DE102010000573B4 - Method of controlling the power of a suction/sweeping device - Google Patents

Abstract

Method for controlling the power of a blower (4) and a brush drive (18) driving a brush (15) of an electrically driven suction/sweeping device (1), wherein a floor covering is detected by means of a floor sensor (21) provided on the bottom of the suction/sweeping device (1) is detected, and the power of the brush drive (18) being increased and the blower power reduced at the same time, depending on the condition of a surface to be vacuumed, if the surface condition produces an increased resistance for the brush drive (18), characterized in that the brush drive ( 18) is controlled by means of a control circuit depending on the floor covering in such a way that a relative maximum cleaning performance is achieved, with a brush speed not being increased further from a point at which the function of the cleaning performance runs asymptotically, with a power distribution from blower (4 ) And brush drive (18) is made so that at a hard floor, where the brush (15) rests on the hard floor, the brushing force is low and the blower power is high, and that with a velor carpet, where the brush (15) sinks slightly into a pile of the velor carpet, the brushing force is medium and the blower power is medium, and that in the case of a looped carpet in which the brush (15) sinks heavily into a pile of the looped carpet, the brushing force is high and the blower power is low.

Description

The invention relates to a method for controlling the power of a blower and a brush drive driving a brush of an electrically driven vacuum/sweeping device, with a floor covering being detected by means of a floor sensor of the vacuum/sweeping device provided on the bottom of the device, and with the condition of a surface to be vacuumed being detected the power of the brush drive is increased and the blower power is reduced at the same time if the surface condition provides increased resistance for the brush drive.

Suction / sweeping devices of the type in question are known. These are used in particular in the household sector for cleaning surfaces, more particularly floor surfaces such as, for example, hard floors in the form of tiled floors or also parquet floors, further, for example, carpeted floors. Such devices have a suction device for cleaning such a surface, with an electrically driven motor/fan unit provided in the device generating a suction air flow that is sucked in through a suction mouth on the bottom of the device that faces the surface to be cleaned. The suction air containing dirt and dust is filtered out in the usual way within the device or alternatively within a main device connected to it in terms of flow. In addition, such devices for mechanical processing of the surface to be cleaned have one or more brushes, in particular a bristle roller extending transversely to a usual direction of travel of the device with bristles extending radially to the roller axis, which are used in particular when cleaning carpeted floors to engage in the carpet pile are suitable. The drive of such a brush or the drive of possibly provided several brushes takes place by means of an electric motor preferably integrated in the device. In this connection it is also known to control the power of the blower and/or the brush drive, in particular as a function of the nature of the surface to be cleaned.

In view of the prior art described above, a technical problem of the invention is seen in further improving a method of the type in question with regard to a targeted use of electrical energy, in particular for driving the fan and the brush.

This problem is initially and essentially solved by the subject matter of claim 1, which is based on the fact that the brush drive is controlled by means of a control circuit depending on the floor covering in such a way that a relative maximum cleaning performance is achieved, with from a point at which the function of the cleaning performance runs asymptotically, a brushing speed is not further increased, the power distribution of fan and brush drive being carried out in such a way that on a hard floor where the brush is lying on the hard floor, the brushing force is small and the fan power is high, and that in the case of a velor carpet, in which the brush sinks slightly into a pile of the velor carpet, the brushing force is medium and the blower power is medium, and that in the case of a loop pile carpet, in which the brush sinks heavily into a pile of the loop pile carpet, the brushing force is high and the blower power is small. As a result of the proposed method, the electrical energy for operating the blower and the brush drive is used in a targeted manner, this also advantageously while offering a constant cleaning performance with the most constant possible power consumption. The cleaning performance is essentially directly related to the total electrical energy used, at least in relation to the blower and the brush drive. If the brush cleaning system is considered alone first, the brush performance required to achieve good cleaning results depends on the surface. On hard floors, for example, only a very low brushing power is required. Accordingly, the brush can rotate slowly. On carpets, on the other hand, a greater brushing power is required and therefore the brush must be rotated more quickly. However, even turning the brush quickly on very high-pile carpets does not result in a significant increase in cleaning performance. From a certain point, the function cleaning performance = f (brush performance, speed) runs asymptotically. From an energy-efficient point of view, it therefore makes no practical sense to further increase the brush speed and thus the energy consumption. According to the invention, a control circuit which controls the brush depending on the floor or the floor covering and thus achieves a relative maximum of the cleaning performance from the point of view of favorable energy efficiency is thus helpful for optimal and sensible energy utilization.

For this purpose, in the embodiment according to the invention, floor sensors are provided in the device, which, possibly in addition to a distance measurement, are used to detect the floor covering. In this context, ultrasonic sensors are known as ground sensors. In this regard, the DE 10113 105 A1 referred. The content of this patent application is hereby incorporated in its entirety into the disclosure of the present invention, also for the purpose of incorporating features of this patent application into claims of the present invention to include. Alternatively, optical infrared light measuring systems are also known, in which case the floor covering can be inferred from the reflected light energy. Depending on the type of floor, different signals are received via the floor sensor or sensors, so that in particular common hard floors can be distinguished from carpeted floors. In this way, the measured values can be used to draw sufficiently good conclusions between hard floors (= low brushing speed required) and carpeted floors (= high brushing speed). In this regard, there are preferably two or more, more preferably three to five floor sensors, it being possible for the signal to be used as a weighted value from all sensors. For example, at a carpet edge in the transition to a hard floor, the carpet is preferably recognized and displayed by at least two sensors, so that a corresponding control stage is selected.

In a further preferred embodiment, these floor sensors are in combination with other sensors that allow conclusions to be drawn about the floor covering, in particular for using the results determined in this way for the plausibility check of the measurement results of the floor sensor or sensors. The power consumption of the blower motor is also preferably used. The floor covering can also be indirectly inferred from the fan throttling and thus from a change in the motor current. The blower motor is not throttled very much on hard floors, but more on carpeted floors. If the power consumption of the brush drive also increases or decreases, the motor current of the brush drive is lower on hard floors than on carpeted floors. Correspondingly, at least an approximate ground detection is achieved based on the detection of the rotational resistance of the brush. A device of the type in question with such a rotary resistance detection of the brush is, for example EP 1396 222 A2 known. Their content is hereby also included in its entirety in the disclosure of the present invention, also for the purpose of including features of this patent application in claims of the present invention.

If the brush is mounted on a pivotable drive rocker, as is also known from the above-described European patent application, it is also possible (possibly additionally) to determine the floor covering via the deflection travel of the drive rocker. In the case of, for example, high-pile, soft carpet floors, the preferably provided rolling or traversing wheels of the device sink into the subsoil—here into the pile—so that the device quasi floats above the chassis-side floor area. This results in a rebound of the drive rocker carrying the brush in the direction of the interior of the device, which rebound preferably offers a measurement result, whereby an additional criterion is established, which the type of soil, preferably classified together with the floor sensors, further, for example, the drive rocker can be fully retracted This can be achieved, for example, as a result of a blockage (getting stuck on an obstacle). Here, the brush drive and preferably also the blower are regulated down to a low output in order to save energy. The force on the ground and the resulting frictional torque can be measured using suitable sensors. For this purpose, for example, spring-displacement systems or rotary encoders are available, which are also arranged, for example, in the pivot point of the drive rocker or above it. The preferred electrical signals from the sensors are evaluated, for example, by a control algorithm in the electronics on the device.

This floor covering classification is used within a device-internal control for the targeted control of the blower and the brush drive. For this purpose, comparative values are preferably stored in the controller, on the basis of which the preferably most favorable energy distribution for the blower and the brush drive is calculated in comparison to the determined floor covering value. In the case of a carpeted floor and the associated increased resistance of the brush drive, for example, the power of the brush drive is increased and at the same time the blower power is reduced, with the extent of the increase in the drive power of the brush and the extent of the reduction in the blower power also being dependent on a pile height of the brush carpeting. If, on the other hand, a hard floor is determined, then preferably - based on a standard power consumption or based on a power distribution triggered as a result of a previously carried out measurement - power with respect to the brush drive is subtracted and the blower power is increased accordingly, since hard floors are preferably cleaned predominantly by means of an air stream can be.

Further features of the invention are explained below, also in the description of the figures, often in their preferred assignment to the subject matter of claim 1 or to features of other claims. However, they can also be of importance in an assignment to only individual features of claim 1 or of the respective further claim, or in each case independently.

It is further preferred that the power distribution of the fan and brush drive is changed in such a way that the total electrical power is not changed or is changed only slightly. Accordingly, it is preferably independent of the detected floor covering and the performance associated with it Distribution always has the same overall performance, so that further advantageously the total power consumption of the device is at least approximately the same regardless of the floor covering. Even a slight change in the amount of 10% or less proves to be advantageous in terms of energy-efficient operation of the device.

In order not to act too much in the range of lower powers due to a control-side decision table, in particular in the regulation, it is provided in a further preferred embodiment that the power distribution is cyclically shifted to a predetermined standard power consumption of the blower and brush drive, after which the regulation begins again.

The respective increase and decrease in the power of the blower is preferably based on a standard power consumption, in which standard setting there is preferably an even distribution of the cleaning power of the brush and blower. In a further preferred embodiment, in the standard power consumption, the cleaning performance of the brush drive is 50%-70% and that of the fan is 30%-50%, more preferably 60% brush drive and 40% fan. Furthermore, an increase in the power of the brush drive or the blower with regard to a total power consumption of up to preferably 70%-90% is preferably achieved and a corresponding reduction in power with regard to a total power to 30%-10%. In addition, there is also the option of completely switching off the brush drive or the fan, reducing it to zero power accordingly and assigning 100% of the total power to the fan or brush drive.

For use on hard floors, the power of the brush drive is preferably reduced to 50% - 70% of the standard value. In this case, the blower output is preferably retained or set to the maximum value. On carpet, the unreduced power of the brush drive is preferred, while the blower power is preferably maintained or set to a minimum value of, for example, 10%-20% of the standard power consumption.

A variation of the driving speed, in particular a reduction thereof, is also preferably provided for areas that are to be cleaned particularly intensively. However, this is preferably not varied for normal cleaning operation.

An additional disk brush that is preferably provided at one corner of the device, possibly arranged at the two front corners of the device, is used for cleaning when driving along walls or edges. This is preferably switched off when cleaning carpeted areas. When cleaning hard floors, such a disc brush with a reduced speed - compared to a wall or edge edge travel - can increase the effective working width of the device, so that the increase in efficiency is also supported by fewer required travels per area.

The proposed method proves to be particularly advantageous in an embodiment of the suction/sweeping device in the form of a battery-operated device, more preferably in the form of an automatically movable suction/sweeping device. In contrast to mains-operated suction and sweeping devices, such so-called cleaning robots carry only a limited amount of electrical energy in the accumulator. As a result of the proposed solution, the limited electrical energy is used in a targeted manner while maintaining a good cleaning result.

• 1 ein elektrisch angetriebenes Saug-/ Kehrgerät in Form eines Vorsatzgerätes für einen handgeführten Haushalts-Staubsauger;
• 2 den schematischen Schnitt gemäß der Linie II - II in 1;
• 3 das Saug-/Kehrgerät in einer zweiten Ausführungsform in Art eines selbsttätig verfahrbaren Reinigungsroboters;
• 4 den schematisch dargestellten Vertikalschnitt durch das Gerät gemäß 3.

The invention is explained in more detail below with reference to the attached drawing, which only shows two exemplary embodiments. It shows:

• 1 an electrically driven suction/sweeping device in the form of an attachment for a hand-held household vacuum cleaner;
• 2 the schematic section according to the line II - II in 1 ;
• 3 the suction/sweeping device in a second embodiment in the form of an automatically movable cleaning robot;
• 4 according to the schematically represented vertical section through the device 3 .

Shown and described is initially with reference to 1 a suction/sweeping device 1 in the form of an attachment for a vacuum cleaner 2, in particular an electric household vacuum cleaner, which is also designed as a hand-held handle device. This vacuum cleaner 2 has a base unit 3, in which a Electric motor for a fan 4 is added. A dust collection chamber provided for receiving the vacuumed dust is docked to the base unit 3 . This includes a dust filter bag 5.

The fan 4 integrated in the base unit 3 is supplied with power via an electric cable 6.

Furthermore, the base unit 2 has a swan-neck-shaped extension which extends over the area of the dust collection chamber. In the area of the free end, this extension forms a plug-in socket for a handle 7 of the vacuum cleaner 2. The handle 7 is provided with an actuating handle 8, which has a thumb-operated control unit in the form of a slide switch, via which slide switch the power of the fan accommodated in the base unit 3 can be adjusted 4 is manually adjustable by the operator.

For tilling the soil, the base unit 3 is connected in terms of flow to the suction/sweeping unit 1 designed as an attachment.

This suction/sweeping device 1 has a suction mouth 11 which faces the floor 9 to be cleaned and is formed in the device floor 10 . The latter leads via a suction channel 12 penetrating the device 1 to an outwardly directed connecting piece 13, via which both the fluidic and electrical connection to the base device 3 is achieved.

Furthermore, a brush 15 is arranged in the suction chamber 14 forming the suction mouth 11 on the bottom side. In the exemplary embodiment shown, this is a brush roller with a roller axis x, which extends transversely to a normal direction of travel of the device 1 . The bristles 16 of the brush 15, which are fastened to the roller body and extend radially outwards, pass through the suction mouth 11 for treating the floor 9 to be cleaned.

The brush 15 is arranged so that it can rotate freely about the roller axis x on a cantilever arm 17 that is pivotably mounted in the housing of the device 1. This is designed like a swing arm, with a free end area of the cantilever arm 17 engaging in the suction mouth 11 serving to support the brush 15. The opposite end of the cantilever arm 17 is pivoted about a pivot axis y running parallel to the roller axis x, which also forms the shaft axis of a brush drive 18 in the form of an electric motor in the illustrated embodiment. This brush drive 18 preferably acts on the brush 15 via a belt drive 19 which is further preferably arranged inside the cantilever arm 17 .

The cantilever arm 17 is supported on the upper side by a spring 20 in such a way that the cantilever arm 17 is acted upon in the direction of the floor 9 to be cleaned.

A floor sensor 21 is also provided on the device floor side. This is formed by an ultrasonic transducer directed toward the floor 9 . Its measurement results are fed to a controller 22, in which the type of floor covering is determined according to predetermined algorithms.

Furthermore, in the exemplary embodiment shown, the motor current of the brush drive 18 is also measured via the controller 22 in the course of cleaning the floor 9, which current consumption as a function of the rotational resistance of the brush 15 also allows conclusions to be drawn about the floor covering. In addition, if necessary, the amount of displacement of the cantilever arm 17 in terms of height is also recorded, for example as a result of a spring-displacement system or by determining using a rotary encoder in the area of the pivot axis y.

The power distribution of fan 4 and brush drive 18 is carried out by means of further control algorithms stored in controller 22, this also in direct dependence on the detected floor covering, with this power distribution being cyclically reset to a predetermined standard power consumption of fan 4 and brush drive 18, after which the regulation begins again.

The total power consumption in the device 1 or in the device 1 and the vacuum cleaner 2 preferably remains constant regardless of the respective power distribution.

The following table shows the power distribution of fan 4 and brush drive 18 as an example in connection with three different floor coverings: hard floor: brushing force small Brush is on the ground High power blower Velor carpet: Medium brushing power Lightly brush the pile Medium power blower Loop: brushing force high Brush heavily in the pile Low power blower

As a result of the power control described, a uniform cleaning result can be achieved independently of the floor covering, with the overall power preferably remaining the same.

the 3 and 4 show a second embodiment of a suction/sweeping device 1 in the form of an automatically movable device, further in the form of a cleaning robot.

As can be seen in particular from the sectional view in 4 As can be seen, this device 1 also has a suction mouth 11 which is embodied in the device base 10 and is directed towards the floor 9 to be cleaned. The suction mouth 11 transitions into a suction chamber 14 which is fluidically connected to a dust collection chamber 23 via a suction channel 12 . A blower 4 is connected to the dust collection space 23 on the vacuum side downstream of the dust collection space 23 in terms of flow. On the overpressure side, another channel leads from the blower 4 for blowing out the air freed from dust and dirt through a blow-out grille 24 to the outside.

As in the first exemplary embodiment, a roller-like brush 15 is also arranged in the autonomously movable device 1 within the suction chamber 14, the roller axis x of which runs transversely to a normal direction of travel of the device 1. Here, too, the bristles 16 pass through the suction mouth 11 for mechanical processing of the nurturing soil 9.

Also provided in the housing of the device 1 is a brush drive 18 in the form of an electric motor, which acts on the brush 15 via a belt drive 19, shown only schematically.

The power supply of the brush drive 18 and the blower 4 and also a drive motor (not shown) for travel wheels 25 of the device 1 is achieved by an accumulator 26 accommodated in the device 1. This is also used to supply power to a controller 22 in the device 1.

On the underfloor side, i.e. further in the area of the device floor 10, a floor sensor 21 is provided, preferably in the form of an ultrasonic transducer directed at the floor 9 or an infrared sensor, via which the type of floor covering can be determined.

The power control of the brush drive 18 and the fan 4 also takes place here depending on the measurement result of the floor sensor 21, as described in more detail with regard to the first exemplary embodiment, which measurement result is optionally compared with a result of a current consumption measurement of the brush drive 18 Embodiment, the brush 15 can be mounted on a rocker, in which case, possibly additionally, the immersion path and/or the pivoting angle of the rocker is used to determine the floor covering.

As a result of the method described above, a time-maximized work cycle can be achieved, in particular in connection with an autonomously operating device 1, which carries an accumulator 26 with a limited amount of electrical energy for the power supply, in which a corresponding power distribution is carried out depending on the respective floor covering. The created control circuit helps to achieve optimal and sensible energy utilization, which control circuit controls the brush drive 18 and the fan 4 depending on the floor covering and thus achieves a relative maximum of the cleaning performance and cleaning duration.

Reference List

1

suction/sweeping device

2

vacuum cleaner

3

base unit

4

fan

5

dust filter bag

6

electric cable

7

stalk

8th

operating handle

9

floor

10

device shelf

11

suction mouth

12

suction channel

13

connecting piece

14

suction chamber

15

brush

16

bristles

17

boom arm

18

brush drive

19

belt drive

20

Feather

21

floor sensor

22

steering

23

dust collection room

24

exhaust grille

25

misconduct

26

accumulator

x

roller axis

y

pivot axis

Claims (4)

Method for controlling the power of a blower (4) and a brush drive (18) driving a brush (15) of an electrically driven suction/sweeping device (1), wherein a floor covering is detected by means of a floor sensor (21) provided on the bottom of the suction/sweeping device (1) is detected, and the power of the brush drive (18) being increased and the blower power reduced at the same time, depending on the condition of a surface to be vacuumed, if the surface condition produces an increased resistance for the brush drive (18), characterized in that the brush drive ( 18) is controlled by means of a control circuit depending on the floor covering in such a way that a relative maximum cleaning performance is achieved, with a brush speed not being increased further from a point at which the function of the cleaning performance runs asymptotically, with a power distribution from blower (4 ) And brush drive (18) is made so that at a hard floor, where the brush (15) rests on the hard floor, the brushing force is low and the blower power is high, and that with a velor carpet, where the brush (15) sinks slightly into a pile of the velor carpet, the brushing force is medium and the blower power is medium, and that in the case of a looped carpet in which the brush (15) sinks heavily into a pile of the looped carpet, the brushing force is high and the blower power is low. procedure after claim 1 , characterized in that the change in the power distribution of the blower (4) and brush drive (18) is carried out in such a way that the total electrical power is not changed or is changed only slightly. Method according to one of the preceding claims, characterized in that the power distribution is shifted cyclically into a predetermined standard power consumption of the blower (4) and brush drive (18). Method according to one of the preceding claims , characterized in that the suction/sweeping device is a battery-operated device.

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