference value fuzzy lower level and the upper reference value fuzzy upper level depending on the updated dry clothes mass dry_mass_update, for example by means of step STP 71 , for example by replacing value dry mass with dry_mass_update in the table above.

[00209] The method described can be performed by the washing machine 1 described, in particular by the electronic control system 16 in signal connection with the electric motor 14, the treatment system 3, 6, 7, 8, 9, 12, 13, 18, 20, 21 , 31 , and the user interface 17.