EP1136027A2 - Floor treating apparatus and method for recognizing a state of floor respectively for aligning the drive movement - Google Patents

Abstract

The floor cleaning head (1) of a vacuum cleaner has a motor driven rotary carpet brush (3) and a linear hard floor brush (6) which are automatically raised or lowered by a control system using an ultrasonic transmitter (9) and receiver (10) according to the type of floor surface.

Description

The invention initially relates to a floor care device, such as in particular a vacuum cleaner, possibly with a motor-driven carpet brush, with one Ultrasonic soil detection, the soil detection Has ultrasonic transducers that act as ultrasonic transmitters or ultrasound receiver work.

For floor care, such as vacuuming, becomes dependent the device for the type of floor to be maintained configured accordingly, for example by adapting the Suction power or hard floors by limiting the Suction mouth by extending bristle strips or the like. For devices that have a motor-driven Have carpet brush, this is one Care of such a hard floor deactivated. This different configurations can be done manually the user can be set. It is known this Settings of the device depending on the surface structure of the soil to be maintained automatically, self-regulating. Here, for example, the DE-T2 691 20 176, from which it is known the surface quality by means of ultrasonic transducers of the floor covering. For example, Carpets on a soft surface; Tiles and PVC coverings, on the other hand, can be classified as hard. This different structures affect acting sound waves. While hard coverings this Reflect waves strongly, they are from soft (carpets) mostly absorbed. Using an ultrasound transmitter a signal is directed to the floor. The reflected signal is from an ultrasound receiver added. The received signal is evaluated and leaves about the reflection or absorption behavior Conclusions about the type of flooring.

In view of the prior art described above becomes a technical problem of the invention seen in it, a floor care device, such as in particular a vacuum cleaner of the type in question with regard to further develop soil detection in an advantageous manner.

This task is first and foremost with Subject of claim 1 solved, with reference to it is that the same ultrasonic transducer both as an ultrasound transmitter as an ultrasound receiver is working. As a result of this configuration, an im Construction of simplified soil detection implemented. This is achieved in that a very short transmit pulse is placed on the ultrasonic transducer and this then switch directly to reception mode. Based on the amplitude of the reflected and received Signals can reflect or absorb behavior of the floor covering can be determined. At high amplitudes there is a hard floor, for small ones a carpet. The received signal is first amplified and then rectified. Because the output signal due to the movement of the device over the one to be maintained Soil does not have a constant level expedient to form an average, what with a Filter - a low pass filter - is achieved. After that can with a downstream comparator between different floor coverings can be distinguished. It has proved to be favorable, the rectified signal filter less and the evaluation with a Perform Schmitt trigger with hysteresis, whereby the response time of the circuit is significantly improved is. With a Schmitt trigger, a must first certain minimum level (minimum voltage level) exceeded before the output becomes active. The switch off but does not take place at the same voltage level, but on one that is about the switching hysteresis is smaller. According to the ultrasound transducer switched continuously. this happens by means of a sequence control. First, about one Pulse generator given a short pulse to the converter. Then the switch is on the sequence control switched such that the signal from the converter gets to the amplifier, from the time of Excitation until the reflected signal arrives the ringing process must be completed. Further can be the distance between the sensor - the ultrasonic transducer - be kept small to the floor to be maintained.

The invention further relates to a floor care device, especially vacuum cleaners, possibly with a motor-driven carpet brush, with an ultrasonic floor detection, being the ground detection ultrasonic transducer has that as an ultrasonic transmitter or ultrasound receiver work. To a floor care device here of the type in question in particular in terms of soil detection in an advantageous manner it is provided that at least one Ultrasonic transducer with distance to an underbody the device is arranged and that between the sub-floor and the ultrasonic transducer a sound line channel is trained. With this arrangement according to the invention the ultrasonic transducer is preferred both as Transmitter and time-shifted used as a receiver. First, the ultrasound transducer becomes pulsed excited so that a sound wave with its resonance frequency is produced. Since after that the converter resonates, has to pass a certain amount of time he can work as a recipient. This ringing time depends essentially on the bandwidth of the ultrasonic transducer and is, for example, one millisecond. Only after this time can the echo of the transmission signal by reflection on the floor or the surface of the treating the floor again the ultrasonic transducer to reach. To get sufficient amplitudes, a guide through a sound conduction channel is preferred. The ultrasound transducer is at one end of this Formwork line channel arranged. The other, open The end of this channel is at a distance of approx. 0.5 up to 2.5 cm to the floor to be treated in the floor care device arranged, this is more preferred with vertical Alignment of this free sound conduction channel. In this regard it is preferred that the sound line channel be used as Hose is formed. It should be noted here that the inner wall is homogeneous. This means that no edges where the sound is reflected could be present. As a result, one becomes Sound conduction channel preferred, the one curved Has history. It is also proposed that the Sound conduction channel has a length that below Consideration of the speed of sound at least corresponds to the ringing time of the ultrasonic transducer. With a ringing time of around one millisecond results from considering the speed of sound a total distance of sound of about 34 cm and therefore a distance between the ultrasonic transducers and floor to be maintained of approx. 17 cm. Around Distance within a floor care device, such as to offer a suction nozzle of a vacuum cleaner, a correspondingly long, preferably curved sound conduction channel used in the form of a hose, the End of sound exit or entry in the area of the device floor perpendicular to the floor to be maintained is aligned. Through an adapted signal evaluation is also a much shorter education of the Sound conduction channel, a reduction in the cooldown and thus the time until the measurement is evaluated possible so the length of the sound conduction channel is shorter than a path that sound takes during a cooldown. Accordingly Sound conduction channel lengths of 2 to 10 cm, preferably 3 up to 5cm realizable. It proves to be advantageous here that the ultrasonic transducer in the sound conduction channel is arranged. Another advantage is that the formwork duct on the underside with a distance from 0.5 to 1.5 cm to the floor to be maintained ends. The ultrasonic floor detection according to the invention is preferably used in such a way that depending the distance from the ultrasonic detection Suction nozzle to the floor to be maintained is changeable. So the floor of the floor care device is more preferred, such as a suction nozzle when caring for a Carpet on this one. On the other hand, the bottom of the device when maintaining a hard floor to avoid scratching it. The distance of the Suction nozzle floor to the floor to be maintained automatically to be changed. Ultrasound is applied to hard floors reflected and thus the output of the assigned Schmitt triggers enabled what about a logical Linking the lifting of the suction nozzle or the suction nozzle base has the consequence. It is preferred that the Change in height by moving a bristle strip in and out is reached. For example, the evaluated Hard floor signal used to be a servo or to control the like, which in turn a Bristle strips arranged in the area of the nozzle mouth extends. The suction nozzle, For example, in the front area, from the floor to be maintained slightly lifted off. The detection of a carpet causes the bristle strip to retract and goes along with it lowering the suction nozzle. The same applies when lifting the device off the floor. Here too the bristle strip retracted. Regarding the Change in height by moving a bristle strip in and out reference is made to EP B1 0 630 604. The The content of this patent specification is hereby fully included in the disclosure of the present invention, also for the purpose of features of this patent in Include claims of the present invention. In this regard, both digital control of the Bristle strips, i.e. retracting and extending, as well as one linear control conceivable, so the bristle strips can also be brought into one or more intermediate positions are. In a further embodiment of the subject matter of the invention it is provided that depending on the ultrasound signal the size of a suction nozzle mouth changeable is. Next is with floor care equipment, which one have motor-driven carpet brush from Advantage that depending on the ultrasound signal the drive for the carpet brush is switchable. So the carpet brush is only driven when it is recognized a carpet is activated. When a Hard floor or when the device is at a standstill will the carpet brush to avoid damage the floor and / or the brush is not activated. Of There is also the possibility of the suction power of the Vacuum cleaner depending on the ultrasonic signal regulate. For example, if a deep-pile is detected Carpet the maximum and at standstill detection a minimum suction power must be set.

In order to reliably even relatively hard carpets To distinguish hard floors is an ultrasound used by more than 40 kilohertz. This serves preferably a piezo element as an ultrasonic transducer. With appropriate selection of the frequency distinguish different groups of rubbers. Height However, frequencies are due to the high attenuation of the Sound signal in air rather unfavorable. For differentiation of three groups, namely soft carpet, carpet and Hard floor, a frequency of 35 to 60 kilohertz is suitable. Under soft carpet z. B. long-pile coverings like bath mats or the like. For the business of a single transducer system in which the same ultrasonic transducer both as an ultrasound transmitter as well as Ultrasound receiver works, is a sequence control required. This can be designed in this way, for example be that the ultrasonic transducer by means of a switch either acted on by a pulse generator or is coupled to a pulse amplifier. The Ultrasonic transducer is continuously between Sending and receiving switched. Alternatively the design can also be chosen so that the Ultrasonic transducers both constantly with a pulse generator as interconnectable with a pulse amplifier is. As a result, the sequence control is essentially simplified. There is a switch between transmission and reception mode is waived by the reception or Pulse amplifier continuously on the ultrasonic transducer is connected, i.e. also during the transmission pulse. Through the transmit pulse, the receive amplifier is admittedly significantly overridden, but remains during the term of the sound signal is sufficient for the amplifier Time to get out of saturation and the required To deliver sensitivity. This is also done here Evaluation of the potential with a Schmitt trigger or when divided into several groups (soft carpet, Carpet, hard floor, etc.) with an appropriate number the same.

The invention further relates to a floor care device, especially a vacuum cleaner with a, a Suction port with suction port and possibly a motor powered carpet brush, being a Center of gravity of the device in the direction of travel behind the suction mouth, with an ultrasonic floor detection using ultrasonic transmitters and transducers. Around in addition to a floor covering detection using ultrasound also recognizing missing soil, for example when going down enable leading steps by means of ultrasound, it is proposed according to the invention that an ultrasonic transmitter and / or converter in the direction of travel the center of gravity is arranged. As a result of this configuration is by the arrangement of the invention Ultrasound transmitter and / or transducer an autonomous Floor care device realizable. For example Levels recognized early as soon as part of the in front of the center of gravity section protrudes over the edge of a step or the like. In an exemplary embodiment in this regard the ultrasonic transmitter and / or transducer in the direction of travel of the floor care device viewed from the front be arranged. A further development provides that an ultrasonic transmitter and / or transducer on the edge the device is arranged. It is preferred here that two ultrasonic transmitters / transducers on the edges of the device are provided. To a desired suction down to the edge of a leading, for example Ensuring level is at an advantageous level Further development of the subject of the invention is provided, that an ultrasonic transmitter and / or transducer in the direction of travel behind a front edge of the suction mouth, however is placed in front of the focus. Is preferred in this regard further that opposite on both Edge of the suction mouth an ultrasonic transmitter and / or converter is arranged. To a level or The like regardless of the angle at which recognizing this is proposed, it is further proposed that traversing wheels are provided and that the ultrasonic transmitters and / or transducers at a distance the distance between the traversing wheels are arranged so that there is a risk that the Traversing wheel already facing the step over the edge moves before the sensor detects the abyss, counteracted is. In a further development of the subject matter of the invention is used to detect a transition between Two floor coverings provided that two ultrasound transmitters and / or transducers arranged directly next to each other are. As a result of this configuration, transition edges become recognized between different floor coverings, after which the floor care device is enabled to drive parallel to the edge or along the edge. This is a particularly autonomous floor care device capable of efficient even in such transition areas to clean and a surface depending on to clean their changing surface structure. The Known horizontal orientation of autonomous floor care devices at obstacles with this invention a vertical orientation to the nature of the soil added. Due to the arrangement of the ultrasonic transmitter described and / or converter becomes reliable and quickly, d. H. in a direct way, a classification of the Soil type on which the floor care device moves, performed. Thus, an adapted one can be made immediately Reaction of the cleaning unit take place. The aforementioned Arrangements according to the invention can each be in the form an ultrasound transmitter and an associated one Ultrasound receiver be formed. As special A configuration according to has proven to be advantageous here Claim 1, in which the same ultrasonic transducer both as an ultrasound transmitter and as an ultrasound receiver is working.

The invention also relates to a method for detection a floor condition, such as hard floor, carpet or missing soil by means of ultrasound measurement in one Floor care equipment. To a procedure of the one in question Kind regarding the detection of the soil condition to further develop in an advantageous manner, it is proposed that the amplitude of the reflected sound is Detection of the soil condition is evaluated. So leads the evaluation of the signal for corresponding reactions. For example, when recognizing a hard floor a possibly provided carpet brush switched off and also bristle strips to limit the Suction chamber extended. For this purpose, it is further provided that the amplitude of the reflected sound with predetermined Limits are compared. That's an assignment provided, in which when a upper limit of sound intensity hard floor and with a measured value between an upper and a lower limit of carpeting is recognized. Is the However, the measured value is less than the lower limit, see above missing soil is recognized, for example with downward leading Steps or after lifting the floor care device. To further improve soil condition detection, is provided in a further training that only repeated exceeding or falling below a limit value as a criterion for a change in soil condition is used. So when evaluating the Echo amplitude a hysteresis is provided. For example, the carpet must have already been recognized, the amplitude to exceed a higher threshold several times Recognizable hard floor. It is also through this Signal evaluation, even when the device is at a standstill, since there is a small fluctuation range on each other the following measured sound amplitudes are present, which advantageously turns off or on Shut down to a minimum performance of the floor care device leads. To differentiate between the different soil conditions and beyond that It is proposed to further improve standstill detection, that averaging before an evaluation made from a plurality of measured values becomes. Especially when the floor care device moves there are overlaps in the echo signal for example of hard floors and carpets. However, since the Echo amplitude on hard floors is higher on average than for carpets, results from the averaging for the hard floors a higher amplitude than with Carpets. In this regard, it is preferred that a Averaging from 5 or more measured values becomes. From the reflected signal in addition to the information about the soil condition also the Information about a standstill of the floor care device win. Proves to be particularly advantageous a further development of the method that the evaluation of the ultrasound signal is started before the decay time of the transmitted signal has passed. Therefore the sound conduction channel can be adjusted by an adapted signal to a length of 2 to 10cm, preferred 3 to 5cm, can be shortened. The procedure described above can be used with common floor care equipment in the form of vacuum cleaners as well in particular autonomous floor care devices.

The invention further relates to a method for Alignment of the movement of an automatic Floor care device such as a vacuum cleaner in particular along an edge of a particular flooring, such as For example, a carpet, a detection of the Flooring is made using ultrasound. Around especially in the case of autonomous floor care devices Suction along a transition edge from a floor covering to realize an adjacent flooring it is suggested that depending on an acquisition a change of direction when changing the floor covering with regard to the direction of travel of the device. The respective soil type is ultrasonically the device detected, with a detected floor covering change an evaluation electronics, for example driven traversing wheels of the device accordingly a desired behavior, e.g. B. "Driving along the transition edge ". According to this It is possible to design an area with different Systematically cleaning floor coverings, d. H. to drive parallel to edges and transitions. So can can also be cleaned in critical edge areas. It is also proposed in this regard that after a first change in the direction of travel by changing the flooring, the time until another change in the floor covering is detected is additionally recorded and depending on the recorded time the measure of the following change of direction is calculated. As a result of this method according to the invention the direction of travel of the device to the course an edge between two different ones Floor coverings introduced, for example under zigzag Approach of the direction of travel to the edge of the covering. If, as suggested, the time until Detection of another change of flooring additionally recorded, then, for example, is an angular one less change of direction required. This Measurements and changes in direction can lead to that after a short run an approximation is reached in a straight line of travel. Around the time and also the path to the acquisition an almost straight travel direction of the device To shorten, it is intended that the measure of the first Change of direction is more than 90 °.

The invention also relates to an alignment method the movement of an automatic floor care device like especially along a vacuum cleaner an edge of a certain floor covering, such as. a carpet, whereby a detection of the floor covering is carried out by means of ultrasound. To here in advantageously a method of the subject in question Kind of further training, it is suggested that between the amplitude value of the recognized first floor covering and the amplitude value of the recognized second floor covering an average is formed, that of an edge between the first and the second floor covering and that the direction of travel of the device as long and is changed until the mean value mentioned the detected amplitude value in the course of the movement corresponds.

Finally, the invention relates to a method for Alignment of the traversing movement of an automatic Floor care device such as a vacuum cleaner in particular along an edge of a particular flooring, such as For example, a carpet, a detection of the Flooring is made using ultrasound. Around a method for the detection of a floor covering edge to train in an advantageous manner suggested that two juxtaposed Ultrasonic transmitters and / or transducers are provided. In this regard, separate ultrasound transmitters and Ultrasound receiver can be provided. Is preferred however an arrangement according to claim 1, wherein the same Ultrasound transducers as both ultrasound transmitters also works as an ultrasonic receiver. Is preferred in this case the amplitude value of those arranged next to one another Ultrasonic transducer detected. Is the sound amplitude of the first sensor not equal to that of the second sensor, see above the floor care device is on two different ones Coverings. Accordingly, in particular an autonomous floor care device corrective movements the drive wheels this state of the moving device receive or adjust so that the device runs along the marginal edge moves.

Fig. 1

in perspektivischer Darstellung ein Bodenpflegegerät in Form einer Saugdüse mit einer motorisch angetriebenen Teppichbürste;

Fig. 2

eine schematische Schnittdarstellung des Bodenpflegegerätes mit einem erfindungsgemäßen Ultraschall-Wandler zur Ultraschallerkennung, eine erste Ausführungsform betreffend;

Fig. 3

ein Blockschaltbild einer Schaltung der Ultraschall-Erkennung der ersten Ausführungsform;

Fig. 4

zwei Diagramme zur Verdeutlichung der Abhängigkeit des Ausgangssignals eines Schmitt-Triggers zum abgeleiteten Spannungspegels des empfangenen Signals;

Fig. 5

eine schematische Draufsicht auf ein Bodenpflegegerät in Form einer Saugdüse, eine zweite Ausführungsform der Ultraschall-Erkennung betreffend;

Fig. 6

eine der Fig. 2 entsprechende Schnittdarstellung, die Ausführungsform des Bodenpflegegeräts gemäß Fig. 5 betreffend;

Fig. 7

eine weitere Schnittdarstellung eines Bodenpflegegerätes, mit angehobener Borstenleiste bei Pflege eines Teppichbodens;

Fig. 8

eine der Fig. 7 entsprechende Darstellung, bei ausgefahrener Borstenleiste zur Pflege eines Hartbodens;

Fig. 9

ein der Fig. 3 entsprechendes Blockschaltbild, jedoch das System der Ultraschall-Erkennung gemäß dem zweiten Ausführungsbeispiel betreffend;

Fig. 10

eine schematische Unteransicht gegen ein Bodenpflegegerät in einer weiteren Ausführungsform mit einer Ultraschall-Erkennung;

Fig. 11

eine der Fig. 10 entsprechende Darstellung, eine weitere Ausführungsform betreffend;

Fig. 12

die Unteransicht gegen eine alternative Ausführung des Bodenpflegegerätes;

Fig. 13

eine weitere Unteransicht gegen ein Bodenpflegegerätes;

Fig. 14

ein Blockschaltbild einer Schaltung zur Ultraschall-Erkennung, gemäß einer dritten Ausführungsform;

Fig. 15 bis 21

Blockschaltbilder einzelner Programmteile der Schaltung gemäß Fig. 14;

Fig. 22

ein Diagramm zur Verdeutlichung unterschiedlicher, eingelesener Echosignale;

Fig. 23 bis 25

Blockschaltbilder weiterer Programmteile der Schaltung gemäß Fig. 14.

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

Fig. 1

in perspective a floor care device in the form of a suction nozzle with a motor-driven carpet brush;

Fig. 2

is a schematic sectional view of the floor care device with an ultrasonic transducer according to the invention for ultrasonic detection, relating to a first embodiment;

Fig. 3

a block diagram of a circuit of the ultrasonic detection of the first embodiment;

Fig. 4

two diagrams to illustrate the dependence of the output signal of a Schmitt trigger on the derived voltage level of the received signal;

Fig. 5

a schematic plan view of a floor care device in the form of a suction nozzle, relating to a second embodiment of ultrasonic detection;

Fig. 6

2 shows a sectional view corresponding to the embodiment of the floor care device according to FIG. 5;

Fig. 7

another sectional view of a floor care device, with raised bristle strip when caring for a carpet;

Fig. 8

a representation corresponding to Figure 7, with extended bristle strip for the maintenance of a hard floor.

Fig. 9

a block diagram corresponding to FIG 3, but relating to the system of ultrasonic detection according to the second embodiment.

Fig. 10

a schematic bottom view against a floor care device in a further embodiment with an ultrasonic detection;

Fig. 11

a representation corresponding to FIG. 10, relating to a further embodiment;

Fig. 12

the bottom view against an alternative embodiment of the floor care device;

Fig. 13

a further bottom view against a floor care device;

Fig. 14

a block diagram of a circuit for ultrasonic detection, according to a third embodiment;

15 to 21

Block diagrams of individual program parts of the circuit according to FIG. 14;

Fig. 22

a diagram to illustrate different, read echo signals;

23 to 25

Block diagrams of further program parts of the circuit according to FIG. 14.

Is shown and described initially with reference to Fig. 1 shows a floor care device 1 in the form of an attachment for a vacuum cleaner with an electric motor 2 powered carpet brushes 3. Push the latter through the bottom 4 of the care device 1 in the area of a Suction mouth 5 for mechanical support of the cleaning process when caring for carpets.

For processing hard floors, such as tile floors, the care device 1 has the suction mouth in a known manner 5 upstream a bristle strip 6, which at caring for carpets or the like is so that the suction mouth 5 on the to be treated Carpeting. The bristle strip is on hard floors 6 extended so that the suction mouth 5 of the suction nozzle or the care device 1 from the person to be treated Soil - here hard floor - lifts off.

That depends on the nature of the to be cared for Soil 7 required switching on and off Carpet brush drive and the retraction and extension of the Bristle strip 6 is according to the invention on a care device side Electronics controlled. This is served by a Ultrasonic soil detection to determine the surface quality of the soil to be maintained 7.

Floor coverings differ in their surface structure. While carpets have a soft surface, are z. B. Tiles and PVC coverings can be classified as hard. According to the care to be taken Bottom 7 directed an ultrasonic wave. The different Structures of the floor coverings have corresponding ones Effects on the impacting sound waves.

Underside is at a distance from the one to be maintained Bottom 7 provided an ultrasonic transducer 8, which both as an ultrasonic transmitter 9 and as an ultrasonic receiver 10 works. This ultrasound transducer is, according to the invention, a piezo element (piezo crystal). An ultrasound of more is used for soil detection used as 30 kilohertz.

The ultrasonic floor detection works with a continuous Broadcast signal. Advantageously, a small distance a to the floor 7 to be maintained of less than 40 mm (see FIG. 2).

The system according to the invention works with a single one Ultrasonic transducer 8. This is made possible by that to the ultrasonic transducer according to the embodiment 2 and 3, a very short transmit pulse is given and then switched to reception mode becomes.

The mode of operation is based on the block diagram in FIG. 3 the ultrasonic soil detection explained in more detail. The ultrasound transducer 8 is used in this system switched continuously. This is done using a sequence control 11. First, a Pulse generator 12 sends a short pulse to the ultrasound transducer 8 given. Then a switch 13 switched via the sequencer 11 such that the Signal from the ultrasonic transducer 8 to a pulse amplifier 14 arrives. After amplifying the received signal it is then rectified. The Rectifier has the reference number 15 in FIG. 3 the output signal due to the constant movement of the Care device 1 on the floor 7 to be maintained constant level is averaging required, which is achieved with a filter 16. After that, you can use a simple comparator between different floor coverings can be distinguished. It has proved to be cheap, however, the rectified Filter signal U less strongly and the evaluation with a Schmitt trigger 17 with hysteresis. This will change the response time of the circuit clearly improved. With a Schmitt trigger 17 must first a certain minimum level (minimum voltage level U) are exceeded before the output is active becomes. Switching off is not the same Level of tension, but rather on one that is about the Switching hysteresis is smaller.

4 shows the mode of operation of the Schmitt trigger 17 shown with hysteresis. It can be seen that if a voltage level A is exceeded, the output side of the Schmitt trigger 17 results in a signal C. Accordingly, the Schmitt trigger became 17th assignable flooring recognized.

Only after falling below a minimum voltage level B, which is about the switching hysteresis of the Schmitt trigger 17 is less than the switch-on voltage level A, the Schmitt trigger 17 is reset to a Low signal.

The output signal C of the Schmitt trigger 17 is in a logical link 18 for determining the floor covering evaluated.

According to the desired subdivision for recognition different floor coverings are correspondingly many Arrange Schmitt trigger 17 in parallel. The output signal D of the logic operation 18 can be advantageous Can be used depending on the recognized flooring the carpet brushes 3 on or turn off or the bristle strips 6 retract or extend. In addition, another can Differentiation of different types of carpets (low and deep pile floors) the suction power of the Care device can be controlled electronically.

You can also use it to visually confirm the flooring detection Control lights 19 in the care device 1 can be controlled.

In the soil detection system according to FIGS. 5 to 9 is also an ultrasonic transducer 8 at the same time Ultrasonic transmitter 9 and as an ultrasonic receiver 10 used. Here is the ultrasonic transducer pulsed so that a sound wave with his Resonance frequency is generated. Now the ultrasonic transducer 8 resonates, needs a certain amount of time lapse until the recipient can work. This ringing time essentially depends on the Bandwidth of the converter 8 and is in the inventive System about a millisecond. Only after During this time, the echo of the transmission signal may be reflected at the bottom 7 or the surface again the transducer Reach 8. Taking into account the speed of sound In this case there is a total distance the sound of 34 cm and thus a distance between the ultrasonic transducers 8 to the floor to be maintained of approx. 17 cm.

Now to get a sufficient amplitude, will guide the sound through a tube trained sound conduction channel 20 made. The Ultrasonic transducer 8 is in this case at one end 21 in introduced the hose or sound conduction channel 20 and attached. The other, free end 22 of the sound conduction channel 20 is perpendicular to the floor 7 to be maintained in Device floor 4 arranged so that the open exit surface of the sound conduction channel 20 essentially is aligned parallel to the floor 7 to be detected.

Furthermore, the arrangement is chosen so that the free End 22 of the sound conduction channel 20 on the underbody side at a distance of 0.5 to 1.5 cm from the one to be cared for Floor 7 ends.

The hose or the sound conduction channel 20 can certainly be curved through the care device 1. This results in a space-saving arrangement of the Detection system in the care device 1. Here is just make sure that the inner wall of the Sound conduction channel 20 is homogeneous, d. H. it may there are no edges where the sound reflects could be.

The open end 22 of the sound conduction channel is advantageously 20 in the usual machining direction r the bristle strip 6 and possibly in front of the carpet brushes 3 arranged.

In the illustrated embodiment, three Groups, such as soft carpets, carpets and hard floors recognized, for which a frequency of 35 to 60 kilohertz is used. Long pile, for example, are covered by soft carpets Coverings such as bath mats or the like.

As can be seen from the block diagram in FIG. 9, can also be done by connecting additional Schmitt triggers 17 further groups of floor coverings can be recognized.

For the operation of such a converter system a sequential control system as described above Embodiment required. In the case of the invention Solution according to the second embodiment is based on a switchover between transmit and receive operation dispenses with the fact that the pulse amplifier 14 (receiving amplifier) continuously on the ultrasonic transducer 8 accordingly, also during the transmission pulse. By amplifier 14 is significantly overdriven this transmission pulse, however, remains during the runtime of the broadcast signal x enough time for amplifier 14 to turn off of saturation and the required sensitivity to deliver. Through the filter 16 and the rectifier 15 becomes the influence of the received pulse y converted into a constant DC voltage and only the variable portion of the reflected signal y leads to a shift in the potential U at the output of the Rectifier 15 or filter 16. The evaluation this potential occurs in the manner described one or more Schmitt triggers 17.

Depending on which output of the Schmitt trigger 17 is active is switched on, the evaluation electronics Switching the carpet brushes, if any 3 and the bristle strip 6.

As can be seen in FIG. 7, one is recognized Carpeted the bristle strip 6 retracted, what a Servo 23, not shown, via the electronics depending on the output signal D of the logical Link 18 is driven.

The device floor 4 and thus the suction mouth 5 of the care device 1 on the surface of the floor 7 to be maintained (see FIG. 7).

On the other hand, is due to the ultrasonic soil detection Hard floor detected, so it is done by appropriate control the servo 23 an extension of the front Bristle strip 6, which leads to a lifting of the care device 1 and thus to a spacing of the device base 4 leads to the floor 7 to be maintained (cf. FIG. 8).

10 to 13 show schematic bottom views against floor care devices 1, in particular autonomous floor care devices 1 with electric motor driven if necessary Traversing wheels 26 and in the direction of travel r in front of these arranged suction mouth 5, in the area of which a Carpet brush 3 is arranged.

These alternative floor care devices 1 have one exemplary circular cross-section, where a Center of gravity Sp of device 1 in the direction of travel r behind the suction mouth 5 and therefore also behind the carpet brush 3 lies in the middle between the travel wheels 26.

In Fig. 10 is an embodiment with an ultrasonic transducer 8, which is shown in the direction of travel r on the front of the device 1 in the area of the device base 4 and thus in the direction of travel r before the focus Sp is arranged. These are preferably an ultrasonic transducer 8 according to those previously described Embodiments. This works accordingly both as an ultrasonic transmitter 9 and as an ultrasonic receiver 10th

This ultrasonic transducer 8 is used according to the previously described embodiments for the detection of Soil condition. For example, this converter 8. Hard floor or carpet recognized. Beyond that especially when the floor care device is used autonomously 1 advantageous that by means of the converter 8 also missing soil is recognized, for example a downward leading Step. As a result, the evaluated Signal of the ultrasonic transducer 8 not only for Switching the cleaning type - hard floor cleaning to Carpet cleaning and vice versa - but also for Course correction by controlling the travel wheels 26 serve.

To such a downward level 28 also at starting the device 1 at an acute angle 11 can detect further ultrasonic transducers 8 arranged on the edge of the care device 1 his. These are preferably opposite in the area the two narrow edges of the suction mouth 5 are provided, with a distance between them in addition to Transducer 8 arranged on the end face 8 is adapted to the distance between the travel wheels 26 to each other.

This arrangement is advantageous the converter 8 also has a downward step 28 recognized by approaching an acute angle before one of the traversing wheels 26 travels over the step edge. The evaluation electronics that determine the missing floor then causes a course correction by control the traction wheels 26 driven by an electric motor.

In order to clean the floor to be maintained up to to ensure the edge of stair 28 are the ultrasonic transducers assigned to the suction mouth 5 8 further preferred, but not shown in detail, behind a front edge 27 of the suction mouth 5 arranged.

In addition, a missing floor can also be found in one Lifting the maintenance device 1 off the floor to be maintained can be determined, which is particularly the case with conventional handheld vacuum cleaners to switch off the possibly provided Carpet brushes 3 and to reduce the suction power leads.

The edge of the suction mouth 5 can also be provided Ultrasonic transducer 8 for aligning the movement r along an autonomous floor care device 1 of an edge of a certain floor covering. So can, for example, by means of ultrasound the edge of a Carpet can be determined. As soon as via the evaluation electronics the change in the floor covering is recorded, a change in direction with respect to the direction of travel r made of floor care device 1, initially the measure of a first change of direction preferably more than 90 °. After this first one, by changing the flooring caused change in the direction of travel r after every further floor covering change detection further changes in direction made in Dependence on a recorded time between two Flooring changes are calculated. As a result the floor care device 1 zigzag along an edge of a carpet or the like led, the changes of direction quickly and to be carried out continuously to conclude an almost straight-line driving of the floor care device 1 along the edge of the covering.

Another solution, not shown, for determining the edge of the covering edge suggests that between the amplitude value the recognized first floor covering and the amplitude value an average of the detected second floor covering is formed, the one edge between the corresponds to both floor coverings 7 and 7 '. After that will the floor care device 1 in terms of its orientation the direction of travel r is controlled as long and as often, until the mean value formed is the detected amplitude value corresponds in the course of the traversing movement.

An alternative training for the detection of a floor covering edge is shown in FIG. Here are opposite at the two edges of the suction mouth 5 two ultrasonic transducers 8 are arranged side by side, an arrangement can also be selected here can, in which this ultrasonic transducer 8 in Direction of travel r behind a front edge 27 of the suction mouth 5 are positioned.

This parallel arrangement of the ultrasonic transducers 8 are adjacent floor coverings 7, 7 'and thus the edge 25 of a floor covering can be detected. Here are arranged in parallel by means of the two Ultrasonic transducer 8 different sound amplitudes detected. By correcting the travel wheels 26 can this state of the moving floor care device 1 received or settled. The floor care device 1 then moves along the edge 25.

13 shows a preferred combination of the solutions 10 and 12.

The provided ultrasound transducers 8 are used according to the invention the detection of the soil condition (e.g. Hard floor, carpeting or lack of floor) Detection of the transition between two floor coverings 7, 7 'and also for the detection of the standstill of the floor care device 1, a corresponding the amplitude value determining the standstill leads to that, for example, the care device 1 for saving energy and to avoid damage to the nursing floor 7 switches off or is brought down to minimum performance.

The mode of operation is based on the block diagram in FIG the ultrasonic control explained in more detail. The Individual program parts P1 to P10 are shown in FIGS. 15 to 25 explained in more detail. The edition of the known Operating conditions of the floor care device only take place on End of each program cycle. This has the condition that the respectively recognized states, such as. B. Hard floor, carpet or missing floor initially be saved in a state variable. At the end the variables are then queried and the corresponding one Output to the outputs of a microcontroller.

In the first program part P1 shown in FIG. 15 After a start P11 there is an initialization P12 and a preset of the constants and Variables P13.

The program cycle then begins, in the program section P2 (FIG. 16) there is first a pulse output P21. After the output of four pulses, for example, passes a certain time until the echo signal arrives. The query after the time has elapsed is indicated by a Loop P22 implemented, which is only exited when timer overflow occurred.

After the waiting period has elapsed, the Start address of the table for the echo signal (P31 in Program part P3, see Fig. 17) of the analog-digital converter configured (P33) and then at the analog / digital input applied signal of the ultrasonic transducer read.

After starting the analog / digital conversion (P34) and a check whether this conversion has ended (P35) becomes the result of the analog / digital conversion under P36 filed in the table.

In order to acquire the complete echo signal, there are, for example, 32 Read in values one after the other, which is done under P38 corresponding query is made. If the answer is negative is over a loop counter P37, which input was set to one under P32, another Analog / digital conversion carried out.

Will the query under P38 after reading 32 values if yes, one takes place in program part P4 (FIG. 18) Detection of the echo signal. For this, the imported Transducer signal first examined whether a Echo signal is present. This is the decay behavior the ultrasonic transducer as a table in the program memory filed. As soon as the read value is larger than the value stored in the table is an echo signal available. If the floor care device 1 is lifted off or the ultrasonic transducer is missing ground, e.g. a downward step is captured and thus the ultrasonic transducer measures against free space, there is no echo signal.

At P41, this is the start address of the table a loop counter is stored for the echo signal one set and then the counter value under P42 corresponding value from the stored decay table read out. At P43, the converter signal is compared with the Table value compared. Here is the converter signal smaller than the table value, so is first under P45 checked whether the maximum number of passes was achieved. If this is not the case, then under P44 the counter continued and the loop again run through.

However, the maximum number of runs was at If P45 is determined, the transition to Program part P9 (Fig. 24).

However, if there is an echo signal, i. H. in the Checking in P43, the converter signal turns out to be larger than the table value, is then in the program lower part P5 (Fig. 19) the maximum of the echo signal determined and averaging performed.

The maximum amplitude is used to evaluate the echo signal relevant (see description of the first embodiment). The determination of the maximum amplitude in the echo signal happens according to the program sub-part P5 in Fig. 19. First a maximum variable is shown under P51 set to zero and then a table value under P52 compared with the previously determined maximum value. If the table value is the larger value, then the maximum value is stored in a maximum variable (P53). However, it has been determined under P52 that the table value is less than the previous maximum, so there is no storage under P53.

Finally, it is checked under P54 whether the end of the Table was reached. If not, it will Another run via a loop counter P55 causes.

When the end of the table is reached, the transition to Program lower part P6 (Fig. 20), in which the mean of the echo maximum is determined.

A check is first made here under P61 whether a first run is made. Only if it does , a loop counter average is opened under P62 one and a sum variable set to zero. To an accumulation of the echo maximum under P63 becomes at P64 checks whether the overflow has been reached. Is this the case, there is an increment at P65.

Following this overflow check is checked at P66, whether 32 values have been added. Unless the query is negative, the program flow jumps to the program part P10 (Fig. 25), the method of which will be described later becomes.

If, on the other hand, 32 values have been added up, the Program part P6 finally at P67 a division of the Sum by the number 32 and a storage of the Result in a result variable.

The averaging of the echo maximum is for the Desired standstill detection necessary. Furthermore there are advantages in differentiating between Hard floor and carpeting, since one moves Floor care device 1 the echo signals from hard floor and at least partially overlap carpeting. There however, the echo amplitude on hard floors is higher on average lies than with carpets, results from the averaging a higher amplitude for hard floors than with carpets.

When evaluating the mean, the reflected signal in addition to the information about the Soil type or whether the floor care device 1 is lifted off or, for example, has reached a downward step, also the information about a standstill of the floor care device win.

When the reflected echo signal is above a certain Period remains constant in its amplitude, so lets conclude that the floor care device 1 is not is moved.

The read-in echo signal from a moving floor care device 1 shows FIG. 22. From this it can be seen that the echo signal is stronger on hard floors H1 and H2 fluctuates as on carpeting T1 and T2. Therefore at standstill detection on carpeting is less Tolerance limit to be set as on hard floor, otherwise on carpeting with the large tolerance limit of Hartboden would see a standstill, though the floor care device is moved.

21 shows a related sub-section P7, initially being determined on the input side at P71 is whether hard floor was previously recognized. After that will a large tolerance limit for hard floor detection with P72 set. However, if no hard floor has been determined, so at P72 'there is a low tolerance limit set.

It is then checked at P73 whether the mean value is greater than the lower tolerance limit. Is this the If so, it is additionally determined at P74 whether the Mean value is less than the upper tolerance limit. If this is also the case, a run counter becomes available at P75 incremented for standstill. In contrast, with P73 or P74 determines a negative answer, the Flow counter incremented for no standstill (P75 ').

Depending on whether the flow counter for standstill or increment for no standstill becomes independent first of all checked at P76 or P76 'whether the number of maximum runs has been reached. Is if the respective answer is positive, then at P77 the "Standstill" status set or deleted at P77 ', whereupon at P78 or P78 'the counter for "no standstill" and reset for "standstill".

As can be seen further from FIG. 22, the echo amplitude fluctuates with a moving floor care device 1 very much strong. The echo amplitude of Hartboden is partly (see H2) even under that of carpeting (see T1), so that instead of hard floor carpeting recognized could be. However, this is according to the invention avoided.

22, this overlap occurs however only in places on and beyond even for a very short time. Therefore at the Evaluation of the echo amplitude programmed a hysteresis. If carpet has already been recognized, must the echo amplitude several times a higher threshold to recognize hard floor. On the other hand the echo amplitude if hard floor has already been recognized has repeatedly fallen below a lower threshold, to recognize carpeting. The program flow to differentiate the soil condition is shown in Fig. 23 shown using the program part P8. Here depending on a query at P81 whether hard floor has already been recognized or not, a threshold value loaded, so with hard floor detection a lower one Threshold (P82) and an upper one if not recognized Threshold (P82 '). The mean previously determined is then with the loaded threshold at P83 compared. If the mean is greater than the threshold, this is how P84 becomes a flow counter for the hard floor incremented. On the other hand, P84 'turns on Flow counter incremented for the carpet.

Then it is first checked whether the maximum Number of passes for hard floor (P85) or carpet (P85 ') is reached. If the query is positive, is then in the program sub-sections P86 or P86 ' either the status bit "hard floor" set and the Status bits "carpet" and "missing floor" deleted or the status bit "carpet" set and the status bits "hard floor" and "missing floor" deleted. Then the counter at P87 or P87 ' both for carpets and hard floors and missing floor reset. Finally, each according to the value determined at P83 either an increase the sensitivity of the hard floor and a degradation the sensitivity of the carpet at P88 or setting the sensitivity for hard floor and Carpet at normal value at P88 '.

As already mentioned, is when in the read converter signal no echo signal is detected, the floor care device 1 either lifted off or down, for example at the leading stage. After a number to be determined the program sets the corresponding number of runs Bit. So in program part P9 (Fig. 24) first the flow counter increments "missing floor", after which also a query of the maximum runs carried out for the "missing soil" state will (P92).

With P93 the status is set with "missing floor" and the state bits "carpet", "hard floor" and "Standstill" deleted and finally at P94 the Counter for "carpet", "hard floor" and "missing Ground "reset.

The output of the extracted useful signals from the echo signal is done by querying the corresponding bits in the Status byte and setting or deleting the corresponding one Output. A corresponding program sequence P10 is shown in Fig. 25. According to a query with P100, whether hard floor is set or not, with P101 the output "hard floor" is set or at P101 'the "Hard floor" exit deleted. Correspondingly, too in a subsequent query at P102, in which it is checked whether "carpet" is set, either with P103 the output "carpet" is set or at P103 'this output deleted.

There are further queries at P104 and P105 as to whether that Bit "missing floor" or bit "standstill" set is. If one of the two queries is true, then P106 'the corresponding output is set. Otherwise it will the output deleted at P106.

Finally, after going through a holding pattern P107 the program again on the program lower part P2 reset to the next pulse output.

The embodiment according to the invention is a method indicated which on the pulse-echo method based on the intensity of the reflected on floor coverings Ultrasound signals recorded and evaluated. By Evaluation finds a differentiation between hard floors, Carpets or missing floors instead. Likewise can get additional information from the echo signal about a standstill of the floor care device and whether this is lifted off the soil to be maintained become.

The use proves to be advantageous here of a sound channel, which is both the task of sound bundling as well as that of impedance matching. Due to the sound bundling inside the duct, a Blast into the half space on the one in front of the channel Half space between duct end and floor covering limited. Thus the required transmission power and the Reinforcement effort minimized. Through an expansion of the sound channel towards the end are both channel end reflections diminished by jumps in impedance as well an improved directional characteristic for sound radiation achieved.

By averaging and hysteresis in the Evaluation of the echo signal is the influence of the changing ground clearance is reduced.

By building up deep-pile carpets, it can occur that much of the total sound energy is absorbed and therefore no longer for evaluation reached. To counteract this can be further provided be the sensitivity to the detection of the Operating status for "missing floor" and "standstill" belittling.

A further improvement can be achieved by increasing the radiated sound energy can be achieved so that the proportion of reflected sound energy on such floors also increases and so an evaluable echo signal can be achieved.

A possibility is also conceivable, depending on whether no or only a very low echo signal is detected, to increase the radiated sound energy. This is For example, by additional impulses when the Ultrasonic transducer can be implemented. Once the echo amplitude is below a certain value or no echo signal is available at the next edition of the Impulses for the control of the ultrasonic transducer output additional impulses so that the emitted Sound energy is increased and the echo signal is evaluated can be. As soon as the echo signal returns exceeds a certain threshold, the number reset the output pulses.

All of the features disclosed are (in themselves) essential to the invention. In the disclosure of the registration is hereby also the disclosure content of the associated / attached Priority documents (copy of the pre-registration) in full included, also for the purpose of features of these documents in claims of the present application to include.

Claims (34)

Floor care device (1), such as, in particular, a vacuum cleaner, optionally with a motor-driven carpet brush (3), with an ultrasound floor detection, the floor detection having ultrasound transducers (8) acting as ultrasound transmitters (9) or ultrasound receivers (10) work, characterized in that the same ultrasonic transducer (8) works both as an ultrasonic transmitter (9) and as an ultrasonic receiver (10). Floor care device (1) according to the features of the preamble of claim 1, characterized in that at least one ultrasonic transducer (8) is arranged at a distance from an underbody (4) of the device (1) and that between the underbody (4) and the Ultrasonic transducer (8) a sound conduction channel (20) is formed. Floor care device according to one or more of the preceding claims or in particular according thereto, characterized in that the sound conduction channel (20) is designed as a hose. Floor care device according to one or more of the preceding claims or in particular according thereto, characterized in that the sound conduction channel (20) has a curved course. Floor maintenance device according to one or more of the preceding claims or in particular according thereto, characterized in that the sound conduction channel (20) has a length which, taking into account the speed of sound, corresponds at least to the ringing time of the ultrasound transducer (8). Floor maintenance device according to one or more of the preceding claims or in particular according thereto, characterized in that the length of the sound conduction channel is shorter than it corresponds to a path which the sound travels during a decay time. Floor care device according to one or more of the preceding claims or in particular according thereto, characterized in that the length of the sound conduction channel corresponds to 2 to 10 cm. Floor care device according to one or more of the preceding claims or in particular according thereto, characterized in that the ultrasound transducer (8) is arranged in the sound conduction channel (20). Floor maintenance device according to one or more of the preceding claims or in particular according thereto, characterized in that the sound conduction channel (20) ends on the underbody side at a distance of 0.5 to 1.5 cm from the floor (7) to be maintained. Floor maintenance device according to one or more of the preceding claims or in particular according thereto, characterized in that the distance between a suction nozzle and the floor (7) to be maintained can be changed as a function of the ultrasound detection. Floor care device according to one or more of the preceding claims or in particular according thereto, characterized in that the change in height is achieved by retracting and extending a bristle strip (6). Floor care device according to one or more of the preceding claims or in particular according thereto, characterized in that the size of a suction nozzle mouth can be changed as a function of the ultrasound signal. Floor maintenance device according to one or more of the preceding claims or in particular according thereto, characterized in that the drive for a carpet brush (3) can be switched as a function of the ultrasound signal. Floor care device according to one or more of the preceding claims or in particular according thereto, characterized in that the suction power can be regulated as a function of the ultrasound signal. Floor care device according to one or more of the preceding claims or in particular according thereto, characterized in that a piezo element is used as the ultrasonic transducer (8). Floor care device according to one or more of the preceding claims or in particular according thereto, characterized in that the ultrasound transducer (8) is acted upon by a switch (13) either by a pulse generator (12) or coupled to a pulse amplifier (14) is. Floor care device according to one or more of the preceding claims or in particular according thereto, characterized in that the ultrasound transducer (8) can be connected continuously both with a pulse generator (12) and with a pulse amplifier (14). Floor care device (1), in particular a vacuum cleaner with a suction channel having a suction mouth (5) and possibly a motor-driven carpet brush (3), with a center of gravity (Sp) of the device (1) in the direction of travel (r) behind the suction mouth (5), with an ultrasonic floor detection by means of an ultrasonic transmitter (9) and transducer (8), characterized in that an ultrasonic transmitter (9) and / or transducer (8) in the direction of travel (r) in front of the center of gravity (Sp) is arranged. Floor care device according to claim 18 or in particular according thereto, characterized in that an ultrasonic transmitter (9) and / or transducer (8) is arranged at the edge of the device (1). Floor care device according to one or more of claims 18 and 19 or in particular according thereto, characterized in that an ultrasonic transmitter (9) and / or transducer (8) in the direction of travel (r) behind a front edge (27) of the suction mouth (5) but before Center of gravity (Sp) is arranged. Floor care device according to one or more of claims 18 to 20 or in particular according thereto, characterized in that an ultrasonic transmitter (9) and / or transducer (8) is arranged opposite on both edge edges of the suction mouth (5). Floor care device according to one or more of claims 18 to 21 or in particular according thereto, characterized in that traversing wheels (26) are provided and in that the ultrasonic transmitters (9) and / or transducers (8) correspond to each other at a distance between the traversing wheels (26) Distance are arranged. Floor care device according to one or more of claims 18 to 22 or in particular according thereto, characterized in that two ultrasonic transmitters (9) and / or transducers (8) are arranged directly next to one another. Method for recognizing a floor condition, such as hard floor, carpet or missing floor, by means of ultrasound measurement in a floor care device (1), characterized in that the amplitude of the reflected sound is evaluated in order to detect the floor condition. A method according to claim 24 or in particular according thereto, characterized in that the amplitude of the reflected sound is compared with predetermined limit values. Method according to one or more of claims 24 and 25 or in particular according thereto, characterized in that only a repeated exceeding or falling below a limit value is used as a criterion for a change in the soil condition. Method according to one or more of claims 24 to 26 or in particular according thereto, characterized in that an averaging is carried out from a plurality of measured values before an evaluation. Method according to one or more of claims 24 to 27 or in particular according thereto, characterized in that an averaging is carried out from 5 or more measured values. Method according to one or more of claims 24 to 28 or in particular according thereto, characterized in that the evaluation of the ultrasonic signal is started before the decay time of the transmitted signal has elapsed. Method for aligning the movement of an automatic floor care device (1) such as, in particular, a vacuum cleaner along an edge (25) of a specific floor covering (7, 7 '), such as a carpet, whereby the floor covering (7, 7') is identified by means of ultrasound is carried out, characterized in that, depending on the detection of the change in the floor covering (7, 7 '), a change in direction with respect to the direction of travel (r) of the device (1) is carried out. Method according to claim 30 or in particular according thereto, characterized in that after a first change in the direction of travel (r), caused by a change in the floor covering (7, 7 '), the time until a further change in the floor covering (7, 7') ) is additionally recorded and the measure of the following change in direction is calculated depending on the recorded time. Method according to one or more of claims 30 and 31 or in particular according thereto, characterized in that the dimension of the first change in direction is more than 90 °. Method for aligning the movement of an automatic floor care device (1) such as, in particular, a vacuum cleaner along an edge (25) of a specific floor covering (7, 7 '), such as a carpet, whereby the floor covering (7, 7') is identified by means of ultrasound is carried out, characterized in that an average value is formed between the amplitude value of the detected first floor covering (7) and the amplitude value of the second floor covering (7 '), which is an edge (25) between the first and the second floor covering (7, 7') ) and that the direction of travel (r) of the device is changed until the stated mean value corresponds to the detected amplitude value in the course of the travel movement. Method for aligning the movement of an automatic floor care device (1) such as, in particular, a vacuum cleaner along an edge (25) of a specific floor covering (7, 7 '), such as a carpet, whereby the floor covering (7, 7') is identified by means of ultrasound is carried out, characterized in that two ultrasound transmitters (9) and / or transducers (8) arranged next to one another are provided.

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