Floor robot with a rotatable side brush

Abstract

A floor robot (100) for cleaning a floor surface (105) comprises a side brush (120) with a rotational axis extending in a vertical direction; the side brush (120) comprising at least one radially projecting cleaning arm (130) that can be guided across the floor surface (105) by rotating the side brush (120); a motor (125) for driving the side brush (120) about the rotational axis; and a control device (145). The control device (145) is configured to control the side brush (120) into a predetermined rotational position.

Description

[0001] The invention relates to the control of a side brush of a floor-cleaning robot. In particular, the invention relates to the control of the side brush in a corner of a floor area to be cleaned.

[0002] A floor robot is designed to clean a floor surface. For improved cleaning along an edge or a concave area between the floor surface and a lateral boundary, such as a wall or furniture, a side brush can be provided. The side brush is usually attached to the front and sides of the floor robot and can rotate about a vertical axis. The side brush comprises cleaning arms that are guided over the floor surface as the side brush rotates, moving dirt away from the edge and preferably into a pickup area of ​​the floor robot. The pickup area can be formed by a suction mouth through which air and dirt can be sucked in.

[0003] If the robotic floor cleaner enters a corner where the floor meets two side walls, the side brush should also sweep away dirt there. The cleaning arms are long enough to reach right into the corner.

[0004] EP 3 082 541 B1 proposes an adapted speed control for a rotating side brush on a floor-cleaning robot. The rotational speed of the side brush can be controlled depending on the driving speed of the floor-cleaning robot. This prevents the side brush from falling below a predetermined minimum speed.

[0005] It has been shown that in certain situations, the cleaning effect of the side brush is not always satisfactory, and dirt can remain on the floor surface. One object underlying the present invention is to provide an improved technique for cleaning a corner using a floor robot with a side brush. The invention solves this problem by means of the subject matter of the independent claims. Subordinate claims specify preferred embodiments.

[0006] According to a first aspect of the present invention, a floor robot for cleaning a floor surface comprises a side brush with a rotation axis extending in a vertical direction; wherein the side brush comprises at least one radially projecting cleaning arm that can be guided over the floor surface with rotation of the side brush; a motor for driving the side brush about the rotation axis; and a control device. The control device is configured to control the side brush into a predetermined rotational position.

[0007] The side brush's rotation axis can form an angle of approximately 90° with the floor surface. Optionally, the angle can also be smaller. To ensure thorough cleaning of the floor surface, it is preferable that the angle is no smaller than approximately 60°.

[0008] The cleaning arm may, for example, comprise a fiber bundle or a flexible arm, such as one made of plastic or rubber, and is preferably long enough to extend beyond the contour of the floor robot. It has been recognized that, due to its elasticity, the cleaning arm may hurl dirt around uncontrollably or may not relax quickly enough near a lateral boundary, so that it does not reach its full radial length and part of the floor surface may remain uncleaned.

[0009] The side brush can be controlled in its rotational position, its direction of rotation and / or its rotational speed. In particular, the side brush can be significantly slowed down or stopped in a predetermined rotational position so that the cleaning arm points in a predetermined direction. This can be used, for example, to allow the cleaning arm to relax completely so that it assumes its full radial length and points in a predetermined direction. This allows a section of the floor surface to be reached more effectively. Dirt can be prevented from being thrown around. In another application, the cleaning arm can perform a different task, for example by being guided across the floor surface by the movement of the floor robot like a stationary broom. The cleaning arm can also be stopped in a rotational position that allows cleaning or self-cleaning of the cleaning arm.

[0010] In one embodiment, the motor is configured to move the side brush to a predetermined position. For this purpose, the motor can comprise a stepper motor, for example. A synchronous motor can also be used, which can be commutated or permanently excited. The rotational position of the synchronous motor can be controlled by driving electrical currents through three phases.

[0011] Preferably, a position sensor is provided for determining a rotational position of the side brush. The position sensor can be designed as an index sensor and provide a pulse when the side brush has assumed a predetermined rotational position. An incremental change in the rotational position can be tracked from there.

[0012] The position sensor can also be configured to detect the absolute rotational position of the side brush. For this purpose, the position sensor can comprise an absolute sensor or be designed as a combination of an index sensor and an incremental sensor. In this embodiment, an output signal from the position sensor directly reflects the rotational position of the motor or the side brush. The motor can have a reduction gear, which can be self-locking, for example, as a worm gear.

[0013] The motor is further preferably configured to hold the side brush in a predetermined rotational position. An external force acting on the side brush cannot change the rotational position. This can apply both when the side brush is stationary and when the side brush is rotating at a predetermined speed. If the motor does not include a self-locking gear, the motor can actively counteract any deflection of the side brush from a predetermined rotational position.

[0014] The rotation of the side brush can be controlled by moving it to a predetermined sequence of rotational positions. The transition between successive rotational positions is preferably smooth or fluid. Acceleration or deceleration of the rotational movement can be actively counteracted.

[0015] The motor can be configured to control the rotation speed of the side brush depending on its rotational position. For example, the cleaning arm can be moved across the floor more slowly in a first angular range and more quickly in a subsequent second angular range. This allows for better control of dirt lying on the floor without throwing it away.

[0016] A floor robot for cleaning a floor surface comprises a side brush with a rotational axis extending in a vertical direction; wherein the side brush comprises at least one radially projecting cleaning arm that can be guided over the floor surface with rotation of the side brush. According to a further aspect of the present invention, a method for controlling such a floor robot comprises steps of controlling a rotational speed of the side brush depending on its rotational position while the floor robot moves over the floor surface or treats the floor surface using another cleaning device.

[0017] Depending on the rotation position, the rotation speed can be reduced to a standstill, allowing the cleaning arm to point in a predetermined direction. In various predetermined situations, the improved control of the rotation position can be used to specifically improve the cleaning results of the floor surface, implement a new floor cleaning technique, or enhance the self-cleaning of the side brush.

[0018] The method can be carried out partially or completely by means of a cleaning robot described herein. The cleaning robot can comprise a control device with a preferably electronically implemented processing device. The processing device can comprise, for example, a programmable microcomputer or microcontroller. The method can be in the form of a computer program product with program code means. The computer program product can also be stored on a computer-readable data carrier. Features or advantages of the method can be transferred to the device, and vice versa.

[0019] In a first variant, the floor robot is moved into a corner on the floor. The side brush can be stopped in a rotating position so that a cleaning arm points into the corner. This allows the cleaning arm to penetrate deeper into the corner and reach the dirt lying there. The dirt can be removed from the corner by moving the floor robot.

[0020] Alternatively, the side brush can be rotated for this purpose. The side brush's rotation speed can be dependent on its rotational position. A slow rotation can be used to carefully move dirt out of the corner. A faster rotation can be used to project dirt in a specific direction or to direct the cleaning arm or another cleaning arm into the corner. Optionally, phases of rotation can alternate with phases of standstill.

[0021] In a second variant, the floor robot is controlled along a lateral boundary. The side brush can be stopped in a rotating position so that the cleaning arm points diagonally in the direction of travel, ideally touching the boundary. The rotating position is also preferably selected so that the cleaning arm just barely touches the boundary. This allows the forward movement of the floor robot to move dirt lying on the floor near the boundary, similar to a blade or snowplow.

[0022] The side brush can be temporarily rotated to move dirt away from the side barrier. The floor-cleaning robot can stop or continue driving to do this. The dirt can be moved toward the floor-cleaning robot's suction port, which is connected to a fan and designed to vacuum dirt from the floor surface. The suction port is typically located at the front of the floor-cleaning robot's underside.

[0023] In a third variant, the side brush comprises several cleaning arms that form a predetermined angle with respect to the rotation axis. The side brush can be stopped in a rotational position so that both cleaning arms point diagonally in the direction of travel. The cleaning arms can form a kind of funnel into which dirt is collected by the movement of the floor robot. This allows for more efficient collection of coarse dirt, for example.

[0024] The side brush can be temporarily rotated so that dirt is moved toward a pickup device on the floor-cleaning robot. The pickup device can, in particular, comprise a suction nozzle. Periods of standstill and movement of the side brush can alternate.

[0025] In a fourth variant, the cleaning arm can be self-cleaned. The floor robot includes a suction nozzle for picking up dirt from the floor surface. The side brush can be rotated so that the cleaning arm overlaps the suction nozzle as much as possible. Dirt caught on the cleaning arm or stuck to it can be vacuumed through the suction nozzle or combed off by a rotating brush roller located in the suction nozzle. The cleaning arm can then be used more effectively to clean the floor surface. Wear and tear on the cleaning arm can be significantly reduced through regular self-cleaning.

[0026] In a fifth variant, the floor robot comprises a further side brush with a rotation axis extending in a vertical direction; wherein the side brush comprises at least one further radially projecting cleaning arm, which can be guided over the floor surface with a rotation of the further side brush.

[0027] The cleaning areas of the side brush and the additional cleaning brush can partially overlap. The side brush can be stopped in a rotating position so that the cleaning arm points toward the rotation axis of the additional side brush. To do this, the additional side brush can be rotated so that it can more effectively clean the cleaning arm directed toward it. Dirt brushed off by the cleaning arm can be moved by the additional side brush toward a suction nozzle. Reverse operation, in which a cleaning arm of the additional side brush is cleaned by the side brush, is also possible.

[0028] The rotation axis of the additional side brush can form an angle of approximately 90° with the floor surface. Optionally, the angle can also be smaller. To ensure thorough cleaning of the floor surface, it is preferable that the angle is not less than approximately 60°. The rotation axes of the side brush and the additional side brush can be parallel to each other or form an acute angle.

[0029] The invention will now be described in more detail with reference to the accompanying figures, in which: Figure 1 shows a floor robot; Figure 2 shows a brush of a floor robot in a first situation; Figure 3 shows a brush of a floor robot in a second situation; Figure 4 shows a brush of a floor robot in a third situation; Figure 5 shows a brush of a floor robot in a fourth situation; and Figure 6 shows brushes of a floor robot in a fifth situation. represent.

[0030] Figure 1shows a floor robot 100 configured to clean a floor surface 105. The floor robot 100 is schematically illustrated in a bottom view. A base of the floor robot 100 is, for example, D-shaped. Two drive wheels 110 are provided to move the floor robot 100 across the floor surface 105. Dirt can be sucked off the floor surface 105 through a suction port 115. Not shown is a suction unit for creating an air flow through the suction port 115 and a filter for separating sucked-in dirt. Optionally, a brush roller can be provided in the area of ​​the suction port 115, which can be driven about a horizontal axis of rotation. Also optionally, a device for wet cleaning the floor surface 105 can be provided, in particular a pad or a similar device that can be moistened with a liquid from a reservoir.

[0031] A side brush 120 is attached to the side of the floor robot 100, preferably at the front in the direction of travel. The side brush 120 comprises an optional central body and one or more radially projecting cleaning arms 130, which can be guided over the floor surface 105 by means of a rotational movement about a substantially vertical axis of rotation 135. A drive motor 125 is provided to rotate the side brush 120, which optionally includes a gear that can, in particular, implement a reduction gear. The drive motor 125 can preferably be controlled such that the side brush assumes a predetermined rotational position. A position sensor 140 can be provided to determine a current rotational position of the side brush 120.

[0032] In the illustrated embodiment, three cleaning arms 130 are provided on the side brush 120, each attached to one side of the central body and evenly distributed in the circumferential direction with respect to the rotation axis. The cleaning arms 130 can be slightly inclined downwards so that their free ends are pressed slightly against the floor surface 105. A circle with a dashed line indicates a cleaning area that can be swept by the cleaning arms 130. A radius of the cleaning area depends on the range of the projecting cleaning arms 130. If the floor robot 100 approaches a boundary 150, the cleaning arms 130 can be bent against their direction of rotation as they rotate around the rotation axis.

[0033] A cleaning arm comprises a number of fibers that are grouped together at one end and attached to the central body, which is driven by the drive motor 125. The fibers can, for example, comprise natural hair or natural bristles, or be made of a plastic (synthetic) or rubber. Natural or rubber fibers are typically somewhat thicker and somewhat more resistant to permanent deformation than synthetic fibers. Furthermore, a rubber fiber can exhibit reduced abrasion and thus a longer service life.

[0034] Components of the floor robot 100 can preferably be controlled by a control device 145. The control device 145 is preferably configured to control a movement of the floor robot 100 across the floor surface 105 depending on boundaries 150 of the floor surface 105 and objects located thereon. For this purpose, the control device 145 can comprise a map memory containing map information about a household in which the floor surface is located. Furthermore, a sensor for scanning an environment can be provided.

[0035] Figure 2 shows in an upper area a section of a floor robot 100 in a view from below (cf. Figure 1 ) and in a lower area an exemplary curve 200 of a rotational speed of the side brush 120. In a horizontal direction a time and in a vertical direction a rotational speed are plotted.

[0036] The floor robot 100 is moved into corner 155 in a section 205 with the driven side brush 120. The side brush 120 is then slowed down in a section 210 and finally stopped in a section 215 in a rotational position in which a cleaning arm 130 points or extends as precisely as possible into the corner 155. The flexible cleaning arm 130 can relax and extend far into the corner 155. After a predetermined holding time, the side brush 120 can be slowly rotated in a section 220 so that the cleaning arm 130 can carefully remove dirt from the corner 155. At the same time, another cleaning arm 130 can be inserted into the corner 150, and the process can begin again. After a predetermined number of further sections 215 and 220, the side brush 120 can be rotated at a higher rotational speed in a section 225 in order to convey remaining residual dirt with spin to the suction mouth 115.This process can be repeated once or several times.

[0037] Figure 3 shows a floor robot 100 in a similar representation as Figure 1 Below, a path 300 is shown. However, there is no corner 155 here; instead, the floor robot 100 moves along a boundary 150, for example, a wall that borders the floor area 105.

[0038] In a section 305, the floor robot 100 approaches the boundary 150, while the side brush 120 can rotate at a normal rotational speed. In a section 310, the side brush 120 can be decelerated and stopped in the position shown above. In this position, a cleaning arm 130 extends obliquely in the direction of travel so that its end touches the boundary 150. In a section 315, the floor robot 100 can continue to move, allowing dirt to be moved away from the boundary 150 by the obliquely positioned cleaning arm 130.

[0039] Optionally, after a predetermined time or distance traveled by the floor robot 100, the side brush can be slowly rotated further by a predetermined angle in a section 320. This allows dirt to be transported from the front of the cleaning arm 130 toward the suction nozzle 115 before the dirt piles up to the point where it pushes over the cleaning arm 130. At the same time, another cleaning arm 130 can be moved to the boundary 150. This process can be repeated as needed. The side brush 120 can then be accelerated again in a section 325.

[0040] Figure 4 shows a floor robot 100 in a similar representation as Figure 1 . A path 400 is shown below. Here, the floor robot 100 is not located within a boundary 150, but can move freely across the floor surface 105.

[0041] In a section 405, the side brush 120 is rotated at a normal rotational speed; the floor robot 100 can be moving or stationary. In a section 410, the side brush is decelerated and finally stopped in a section 415 in the rotational position shown above. The side brush 120 has at least two cleaning arms 130 that form an angle with each other with respect to the rotational axis 135. In the present case, three cleaning arms 130 are provided, which are evenly distributed around a circumference so that adjacent cleaning arms each form an angle of approximately 120° with each other. The side brush 120 is preferably stopped in a position such that two adjacent cleaning arms 130 protrude forward in a V-shape and form a type of funnel in which dirt, in particular coarse dirt, is collected as the floor robot 105 moves.

[0042] Optionally, after a predetermined travel distance or time, the side brush 120 can be rotated slowly in a section 420 to feed collected dirt to the suction nozzle. At the same time, another pair of cleaning arms 130 can be directed forward. Phases of standstill 415 and rotation 420 of the side brush 120 can alternate as often as desired. Afterward, the side brush can be accelerated back to a normal rotation speed in a section 425.

[0043] Figure 5 shows a floor robot 100 in a similar representation as Figure 1 A progression 500 is shown below. The floor robot 100 can be located away from a boundary 150 and is preferably stationary. In this configuration, self-cleaning of one of the cleaning arms 130 can be performed.

[0044] In a section 505, the side brush 120 can be rotated at a normal rotational speed. In a section 510, the rotation can be slowed down. In a section 515, the side brush can be rotated very slowly so that a cleaning arm 130 slowly passes over the suction mouth 115. Preferably, the side brush 120 is briefly stopped when the cleaning arm 130 has reached a maximum degree of coverage with the suction mouth 115. The movement past the suction mouth 115 can be repeated in the reverse direction. The side brush 120 can then be rotated further in a section 520 so that a subsequent cleaning arm 130 can clean the suction mouth 115.

[0045] Once all cleaning arms 130 of the side brush 120 have passed the suction nozzle 115 a sufficient number of times, the side brush 120 can be rotated faster in a section 525. This process can be repeated as often as desired.

[0046] Figure 6shows a floor robot 100 in a similar representation as Figure 1 . Here, the floor robot 100 comprises a further side brush 120', which is preferably constructed correspondingly to the side brush 120 and comprises at least one further cleaning arm 130'. Rotation areas of the side brushes 120, 120' overlap each other, so that the cleaning arms 130, 130' can mutually sweep over each other. In the lower area of Figure 6 Two courses are shown, one of which is assigned to the side brush 120 and the other to the further side brush 120'.

[0047] For self-cleaning of the cleaning arms 130, 130', the following procedure can be followed: In sections 605 to 620, which in pairs correspond to sections 505 to 520 in the embodiment of Figure 5, the side brush 120 may be slowed down and then rotated so that its cleaning arms 130 point sequentially toward the further side brush 120'. During this process, the further side brush 120' may be controlled to rotate at a predetermined rotational speed to brush the cleaning arms 130.

[0048] The procedure can then be reversed so that the additional cleaning arms 130' of the additional side brush 120' are cleaned one after the other by means of the side brush 120. In general, the side brush 120, 120' to be cleaned is preferably rotated more slowly than the one used for cleaning. When cleaning the additional side brush 120', sections 605' to 620' can be passed through, which correspond in pairs to sections 605 to 620.

[0049] Optionally, an air flow can be caused through the suction mouth 115 during the entire process in order to collect brushed-off dirt as much as possible or to suck it away from the floor surface 105.

[0050] It should be noted that options, sections or measures may be added between the described processes of the Figures 2 to 6 can be adopted or transferred. Described sections can be understood as steps of procedures. Reference symbol

[0051] 100Floor robot 105Floor surface 110Drive wheel 115Suction mouth 120Side brush 120'Additional side brush 125Drive motor 130Cleaning arm 130'Additional cleaning arm 135Rotation axis 140Position sensor 145Control device 150Limitation 155Corner 205-225 sections 305-325 sections 405-425 sections 505-525 sections 605-620 sections 605'-620' sections

Claims

1. A floor robot (100) for cleaning a floor surface (105); wherein the floor robot (100) comprises: - a side brush (120) with a rotation axis extending in a vertical direction; - wherein the side brush (120) comprises a radially projecting cleaning arm (130) which can be guided over the floor surface (105) with a rotation of the side brush (120); - a motor (125) for driving the side brush (120) about the rotation axis; and - a control device (145) which is configured to control the side brush (120) into a predetermined rotational position.

2. Floor robot (100) according to claim 1, further comprising a position sensor (140) for determining a rotational position of the side brush (120).

3. Floor robot (100) according to claim 2, wherein the position sensor (140) is configured to detect an absolute rotational position of the side brush (120).

4. Floor robot (100) according to one of the preceding claims, wherein the motor (125) is configured to hold the side brush (120) in a predetermined rotational position.

5. Floor robot (100) according to one of the preceding claims, wherein the motor (125) is configured to control the rotational speed of the side brush (120) depending on its rotational position.

6. A method (200-600) for controlling a floor robot (100) for cleaning a floor surface (105); wherein the floor robot (100) comprises a side brush (120) with a rotation axis that extends in a vertical direction; wherein the side brush (120) comprises a radially projecting cleaning arm (130) that can be guided over the floor surface (105) with a rotation of the side brush (120); wherein the method comprises the following steps: - controlling a rotational speed of the side brush (120) as a function of its rotational position; - while the floor robot (100) moves over the floor surface (105); - or processes the floor surface (105) by means of a further cleaning device.

7. The method (200) according to claim 6, wherein the floor robot (100) is moved into a corner on the floor surface (105); wherein the side brush (120) is stopped in a rotational position such that a cleaning arm (130) points into the corner.

8. The method (200) of claim 7, wherein the side brush (120) is rotated at a rotational speed that depends on the rotational position of the side brush (120).

9. The method (300) according to claim 6, wherein the floor robot (100) is controlled along a lateral boundary; wherein the side brush (120) is stopped in a rotational position such that the cleaning arm (130) points obliquely in the direction of travel and thereby touches the boundary.

10. The method (300) of claim 9, wherein the side brush (120) is temporarily rotated to move dirt away from the side boundary.

11. The method (400) according to claim 6, wherein the side brush (120) comprises a plurality of cleaning arms (130) that enclose a predetermined angle with respect to the rotation axis; wherein the side brush (120) is stopped in a rotational position such that both cleaning arms (130) point obliquely in the direction of travel.

12. The method (400) of claim 11, wherein the side brush (120) is temporarily rotated to move dirt toward a pickup device of the floor robot (100).

13. The method (500) according to claim 6, wherein the floor robot (100) comprises a suction mouth for picking up dirt from the floor surface (105); and the side brush (120) is stopped in a rotational position such that the cleaning arm (130) maximally overlaps the suction mouth.

14. The method (600) according to claim 6, wherein the floor robot (100) comprises a further side brush (120') with a rotation axis extending in a vertical direction; wherein the further side brush (120') comprises at least one further radially projecting cleaning arm (130') which can be guided over the floor surface (105) with a rotation of the further side brush (120'); wherein the side brush (120) is stopped in a rotational position such that the cleaning arm (130) points towards the rotation axis of the further side brush (120'); and the further side brush (120') is set in rotation.

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