Vacuum cleaner comprising soft soil detection means

The vacuum cleaner system quickly and reliably detects floor types by calculating current variation parameters, allowing adaptive suction power adjustments, improving cleaning performance and energy efficiency.

EP4740811A1Pending Publication Date: 2026-05-13SEB SA
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Patent Information

Authority / Receiving Office
EP · EP
Patent Type
Applications
Current Assignee / Owner
SEB SA
Filing Date
2025-11-06
Publication Date
2026-05-13

AI Technical Summary

Technical Problem

Existing vacuum cleaners face challenges in reliably and quickly detecting the type of floor surface being cleaned, leading to inefficient and ergonomically impaired operation, particularly when transitioning between hard and soft floors.

Method used

A vacuum cleaner system that uses an electronic control unit to calculate current variation parameters and compare them with threshold values to detect floor types, allowing rapid adjustment of suction power and speed based on whether the suction head is on a soft or hard floor, without requiring specific floor detection devices.

Benefits of technology

Enables reliable and rapid detection of floor type changes, optimizing cleaning performance and energy consumption by automatically adapting to different surfaces, thus enhancing ergonomics and efficiency.

✦ Generated by Eureka AI based on patent content.

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Abstract

The vacuum cleaner includes a suction head (5) comprising a rotating brush (18); a brush drive motor (21) configured to rotate the rotating brush (18); a suction motor configured to generate an airflow through the suction head (5); and an electronic control unit configured to calculate an intensity variation parameter from intensity values ​​measured by an intensity measuring device and to detect that the suction head (5) is being moved on a soft floor based on a comparison of the calculated intensity variation parameter with a soft floor detection threshold value and a comparison of the intensity of the electric current applied to the brush drive motor (21) with an intensity threshold value.
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Description

technical field

[0001] The present invention relates to the field of vacuum cleaners equipped with a suction head, also called a vacuum cleaner nozzle, allowing the suction of dust and waste present on a surface to be cleaned. State of the art

[0002] Vacuum cleaners equipped with a suction head are well-known on the market; they allow for the cleaning of surfaces by suction, removing dust and debris. The surface to be vacuumed can be, for example, a hard floor, such as tile, parquet, or laminate flooring, or a soft floor, such as carpet or rugs.

[0003] A suction head includes, as is known: a head body comprising a sole having an underside and a suction mouth opening into the underside of the sole, the underside of the sole being intended to be positioned adjacent to the surface to be vacuumed during the use of the vacuum cleaner, a rotating brush which is housed in a receiving compartment delimited by the head body and which is mobile in rotation about an axis of rotation, and a rotational drive mechanism configured to drive the rotating brush in rotation about the axis of rotation, the rotational drive mechanism comprising a brush drive motor coupled in rotation to the rotating brush.

[0004] In order to improve the cleaning performance of a vacuum cleaner of the aforementioned type, it is known to equip it with a measuring device configured to measure the intensity of the electrical current applied to the brush drive motor, to detect the type of floor encountered by the suction head according to the intensity values ​​measured by the measuring device, and to adapt the suction power generated by the vacuum cleaner's suction motor according to the type of floor detected.

[0005] In particular, document FR3137557 discloses a vacuum cleaner comprising an electronic control unit configured to: calculate a dispersion indicator, such as the variance or standard deviation, of the intensity values ​​measured by the measuring device, each dispersion indicator value being calculated from a limited series of successive intensity values ​​measured by the measuring device, and detect that the suction head is moved on soft ground, and for example from hard ground to soft ground, when the dispersion indicator exceeds the detection threshold value.

[0006] Such a configuration of the vacuum cleaner makes it possible to detect a movement of the suction head on a soft floor without requiring the presence of a specific floor detection device, which reduces the manufacturing costs of the vacuum cleaner according to the present invention.

[0007] However, in order to reliably and repeatedly detect that the suction head is being moved on a soft floor, the electronic control unit is specifically configured to detect that the suction head is being moved on a soft floor only when several successive dispersion indicator values ​​are greater than the detection threshold value.

[0008] Although such a vacuum cleaner configuration ensures reliable and efficient detection of movement of the suction head on a soft floor and therefore allows automatic adjustment of at least one operating parameter of the vacuum cleaner when it is moved on a soft floor, it induces a response time that is too long to detect a change in the type of floor cleaned by the vacuum cleaner (in particular several back-and-forth movements of the suction head on the soft floor are required to ensure detection of the soft floor), which impairs the ergonomics of the latter. Summary of the invention

[0009] The present invention aims to remedy all or part of these drawbacks.

[0010] The technical problem underlying the invention consists in particular of providing a vacuum cleaner with a simple and ergonomic structure, while ensuring reliable detection of the types of floor encountered by the vacuum cleaner in order to give the vacuum cleaner increased cleaning performance and / or increased autonomy performance.

[0011] To this end, the present invention relates to a vacuum cleaner comprising: a suction head comprising a soleplate having an underside configured to be oriented towards a surface to be cleaned and a suction inlet opening into the underside of the soleplate and through which outside air can be drawn in by the vacuum cleaner, the suction head further comprising a rotating brush movable around an axis of rotation, a rotating drive mechanism configured to rotate the rotating brush around the axis of rotation, the rotating drive mechanism comprising a brush drive motor rotationally coupled to the rotating brush, a suction motor configured to generate an airflow through the suction inlet and into the suction head, a current measuring device configured to measure the intensity of the electric current applied to the brush drive motor, and an electronic control unit configured to control the operation of the vacuum cleaner,The electronic control unit is further configured to: ∘ calculate a current variation parameter from current values ​​measured by the current measuring device, ∘ compare the calculated current variation parameter with a soft soil detection threshold value, and ∘ compare the current (this current can be a single measurement, multiple current measurements, or an average of multiple current measurements, which must be greater than the current threshold value) of the electric current applied to the brush drive motor with a current threshold value.

[0012] The electronic control unit is further configured to detect that the suction head is moved on a soft floor, and for example from a hard floor to a soft floor, based on the result of comparing the calculated intensity variation parameter with the soft floor detection threshold value and the result of comparing the intensity of the electric current applied to the brush drive motor with the intensity threshold value, and to adjust, for example to decrease or increase, the suction power of the vacuum cleaner to a predetermined soft floor suction power, which has a non-zero value, when the electronic control unit detects that the suction head is moved on a soft floor, and for example from a hard floor to a soft floor.

[0013] This vacuum cleaner configuration allows for the reliable and rapid detection of suction head movement on soft floors under normal operating conditions. Specifically, suction head movement on soft floors is detected based on two different parameters, enabling rapid detection since it eliminates the need to confirm a peak in the calculated intensity variation parameter with a large number of successive calculated values ​​of said intensity variation parameter.

[0014] Furthermore, this vacuum cleaner configuration automatically adapts its operation during soft floor cleaning. For example, the electronic control unit can be configured to reduce the vacuum cleaner's suction power to a predetermined soft floor setting, and the motor's rotation speed to a predetermined soft floor setting, when the electronic control unit detects that the vacuum head is moving across a soft surface. This configuration helps to minimize the vacuum cleaner's energy consumption during soft floor cleaning.Conversely, the electronic control unit can be configured, for example, to increase the vacuum cleaner's suction power to a predetermined soft floor suction level, and to increase the suction motor's rotation speed to a predetermined soft floor suction speed, when the electronic control unit detects that the suction head is being moved across a soft floor. Such a configuration of the vacuum cleaner allows for increased cleaning performance during the cleaning phase on soft floors.

[0015] Therefore, the vacuum cleaner according to the present invention makes it possible to quickly and reliably detect a movement of the suction head on a soft floor without requiring the presence of a specific floor detection device, while also making it possible, depending on factory settings or settings selected by a user, to increase the suction performance of the vacuum cleaner during a soft floor cleaning phase or to limit the electrical consumption of the vacuum cleaner during a soft floor cleaning phase.

[0016] The vacuum cleaner may also have one or more of the following characteristics, taken alone or in combination.

[0017] According to one embodiment of the invention, the electronic control unit is configured to detect that the suction head is moved on a soft floor when it is determined that the calculated intensity variation parameter is greater than or equal to the soft floor detection threshold value (i.e., reaches or exceeds the soft floor detection threshold value) and it is then determined that the intensity of the electric current applied to the brush drive motor is greater than or equal to the intensity threshold value (i.e., reaches or exceeds the intensity threshold value).

[0018] In other words, the electronic control unit is configured to detect that the suction head is being moved on soft floor when it is determined that the calculated intensity variation parameter is greater than or equal to the soft floor detection threshold value (i.e., reaches or exceeds the soft floor detection threshold value) and that, following the determination that the calculated intensity variation parameter has reached or exceeded the floor detection threshold value (and for example following the determination that the calculated intensity variation parameter has reached or exceeded the floor detection threshold value), it is determined that the intensity of the electric current applied to the brush drive motor is greater than or equal to the intensity threshold value (i.e., reaches or exceeds the intensity threshold value).According to one embodiment of the invention, the electronic control unit is configured to detect that the suction head is moved on soft ground when the calculated intensity variation parameter remains greater than or equal to the soft ground detection threshold value for a predetermined period of time and that, after said predetermined period of time, at least one measured intensity value is greater than or equal to the intensity threshold value.

[0019] In other words, the electronic control unit is configured to detect that the suction head is only being moved on soft flooring: if, during a predetermined period of time from the moment a calculated value of the intensity variation parameter reached or exceeded the soft soil detection threshold value, each calculated value of the intensity variation parameter is greater than or equal to the soft soil detection threshold value and if, after said predetermined period of time, at least one measured intensity value is greater than or equal to the intensity threshold value.

[0020] The determination of the calculated value of the intensity variation parameter and the comparison of the calculated value of the intensity variation parameter to the soft soil detection threshold value carried out during the predetermined time period correspond to a 1st test.

[0021] Following the 1st test, the measurement of said at least one intensity value and the comparison of this intensity value to the intensity threshold value correspond to a 2nd test.

[0022] According to one embodiment of the invention, the predetermined time period (of the first test) is between 50 ms and 1 s, preferably between 100 ms and 300 ms. The duration of the second test, for comparing a measured intensity value to the intensity threshold value, is shorter than that of the first test and is generally less than 50 ms. Performing the first and second tests consecutively provides a reliable result for determining whether the suction head is on a soft surface.

[0023] The inventors were also able to determine that carrying out two or more successive tests, each using only one intensity variation parameter compared to a soft floor detection threshold value, would be just as reliable as carrying out the 1st and 2nd tests according to the invention, but would increase the reaction time to adjust the vacuum cleaner's suction power to a predetermined soft floor suction power.

[0024] The inventors also determined that performing two successive tests, each using at least one measurement of an intensity value compared to a threshold intensity value, would be faster than performing the first and second tests according to the invention, but would be less reliable. Indeed, a measurement of intensity alone is insufficient to reliably detect soft ground. For example, using only an intensity measurement compared to a threshold intensity value as the detection parameter, poor brush maintenance (e.g., hair wrapped around the brush's rotation axes) could lead to the erroneous detection of a single soft spot.

[0025] Finally, the inventors also determined that detection implementing only the 1st test (using an intensity variation parameter compared to a soft soil detection threshold value) or implementing both tests but carrying out the 2nd test before the 1st test; or implementing both tests but carrying out the 2nd test at the same time as the 1st; would be insufficiently reliable and could also lead to the erroneous detection of a single slack. For example, crossing a door threshold could lead to the erroneous detection of a single slack.

[0026] In another advantageous embodiment, if the first test determines that the calculated value of the intensity variation parameter is less than the soft soil detection threshold value, the second test, which includes measuring at least one intensity value and comparing it to the intensity threshold value, is not performed. In other words, if the first test fails, the second test is not performed.

[0027] According to one embodiment of the invention, the electronic control unit is configured to detect that the suction head is moved on a soft floor if several successive values ​​of the intensity variation parameter, for example between 2 and 6 values, are greater than or equal to the soft floor detection threshold value and if it is then determined that the intensity of the electric current applied to the brush drive motor is greater than or equal to the intensity threshold value.

[0028] According to one embodiment of the invention, the electronic control unit is configured to adjust, for example to decrease or increase, the rotation speed of the suction motor to a predetermined soft floor suction speed when the electronic control unit detects that the suction head is being moved on a soft floor, and for example from a hard floor to a soft floor.

[0029] According to one embodiment of the invention, the calculated intensity variation parameter is a dispersion indicator, also called the dispersion parameter, of the intensity values ​​measured by the intensity measuring device, or the amplitude of variation of the intensity values ​​measured by the intensity measuring device.

[0030] According to one embodiment of the invention, the dispersion indicator is representative of the dispersion of the deviations of the intensity values ​​from a reference value.

[0031] According to one embodiment of the invention, the dispersion indicator is the variance or standard deviation of the intensity values ​​measured by the intensity measurement device.

[0032] According to one embodiment of the invention, the electronic control unit is configured to calculate a sliding dispersion indicator, such as the sliding variance or the sliding standard deviation, of the intensity values ​​measured by the measuring device.

[0033] According to one embodiment of the invention, each value of the intensity variation parameter, and for example each value of the dispersion indicator, is calculated from a limited series of successive intensity values ​​measured by the intensity measurement device.

[0034] According to one embodiment of the invention, each limited series of successive measured intensity values ​​comprises between 5 and 20, advantageously between 5 and 15, and for example 10, successive measured intensity values.

[0035] According to one embodiment of the invention, the time interval between two successive measured intensity values ​​is between 5 and 30 ms, and is for example about 25 ms.

[0036] According to one embodiment of the invention, the reference value is an average intensity value defined for each limited series, and more particularly an average of the successive intensity values ​​measured for the respective limited series.

[0037] According to one embodiment of the invention, the electronic control unit is configured to detect that the suction head is being moved on a hard floor, for example from a soft floor to a hard floor, when it is determined that the calculated intensity variation parameter is less than a hard floor detection threshold value and that the intensity (this intensity can be a single measurement, several intensity measurements, or an average of several intensity measurements, all of which must be less than the intensity threshold value) of the electric current applied to the brush drive motor is also less than the intensity threshold value. Such a configuration of the vacuum cleaner makes it possible to detect movement of the suction head on a hard floor without requiring a specific floor detection device, thereby reducing the manufacturing costs of the vacuum cleaner according to the present invention.In addition, such a vacuum cleaner configuration allows, for example, the operation of the vacuum cleaner to be adapted during a phase of cleaning a hard floor.

[0038] According to one embodiment of the invention, the threshold value for detecting hard soil is lower than the threshold value for detecting soft soil.

[0039] According to one embodiment of the invention, the electronic control unit is configured to detect that the suction head is moved on a hard floor when the calculated intensity variation parameter remains below the hard floor detection threshold value for a predetermined detection time and that, after said predetermined detection time, at least one of the measured intensity values, and for example each of the measured intensity values, is below the intensity threshold value.

[0040] In other words, the electronic control unit is configured to detect that the suction head is moved on a hard floor only if, during a predetermined detection period from the moment a calculated value of the intensity variation parameter falls below the hard floor detection threshold value, each calculated value of the intensity variation parameter is less than the hard floor detection threshold value and if, after said predetermined detection period, at least one of the measured intensity values, and for example each of the measured intensity values, is less than the intensity threshold value.

[0041] According to one embodiment of the invention, the predetermined detection time is between 50 ms and 1 s, and advantageously between 100 ms and 300 ms.

[0042] According to one embodiment of the invention, the electronic control unit is configured to detect that the suction head is moved on a hard floor if several successive values ​​of the intensity variation parameter, for example between 2 and 6 values, are less than the hard floor detection threshold value and if it is subsequently determined that the intensity of the electric current applied to the brush drive motor is less than the intensity threshold value.

[0043] Advantageously, the successive values ​​for detecting a movement of the suction head on a hard floor are more numerous than the successive value(s) for detecting a movement of the suction head on a soft floor, in order to avoid false detections of hard floors or untimely detections of hard floors due, for example, to lifting of the suction head, or to movements causing the suction head to occasionally come out of a soft floor, such as a carpet.

[0044] According to one embodiment of the invention, the electronic control unit is configured to adjust, for example to decrease or increase, the suction power of the vacuum cleaner to a predetermined hard floor suction power, which has a non-zero value, when the electronic control unit detects that the suction head is moved on a hard floor, and for example from a soft floor to a hard floor.

[0045] Thus, the electronic control unit can be configured to reduce the vacuum cleaner's suction power to a predetermined hard floor suction power, and for example, to reduce the rotation speed of the vacuum motor to a predetermined hard floor suction speed, when the electronic control unit detects that the vacuum head is being moved onto a hard floor, for example, from a soft floor to a hard floor. Such a configuration of the vacuum cleaner helps to limit its power consumption during hard floor cleaning.

[0046] Conversely, the electronic control unit can be configured to increase the vacuum cleaner's suction power to a predetermined hard floor suction power, and for example, increase the rotation speed of the suction motor to a predetermined hard floor suction speed, when the electronic control unit detects that the suction head is being moved onto a hard floor, for example, from a soft floor to a hard floor. Such a configuration of the vacuum cleaner allows for increased cleaning performance during the hard floor cleaning phase.

[0047] According to one embodiment of the invention, the electronic control unit is configured to adjust, for example to decrease or increase, the rotation speed of the suction motor to a predetermined hard floor suction speed when the electronic control unit detects that the suction head is being moved on a hard floor.

[0048] According to one embodiment of the invention, the predetermined hard floor suction speed is less than the predetermined soft floor suction speed.

[0049] According to another embodiment of the invention, the predetermined hard floor suction speed is greater than the predetermined soft floor suction speed.

[0050] According to one embodiment of the invention, the electronic control unit is configured to: detect that the suction head is stationary on a soft floor when the intensity variation parameter is less than the soft floor detection threshold value and the intensity of the electric current applied to the brush drive motor is greater than the intensity threshold value, and change at least one vacuum cleaner cleaning parameter when the electronic control unit detects that the suction head is stationary on a soft floor.

[0051] Such a configuration of the vacuum cleaner according to the present invention makes it possible, for example, to automatically reduce the suction power of the vacuum cleaner and / or the rotation speed of the rotating brush, and therefore to reduce the friction forces applied by the rotating brush on a soft floor when the suction head is stationary on this soft floor while the vacuum cleaner is in operation. The vacuum cleaner according to the present invention thus ensures the protection of the surfaces to be cleaned, and in particular soft floors, and also optimizes the vacuum cleaner's power consumption, which is advantageous if the vacuum cleaner is equipped with a rechargeable battery.

[0052] According to one embodiment of the invention, the electronic control unit is configured to detect that the suction head is stationary on a soft floor if several successive values ​​of the intensity variation parameter, and for example of the dispersion indicator, for example between 3 and 30 values, are less than the soft floor detection threshold value and if the intensity of the electric current applied to the brush drive motor is also greater than the intensity threshold value.

[0053] According to one embodiment of the invention, the electronic control unit is configured to reduce the rotational speed of the suction motor to a predetermined protection speed and / or to reduce the rotational speed of the brush drive motor to a predetermined brush speed when the electronic control unit detects that the suction head is stationary on a soft floor.

[0054] According to one embodiment of the invention, the threshold intensity value is greater than an average value of the intensity of the electric current applied to the brush drive motor during a previous movement phase of the suction head on a hard floor.

[0055] According to one embodiment of the invention, the electronic control unit is configured to calculate an average value of the intensity of the electric current applied to the brush drive motor during a phase of movement of the suction head on a soft floor, for example during a previous phase of movement of the suction head on a soft floor or during the most recent phase of movement of the suction head on a soft floor, and to define the threshold value of intensity as a function of said calculated average value.

[0056] According to one embodiment of the invention, the threshold intensity value corresponds to the calculated average value of the intensity of the electric current applied to the brush drive motor during the movement phase of the suction head on a soft floor, subtracted by a percentage, for example between 3 and 10%, of said calculated average value.

[0057] According to a In the method of embodiment of the invention, the percentage is predetermined.

[0058] According to another embodiment of the invention, the electronic control unit is configured to calculate an average value of the intensity of the electric current applied to the brush drive motor during a phase of movement of the suction head on a hard floor, for example during a previous phase of movement of the suction head on a hard floor or during the most recent phase of movement of the suction head on a hard floor, and to define the threshold value of intensity as a function of said calculated average value.

[0059] According to one embodiment of the invention, the threshold intensity value corresponds to the calculated average value of the intensity of the electric current applied to the brush drive motor during the movement phase of the suction head on a hard floor, to which is added a percentage, for example between 3 and 10%, of said calculated average value.

[0060] According to one embodiment of the invention, the percentage is predetermined.

[0061] According to one embodiment of the invention, the vacuum cleaner is a stick vacuum cleaner.

[0062] The present invention further relates to a method for controlling a vacuum cleaner, comprising the following steps: to provide a vacuum cleaner comprising: ∘ a suction head including a rotating brush that rotates about an axis of rotation and a soleplate having an underside configured to be oriented towards a surface to be cleaned and a suction inlet opening into the underside of the soleplate through which outside air can be drawn in by the vacuum cleaner, ∘ a rotary drive mechanism configured to rotate the rotating brush about the axis of rotation, the rotary drive mechanism including a brush drive motor rotationally coupled to the rotating brush, ∘ a suction motor configured to generate an airflow through the suction inlet and into the suction head, ∘ a current measuring device configured to measure the intensity of the electric current applied to the brush drive motor,and ∘ an electronic control unit configured to control the operation of the vacuum cleaner, measure the intensity of the electric current applied to the brush drive motor, calculate a current variation parameter from the measured current values, compare the calculated current variation parameter with a soft floor detection threshold value, compare the intensity of the electric current applied to the brush drive motor with a current threshold value, detect that the vacuum head is moving on a soft floor, and for example from a hard floor to a soft floor, depending on the result of comparing the calculated current variation parameter with the soft floor detection threshold value (1st test) and the result of comparing the intensity of the electric current applied to the brush drive motor with the current threshold value (2nd test), and adjust, for example decrease or increase,The vacuum cleaner's suction power is set to a predetermined soft floor suction power, which has a non-zero value, when it is detected that the suction head is being moved on a soft floor, for example from a hard floor to a soft floor.

[0063] According to one embodiment of the invention, the method includes a step of detecting that the suction head is moved on a soft floor, and for example from a hard floor to a soft floor, when it is determined that the intensity variation parameter is greater than or equal to the soft floor detection threshold value (1st test) and it is then determined that the intensity of the electric current applied to the brush drive motor is greater than or equal to the intensity threshold value (2nd test).

[0064] In other words, the method includes a step of detecting that the suction head is being moved on a soft floor, and for example from a hard floor to a soft floor, when it is determined that the calculated intensity variation parameter is greater than or equal to the soft floor detection threshold value (i.e., reaches or exceeds the soft floor detection threshold value) and that, following the determination that the calculated intensity variation parameter has reached or exceeded the floor detection threshold value (and for example following the determination that the calculated intensity variation parameter has reached or exceeded the floor detection threshold value), it is determined that the intensity of the electric current applied to the brush drive motor is greater than or equal to the intensity threshold value (i.e., reaches or exceeds the intensity threshold value).

[0065] According to one embodiment of the invention, the method includes a step of adjusting, and for example increasing or decreasing, the rotational speed of the suction motor to a predetermined soft floor suction speed when it is detected that the suction head is being moved over a soft floor, for example from a hard floor to a soft floor.

[0066] According to one embodiment of the invention, the method includes a step of detecting that the suction head is moved on a hard floor, and for example from a soft floor to a hard floor, when the intensity variation parameter is less than a hard floor detection threshold value and the intensity of the electric current applied to the brush drive motor is less than the intensity threshold value.

[0067] According to one embodiment of the invention, the method includes a step of adjusting, and for example decreasing or increasing, the rotation speed of the suction motor to a predetermined hard floor suction speed when it is detected that the suction head is being moved on a hard floor, and for example from a soft floor to a hard floor.

[0068] According to one embodiment of the invention, the process comprises the steps of: detect that the suction head is stationary on a soft floor when it is determined that the intensity variation parameter is less than the soft floor detection threshold value and it is then determined that the intensity of the electric current applied to the brush drive motor is greater than or equal to the intensity threshold value, and change at least one vacuum cleaner cleaning parameter when it is detected that the suction head is stationary on a soft floor.

[0069] According to one embodiment of the invention, the method includes a step of reducing the rotational speed of the suction motor to a predetermined protection speed and / or reducing the rotational speed of the brush drive motor to a predetermined brush speed when it is detected that the suction head is stationary on a soft floor. Brief description of the figures

[0070] In any case, the invention will be well understood with the aid of the following description with reference to the attached schematic drawings representing, by way of non-limiting example, one embodiment of this vacuum cleaner. There figure 1 is a front perspective view of a vacuum cleaner according to the present invention. figure 2 is a partial perspective view of the vacuum cleaner figure 1 . There figure 3 is a partial longitudinal cross-sectional view of the vacuum cleaner figure 1 . There figure 4is a perspective view of a vacuum cleaner suction head figure 1 . There figure 5 is a cross-sectional view of the suction head figure 4 . There figure 6 is a longitudinal cross-sectional view of the suction head of the figure 4 . There figure 7 is a diagram representing the steps in a vacuum cleaner control process figure 1 . There figure 8 is a diagram representing the time evolution of the intensity of the electric current applied to a vacuum cleaner brush drive motor figure 1 and the temporal evolution of a dispersion indicator of the intensity values ​​of the electric current applied to a brush drive motor during different cleaning phases. figure 9is a diagram representing the time evolution of the intensity of the electric current applied to a brush drive motor and the time evolution of the dispersion indicator during different cleaning phases. Detailed description

[0071] There figure 1 represents a vacuum cleaner 2, and more particularly a stick vacuum cleaner, comprising a main body 3, a handle 4 mechanically connected to the main body 3, and a suction head 5 configured to be in contact with a floor to be cleaned. However, the vacuum cleaner 2 according to the present invention could also be a canister vacuum cleaner without departing from the scope of the present invention.

[0072] The main body 3 includes in particular a vacuum housing 6 and a suction nozzle 7 which is advantageously arranged at a lower end of the vacuum housing 6 and to which the suction head 5 is attached directly or via a suction tube 8. The main body 3 further includes a suction conduit 9 arranged in the vacuum housing 6 and fluidly connected to the suction nozzle 7.

[0073] The vacuum cleaner 2 further comprises a waste separation and collection device 11 which is removably mounted on the main body 3, so that it can be cleaned. Advantageously, the waste separation and collection device 11 is of the cyclonic type.

[0074] The waste separation and collection device 11 includes in particular an air inlet opening (not visible in the figures) which is fluidly connected to the suction duct 9. Thus, the suction duct 9 is configured to fluidly connect the suction head 5 to the air inlet opening of the waste separation and collection device 11.

[0075] As shown on the figure 3 The vacuum cleaner 2 also includes a suction motor 12, also called a motor-fan, configured to generate an airflow through the suction head 5, the suction duct 9 and the waste separation and collection device 11. The suction motor 12 is more particularly arranged in the vacuum cleaner housing 6. As is known, the suction motor 12 includes a fan and an electric motor configured to drive the fan in rotation.

[0076] As shown on the figures 4 to 6The suction head 5 comprises a head body 13 configured to be moved over a surface to be cleaned. According to the embodiment shown in the figures, the head body 13 has a generally rectangular shape.

[0077] The head body 13 includes a sole 14, for example made of plastic, having an underside 15 configured to be oriented towards the surface to be cleaned.

[0078] The head body 13 further includes a suction mouth 16 opening into the lower face 15 of the sole 14 and through which outside air can be drawn in by the vacuum cleaner 2. Advantageously, the suction mouth 16 has an elongated shape and extends along an extension direction D1 which extends perpendicularly to a direction of movement D2 of the suction head 5.

[0079] The head body 13 further includes a receiving housing 17 which opens into the lower face 15 of the sole 14 via the suction mouth 16. Thus, according to the embodiment shown in the figures, the receiving housing 17 forms a suction chamber.

[0080] The suction head 5 also includes a rotating brush 18 which is mounted movably in rotation in the receiving housing 17 along an axis of rotation A which is substantially coincident with the central axis of the rotating brush 18. Advantageously, the rotating brush 18 is mounted removably in the receiving housing 17, and is configured to be inserted into and removed from the receiving housing 17 in a mounting direction which can, for example, extend transversely, and preferably perpendicularly, to the direction of movement D2 of the suction head 5.

[0081] According to the embodiment shown in the figures, the rotary brush 18 comprises a brush body 18.1 which is, for example, tubular, and bristles (not visible in the figures) provided on the external surface of the brush body 18.1. Advantageously, the brush body 18.1 is cylindrical with a circular cross-section, and the rotary brush 18 comprises one or more rows of bristles extending, for example, helically around the central axis of the rotary brush 18. According to an alternative embodiment not shown in the figures, the rows of bristles could be replaced by elastically deformable strips or by a foam cleaning sleeve.

[0082] The suction head 5 further comprises a rotation drive mechanism 19 configured to rotate the rotating brush 18 around the axis of rotation A. According to the embodiment shown in the figures, the rotation drive mechanism 19 is housed in the head body 13, and comprises a brush drive motor 21 provided with an output shaft mechanically coupled to the rotating brush 18.

[0083] Advantageously, the vacuum cleaner 2 includes a current measuring device 22 configured to measure the current intensity I applied to the brush drive motor 21. The current measuring device 22 can, for example, be located in the suction head 5, in the main body 3, or in the handle 4.

[0084] The suction head 5 also includes a connecting sleeve 23 which is fluidly connected to the receiving housing 17, and therefore to the suction mouth 16, and to which the suction nozzle 7 of the vacuum cleaner 2 is intended to be connected, and more particularly to which a lower part of the suction tube 8 is intended to be attached. Advantageously, the suction head 5 includes an articulation device 24 mechanically connecting the connecting sleeve 23 to the head body 13, so as to allow the head body 13 to pivot forward and backward when the suction head 5 is moved along the direction of movement D2.

[0085] The vacuum cleaner 2 also includes an electronic control unit 25 configured to control the operation of the vacuum cleaner 2, and in particular to adapt the operation of the vacuum cleaner 2 according to the type of floor on which the suction head 5 is moved. The electronic control unit 25 can, for example, be located in the vacuum cleaner housing 6 or in the handle 4.

[0086] The electronic control unit 25 is configured in particular to calculate an intensity variation parameter from intensity values ​​measured by the intensity measuring device 22, compare the calculated intensity variation parameter with a soft soil detection threshold value Vsm, and compare the intensity I of the electric current applied to the brush drive motor 21 with an intensity threshold value Vsi.

[0087] Advantageously, the threshold value of intensity Vsi is greater than an average value of the intensity I of the electric current applied to the brush drive motor 21 during a previous phase of movement of the suction head 5 on a hard floor.

[0088] According to one embodiment of the invention, the electronic control unit 25 is configured to calculate an average value of the current intensity I applied to the brush drive motor 21 during each phase of movement of the suction head 5 on a soft floor, and to define the threshold value of the current intensity Vsi based on the average value calculated for the most recent phase of movement of the suction head 5 on a soft floor. The threshold value of the current intensity Vsi may, for example, correspond to the calculated average value of the current intensity I applied to the brush drive motor 21 during the most recent phase of movement of the suction head 5 on a soft floor, subtracted by a percentage, for example, between 3 and 10%, of said calculated average value.

[0089] According to another embodiment of the invention, the electronic control unit 25 could be configured to calculate an average value of the current intensity I applied to the brush drive motor 21 during each phase of movement of the suction head 5 on a hard floor, and to define the threshold value of the current intensity Vsi based on the average value calculated for the most recent phase of movement of the suction head 5 on a hard floor. The threshold value of the current intensity Vsi could, for example, correspond to the calculated average value of the current intensity I applied to the brush drive motor 21 during the most recent phase of movement of the suction head 5 on a hard floor, plus a percentage, for example, between 3 and 10%, of said calculated average value.

[0090] According to yet another embodiment of the invention, the threshold value of intensity Vsi could be predetermined, and be for example between 400 and 600 mA.

[0091] According to one embodiment of the invention, the intensity variation parameter is a dispersion indicator ID, such as the variance or standard deviation, of the intensity values ​​measured by the intensity measuring device 22, and each dispersion indicator value is calculated from a limited series of successive intensity values ​​measured by the intensity measuring device 22. Each limited series of successive measured intensity values ​​may comprise between 5 and 20, advantageously between 5 and 15, and for example 10, successive measured intensity values, and the time interval between two successive measured intensity values ​​may be between 15 and 30 ms, and is for example about 25 ms.

[0092] When the calculated dispersion indicator ID is the standard deviation, the electronic control unit 25 is configured to: calculate, for each limited series, an average of the successive measured intensity values ​​belonging to said limited series, calculate, for each limited series, the deviations, with respect to the respective calculated average, of the successive measured intensity values ​​belonging to said limited series, and calculate, for each limited series, the root mean square of the deviations calculated for said limited series.

[0093] The root mean square calculated for each limited series corresponds to the standard deviation value calculated for said limited series.

[0094] When the calculated dispersion indicator (ID) is the variance, the calculated variance value for each limited series corresponds to the square of the root mean square calculated for that limited series. In other words, when the calculated dispersion indicator (ID) is the variance, the electronic control unit 25 is configured to calculate, for each limited series, the mean of the squared deviations from the mean for that limited series.

[0095] The electronic control unit 25 is more particularly configured to detect that the suction head 5 is moved on a soft floor, and for example from a hard floor to a soft floor, depending on the result of comparing the calculated intensity variation parameter with the soft floor detection threshold value Vsm and the result of comparing the intensity I of the electric current applied to the brush drive motor 21 with the intensity threshold value Vsi.

[0096] According to one embodiment of the invention, the electronic control unit 25 is configured to detect that the suction head 5 is moved on a soft floor, and for example from a hard floor to a soft floor, when it is determined that the calculated intensity variation parameter, and for example the dispersion indicator ID, reaches or exceeds the soft floor detection threshold value Vsm and it is then determined that the intensity I of the electric current applied to the brush drive motor 21 is greater than or equal to the intensity threshold value Vsi.

[0097] According to another embodiment of the invention, the electronic control unit 25 could be configured to detect that the suction head 5 is moving on soft ground when the calculated intensity variation parameter, for example the dispersion indicator ID, remains greater than or equal to the soft ground detection threshold value Vsm for a predetermined time period T1 and that, after said predetermined time period T1, at least the measured intensity value is greater than or equal to the intensity threshold value Vsi. The predetermined time period T1 may, for example, be between 50 ms and 1 s, and advantageously between 100 ms and 300 ms.

[0098] According to yet another embodiment of the invention, the electronic control unit 25 could be configured to detect that the suction head 5 is moved on a soft floor only if one or more successive values ​​of the intensity variation parameter, for example between 2 and 6 values, are greater than or equal to the soft floor detection threshold value Vsm and if it is subsequently determined that the intensity I of the electric current applied to the brush drive motor 21 is greater than or equal to the intensity threshold value Vsi.

[0099] The electronic control unit 25 is further configured to adjust, for example to decrease or increase, the suction power of the vacuum cleaner 2 to a predetermined soft floor suction power, which has a non-zero value, when the electronic control unit 25 detects that the suction head 5 is moved on a soft floor, and for example from a hard floor to a soft floor.

[0100] The electronic control unit 25 can, for example, be configured to reduce the suction power of the vacuum cleaner 2 to a predetermined soft floor suction power, and, for example, reduce the rotation speed of the vacuum motor 12 to a predetermined soft floor suction speed, when the electronic control unit 25 detects that the suction head 5 is being moved across a soft floor. Such a configuration of the vacuum cleaner 2 makes it possible to limit the vacuum cleaner 2's power consumption during a soft floor cleaning phase.

[0101] The electronic control unit 25 could, for example, be configured to increase the suction power of the vacuum cleaner 2 to a predetermined soft floor suction power, and, for example, increase the rotation speed of the vacuum motor 12 to a predetermined soft floor suction speed, when the electronic control unit 25 detects that the suction head 5 is being moved across a soft floor. Such a configuration of the vacuum cleaner 2 makes it possible to increase the vacuum cleaner's cleaning performance during the soft floor cleaning phase.

[0102] Therefore, the vacuum cleaner 2 according to the present invention makes it possible to detect a movement of the suction head 5 on a soft floor without requiring the presence of a specific floor detection device, while also making it possible, depending on factory settings or settings selected by a user, to increase the suction performance of the vacuum cleaner 2 during a phase of cleaning a soft floor or to limit the electrical consumption of the vacuum cleaner 2 during a phase of cleaning a soft floor.

[0103] According to one embodiment of the invention, the electronic control unit 25 is further configured to detect that the suction head 5 is moved on a hard floor, and for example from a soft floor to a hard floor, when it is determined that the calculated intensity variation parameter, and for example the dispersion indicator ID, is less than a hard floor detection threshold value (which may be less than or the same as the soft floor detection threshold value Vsm) and it is then determined that the intensity I of the electric current applied to the brush drive motor 21 is less than the intensity threshold value Vsi.

[0104] According to another embodiment of the invention, the electronic control unit 25 could be configured to detect that the suction head 5 is moving on a hard floor when the calculated intensity variation parameter, for example the dispersion indicator ID, remains below the hard floor detection threshold value for a predetermined detection time T2 and that, after said predetermined detection time T2, at least one of the measured intensity values, for example each of the measured intensity values, is below the intensity threshold value Vsi. The predetermined detection time T2 is greater than 500 ms, and may, for example, be between 500 ms and 1 s. According to one embodiment of the invention, the predetermined detection time T2 is greater than the predetermined time period T1.

[0105] According to yet another embodiment of the invention, the electronic control unit 25 could be configured to detect that the suction head 5 is moved on a hard floor if several successive values ​​of the intensity variation parameter, for example between 2 and 6 values, are less than the hard floor detection threshold value and if it is subsequently determined that the intensity I of the electric current applied to the brush drive motor 21 is less than the intensity threshold value Vsi.

[0106] Advantageously, the electronic control unit 25 is configured to adjust, for example to decrease or increase, the suction power of the vacuum cleaner 2 to a predetermined hard floor suction power, which has a non-zero value, when the electronic control unit 25 detects that the suction head 5 is moved on a hard floor, and for example from a soft floor to a hard floor.

[0107] The electronic control unit 25 can, for example, be configured to reduce the suction power of the vacuum cleaner 2 to a predetermined hard floor suction power, and, for example, to reduce the rotational speed of the vacuum motor 12 to a predetermined hard floor suction speed, when the electronic control unit 25 detects that the vacuum head 5 is being moved on a hard floor. Such a configuration of the vacuum cleaner 2 makes it possible to limit the vacuum cleaner 2's power consumption during a hard floor cleaning phase. According to such an embodiment of the invention, the predetermined hard floor suction speed is lower than the predetermined soft floor suction speed.

[0108] The electronic control unit 25 could, for example, be configured to increase the suction power of the vacuum cleaner 2 to a predetermined hard floor suction power, and, for example, increase the rotational speed of the vacuum motor 12 to a predetermined hard floor suction speed, when the electronic control unit 25 detects that the vacuum head 5 is being moved across a hard floor. Such a configuration of the vacuum cleaner 2 makes it possible to increase the cleaning performance of the vacuum cleaner 2 during a hard floor cleaning phase. According to such an embodiment of the invention, the predetermined hard floor suction speed is greater than the predetermined soft floor suction speed.

[0109] The electronic control unit 25 is further configured to: detect that the suction head 5 is stationary on a soft floor when the intensity variation parameter, and for example the dispersion indicator ID, is less than the soft floor detection threshold value Vsm and the intensity I of the electric current applied to the brush drive motor 21 is greater than the intensity threshold value Vsi, and modify at least one cleaning parameter of the vacuum cleaner 2, and for example reduce the rotation speed of the suction motor 12 to a predetermined protection speed, which is for example between the soft floor suction speed and the hard floor suction speed, when the electronic control unit 25 detects that the suction head 5 is stationary on a soft floor.

[0110] Thus, the electronic control unit 25 is configured to control the operation of the vacuum cleaner 2 according to a first operating mode, called the hard floor operating mode, when the intensity variation parameter, and for example the dispersion indicator ID, is less than the hard floor detection threshold value and the intensity I of the electric current applied to the brush drive motor 21 is less than the intensity threshold value Vsi; to control the operation of the vacuum cleaner 2 according to a second operating mode, called the soft floor operating mode, when the intensity variation parameter, and for example the dispersion indicator ID, is greater than or equal to the soft floor detection threshold value Vsm and the intensity I of the electric current applied to the brush drive motor 21 is greater than the intensity threshold value Vsi; and to control the operation of the vacuum cleaner 2 according to a third operating mode,said protection mode, when the intensity variation parameter, and for example the dispersion indicator ID, is less than the soft soil detection threshold value Vsm and the intensity I of the electric current applied to the brush drive motor 21 is greater than the intensity threshold value Vsi.

[0111] The electronic control unit 25 can, for example, be configured so that the rotation speed of the suction motor 12 is minimum (or maximum) when the vacuum cleaner 2 is operating in the first operating mode, so that the rotation speed of the suction motor 12 is maximum (or minimum) when the vacuum cleaner 2 is operating in the second operating mode, and so that the rotation speed of the suction motor 12 is between the minimum speed and the maximum speed when the vacuum cleaner 2 is operating in the third operating mode.

[0112] A method for controlling the vacuum cleaner 2 according to the present invention may, for example, include in particular: a measurement step S1 consisting of measuring the intensity I of the electric current applied to the brush drive motor 21, a calculation step S2 consisting of calculating a dispersion indicator ID, such as the variance or standard deviation, of the measured intensity values, each value of the dispersion indicator being calculated from a limited series of successive measured intensity values, if it is determined that the dispersion indicator ID is greater than or equal to the soft floor detection threshold value Vsm and if it is subsequently determined that the intensity I of the electric current applied to the brush drive motor 21 is greater than or equal to the intensity threshold value Vsi, a control step S3 consisting of detecting that the suction head 5 is being moved on a soft floor, and for example from a hard floor to a soft floor, and adjusting, for example decrease or increase, the rotational speed of the suction motor 12 to the predetermined soft floor suction speed,If it is determined that the dispersion indicator ID is less than the soft floor detection threshold value Vsm and if it is subsequently determined that the intensity I of the electric current applied to the brush drive motor 21 is greater than the intensity threshold value Vsi, a control step S4 consisting of detecting that the suction head 5 is stationary on a soft floor and reducing the rotational speed of the suction motor 12 to the predetermined protection speed, and if it is determined that the dispersion indicator ID is less than the hard floor detection threshold value and if it is subsequently determined that the intensity I of the electric current applied to the brush drive motor 21 is less than the intensity threshold value Vsi, a control step S5 consisting of detecting that the suction head 5 is moving on a hard floor, and for example from a soft floor to a hard floor, and adjusting, for example decrease or increase,The rotation speed of the suction motor is set to the predetermined hard floor suction speed.

[0113] According to another embodiment of the invention, the intensity variation parameter could be the amplitude of variation of the intensity values ​​measured by the intensity measuring device 22 (and not an indicator of dispersion of the intensity values ​​measured by the intensity measuring device 22), and for example deviations of the maximum and minimum values, belonging to a limited series of measured intensity values, from a reference value, such as an average of the measured intensity values ​​belonging to said limited series.

[0114] According to yet another embodiment of the invention, the electronic control unit 25 could be configured to stop the vacuum cleaner 2, i.e. to cut off the power supply to the vacuum cleaner 2, when the electronic control unit 25 detects that the suction head 5 is stationary on a soft floor.

[0115] Of course, the present invention is in no way limited to the embodiments described and illustrated, which have been given only by way of example. Modifications remain possible, particularly with regard to the composition of the various elements or by substitution of technical equivalents, without departing from the scope of protection of the invention.

Claims

1. Vacuum cleaner (2) comprising: - a suction head (5) including a soleplate (14) having an underside (15) configured to be oriented towards a surface to be cleaned and a suction inlet (16) opening into the underside (15) of the soleplate (14) and through which outside air can be drawn in by the vacuum cleaner (2), the suction head (5) further comprising a rotating brush (18) movable in rotation about an axis of rotation (A), - a rotational drive mechanism (19) configured to drive the rotating brush (18) in rotation about the axis of rotation (A), the rotational drive mechanism (19) including a brush drive motor (21) rotationally coupled to the rotating brush (18), - a suction motor (12) configured to generate an airflow through the suction inlet (16) and into the suction head (5),- a current measurement device (22) configured to measure the current (I) applied to the brush drive motor (21), and - an electronic control unit (25) configured to control the operation of the vacuum cleaner (2), the electronic control unit (25) being further configured to: ∘ calculate a current variation parameter from current values ​​measured by the current measurement device (22), ∘ compare the calculated current variation parameter with a soft floor detection threshold value (Vsm), and ∘ compare the current (I) applied to the brush drive motor (21) with a current threshold value (Vsi), , characterized in thatThe electronic control unit (25) is configured to detect that the suction head (5) is moved on a soft floor based on the result of comparing the calculated intensity variation parameter with the soft floor detection threshold value (Vsm) and the result of comparing the intensity (I) of the electric current applied to the brush drive motor (21) with the intensity threshold value (Vsi), and to adjust the suction power of the vacuum cleaner (2) to a predetermined soft floor suction power, which has a non-zero value, when the electronic control unit (25) detects that the suction head (5) is moved on a soft floor.

2. Vacuum cleaner (2) according to claim 1, wherein the electronic control unit (25) is configured to detect that the suction head (5) is moved on a soft floor when it is determined that the calculated intensity variation parameter is greater than or equal to the soft floor detection threshold value (Vsm) and it is subsequently determined that the intensity (I) of the electric current applied to the brush drive motor (21) is greater than or equal to the intensity threshold value (Vsi).

3. Vacuum cleaner (2) according to claim 1 or 2, wherein the electronic control unit (25) is configured to detect that the suction head (5) is moved on soft ground when the calculated intensity variation parameter remains greater than or equal to the soft ground detection threshold value (Vsm) for a predetermined time period (T1) and that, after said predetermined time period (T1), at least one measured intensity value is greater than or equal to the intensity threshold value (Vsi).

4. Vacuum cleaner (2) according to any one of claims 1 to 3, wherein the electronic control unit (25) is configured to adjust the rotational speed of the suction motor (12) to a predetermined soft floor suction speed when the electronic control unit (25) detects that the suction head (5) is being moved on a soft floor.

5. Vacuum cleaner (2) according to any one of claims 1 to 4, wherein the calculated intensity variation parameter is a dispersion indicator (DI) of the intensity values ​​measured by the intensity measuring device (22), or the amplitude of variation of the intensity values ​​measured by the intensity measuring device (22).

6. Vacuum cleaner (2) according to any one of claims 1 to 5, wherein each value of the intensity variation parameter is calculated from a limited series of successive intensity values ​​measured by the intensity measuring device (22).

7. Vacuum cleaner (2) according to any one of claims 1 to 6, wherein the electronic control unit (25) is configured to detect that the suction head (5) is moved on a hard floor when it is determined that the calculated intensity variation parameter is less than a hard floor detection threshold value and it is further determined that the intensity (I) of the electric current applied to the brush drive motor (21) is less than the intensity threshold value (Vsi).

8. Vacuum cleaner (2) according to any one of claims 1 to 7, wherein the electronic control unit (25) is configured to detect that the suction head (5) is moved on a hard floor when the calculated intensity variation parameter remains below the hard floor detection threshold value for a predetermined detection time (T2) and that, after said predetermined detection time (T2), at least one of the measured intensity values ​​is below the intensity threshold value (Vsi).

9. Vacuum cleaner (2) according to claim 7 or 8, wherein the electronic control unit (25) is configured to adjust the suction power of the vacuum cleaner (2) to a predetermined hard floor suction power, which has a non-zero value, when the electronic control unit (25) detects that the suction head (5) is moved on a hard floor.

10. Vacuum cleaner (2) according to any one of claims 1 to 9, wherein the electronic control unit (25) is configured to: - detect that the suction head (5) is stationary on a soft floor when the intensity variation parameter is less than the soft floor detection threshold value (Vsm) and the intensity (I) of the electric current applied to the brush drive motor (21) is greater than the intensity threshold value (Vsi), and - modify at least one cleaning parameter of the vacuum cleaner (2) when the electronic control unit (25) detects that the suction head (5) is stationary on a soft floor.

11. Method for controlling a vacuum cleaner (2), comprising the following steps: - providing a vacuum cleaner (2) comprising: ∘ a suction head (5) including a rotating brush (18) movable in rotation about an axis of rotation (A) and a soleplate (14) having an underside (15) configured to be oriented towards a surface to be cleaned and a suction inlet (16) opening into the underside (15) of the soleplate (14) and through which outside air can be drawn in by the vacuum cleaner (2), ∘ a rotary drive mechanism (19) configured to rotate the rotary brush (18) about the axis of rotation (A), the rotary drive mechanism (19) including a brush drive motor (21) rotationally coupled to the rotary brush (18), ∘ a suction motor (12) configured to generate an airflow through the suction inlet (16) and in the suction head (5),• a current measurement device (22) configured to measure the current (I) applied to the brush drive motor (21), and • an electronic control unit (25) configured to control the operation of the vacuum cleaner (2), - measure the current (I) applied to the brush drive motor (21), - calculate a current variation parameter from measured current values, - compare the calculated current variation parameter with a soft floor detection threshold value (Vsm), and - compare the current (I) applied to the brush drive motor (21) with a current threshold value (Vsi), , characterized in thatThe method further includes: - detecting that the suction head (5) is moved on a soft floor based on the result of comparing the calculated intensity variation parameter with the soft floor detection threshold value (Vsm) and the result of comparing the intensity (I) of the electric current applied to the brush drive motor (21) with the intensity threshold value (Vsi), and - adjusting the suction power of the vacuum cleaner (2) to a predetermined soft floor suction power, which has a non-zero value, when it is detected that the suction head (5) is moved on a soft floor.