WO2004058028A2

WO2004058028A2 - Mobile soil cultivation appliance

Info

Publication number: WO2004058028A2
Application number: PCT/EP2003/013364
Authority: WO
Inventors: Hendrik Rust; Harald Mayer; Markus Dünne
Original assignee: Alfred Kärcher Gmbh & Co. Kg
Priority date: 2002-12-23
Filing date: 2003-11-27
Publication date: 2004-07-15
Also published as: AU2003298144A1; DE10261787B3; DE10262191A1

Abstract

The invention relates to a mobile, automotive, self-steering soil cultivation appliance comprising a soil cultivation unit, a drive unit and a control unit which is coupled to the drive unit. A sensor device is associated with said control unit, said sensor device being used to differentiate the state of the soil surface before cultivation and the state of the soil surface after cultivation. The aim of the invention is to improve one such soil cultivation appliance such that the working time required for cultivating a soil surface can be reduced. To this end, the direction of travel of the soil cultivation appliance can be controlled by means of the control unit, according to the cultivation state of the soil surface detected by the sensor device, thus avoiding going over already cultivated soil surface areas.

Description

Mobile tillage device

The invention relates to a mobile tillage device for working a floor area, which is designed to be self-propelled and self-steering and has a tillage unit, a drive unit and a control unit, the control unit for controlling the direction of travel of the tillage device being connected to the work unit and the control unit being assigned a sensor device, by means of which the processing state of the floor surface before its processing can be distinguished from the processing state after its processing.

With the aid of such soil cultivation devices, a floor surface can be worked, in particular cleaned, without the use of an operator. The soil tillage implement is moved along the soil surface to be worked. For this purpose, it can be provided, for example, that the control unit can be given a course of travel direction along which the tillage implement moves. Such a soil cultivation device is known in the form of a mobile floor cleaning device from US Pat. No. 5,613,261. This comprises an optical sensor device with a light source, with the aid of which light radiation is directed onto the floor surface to be cleaned, and with the aid of a light-sensitive sensor element, light radiation reflected from the floor surface can be received and converted into an electrical signal. Since a cleaned floor surface has a different reflection behavior than an unpurified floor surface, an already cleaned floor surface area can be determined by the intensity of the reflected radiation an uncleaned floor area. In the floor cleaning device known from US Pat. No. 5,613,261, this gives the possibility of controlling the operation of the floor treatment unit as a function of the intensity of the reflected radiation, so that careful cleaning can be carried out in the case of a dirty floor surface, while with little or the soil cultivation unit can be switched off or switched to an operating mode with a lower cleaning quality. If the floor surface is particularly dirty, a back and forth movement of the floor cleaning device can also be caused. It can thus be achieved that less dirty floor surface areas are processed with less intensity than heavily soiled floor area areas, so that overall the working time for cleaning the entire floor area can be reduced.

However, it has been shown that even when using a floor cleaning device, as is known from US Pat. No. 5,613,261, a considerable amount of time is required to completely process a floor area.

The object of the present invention is to develop a mobile soil cultivation device of the type mentioned at the outset in such a way that the working time required for cultivating a floor area can be reduced.

This object is achieved according to the invention in a mobile tillage device of the generic type in that the direction of travel of the tillage device depends on the processing state of the Sensor device detected floor area is controllable by means of the control unit, overrunning already processed floor area areas can be avoided. It has been shown that with such a configuration of the soil cultivation device, the working time required for cultivating a floor area can be considerably reduced. For this purpose, the control unit has a control algorithm which ensures that floor surface areas which have already been processed are not run over a second time if possible. Rather, a segmentation of the floor area to be worked can be achieved in such a way that individual floor area segments are cleaned one after the other and the soil cultivating device is, if possible, not moved over previously processed floor area areas and leaves an already processed floor area area within the shortest possible time. For example, it can be provided that the control unit provides a control signal to activate a change in the direction of travel by a predetermined angle, for example by 90 °, when an already processed floor area area is reached.

It is particularly advantageous if, by means of the sensor device, a border area between an already processed floor area area and a not yet processed floor area area can be detected and the tillage implement can be moved automatically along the border area. For example, it can be provided that the tillage implement can be automatically aligned parallel to the border line and moved along the border when a border line between an already processed floor area area and a not yet processed floor area area is reached.

In a particularly preferred embodiment it is provided that by means of the sensor device the processing states of two soil surface areas offset from one another transversely to a main direction of movement of the soil cultivation device can be detected and that the direction of travel of the soil cultivation device can be controlled as a function of the processing states of the two detected soil surface areas. Such a configuration of the soil cultivation device enables the soil cultivation device to be moved in a structurally simple manner along a boundary line between an already processed and a not yet processed soil surface area.

In order to use the sensor device to detect two floor surface areas that are offset from one another transversely to a main direction of movement of the soil cultivation device, it can be provided that the sensor device detects the two floor surface areas alternately and relates the respectively recorded processing states to one another. In this case, the sensor device can have an areally extended sensor element which enables a location-dependent detection of the processing states of the two floor surface areas.

The sensor device can have a single sensor element, which is preferably extended in terms of area and with which the processing state of a floor surface area can be detected.

It is advantageous if the sensor device comprises at least two sensor elements, each of which processes the processing state of one of the two transversely

Detect the main direction of movement of the tillage implement offset areas of the surface of the floor and each provide a corresponding sensor signal and if the direction of travel of the tillage implement can be controlled depending on the two sensor signals.

The assembly and, if necessary, a repair of the sensor device can be simplified in that the two sensor elements can be handled independently. Here, the two sensor elements are designed as independent components, each of which transmits a sensor signal to the control device, by means of which the control unit can assess the processing state of the area of the floor area detected by the respective sensor element.

The tillage unit preferably extends transversely to the main direction of movement of the tillage device, and by means of the sensor device the tillage states can be detected from the two floor surface areas, each of which is arranged adjacent to an end area of the tillage unit with respect to its extension transverse to the main direction of movement. In such an embodiment of the soil cultivation device according to the invention, the soil cultivation unit extends between the two soil surface areas detected by the sensor device, so that in each case a portion of the soil surface is worked which extends between the two soil surface areas which have a different processing state. The tillage unit preferably comprises a cleaning unit and the degree of soiling of the floor surface can be determined by means of the sensor device. This makes it possible to clean a floor surface within a short time, for example sweeping, vacuuming or wiping.

It can be provided, for example, that the cleaning unit has a sweeping brush arrangement extending transversely to the main direction of movement of the soil cultivation device and that the degree of soiling of the floor surface areas cleaned or to be cleaned by an end region of the sweeping brush arrangement can be detected by means of the sensor device.

The sweeping brush arrangement can in this case have a plurality of sweeping brushes which are arranged offset from one another transversely to the main direction of movement of the tillage implement, each of the sweeping brushes preferably being assigned a sensor element which detects the degree of soiling of the respective cleaned or cleaned floor area region.

In an embodiment which can be produced at low cost, it is provided that the sweeping brush arrangement has a rotatable brush roller, the axis of rotation of which is preferably oriented transversely to the main direction of movement of the tillage implement.

In a preferred embodiment, a separate sensor element, which detects the degree of contamination of the floor surface, is assigned to an end region of the sweeping brush arrangement. The sensor element can do this respective end region of the sweeping brush arrangement can be arranged directly adjacent.

It is advantageous if the cleaning action of the sweeping brush arrangement is supported by a suction unit which generates a suction flow in the area of the sweeping brush arrangement. For this purpose, it can be provided that the cleaning unit has a suction unit which is in flow communication with the sweeping brush arrangement via at least one suction channel, the suction channel receiving a dirt collecting container, and the sensor arrangement can be arranged on a wall of the suction channel or the dirt collecting container.

It is advantageous here if at least one sensor element of the sensor arrangement is arranged on the inside on the wall of the suction channel or of the dirt collecting container. Such an arrangement of the at least one sensor element makes it possible to directly apply the dirt particles to the sensor element, which are detached from the floor area to be cleaned by the respectively assigned end region of the sweeping brush arrangement. The degree of contamination can be determined in a simple manner by detecting the amount of dirt particles acting on the respective sensor element.

Alternatively and / or in addition, it can be provided that at least one sensor element of the sensor arrangement is arranged on the outside on the wall of the suction channel or of the dirt collecting container. The sensor element is there protected from direct exposure to dirt particles so that the life of the sensor element can be increased.

To detect the processing state, in particular the degree of soiling of the floor surface, it can be provided that the sensor device mechanically detects the floor surface, for example by means of tactile sensors. However, it is particularly advantageous if the sensor device detects the processing state of the floor surface without contact.

The sensor device preferably comprises at least one optical sensor element, ie a sensor element with a radiation-sensitive, in particular spatially resolving detector and evaluation electronics assigned to the detector. Imaging optics can be arranged upstream of the detector, and image evaluation can be carried out by means of the evaluation electronics. A predetermined image evaluation algorithm can be used to evaluate an image of a section of the floor surface projected onto the radiation-sensitive detector such that the processing state of the floor surface can be detected. For example, the degree of contamination of the floor surface can be recorded without contact. The soil tillage condition can be optically recorded, for example, by means of infrared radiation or also by means of visible light radiation. A radiation source, for example a light source, can be assigned to the sensor element in order to illuminate the bottom surface area detected by the sensor element. It is expedient if the processing state of the floor surface can be determined on the basis of the intensity of a light radiation reflected from the floor surface.

It is particularly favorable if the sensor device has at least one piezoelectric sensor element. Such sensor elements are known, for example, from European patent EP 0 759 157 B1. If such sensors are subjected to a mechanical force, they provide an electrical signal on their surface. The application of force can take place in that the sensor elements are directly exposed to dirt particles which are detached from the floor surface to be cleaned. However, it can also be provided that the at least one piezoelectric sensor element interacts with the wall of the suction channel or the dirt collecting container and absorbs the vibrations of the wall caused by the dirt particles and converts them into an electrical signal. Shocks to the wall, which are caused by the movement of the tillage implement, can be filtered out by means of an electrical filter unit arranged downstream of the sensor element.

In a particularly preferred embodiment of the soil cultivation device according to the invention, dirt particles can be detached from the floor surface by means of the cleaning unit and the amount of detached dirt particles can be determined by means of the sensor device. As already mentioned, the degree of contamination of the floor surface can be deduced from the amount of detached dirt particles.

Preferably, not only the amount of detached dirt particles can be determined by means of the sensor device, but also their size can be determined. Such a range of sizes not only enables a statement to be made about the absolute degree of contamination of the floor surface, but also gives information an indication of what type of pollution is present. This enables the cleaning mode to be selected depending on the type of contamination of the floor surface, for example the mode of operation of the cleaning unit and / or the driving speed of the soil cultivation device can be matched to the type of contamination.

As already explained, it is expedient if the operation of the soil cultivation unit, for example the cleaning unit, can be controlled by means of the sensor device as a function of the cultivation state of the soil surface, in particular the degree of contamination of the soil surface. For example, it can be provided that the cleaning unit is switched off or switched to an operating mode with low energy consumption (stand-by operating mode) when the level of soiling is low, while an energy-intensive operating mode of the cleaning unit is selected in the case of a high degree of contamination.

A particularly short working time for processing, in particular cleaning a floor area, can be achieved in that the control unit can be provided with a position-dependent reference value for the processing status, for example the degree of contamination, of the floor area after optimal processing and that the current processing status is comparable with the reference value, the direction of travel and / or the driving speed of the tillage device and / or the mode of operation of the tillage unit can be controlled as a function of the deviation of the current tillage condition from the reference value. With such a configuration of the soil tillage implement according to the invention, before it actual work assignment or during a first work assignment, a learning trip with a defined tillage condition, for example with an optimally cleaned floor area. During the learning trip, the processing status, e.g. B. the degree of pollution, the floor area can be stored in a memory element of the control unit as a reference value. These reference values with an optimally processed floor area can then be used for comparison with the respective current processing state. If it is determined that the current cultivation state is worse than the reference value determined during the learning run of the soil cultivation device, an operating mode of the soil cultivation unit is activated and the soil surface is processed. However, if it is determined that no cultivation is required in a certain floor surface segment, since there is only a relatively small deviation of the current processing state from the specified reference value, the soil cultivation unit can be switched off or switched to a stand-by operating mode, and this floor surface segment can be operated with a higher one Driving speed are exceeded and / or a change in direction of travel can be carried out in order to reach a floor surface segment which requires processing, for example cleaning, within the shortest possible time.

In a particularly preferred embodiment of the soil cultivation device according to the invention, the time of the last cultivation of the floor area of the control unit can be specified and the direction of travel and / or the driving speed of the soil cultivation device and / or the mode of operation of the soil cultivation unit are dependent on the time period controllable that has passed since the last processing. The time of the last processing can be specified depending on the position, so that individual floor surface segments can be processed with different frequencies. For example, in the case of floor surface cleaning, it can be provided that corridor areas or areas of the floor area that are exposed to heavy public traffic are subjected to intensive cleaning by means of the soil cultivation device after a shorter period of time than floor surface segments that are used only little.

It is advantageous here if the control unit comprises a timing element coupled to a storage element for automatic storage of the time of the current tillage. A manual specification of the time of tillage can be omitted. The timing element can include a date, so that by means of the mobile tillage device, different modes of operation of the tillage unit and / or different course of travel can be used to control the tillage device depending on the date. For example, in the case of a mobile floor cleaning device, comprehensive cleaning of the entire floor area is carried out on working days with public traffic, while on working days without public traffic only a partial cleaning of the floor area is carried out and cleaning of the floor area is completely omitted on Sundays and public holidays ,

It is particularly expedient if the control unit can be used to carry out automatic, time-dependent navigation planning in such a way that the control unit is based on the degree of contamination of the floor area in each case. before automatically optimizing the required operating parameters of the cleaning unit and / or the frequency of the cleaning cycles, with the aim of cleaning a floor surface within the shortest possible time with the least possible energy expenditure.

It is advantageous if the control unit is assigned a distance sensor for determining a lateral distance between the tillage implement and an obstacle, and if the direction of travel and / or the driving speed of the tillage implement and / or the mode of operation of the cleaning unit is dependent on the distance of the tillage implement from the obstacle are controllable. Such a configuration makes it possible to move the soil cultivation device automatically along an obstacle, for example along a wall or a step.

The following description of a preferred embodiment of the invention serves in conjunction with the drawing for a more detailed explanation. Show it:

Figure 1 is a schematic side view of a soil tillage implement according to the invention;

Figure 2 is a schematic bottom view of the soil tillage implement;

Figure 3 is a longitudinal sectional view of the soil tillage implement; FIG. 4: a functional diagram of a program sequence for controlling the direction of travel of the tillage implement; and

Figure 5: an illustration of the direction of travel of the floor cleaning device when cleaning a floor surface.

1 to 3 schematically show a soil cultivation device according to the invention in the form of a floor cleaning device, which is generally designated by reference number 10. It comprises a base plate 12, on which a cover 13 is placed and which is fixed to a chassis 14. Two drive wheels 16, 17 are rotatably mounted on the chassis 14 about a common axis of rotation 15, each of which is assigned a drive motor 18 or 19. The drive motors 18, 19 are held on the chassis 14 and are in electrical connection via connecting lines (not shown in the drawing) to a control unit 20 arranged on a cover plate 21 and to known electric batteries (not shown in the drawing).

The base plate 12 has a dirt inlet opening 22, on which a brush roller 26, which is aligned transversely to the main direction of movement 24 of the floor cleaning device, is arranged. The brush roller 26 is rotatably held in the region of the dirt inlet opening 22 and has a multiplicity of radially oriented brushes 27 which are fixed to a shaft 28 and which project with their free ends downward over the dirt inlet opening 22. The bottom plate 12 and the cover plate 21 define between them a suction channel 30 which is in flow connection with the dirt inlet opening 22 stands and carries at its rear end facing away from the dirt inlet opening 22 an intake port 32 on which a suction turbine 34 is held. The suction turbine 34 can be driven in rotation by an electric drive motor 36 and is in flow connection with the dirt inlet opening 22 via the suction nozzle 32 and the suction channel 30.

A dirt filter 38 is arranged within the suction channel 30, and the area of the suction channel 32 between the dirt filter 38 and the dirt inlet opening 22 forms a dirt collecting container 40, the fill level of which is monitored by a fill level sensor 42 which is in electrical connection with the control unit 20. To clean a bottom surface 44, the suction turbine generates a suction flow, illustrated by arrows 46 in FIG. 3, with the aid of which dirt particles, which have been detached from the bottom surface 44 to be cleaned due to the mechanical action of the brush roller 26, pass through the dirt inlet opening 22 into the dirt collecting container 40 can be transferred.

The drive wheels 16, 17, in combination with the drive motors 18 and 19, form a drive unit for moving the floor cleaning device 10 along the bottom surface 44, and the brush roller 26 forms a cleaning unit for cleaning the bottom surface 44, the dirt pickup achievable by means of the brush roller 26 being achieved by the of the suction turbine 34 induced suction flow 46 is supported.

The brush roller 26 is aligned perpendicular to the main direction of movement 24, and are each assigned to an end region of the brush roller 26 two dirt sensors 50, 51 of the brush roller 26 are arranged facing a dirt-trap threshold 48 on the rear delimiting the dirt inlet opening 22. They are each electrically connected to the control unit 20 via a signal line 54 and are directly acted upon by the dirt particles which are detached from the bottom surface 44 by means of the respective end regions of the brush roller 26. In the exemplary embodiment shown, they are designed in the form of piezoelectric sensors which, depending on the number and the mass of the dirt particles hitting them, transmit a corresponding sensor signal to the control unit 20 via the signal lines 54. By means of the two dirt sensors 50 and 51, the degree of soiling of the bottom surface area, which is arranged at the level of the respective end area of the brush roller 26, can thus be detected. The two dirt sensors 50 and 51 are arranged at a distance from one another and are positioned perpendicular to the main direction of movement 24, that is to say parallel to the common axis of rotation 15 of the two drive wheels 16 and 17. In their entirety, the two dirt sensors 50 and 51 form a sensor device of the floor cleaning device 10, wherein the degree of soiling of the floor surface 44 can be detected simultaneously in two different areas with the aid of the sensor device. If the two dirt sensors 50 and 51 are only exposed to a relatively small number of dirt particles, this is interpreted by the control unit 20 in such a way that the floor surface areas detected by the two dirt sensors 50 and 51 have already been cleaned. If instead there is a high accumulation of dirt particles, this is interpreted by the control unit 20 in such a way that an uncleaned area of the floor surface is detected by the two dirt sensors 50 and 51.

If the sensor signals provided by the two dirt sensors 50 and 51 of the control unit 20 differ from one another, this is interpreted by the control unit 20 in such a way that one of the two dirt sensors detects an already cleaned floor area area and the other dirt sensor detects an unpurified floor area area, that is to say that the floor cleaning device 10 is currently moving along a boundary line between an already cleaned floor area and a still unpurified floor area. Different sensor signals from the two dirt sensors 50 and 51 enable the control unit 20 to control the drive motors 18 and 19 of the drive wheels 16 and 17 in such a way that the floor cleaning device 10 follows such a boundary line. A resulting course of travel direction when cleaning a floor surface is described in more detail below with reference to FIGS. 4 and 5.

First of all, however, it should be pointed out that the positioning of the two dirt sensors 50 and 51 does not necessarily have to take place in the region of the sweeping threshold 48. For the embodiment shown, it is only important that the two dirt sensors 50 and 51 are arranged offset to one another transversely to the main direction of movement 24 and that the number of dirt particles occurring detected by the dirt sensors gives an indication of the respective degree of contamination, which is related to the main direction of movement 24 in the area the dirt sensors are present. In particular, it can be provided that the dirt sensors 50 and 51 are arranged outside the suction channel 30 on the wall thereof. Such a position tioning is shown in Figure 3 using the example of a piezoelectric dirt sensor with the reference numeral 56. The mechanical shocks that are caused by the dirt particles on impact with the wall of the suction channel 30 can be detected by the dirt sensor 56.

As already explained, by means of the two dirt sensors 50 and 51, the processing state of the floor surface 44, namely its degree of soiling, can be detected on two floor surface areas arranged at a distance from one another and offset transversely to the main direction of movement 24. This enables the floor area 44 to be run over completely within a short time, wherein already cleaned floor area areas are not run over a second time if possible. Such a second running over of cleaned floor surface areas is only necessary if either an unsatisfactory cleaning result was achieved during the first cleaning or if an already cleaned floor area area is to be left again.

The control of the direction of travel by means of the control unit 20 as a function of the degree of soiling, which is detected by the two dirt sensors 50 and 51, enables the base surface 44 to be segmented, individual segments of the base surface being cleaned in succession. For this purpose, a control algorithm such as that illustrated in FIGS. 4 and 5 is used for the floor cleaning device 10 for the control unit 20. After the floor cleaning device 10 has been started, it is moved in a straight direction by means of the control unit 20 and at the same time the floor surface which has been driven over is cleaned using the suction turbine 34 and the brush roller 26. By means of Known and therefore not shown in the drawing collision detectors that are connected to the control unit 20, a collision of the floor cleaning device 10 with an obstacle can be detected. If, for example, there is a collision with a room wall 63, the floor cleaning device 10 changes the direction of travel by the control unit 20 generating a control command for rotating the floor cleaning device 10 to the left by a fixed angle, for example by 90 °, or also by a random angle to align the floor cleaning device 10 parallel to the obstacle, that is to say parallel to the room wall 63 in the exemplary embodiment shown. The travel of the floor cleaning device 10 is then continued in the direction of travel then assumed until either a new collision occurs and a corresponding change in direction of travel is carried out, or until an already cleaned area of the floor surface, that is to say a dirt edge, is detected by the dirt sensors 50 and 51. In the course of the travel direction shown in FIG. 5, the first time a dirt edge is reached by the floor area 65 is illustrated. If such a dirt edge is detected, the control unit 20 generates a command to change the direction of travel, the floor cleaning device 10 aligning itself parallel to the dirt edge. Then the floor cleaning device continues to travel in a straight direction until either a new dirt edge is detected or an obstacle appears in order to then change the direction and direction of the floor cleaning device again parallel to the obstacle or parallel to the dirt edge. The journey is then continued until an uncleaned area of the floor surface can no longer be reached without passing over a dirt edge. In the direction of travel illustrated in FIG. 5, this is on the point 67 of the bottom surface 44 is the case. Since, in such a positioning, the floor treatment device can no longer clean an uncleaned floor area without exceeding a dirt edge, the control unit 20 generates a command to drive over an already cleaned floor area area, so that the floor cleaning device 10 moves out of the cleaned floor area segment. To this end, the control unit 20 can be given a specific direction command, alternatively it can be provided that the control unit 20 causes the floor cleaning device 10 to rotate by a random angle.

The drive over the area of the floor area that has just been cleaned is then continued in a straight direction until a new collision with an obstacle, for example with the room wall 69 shown in FIG. 5, occurs, and the floor cleaning device 10 is then moved again in the manner explained above, wherein the floor cleaning device 10 is aligned parallel to a room wall or parallel to a dirt edge until a new segment of the floor surface 44 is completely cleaned.

The essentially spiral or meandering movement continues until no more uncleaned bottom surface segment can be detected. In the course of the travel direction shown in FIG. 5, this is the case at point 71 of the floor surface 44. The cleaning run of the floor cleaning device 10 is then ended. In order to simplify the travel of the floor cleaning device 10 along an obstacle, the floor cleaning device 10 has, arranged on the top of the cover 13, side-facing distance sensors 73, which can be configured, for example, as infrared or ultrasonic sensors and are known per se to the person skilled in the art. The distance sensors 73 can be used to drive at a constant distance from an obstacle.

From the foregoing it becomes clear that a floor surface 44 to be cleaned can be completely cleaned within a short time by means of the floor cleaning device 10 according to the invention, where possible cleaned areas are not run over a second time. As a result, the working time for cleaning the floor surface 44 can be considerably reduced.

In order to be able to additionally accelerate the cleaning of the floor surface 44, the control unit 20 of the floor cleaning device 10 includes a memory element 75 and a timer element 77. After an optimal cleaning of the floor surface 10, the degree of contamination that occurs as a function of the position, depending on the position, during a learning trip two dirt sensors 50 and 51 are detected, can be stored as reference values.

During a cleaning run of the floor cleaning device 10, as illustrated in FIG. 5, the stored, position-dependent reference values are compared with the current degrees of contamination of the floor surface 44. If the control unit 20 determines that there is only a slight deviation between the current levels of contamination and the reference values, it increases the driving speed of the floor cleaning device 10 and controls both the suction turbine 34 and an electric motor used for rotating the brush roller 26 in such a way that they pass into an energy-saving stand-by operating mode. If, on the other hand, the control unit 20 determines that the current degrees of soiling have a deviation from the stored reference values that exceed a predetermined tolerance value, the suction turbine 34 and the electric motor of the brush roller 26 are activated to full power, and at the same time the driving speed of the floor cleaning device 10 is reduced , Floor areas that do not require cleaning can thus be run over at excessive speed and at the same time the energy consumption of the floor cleaning device 10 can be considerably reduced.

The time of the respective cleaning of the bottom surface 44 is stored in the memory element 75, and when the bottom surface 44 is cleaned again, the time elapsed since the last cleaning is determined by the control unit 20. Depending on the length of the time span, the cleaning run is then carried out at increased or reduced driving speed. In addition, it can be provided that after a predetermined period of time, the control unit 20 automatically activates the cleaning run of the floor cleaning device 10 without an external start signal.

Claims

1.Mobile soil cultivation device for cultivating a floor area, which is designed to be self-propelled and self-steering and has a soil cultivation unit, a drive unit and a control unit, the control unit for controlling the direction of travel of the soil cultivation device being connected to the drive unit and the control unit being assigned a sensor device by means of which the processing state of the floor surface prior to its processing can be distinguished from the processing state after its processing, characterized in that the direction of travel of the soil cultivation device (10) can be controlled by the control unit (20) depending on the processing state of the floor surface detected by the sensor device (50, 51), driving over already processed floor surface areas can be avoided.

2. Soil cultivation device according to claim 1, characterized in that by means of the sensor device (50, 51) the processing states of two transverse to a main direction of movement (24) of the soil cultivation device (10) offset from each other surface area areas can be detected and that the direction of travel of the tillage device (10) in Dependent on the processing states of the two recorded floor area areas is controllable.

3. Soil cultivation device according to claim 1 or 2, characterized in that the soil cultivation device (10) can be moved automatically along a boundary between a processed floor area and an unprocessed floor area.

4. Soil cultivation device according to claim 1 or 2, characterized in that the sensor device comprises two sensor elements (50, 51), each of which detects the processing state of one of the two transverse to the main direction of movement (24) of the soil cultivation device (10) offset from each other and each one provide the appropriate sensor signal and that the direction of travel can be controlled as a function of the two sensor signals.

5. Soil cultivation device according to claim 3, characterized in that the two sensor elements (50, 51) can be handled independently.

6. Soil cultivation device according to one of the preceding claims, characterized in that the tillage unit (26) extends transversely to the main direction of movement (24) of the tillage device (10) and that by means of the sensor device (50, 51) the cultivation states of the two floor surface areas can be detected, each of which is arranged adjacent to an end region of the tillage unit (26) with respect to its extension transverse to the main direction of movement (24).

7. Soil cultivation device according to one of the preceding claims, characterized in that the tillage unit comprises a cleaning unit (26) and that by means of the sensor device (50, 51) the degree of contamination of the floor surface (44) can be detected.

8. Soil cultivation device according to claim 6, characterized in that the cleaning unit has a transverse to the main direction of movement (24) of the tillage device (10) extending sweeping brush arrangement (26) and that by means of the sensor device (50, 51) the degree of contamination of each of an end region Sweeping brush arrangement (26) cleaned or to be cleaned floor surface areas can be detected.

9. Soil cultivation device according to claim 7, characterized in that the sweeping brush arrangement has a rotatable brush roller (26).

10. Soil cultivation device according to claim 7 or 8, characterized in that in each case an end region of the sweeping brush arrangement (26) is assigned a separate sensor element (50, 51) detecting the degree of contamination of the floor surface.

11. Soil cultivation device according to claim 7, 8 or 9, characterized in that the cleaning unit has a suction unit (34) which is in flow connection with the sweeping brush arrangement (26) via at least one suction channel (30), the suction channel (30) being a dirt collecting container (40) and that the sensor arrangement

(50, 51) is arranged on a wall (48) of the suction channel (30) or the dirt collecting container (40).

12. Soil cultivation device according to claim 10, characterized in that at least one sensor element (50, 51) of the sensor arrangement on the inside on the wall (48) of the suction channel (30) or the dirt collecting container (40) is arranged.

13. Soil cultivation device according to claim 10, characterized in that at least one sensor element (56) of the sensor arrangement is arranged on the outside on the wall of the suction channel (30) or the dirt collecting container (40).

14. Soil cultivation device according to one of the preceding claims, characterized in that the sensor device (50, 51) detects the processing state of the floor surface (44) without contact.

15. Soil cultivation device according to one of the preceding claims, characterized in that the sensor device has at least one piezoelectric sensor element (50, 51).

16. Soil cultivation device according to one of claims 6 to 14, characterized in that by means of the cleaning unit (26) from the bottom surface (44) dirt particles can be detached and the amount of detached dirt particles can be determined by means of the sensor device (50, 51).

17. Soil cultivation device according to claim 15, characterized in that the size of the detached dirt particles can be determined by means of the sensor device (50, 51).

18. Soil cultivation device according to one of the preceding claims, characterized in that by means of the control unit (20) the operation of the soil cultivation unit (26) is controllable in dependence on the processing state of the floor surface (44).

19. Soil cultivation device according to one of the preceding claims, characterized in that the control unit (20) position-dependent reference values of the processing state of the floor surface (44) can be provided after optimal processing and that the current position-dependent processing state is comparable to the reference values, the direction of travel and / or the driving speed of the tillage device (10) and / or the mode of operation of the tillage unit (26) can be controlled as a function of the deviation of the current tillage state from the reference value.

20. Soil cultivation device according to one of the preceding claims, characterized in that the control unit (20) the time of the last cultivation of the floor surface (44) can be predetermined and that the direction of travel and / or the driving speed of the soil cultivation device (10) and / or the mode of operation of the tillage

unit (26) is controllable depending on the amount of time that has elapsed since the last processing.

21. Soil cultivation device according to claim 19, characterized in that the control unit (20) comprises a timing element coupled to a storage element for automatically storing the time of the current tillage operation.

22. Soil cultivation device according to one of the preceding claims, characterized in that the control unit (20) is assigned a distance sensor (73) for determining a lateral distance between the tillage device and an obstacle (63, 69), and that the direction of travel and / or the Driving speed of the tillage device (10) and / or the mode of operation of the tillage unit (26) depending on the distance of the tillage device (10) from the obstacle (63, 69) can be controlled.