Automatically traveling floor cleaning appliance and method for operating a floor cleaning appliance

Abstract

An automatically traveling floor cleaning appliance during travel is capable of traveling over low obstacles extending lengthwise, typically represented by a carpet border, having an upwardly inclined obstructing surface, with a direction of travel at a right or acute angle with respect to a longitudinal extent of the obstacle. The appliance also has an obstacle detector. The appliance is formed so that the obstacle or an area adjoining same may be cleaned using a procedure in which the appliance assumes a direction of travel based on the extent of the obstacle, and with regard to the obstructing surface includes traveling on a floor area in front of the obstacle, and at a lateral distance of an associated boundary edge of the appliance in the direction of travel from the obstructing surface which is smaller than that corresponding to a width of the appliance perpendicular to the direction of travel.

Claims

1. A method for operating an automatically traveling floor cleaning apparatus, and for cleaning a carpet boarder surface, comprising: providing said appliance having a housing with a housing boundary edge and wheels, and the housing is adapted to travel over an obstacle, wherein the obstacle has a border with an upwardly inclined obstacle surface, wherein the upwardly inclined obstacle surface is the carpet border surface, wherein the appliance travels in a first direction of travel of the appliance which is at a right angle or at an acute angle with respect to an extension of the carpet border surface, and in addition the floor cleaning appliance does have a brush and means for detecting the obstacle, said appliance detecting the obstacle; wherein after the obstacle is detected by the floor cleaning appliance, the first direction of travel of the floor cleaning appliance is changed in such a way that the floor cleaning appliance travels along the carpet border surface in a second direction of travel which is aligned extending substantially parallel to the carpet border surface, wherein there is distance between the housing boundary edge of the appliance and the carpet border surface as the appliance travels in the second direction of travel, and wherein the distance is smaller than a width of the appliance perpendicular to the second direction of travel, and wherein the floor cleaning appliance travels in such a way that the brush achieves a cleaning of the carpet border surface without the appliance traversing the obstacle and in such a way that an end face of the brush is associated with an edge of the obstacle and travels in contact or overlap with the edge of the obstacle; detecting the carpet border surface with a floor sensor, the floor sensor detecting a change in a vertical height of a floor travelled over, wherein the carpet border surface is detected without the wheels of the appliance being on the obstacle; and wherein the cleaning of the carpet border surface occurs when the floor cleaning appliance is traveling in the second direction; and wherein the cleaning of the carpet border surface is performed without traversing the obstacle; and wherein the appliance travels in the second direction multiple times along the edge of the low obstacle with different distances from the housing boundary edge to the edge of the obstacle, one time of the multiple times with the housing boundary edge not overlapping with the edge of the obstacle, and another time of the multiple times with the housing boundary edge having the floor sensor overlapping with the edge of the obstacle, but without the wheels of the appliance being on the obstacle.

2. The method according to claim 1, wherein the floor cleaning appliance has a wall-following sensor and wherein if a signal of the floor sensor but not of the wall-following sensor is detected, it is assessed that an obstacle is present which may be traveled over but not a border which transitions into a wall is present.

3. The method according to claim 1, wherein said cleaning appliance has a bristle reaching over the housing boundary edge of the appliance.

4. The method according to claim 1, wherein as long as the floor sensor overlaps an adjacent area of the carpet border surface, the floor cleaning apparatus travels in a path curving away from the carpet border surface and each time the floor sensor no longer overlaps the adjacent area of the carpet border surface, the floor cleaning apparatus moves back toward the carpet border surface.

5. The method according to claim 1, wherein the appliance detects reaching or traveling over the obstacle by means of the floor sensor based on a change in a distance from the floor.

6. The method according to claim 1, wherein a motor current consumption of a corner cleaning brush is used for detecting the obstacle.

7. The method according to claim 1, wherein a signal of a tactile sensor is used for detecting the obstacle.

8. The method according to claim 1, wherein the brush of the floor cleaning appliance is a corner cleaning brush with bristles which extend beyond a housing plan view contour, during rotation of the corner cleaning brush, and wherein the contour extends straight in a traveling direction and wherein reaching or traveling over the obstacle is detected based on a change in a motor current of an electric motor which drives the corner cleaning brush.

9. The method according to claim 5, wherein the floor sensor is a sensor which operates in a contactless manner.

10. The method according to claim 5, wherein the floor sensor is formed as a contact sensor, and wherein reaching or traveling over the obstacle is detected by the contact sensor.

11. The method according to claim 5, wherein the floor sensor of the floor cleaning appliance is a wall-following sensor, and wherein reaching or traveling over the obstacle is detected based on an evaluation of a signal of the wall-following sensor.

12. The method according to claim 5, wherein the floor cleaning appliance has a housing, having a housing contour based on a top view, with a first wheel having a running surface, and has a first cleaning brush which has a longitudinal axis, and the longitudinal axis of the first cleaning brush is within the housing contour, and wherein the first wheel and the first cleaning brush are situated within the housing contour, such that an end face of the first cleaning brush extends past the first wheel in a direction toward an edge of the housing contour and wherein the floor sensor, based on the same top view, is situated in a sector of the housing contour between the end face of the first cleaning brush and the edge of the housing contour which sector is delimited by the longitudinal axis of the first cleaning brush and a perpendicular with respect to a geometric axis, the perpendicular extending directly outside the running surface on a side of the running surface facing a boundary edge of the housing; and wherein the floor sensor is facing vertically to the floor for measuring the height of the floor below the floor sensor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is explained in greater detail below with reference to the accompanying drawings, which, however, illustrate only one exemplary embodiment. The drawings show the following:

(2) FIG. 1 shows an automatically traveling cleaning appliance during travel along a carpet border;

(3) FIG. 2 shows an illustration corresponding to FIG. 1, with an illustration of the arrangement of the wheel and the disk brush in relation to a housing boundary edge; and

(4) FIG. 3 shows a bottom view of the floor cleaning appliance corresponding to FIG. 1 and FIG. 2, with a possible association of a carpet border during travel.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(5) An automatically traveling floor cleaning appliance 1 is illustrated and described.

(6) This floor cleaning appliance, as shown in particular in conjunction with FIG. 3, has two wheels 2, 3, which in the exemplary embodiment are preferably each individually driven.

(7) In addition, the floor cleaning appliance 1 has a cleaning brush 4 which rotates about a substantially horizontal axis, as well as a corner cleaning brush 5 which rotates about a substantially vertical axis, and which in the exemplary embodiment is preferably formed as a disk brush.

(8) The housing 6 is discernible in a top view of the apparatus (specifically, the bottom view being shown in FIG. 3), it being apparent that the boundary edge of the housing (now once again with reference to FIG. 3) essentially comprises a rectangular portion 7 and a circular portion 8. In the exemplary embodiment, the rectangular portion 7 is also formed with a slightly smaller width than the following adjoining circular portion, the circular portion 8 also having a linearly extending portion 9 which is associated with the rectangular portion 7.

(9) In addition, the floor cleaning appliance has a microprocessor and associated electronic memories, not illustrated in detail, as well as a control device and a control program in which traversal routines are stored, or which are creatable or changeable based on measured or detected parameters.

(10) For detecting a space in which the floor cleaning appliance 1 moves, the floor cleaning appliance has a contactless scanning device, in the exemplary embodiment accommodated in the cover portion 10. In this regard, reference is also made to the prior art mentioned at the outset.

(11) FIG. 1 illustrates a typical traveling situation of the floor cleaning appliance 1.

(12) The floor cleaning appliance 1 initially travels in the illustrated room 11 along a wall 12, for example, whereby the original direction of travel V illustrated here in dashed lines comes about. In the process, the floor cleaning appliance 1 travels over a carpet 13, which has a carpet border 14 as a lengthwise-extending obstacle. In this ease, the carpet border 14 also stands for an upwardly inclined obstructing surface in general terms.

(13) As the result of detection by sensor, optionally also by the detection by scanning, as described, the floor cleaning appliance 1 may determine the course of the carpet border 14 relative to the original direction of travel V of the floor cleaning appliance. When this particular cleaning mode is in any case selected, which may be optional but which may also be provided as a fixed routine, the floor cleaning appliance makes one or more cleaning passes in a direction of travel R which is aligned extending substantially parallel to the carpet border 14.

(14) In this regard, the travel of the appliance is carried out in particular in such a way that the appliance travels at a distance of an obstructing surface in the direction of travel, in the present case the carpet border 14, for example, from an associated boundary edge of the appliance 1 in the direction of travel that is smaller than that corresponding to a width b of the appliance. This serves in particular to clean the surface in front of the obstacle without making contact with the obstacle. This distance may also be successively reduced, optionally in a plurality of passes. The distance may in particular also be smaller than that corresponding to the mentioned width b, for example up to one-hundredth of the mentioned width, or may even extend to a mode of operation in which the appliance comes into contact with the obstacle.

(15) In addition, the distance of a boundary edge, in the exemplary embodiment in particular a housing edge portion 9 or optionally 15 (compare to FIG. 3) from the carpet border 14, optionally also overlapping with the carpet border 14, may be selected in such a way that a corner cleaning brush 5, if such is provided (as also illustrated in FIGS. 1 and 2), travels at a certain overlap, for example centrally with respect to the carpet border 14, with regard to its circular surface area 17 defined by the cleaning bristles 16. However, for such travel the distance may also be set in such a way that the carpet border 14 extends externally tangentially with respect to the circular surface area 17, or preferably as a slight secant with respect to the circular surface area 17.

(16) Furthermore, the distance may be selected in particular in such a way that when a corner cleaning brush is not provided, an end region of the cleaning brush 4, which rotates about a horizontal axis, cleans the mentioned carpet border 14 during this travel. In this regard, different positions may also be achieved, for example in such a way that an end face of the cleaning brush is associated with the obstacle edge, but travels at a certain distance therefrom, or in contact or overlap with the obstacle edge.

(17) It is further preferred that the floor cleaning appliance 1 (see FIG. 3) has a floor sensor 18 which operates in a contacting or contactless manner. It is apparent that the floor sensor 18 is situated in a sector of the housing contour that, based on a geometric axis 19 of an associated wheel 2 or a geometric axis 20 of the cleaning brush 4, is disposed outside this axis 19 or 20, at the boundary edge side of the housing 6. In another alternative definition, provided that a different configuration is thus achieved, the floor sensor 18, based on the same top view, is situated in a sector of the housing contour, which is delimited by the longitudinal axis of the cleaning brush 4 and a perpendicular S with respect to the geometric wheel axis 20, the perpendicular extending directly outside the running surface of the wheel on a side of the running surface facing the boundary edge of the housing.

(18) The travel along the border may thus also be (co-)controlled by means of this floor sensor. As long as the floor sensor 18 is (already) in overlap with the higher adjacent area of the carpet 13, in the particular cleaning operation of interest here, the floor cleaning appliance travels towards the border 14, preferably with a slight tendency to curve away from the border towards the floor area not covered by carpet, so that a return movement back to the carpet occurs each time the sensor no longer registers overlap with the carpet (in the exemplary embodiment) or the floor obstacle in general.

(19) As an alternative to the recognition of the carpet border 14, or the floor obstacle in general, by the sensor, the upwardly inclined obstructing surface may also be recognized by monitoring the motor current of the corner cleaning brush 5 formed as a disk brush, for example. The recorded motor current may then be detected, for example, by a resistive circuit in this regard and evaluated by a control circuit or a control program of the robotic suction device. During a cleaning pass, on a substantially homogeneous surface, the motor current is present in a relatively small bandwidth, i.e., essentially with a constant value, as a function of the condition of the floor to be cleaned. In the case of traveling over an obstacle, such as a carpet border 14, an increased torque occurs which causes an increase in the motor current. If a further evaluation of a signal, for example of a wall-following sensor, indicates that this increased torque/increase in the motor current is not caused, for example, by reaching a space boundary, such as a wall 12 or a piece of furniture, this increase in the motor current may be assessed by the cleaning appliance 1 as traveling over an obstacle. A routine may then be initiated in which travel occurs back and forth multiple times in the same surface region, so that an increase in the motor current, which always occurs in the same way may be assessed as an edge of an obstacle, for example a carpet border 14, and the direction of travel may be oriented corresponding to this detected border 14. This back-and-forth travel multiple times may also optionally be (initially) carried out for the other described sensors.

(20) Additionally or alternatively, a tactile sensor may be provided, which monitors the floor height toward the outside, directly next to the lateral housing edge. If an elevation in the floor surface, in particular without an additional message from a wall-following sensor, for example, is identified, this may also be interpreted as a flat obstacle in the sense of a carpet border 14. Corresponding to the above description of the change in the direction of travel, here as well, optionally after traveling over such an area multiple times, the direction of travel may then be changed and set in such a way that the desired travel along the obstructing surface results.

(21) All features disclosed are (in themselves) pertinent to the invention. The disclosure content of the associated/accompanying priority documents (copy of the prior application) is also hereby included in full in the disclosure of the application, including for the purpose of incorporating features of these documents in claims of the present application. The subsidiary claims in their optional subordinated formulation characterize independent inventive refinement of the prior art, in particular to undertake divisional applications based on these claims.

LIST OF REFERENCE NUMERALS

(22) 1 Floor cleaning appliance b Width 2 Wheel 3 Wheel 4 Cleaning brush 5 Corner cleaning brush 6 Housing 7 Rectangular portion 8 Circular portion 9 Portion 10 Cover portion 11 Room 12 Wall 13 Carpet 14 Carpet border 15 Housing edge portion 16 Cleaning bristles 17 Circular surface area 18 Floor sensor 19 Axis 20 Axis R Direction of travel S Perpendicular V Original direction of travel